Search results for: genes
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 895

Search results for: genes

385 Functional Characterization of Transcriptional Regulator WhiB Proteins of Mycobacterium Tuberculosis

Authors: Sonam Kumari

Abstract:

Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis, possesses a remarkable feature of entering into and emerging from a persistent state. The mechanism by which Mtb switches from the dormant state to the replicative form is still poorly characterized. Proteome studies have given us an insight into the role of certain proteins in giving stupendous virulence to Mtb, but numerous dotsremain unconnected and unaccounted. The WhiB family of proteins is one such protein that is associated with developmental processes in actinomycetes.Mtb has seven such proteins (WhiB1 to WhiB7).WhiB proteins are transcriptional regulators; their conserved C-terminal HTH motif is involved in DNA binding. They regulate various essential genes of Mtbby binding to their promoter DNA. Biophysical Analysis of the effect of DNA binding on WhiB proteins has not yet been appropriately characterized. Interaction with DNA induces conformational changes in the WhiB proteins, confirmed by steady-state fluorescence and circular dichroism spectroscopy. ITC has deduced thermodynamic parameters and the binding affinity of the interaction. Since these transcription factors are highly unstable in vitro, their stability and solubility were enhanced by the co-expression of molecular chaperones. The present study findings help determine the conditions under which the WhiB proteins interact with their interacting partner and the factors that influence their binding affinity. This is crucial in understanding their role in regulating gene expression in Mtbandin targeting WhiB proteins as a drug target to cure TB.

Keywords: tuberculosis, WhiB proteins, mycobacterium tuberculosis, nucleic acid binding

Procedia PDF Downloads 76
384 Cardiac Hypertrophy in Diabetes; The Role of Factor Forkhead Box Class O-Regulation by O-GlcNAcylation

Authors: Mohammadjavad Sotoudeheian, Navid Farahmandian

Abstract:

Cardiac hypertrophy arises in response to persistent increases in hemodynamic loads. In comparison, diabetic cardiomyopathy is defined by an abnormal myocardial changes without other cardiac-related risk factors. Pathological cardiac hypertrophy and myocardial remodeling are hallmarks of cardiovascular diseases and are risk factors for heart failure. The transcription factor forkhead box class O (FOXOs) can protect heart tissue by hostile oxidative stress and stimulating apoptosis and autophagy. FOXO proteins, as sensitive elements and mediators in response to environmental changes, have been revealed to prevent and inverse cardiac hypertrophy. FOXOs are inhibited by insulin and are critical mediators of insulin action. Insulin deficiency and uncontrolled diabetes lead to a catabolic state. FOXO1 acts downstream of the insulin-dependent pathways, which are dysregulated in diabetes. It regulates cardiomyocyte hypertrophy downstream of IGF1R/PI3K/Akt activation, which are critical regulators of cardiac hypertrophy. The complex network of signaling pathways comprising insulin/IGF-1 signaling, AMPK, JNK, and Sirtuins regulate the development of cardiovascular dysfunction by modulating the activity of FOXOs. Insulin receptors and IGF1R act via the PI3k/Akt and the MAPK/ERK pathways. Activation of Akt in response to insulin or IGF-1 induces phosphorylation of FOXOs. Increased protein synthesis induced by activation of the IGF-I/Akt/mTOR signaling pathway leads to hypertrophy. This pathway and the myostatin/Smad pathway are potent negative muscle development regulators. In cardiac muscle, insulin receptor substrates (IRS)-1 or IRS-2 activates the Akt signaling pathway and inactivate FOXO1. Under metabolic stress, p38 MAPK promotes degradation of IRS-1 and IRS-2 in cardiac myocytes and activates FOXO1, leading to cardiomyopathy. Sirt1 and FOXO1 interaction play an essential role in starvation-induced autophagy in cardiac metabolism. Inhibition of Angiotensin-II induced cardiomyocyte hypertrophy is associated with reduced FOXO1 acetylation and activation of Sirt1. The NF-κB, ERK, and FOXOs are de-acetylated by SIRT1. De-acetylation of FOXO1 induces the expression of genes involved in autophagy and stimulates autophagy flux. Therefore, under metabolic stress, FOXO1 can cause diabetic cardiomyopathy. The overexpression of FOXO1 leads to decreased cardiomyocyte size and suppresses cardiac hypertrophy through inhibition of the calcineurin–NFAT pathway. Diabetes mellitus is associated with elevation of O-GlcNAcylation. Some of its binding partners regulate the substrate selectivity of O-GlcNAc transferase (OGT). O-GlcNAcylation of essential contractile proteins may inhibit protein-protein interactions, reduce calcium sensitivity, and modulate contractile function. Uridine diphosphate (UDP)-GlcNAc is the obligatory substrate of OGT, which catalyzes a reversible post-translational protein modification. The increase of O-GlcNAcylation is accompanied by impaired cardiac hypertrophy in diabetic hearts. Inhibition of O-GlcNAcylation blocks activation of ERK1/2 and hypertrophic growth. O-GlcNAc modification on NFAT is required for its translocation from the cytosol to the nucleus, where NFAT stimulates the transcription of various hypertrophic genes. Inhibition of O-GlcNAcylation dampens NFAT-induced cardiac hypertrophic growth. Transcriptional activity of FOXO1 is enriched by improved O-GlcNAcylation upon high glucose stimulation or OGT overexpression. In diabetic conditions, the modification of FOXO1 by O-GlcNAc is promoted in cardiac troponin I and myosin light chain 2. Therefore targeting O-GlcNAcylation represents a potential therapeutic option to prevent hypertrophy in the diabetic heart.

Keywords: diabetes, cardiac hypertrophy, O-GlcNAcylation, FOXO1, Akt, PI3K, AMPK, insulin

Procedia PDF Downloads 85
383 Whole Coding Genome Inter-Clade Comparison to Predict Global Cancer-Protecting Variants

Authors: Lamis Naddaf, Yuval Tabach

Abstract:

In this research, we identified the missense genetic variants that have the potential to enhance resistance against cancer. Such field has not been widely explored, as researchers tend to investigate mutations that cause diseases, in response to the suffering of patients, rather than those mutations that protect from them. In conjunction with the genomic revolution, and the advances in genetic engineering and synthetic biology, identifying the protective variants will increase the power of genotype-phenotype predictions and can have significant implications on improved risk estimation, diagnostics, prognosis and even for personalized therapy and drug discovery. To approach our goal, we systematically investigated the sites of the coding genomes and picked up the alleles that showed a correlation with the species’ cancer resistance. We predicted 250 protecting variants (PVs) with a 0.01 false discovery rate and more than 20 thousand PVs with a 0.25 false discovery rate. Cancer resistance in Mammals and reptiles was significantly predicted by the number of PVs a species has. Moreover, Genes enriched with the protecting variants are enriched in pathways relevant to tumor suppression like pathways of Hedgehog signaling and silencing, which its improper activation is associated with the most common form of cancer malignancy. We also showed that the PVs are more abundant in healthy people compared to cancer patients within different human races.

Keywords: comparative genomics, machine learning, cancer resistance, cancer-protecting alleles

Procedia PDF Downloads 74
382 Challenging the Theory of Mind: Autism Spectrum Disorder, Social Construction, and Biochemical Explanation

Authors: Caroline Kim

Abstract:

The designation autism spectrum disorder (ASD) groups complex disorders in the development of the brain. Autism is defined essentially as a condition in which an individual lacks a theory of mind. The theory of mind, in this sense, explains the ability of an individual to attribute feelings, emotions, or thoughts to another person. An autistic patient is characteristically unable to determine what an interlocutor is feeling, or to understand the beliefs of others. However, it is possible that autism cannot plausibly characterized as the lack of theory of mind in an individual. Genes, the bran, and its interplay with environmental factors may also cause autism. A mutation in a gene may be hereditary, or instigated by diseases such as mumps. Though an autistic patient may experience abnormalities in the cerebellum and the cortical regions, these are in fact only possible theories as to a biochemical explanation behind the disability. The prevailing theory identifying autism with lacking the theory of mind is supported by behavioral observation, but this form of observation is itself determined by socially constructed standards, limiting the possibility for empirical verification. The theory of mind infers that the beliefs and emotions of people are causally based on their behavior. This paper demonstrates the fallacy of this inference, critiquing its basis in socially constructed values, and arguing instead for a biochemical approach free from the conceptual apparatus of language and social expectation.

Keywords: autism spectrum disorder, sociology of psychology, social construction, the theory of mind

Procedia PDF Downloads 371
381 Same-Day Detection Method of Salmonella Spp., Shigella Spp. and Listeria Monocytogenes with Fluorescence-Based Triplex Real-Time PCR

Authors: Ergun Sakalar, Kubra Bilgic

Abstract:

Faster detection and characterization of pathogens are the basis of the evoid from foodborne pathogens. Salmonella spp., Shigella spp. and Listeria monocytogenes are common foodborne bacteria that are among the most life-threatining. It is important to rapid and accurate detection of these pathogens to prevent food poisoning and outbreaks or to manage food chains. The present work promise to develop a sensitive, species specific and reliable PCR based detection system for simultaneous detection of Salmonella spp., Shigella spp. and Listeria monocytogenes. For this purpose, three genes were picked out, ompC for Salmonella spp., ipaH for Shigella spp. and hlyA for L. monocytogenes. After short pre-enrichment of milk was passed through a vacuum filter and bacterial DNA was exracted using commercially available kit GIDAGEN®(Turkey, İstanbul). Detection of amplicons was verified by examination of the melting temperature (Tm) that are 72° C, 78° C, 82° C for Salmonella spp., Shigella spp. and L. monocytogenes, respectively. The method specificity was checked against a group of bacteria strains, and also carried out sensitivity test resulting in under 10² CFU mL⁻¹ of milk for each bacteria strain. Our results show that the flourescence based triplex qPCR method can be used routinely to detect Salmonella spp., Shigella spp. and L. monocytogenes during the milk processing procedures in order to reduce cost, time of analysis and the risk of foodborne disease outbreaks.

Keywords: evagreen, food-born bacteria, pathogen detection, real-time pcr

Procedia PDF Downloads 218
380 Whole Coding Genome Inter-Clade Comparisons to Predict Global Cancer-Protecting Variants

Authors: Lamis Naddaf, Yuval Tabach

Abstract:

We identified missense genetic variants with the potential to enhance resistance against cancer. Such a field has not been widely explored as researchers tend to investigate the mutations that cause diseases, in response to the suffering of patients, rather than those mutations that protect from them. In conjunction with the genomic revolution and the advances in genetic engineering and synthetic biology, identifying the protective variants will increase the power of genotype-phenotype predictions and have significant implications for improved risk estimation, diagnostics, prognosis, and even personalized therapy and drug discovery. To approach our goal, we systematically investigated the sites of the coding genomes and selected the alleles that showed a correlation with the species’ cancer resistance. Interestingly, we found several amino acids that are more generally preferred (like the Proline) or avoided (like the Cysteine) by the resistant species. Furthermore, Cancer resistance in mammals and reptiles is significantly predicted by the number of the predicted protecting variants (PVs) a species has. Moreover, PVs-enriched-genes are enriched in pathways relevant to tumor suppression. For example, they are enriched in the Hedgehog signaling and silencing pathways, which its improper activation is associated with the most common form of cancer malignancy. We also showed that the PVs are mostly more abundant in healthy people compared to cancer patients within different human races.

Keywords: cancer resistance, protecting variant, naked mole rat, comparative genomics

Procedia PDF Downloads 74
379 Identification of Tissue-Specific Transcription Factors in C. roseus with Emphasis to the TIA Biosynthetic Pathway

Authors: F. M. El-Domyati, A. Atef, S. Edris, N. O. Gadalla, M. A. Al-Kordy, A. M. Ramadan, Y. M. Saad, H. S. Al-Zahrani, A. Bahieldin

Abstract:

Transcriptome retrieved from SRA database of different tissues and treatments of C. roseus was assembled in order to detect tissue-specific transcription factors (TFs) and TFs possibly related to terpenoid indole alkaloids (TIA) pathway. A number of 290 TF-like transcripts along with 12 transcripts related to TIA biosynthetic pathway were divided in terms of co-expression in the different tissues, treatments and genotypes. Three transcripts encoding peroxidases 1 and 12 were downregulated in hairy root, while upregulated in mature leaf. Eight different transcripts of the TIA pathway co-expressed with TFs either functioning downstream tryptophan biosynthesis, e.g., tdc, str1 and sgd, or upstream vindoline biosynthesis, e.g., t16h, omt, nmt, d4h and dat. The results showed no differential expression of TF transcripts in hairy roots knocked down for tdc gene (TDCi) as compared to their wild type controls. There were several evidences of tissue-specific expression of TF transcripts in flower, mature leaf, root/hairy root, stem, seedling, hairy root and immature/mature leaves. Regulation included transcription factor families, e.g., bHLH, MYB and WRKY mostly induced by ABA and/or JA (or MeJA) and regulated during abiotic or biotic stress. The information of tissue-specific regulation and co-expression of TFs and genes in the TIA pathway can be utilized in manipulating alkaloid biosynthesis in C. roseus.

Keywords: SRA database, bHLH, MYB, WRKY, co-expression

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378 Antibiotic and Fungicide Exposure Reveal the Evolution of Soil-Lettuce System Resistome

Authors: Chenyu Huang, Minrong Cui, Hua Fang, Luqing Zhang, Yunlong Yu

Abstract:

The emergence and spread of antibiotic resistance genes (ARGs) have become a pressing issue in global agricultural production. However, understanding how these ARGs spread across different spatial scales, especially when exposed to both pesticides and antibiotics, has remained a challenge. Here, metagenomic assembly and binning methodologies were used to determine the mechanism of ARG propagation within soil-lettuce systems exposed to both fungicides and antibiotics. The results of our study showed that the presence of fungicide and antibiotic stresses had a significant impact on certain bacterial communities. Notably, we observed that ARGs were primarily transferred from the soil to the plant through plasmids. The selective pressure exerted by fungicides and antibiotics contributed to an increase in unique ARGs present on lettuce leaves. Moreover, ARGs located on chromosomes and plasmids followed different transmission patterns. The presence of diverse selective pressures, a result of compound treatments involving antibiotics and fungicides, amplifies this phenomenon. Consequently, there is a higher probability of bacteria developing multi-antibiotic resistance under the combined pressure of fungicides and antibiotics. In summary, our findings highlight that combined fungicide and antibiotic treatments are more likely to drive the acquisition of ARGs within the soil-plant system and may increase the risk of human ingestion.

Keywords: soil-lettuce system, fungicide, antibiotic, ARG, transmission

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377 Genetic Characteristics of Chicken Anemia Virus Circulating in Northern Vietnam

Authors: Hieu Van Dong, Giang Thi Huong Tran, Giap Van Nguyen, Tung Duy Dao, Vuong Nghia Bui, Le Thi My Huynh, Yohei Takeda, Haruko Ogawa, Kunitoshi Imai

Abstract:

Chicken anemia virus (CAV) has a ubiquitous and worldwide distribution in chicken production. Our group previously reported high seroprevalence of CAV in chickens in northern Vietnam. In the present study, 330 tissue samples collected from commercial and breeder chicken farms in eleven provinces in northern Vietnam were tested for the CAV infection. We found that 157 out of 330 (47.58%) chickens were positive with CAV genes by real-time PCR method. Nine CAV strains obtained from the different location and time were forwarded to the full-length sequence of CAV VP1 gene. Phylogenetic analysis of the Vietnamese CAV vp1 gene indicated that the CAVs circulating in northern Vietnam were divided into three distinct genotypes, II, III, and V, but not clustered with the vaccine strains. Among the three genotypes, genotype III was the major one widely spread in Vietnam, and that included three sub-genotypes, IIIa, IIIb, and IIIc. The Vietnamese CAV strains were closely related to the Chinese, Taiwanese, and USA strains. All the CAV isolates had glutamine at amino acid position 394 in the VP1 gene, suggesting that they might be highly pathogenic strains. One strain was defined to be genotype V, which had not been reported for Vietnamese CAVs. Additional studies are required to further evaluate the pathogenicity of CAV strains circulating in Vietnam.

Keywords: chicken anemia virus, genotype, genetic characteristics, Vietnam

Procedia PDF Downloads 134
376 Purification and Pre-Crystallization of Recombinant PhoR Cytoplasmic Domain Protein from Mycobacterium Tuberculosis H37Rv

Authors: Oktira Roka Aji, Maelita R. Moeis, Ihsanawati, Ernawati A. Giri-Rachman

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Globally, tuberculosis (TB) remains a leading cause of death. The emergence of multidrug-resistant strains and extensively drug-resistant strains have become a major public concern. One of the potential candidates for drug target is the cytoplasmic domain of PhoR Histidine Kinase, a part of the Two Component System (TCS) PhoR-PhoP in Mycobacterium tuberculosis (Mtb). TCS PhoR-PhoP relay extracellular signal to control the expression of 114 virulent associated genes in Mtb. The 3D structure of PhoR cytoplasmic domain is needed to screen novel drugs using structure based drug discovery. The PhoR cytoplasmic domain from Mtb H37Rv was overexpressed in E. coli BL21(DE3), then purified using IMAC Ni-NTA Agarose his-tag affinity column and DEAE-ion exchange column chromatography. The molecular weight of the purified protein was estimated to be 37 kDa after SDS-PAGE analysis. This sample was used for pre-crystallization screening by applying sitting drop vapor diffusion method using Natrix (HR2-116) 48 solutions crystal screen kit at 25ºC. Needle-like crystals were observed after the seventh day of incubation in test solution No.47 (0.1 M KCl, 0.01 M MgCl2.6H2O, 0.05 M Tris-Cl pH 8.5, 30% v/v PEG 4000). Further testing is required for confirming the crystal.

Keywords: tuberculosis, two component system, histidine kinase, needle-like crystals

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375 Biological Activities of Flaxseed Peptides (Linusorbs)

Authors: Youn Young Shim, Ji Hye Kim, Jae Youl Cho, Martin J. T. Reaney

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Flaxseed (Linum usitatissimum L.) is gaining popularity in the food industry as a superfood due to its health-promoting properties. The flax plant synthesizes an array of biologically active cyclic peptides or linusorbs (LOs, a.k.a. cyclolinopeptides) from three or more ribosome-derived precursors. [1–9-NαC]-linusorb B3 and [1–9-NαC]-linusorb B2, suppress immunity, induce apoptosis in human epithelial cancer cell line (Calu-3) cells, and inhibit T-cell proliferation, but the mechanism of LOs action is unknown. Using gene expression analysis in nematode cultures and human cancer cell lines, we have observed that LOs exert their activity, in part, through induction of apoptosis. Specific LOs’ properties include: 1) distribution throughout the body after flaxseed consumption; 2) induce heat shock protein (HSP) 70A production as an indicator of stress and address the issue in Caenorhabditis elegans (exposure of nematode cultures to [1–9-NαC]-linusorb B3 induced a 30% increase in production of the HSP 70A protein); 3) induce apoptosis in Calu-3 cells; and 4) modulate regulatory genes in microarray analysis. These diverse activities indicate that LOs might induce apoptosis in cancer cells or act as versatile platforms to deliver a variety of biologically active molecules for cancer therapy.

Keywords: flaxseed, linusorb, cyclic peptide, orbitides, heat shock protein, apoptosis, anti-cancer

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374 From Genome to Field: Applying Genome Wide Association Study for Sustainable Ascochyta Blight Management in Faba Beans

Authors: Rabia Faridi, Rizwana Maqbool, Umara Sahar Rana, Zaheer Ahmad

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Climate change impacts agriculture, notably in Germany, where spring faba beans predominate. However, improved winter hardiness aligns with milder winters, enabling autumn-sown varieties. Genetic resistance to Ascochyta blight is vital for crop integration. Traditional breeding faces challenges due to complex inheritance. This study assessed 224 homozygous faba bean lines for Ascochyta resistance traits. To achieve h²>70%, 12 replicates were required (realized h²=87%). Genetic variation and strong trait correlations were observed. Five lines outperformed 29H, while three were highly susceptible. A genome-wide association study (GWAS) with 188 inbred lines and 2058 markers, including 17 guide SNP markers, identified 12 markers associated with resistance traits, potentially indicating new resistance genes. One guide marker (Vf-Mt1g014230-001) on chromosome III validated a known QTL. The guided marker approach complemented GWAS, facilitating marker-assisted selection for Ascochyta resistance. The Göttingen Winter Bean Population offers promise for resistance breeding.

Keywords: genome wide association studies, marker assisted breeding, faba bean, ascochyta blight

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373 Transcriptional Profiling of Developing Ovules in Litchi chinensis

Authors: Ashish Kumar Pathak, Ritika Sharma, Vishal Nath, Sudhir Pratap Singh, Rakesh Tuli

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Litchi is a sub-tropical fruit crop with genotypes bearing delicious juicy fruits with variable seed size (bold to rudimentary size). Small seed size is a desirable trait in litchi, as it increases consumer acceptance and fruit processing. The biochemical activities in mid- stage ovules (e.g. 16, 20, 24 and 28 days after anthesis) determine the fate of seed and fruit development in litchi. Comprehensive ovule-specific transcriptome analysis was performed in two litchi genotypes with contrasting seed size to gain molecular insight on determinants of seed fates in litchi fruits. The transcriptomic data was de-novo assembled in 1,39,608 trinity transcripts, out of which 6,325 trinity transcripts were differentially expressed between the two contrasting genotypes. Differential transcriptional pattern was found among ovule development stages in contrasting litchi genotypes. The putative genes for salicylic acid, jasmonic acid and brassinosteroid pathway were down-regulated in ovules of small-seeded litchi. Embryogenesis, cell expansion, seed size and stress related trinity transcripts exhibited altered expression in small-seeded genotype. The putative regulators of seed maturation and seed storage were down-regulated in small-seed genotype.

Keywords: Litchi, seed, transcriptome, defence

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372 On the Absence of BLAD, CVM, DUMPS and BC Autosomal Recessive Mutations in Stud Bulls of the Local Alatau Cattle Breed of the Republic of Kazakhstan

Authors: Yessengali Ussenbekov, Valery Terletskiy, Orik Zhanserkenova, Shynar Kasymbekova, Indira Beyshova, Aitkali Imanbayev, Almas Serikov

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Currently, there are 46 hereditary diseases afflicting cattle with known molecular genetic diagnostic methods developed for them. Genetic anomalies frequently occur in the Holstein cattle breeds from American and Canadian bloodlines. The data on the incidence of BLAD, CVM, DUMPS and BC autosomal recessive lethal mutations in pedigree animals are discordant, the detrimental allele incidence rates are high for the Holstein cattle breed, whereas the incidence rates of these mutations are low in some breeds or they are completely absent. Data were obtained on the basis of frozen semen of stud bulls. DNA was extracted from the semen with the DNA-Sorb-B extraction kit. The lethal mutation in the genes CD18, SLC35A3, UMP and ASS of Alatau stud bulls (N=124) was detected by polymerase chain reaction and RFLP analysis. It was established that stud bulls of the local Alatau breed were not carriers of the BLAD, CVM, DUMPS, and BC detrimental mutations. However, with a view to preventing the dissemination of hereditary diseases it is recommended to monitor the pedigree stock using molecular genetic methods.

Keywords: PCR, autosomal recessive point mutation, BLAD, CVM, DUMPS, BC, stud bulls

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371 Mining the Proteome of Fusobacterium nucleatum for Potential Therapeutics Discovery

Authors: Abdul Musaweer Habib, Habibul Hasan Mazumder, Saiful Islam, Sohel Sikder, Omar Faruk Sikder

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The plethora of genome sequence information of bacteria in recent times has ushered in many novel strategies for antibacterial drug discovery and facilitated medical science to take up the challenge of the increasing resistance of pathogenic bacteria to current antibiotics. In this study, we adopted subtractive genomics approach to analyze the whole genome sequence of the Fusobacterium nucleatum, a human oral pathogen having association with colorectal cancer. Our study divulged 1499 proteins of Fusobacterium nucleatum, which has no homolog in human genome. These proteins were subjected to screening further by using the Database of Essential Genes (DEG) that resulted in the identification of 32 vitally important proteins for the bacterium. Subsequent analysis of the identified pivotal proteins, using the KEGG Automated Annotation Server (KAAS) resulted in sorting 3 key enzymes of F. nucleatum that may be good candidates as potential drug targets, since they are unique for the bacterium and absent in humans. In addition, we have demonstrated the 3-D structure of these three proteins. Finally, determination of ligand binding sites of the key proteins as well as screening for functional inhibitors that best fitted with the ligands sites were conducted to discover effective novel therapeutic compounds against Fusobacterium nucleatum.

Keywords: colorectal cancer, drug target, Fusobacterium nucleatum, homology modeling, ligands

Procedia PDF Downloads 359
370 Detection of Brackish Water Biological Fingerprints in Potable Water

Authors: Abdullah Mohammad, Abdullah Alshemali, Esmaeil Alsaleh

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The chemical composition of desalinated water is modified to make it more acceptable to the end-user. Sometimes, this modification is approached by mixing with brackish water that is known to contain a variety of minerals. Expectedly, besides minerals, brackish water indigenous bacterial communities access the final mixture hence reaching the end consumer. The current project examined the safety of using brackish water as an ingredient in potable water. Pseudomonas aeruginosa strains were detected in potable and brackish water samples collected from storage facilities in residential areas as well as from main water distribution and storage tanks. The application of molecular and biochemical fingerprinting methods, including phylogeny, RFLP (restriction fragment length polymorphism), MLST (multilocus sequence typing) and substrate specificity testing, suggested that the potable water P. aeruginosa strains were most probably originated from brackish water. Additionally, all the sixty-four isolates showed multi-drug resistance (MDR) phenotype and harboured the three genes responsible for biofilm formation. These virulence factors represent serious health hazards compelling the scientific community to revise the WHO (World Health Organization) and USEP (US Environmental Protection Agency) A potable water quality guidelines, particularly those related to the types of bacterial genera that evade the current water quality guidelines.

Keywords: potable water, brackish water, pseudomonas aeroginosa, multidrug resistance

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369 White-Rot Fungi Phellinus as a Source of Antioxidant and Antitumor Agents

Authors: Yogesh Dalvi, Ruby Varghese, Nibu Varghese, C. K. Krishnan Nair

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Introduction: The Genus Phellinus, locally known as Phansomba is a well-known traditional folk medicine. Especially, in Western Ghats of India, many tribes use several species of Phellinus for various ailments related to teeth, throat, tongue, stomach and even wound healing. It is one of the few mushrooms which play a pivotal role in Ayurvedic Dravyaguna. Aim: The present study focuses on to investigate phytochemical analysis, antioxidant, and antitumor (in vitro and in vivo) potential of Phellinus robinae from South India, Kerala Material and Methods: The present study explores the following: 1. Phellinus samples were collected from Ranni, Pathanamthitta district of Kerala state, India from Artocarpus heterophyllus Lam. and species were identified using rDNA region. 2. The fruiting body was shadow dried, powdered and extracted with 50% alcohol using water bath at 60°C which was further condensed by rotary evaporator and lyophilized at minus 40°C temperature. 3. Secondary metabolites were analyzed by using various phytochemical screening assay (Hager’s Test, Wagner’s Test, Sodium hydroxide Test, Lead acetate Test, Ferric chloride Test, Folin-ciocalteu Test, Foaming Test, Benedict’s test, Fehling’s Test and Lowry’s Test). 4. Antioxidant and free radical scavenging activity were analyzed by DPPH, FRAP and Iron chelating assay. 5. The antitumor potential of Water alcohol extract of Phellinus (PAWE) is evaluated through In vitro condition by Trypan blue dye exclusion method in DLA cell line and In vivo by murine model. Result and Discussion: Preliminary phytochemical screening by various biochemical tests revealed presence of a variety of active secondary molecules like alkaloids, flavanoids, saponins, carbohydrate, protein and phenol. In DPPH and FRAP assay PAWE showed significantly higher antioxidant activity as compared to standard Ascorbic acid. While, in Iron chelating assay, PAWE exhibits similar antioxidant activity that of Butylated Hydroxytoluene (BHT) as standard. Further, in the in vitro study, PAWE showed significant inhibition on DLA cell proliferation in dose dependent manner and showed no toxicity on mice splenocytes, when compared to standard chemotherapy drug doxorubicin. In vivo study, oral administration of PAWE showed dose dependent tumor regression in mice and also raised the immunogenicity by restoring levels of antioxidant enzymes in liver and kidney tissue. In both in vitro and in vivo gene expression studies PAWE up-regulates pro-apoptotic genes (Bax, Caspases 3, 8 and 9) and down- regulates anti-apoptotic genes (Bcl2). PAWE also down regulates inflammatory gene (Cox-2) and angiogenic gene (VEGF). Conclusion: Preliminary phytochemical screening revealed that PAWE contains various secondary metabolites which contribute to its antioxidant and free radical scavenging property as evaluated by DPPH, FRAP and Iron chelating assay. PAWE exhibits anti-proliferative activity by the induction of apoptosis through a signaling cascade of death receptor-mediated extrinsic (Caspase8 and Tnf-α), as well as mitochondria-mediated intrinsic (caspase9) and caspase pathways (Caspase3, 8 and 9) and also by regressing angiogenic factor (VEGF) without any inflammation or adverse side effects. Hence, PAWE serve as a potential antioxidant and antitumor agent.

Keywords: antioxidant, antitumor, Dalton lymphoma ascites (DLA), fungi, Phellinus robinae

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368 Design of a Recombinant Expression System for Bacterial Cellulose Production

Authors: Gizem Buldum, Alexander Bismarck, Athanasios Mantalaris

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Cellulose is the most abundant biopolymer on earth and it is currently being utilised in a multitude of industrial applications. Over the last 30 years, attention has been paid to the bacterial cellulose (BC), since BC exhibits unique physical, chemical and mechanical properties when compared to plant-based cellulose, including high purity and biocompatibility. Although Acetobacter xylinum is the most efficient producer of BC, it’s long doubling time results in insufficient yields of the cellulose production. This limits widespread and continued use of BC. In this study, E. coli BL21 (DE3) or E. coli HMS cells are selected as host organisms for the expression of bacterial cellulose synthase operon (bcs) of A.xylinum. The expression system is created based on pET-Duet1 and pCDF plasmid vectors, which carry bcs operon. The results showed that all bcs genes were successfully transferred and expressed in E.coli strains. The expressions of bcs proteins were shown by SDS and Native page analyses. The functionality of the bcs operon was proved by congo red binding assay. The effect of culturing temperature and the inducer concentration (IPTG) on cell growth and plasmid stability were monitored. The percentage of plasmid harboring cells induced with 0.025 mM IPTG was obtained as 85% at 22˚C in the end of 10-hr culturing period. It was confirmed that the high output cellulose production machinery of A.xylinum can be transferred into other organisms.

Keywords: bacterial cellulose, biopolymer, recombinant expression system, production

Procedia PDF Downloads 366
367 Genome Sequencing of the Yeast Saccharomyces cerevisiae Strain 202-3

Authors: Yina A. Cifuentes Triana, Andrés M. Pinzón Velásco, Marío E. Velásquez Lozano

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In this work the sequencing and genome characterization of a natural isolate of Saccharomyces cerevisiae yeast (strain 202-3), identified with potential for the production of second generation ethanol from sugarcane bagasse hydrolysates is presented. This strain was selected because its capability to consume xylose during the fermentation of sugarcane bagasse hydrolysates, taking into account that many strains of S. cerevisiae are incapable of processing this sugar. This advantage and other prominent positive aspects during fermentation profiles evaluated in bagasse hydrolysates made the strain 202-3 a candidate strain to improve the production of second-generation ethanol, which was proposed as a first step to study the strain at the genomic level. The molecular characterization was carried out by genome sequencing with the Illumina HiSeq 2000 platform paired end; the assembly was performed with different programs, finally choosing the assembler ABYSS with kmer 89. Gene prediction was developed with the approach of hidden Markov models with Augustus. The genes identified were scored based on similarity with public databases of nucleotide and protein. Records were organized from ontological functions at different hierarchical levels, which identified central metabolic functions and roles of the S. cerevisiae strain 202-3, highlighting the presence of four possible new proteins, two of them probably associated with the positive consumption of xylose.

Keywords: cellulosic ethanol, Saccharomyces cerevisiae, genome sequencing, xylose consumption

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366 Intra-miR-ExploreR, a Novel Bioinformatics Platform for Integrated Discovery of MiRNA:mRNA Gene Regulatory Networks

Authors: Surajit Bhattacharya, Daniel Veltri, Atit A. Patel, Daniel N. Cox

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miRNAs have emerged as key post-transcriptional regulators of gene expression, however identification of biologically-relevant target genes for this epigenetic regulatory mechanism remains a significant challenge. To address this knowledge gap, we have developed a novel tool in R, Intra-miR-ExploreR, that facilitates integrated discovery of miRNA targets by incorporating target databases and novel target prediction algorithms, using statistical methods including Pearson and Distance Correlation on microarray data, to arrive at high confidence intragenic miRNA target predictions. We have explored the efficacy of this tool using Drosophila melanogaster as a model organism for bioinformatics analyses and functional validation. A number of putative targets were obtained which were also validated using qRT-PCR analysis. Additional features of the tool include downloadable text files containing GO analysis from DAVID and Pubmed links of literature related to gene sets. Moreover, we are constructing interaction maps of intragenic miRNAs, using both micro array and RNA-seq data, focusing on neural tissues to uncover regulatory codes via which these molecules regulate gene expression to direct cellular development.

Keywords: miRNA, miRNA:mRNA target prediction, statistical methods, miRNA:mRNA interaction network

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365 Screening of High-Alcohol Producing Yeasts for Manufacturing Process of Whisky

Authors: Byeong-Uk Lim, Young-Ran Song, Sang-Ho Baik

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This study aimed to develop yeast starters for scientific alcohol production and systematic quality control of whisky. A total of 389 yeast strains were isolated from traditional Korean fermentation starter (nuruk) and rice wine (makgeolli), and ten strains were finally selected for their high alcohol productivities, in which their alcohol productions were above 17.3% (v/v) during 10 days under two steps of glucose feeding condition (30% and then 15%, w/v). By 18s rDNA sequence analysis, all strains were identified as Saccharomyces cerevisiae (SC), and they can grow well under 50% (w/v) glucose and 10% (v/v) ethanol conditions. Furthermore, the capability of ten different SC strains to ferment rice wine for whisky was studied. Rice wine was fermented with only steamed rice, water, and two types of enzymes (glucoamylase and α-amylase) during 14 days at 25 °C, and then their oenological properties have been determined. As the results, the fermented rice wines indicated the final pH range of 4.24-4.38 and acidity range of 0.12-0.18. The highest ethanol production of 20.2% (v/v) was found in the fermentation with a SC-156 strain, whereas SC-92 (16.8%) and SC-119 (16.4%) showed significantly lowest ethanol productions. In addition, the residual sugar contents showed negative correlation with alcohol contents. Moreover, this study focused on nucleotide polymorphisms in the MSN2 and MSN4 genes to investigate the cause of the defective stress responses in yeast. Consequently, it was also confirmed that the deletion of the N termini of Msn4p from identified point mutations in SC-63, SC-95, SC-156, SC-158, and SC-160 strains.

Keywords: yeast, high-alcohol, whisky, rice wine

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364 Bioinformatic Study of Follicle Stimulating Hormone Receptor (FSHR) Gene in Different Buffalo Breeds

Authors: Hamid Mustafa, Adeela Ajmal, Kim EuiSoo, Noor-ul-Ain

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World wild, buffalo production is considered as most important component of food industry. Efficient buffalo production is related with reproductive performance of this species. Lack of knowledge of reproductive efficiency and its related genes in buffalo species is a major constraint for sustainable buffalo production. In this study, we performed some bioinformatics analysis on Follicle Stimulating Hormone Receptor (FSHR) gene and explored the possible relationship of this gene among different buffalo breeds and with other farm animals. We also found the evolution pattern for this gene among these species. We investigate CDS lengths, Stop codon variation, homology search, signal peptide, isoelectic point, tertiary structure, motifs and phylogenetic tree. The results of this study indicate 4 different motif in this gene, which are Activin-recp, GS motif, STYKc Protein kinase and transmembrane. The results also indicate that this gene has very close relationship with cattle, bison, sheep and goat. Multiple alignment (MA) showed high conservation of motif which indicates constancy of this gene during evolution. The results of this study can be used and applied for better understanding of this gene for better characterization of Follicle Stimulating Hormone Receptor (FSHR) gene structure in different farm animals, which would be helpful for efficient breeding plans for animal’s production.

Keywords: buffalo, FSHR gene, bioinformatics, production

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363 A Case Study of Misinterpretation of Results in Forensic DNA Cases Due to Expression of Y- Chromosome in Females

Authors: Garima Chaudhary

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The gender of an individual in forensic DNA analysis is normally accessed by using the STR multiplexes with the incorporated gender based marker amelogenin or in other words by presence or absence of Y-Chromosome, but it may not be true in all the cases. We hereby report an interesting case of a phenotypic female carrying a male karyotype (46XY). In the alleged murder case, the deceased female with XY genotype was noticed. The expression of 18 Y-linked genes was studied to measure the extent of expression. Expression at 4 loci was observed that might have caused the misinterpretation in forensic casework. This clinical situation of the deceased in this case was diagnosed as testicular feminization syndrome, which characterize a female phenotype with a male karyotype (46, XY). Most of these cases have SRY (testis determining factor). The genetic explanation of this phenomenon is not very clear. Here, we are discussing the impact of such situations of genetic discrepancy in forensic interpretation of results. In the presented murder case of a phenotypic female, sexual assault was also suspected. For confirmation vaginal swabs and micro slides were also sent to us for DNA examination. After DNA analysis using STR markers, Y-chromosome was detected in the samples which supporting the suspicion of sexual assault before murder. When the reference blood sample of the deceased was analyzed, it was found to be case of testicular feminization syndrome. Interesting inferences were made from the results obtained.

Keywords: DNA profiling, forensic case study, Y chromosome, females

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362 Ethylene Response Factor BnERF from Brassica napus L. Enhances Submergence Tolerance and Alleviates the Oxidative Damage Caused by Submergence in Arabidopsis thaliana

Authors: Sanxiong Fu, Yanyan Lv, Song Chen, Wei Zhang, Cunkou Qi

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Ethylene response factor proteins are known to play an important role in regulating a variety of stress responses in plants, but their exact functions in submergence stress are not completely understood. In this study, we isolated BnERF from Brassica napus L. to study the function of BnERF in submergence tolerance. The expression of BnERF gene in Brassica napus L. and the expression of antioxidant enzyme genes in transgenic Arabidopsis were analyzed by Quantitative RT-PCR. It was found that expression of BnERF is apparently induced by submergence in Brassica napus L. and overexpression of BnERF in Arabidopsis increases the tolerance level to submergence and oxidative stress. Histochemical method detected lower level of H2O2, O2•− and malondialdehyde (MDA) in the transgenic Arabidopsis. Compared to wild type, transgenic lines also have higher soluble sugar content and higher activity of antioxidant enzymes, which helps protect the plants against the oxidative damage caused by submergence. It was concluded that BnERF can increase the tolerance of plants to submergence stress and BnERF might be involved in regulating soluble sugar content and the antioxidant system in the defense against submergence stress.

Keywords: antioxidant enzyme, Arabidopsis, ethylene response factor, submergence

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361 Rapid Detection and Differentiation of Camel Pox, Contagious Ecthyma and Papilloma Viruses in Clinical Samples of Camels Using a Multiplex PCR

Authors: A. I. Khalafalla, K. A. Al-Busada, I. M. El-Sabagh

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Pox and pox-like diseases of camels are a group of exanthematous skin conditions that have become increasingly important economically. They may be caused by three distinct viruses: camelpox virus (CMPV), camel contagious ecthyma virus (CCEV) and camel papillomavirus (CAPV). These diseases are difficult to differentiate based on clinical presentation in disease outbreaks. Molecular methods such as PCR targeting species-specific genes have been developed and used to identify CMPV and CCEV, but not simultaneously in a single tube. Recently, multiplex PCR has gained reputation as a convenient diagnostic method with cost- and time–saving benefits. In the present communication, we describe the development, optimization and validation a multiplex PCR assays able to detect simultaneously the genome of the three viruses in one single test allowing for rapid and efficient molecular diagnosis. The assay was developed based on the evaluation and combination of published and new primer sets, and was applied to the detection of 110 tissue samples. The method showed high sensitivity, and the specificity was confirmed by PCR-product sequencing. In conclusion, this rapid, sensitive and specific assay is considered a useful method for identifying three important viruses in specimens from camels and as part of a molecular diagnostic regime.

Keywords: multiplex PCR, diagnosis, pox and pox-like diseases, camels

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360 Circular Nitrogen Removal, Recovery and Reuse Technologies

Authors: Lina Wu

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The excessive discharge of nitrogen in sewage greatly intensifies the eutrophication of water bodies and threatens water quality. Nitrogen pollution control has become a global concern. The concentration of nitrogen in water is reduced by converting ammonia nitrogen, nitrate nitrogen and nitrite nitrogen into nitrogen-containing gas through biological treatment, physicochemical treatment and oxidation technology. However, some wastewater containing high ammonia nitrogen including landfill leachate, is difficult to be treated by traditional nitrification and denitrification because of its high COD content. The core process of denitrification is that denitrifying bacteria convert nitrous acid produced by nitrification into nitrite under anaerobic conditions. Still, its low-carbon nitrogen does not meet the conditions for denitrification. Many studies have shown that the natural autotrophic anammox bacteria can combine nitrous and ammonia nitrogen without a carbon source through functional genes to achieve total nitrogen removal, which is very suitable for removing nitrogen from leachate. In addition, the process also saves a lot of aeration energy consumption than the traditional nitrogen removal process. Therefore, anammox plays an important role in nitrogen conversion and energy saving. The short-range nitrification and denitrification coupled with anaerobic ammoX ensures total nitrogen removal. It improves the removal efficiency, meeting the needs of society for an ecologically friendly and cost-effective nutrient removal treatment technology. In recent years, research has found that the symbiotic system has more water treatment advantages because this process not only helps to improve the efficiency of wastewater treatment but also allows carbon dioxide reduction and resource recovery. Microalgae use carbon dioxide dissolved in water or released through bacterial respiration to produce oxygen for bacteria through photosynthesis under light, and bacteria, in turn, provide metabolites and inorganic carbon sources for the growth of microalgae, which may lead the algal bacteria symbiotic system save most or all of the aeration energy consumption. It has become a trend to make microalgae and light-avoiding anammox bacteria play synergistic roles by adjusting the light-to-dark ratio. Microalgae in the outer layer of light particles block most of the light and provide cofactors and amino acids to promote nitrogen removal. In particular, myxoccota MYX1 can degrade extracellular proteins produced by microalgae, providing amino acids for the entire bacterial community, which helps anammox bacteria save metabolic energy and adapt to light. As a result, initiating and maintaining the process of combining dominant algae and anaerobic denitrifying bacterial communities has great potential in treating landfill leachate. Chlorella has a brilliant removal effect and can withstand extreme environments in terms of high ammonia nitrogen, high salt and low temperature. It is urgent to study whether the algal mud mixture rich in denitrifying bacteria and chlorella can greatly improve the efficiency of landfill leachate treatment under an anaerobic environment where photosynthesis is stopped. The optimal dilution concentration of simulated landfill leachate can be found by determining the treatment effect of the same batch of bacteria and algae mixtures under different initial ammonia nitrogen concentrations and making a comparison. High-throughput sequencing technology was used to analyze the changes in microbial diversity, related functional genera and functional genes under optimal conditions, providing a theoretical and practical basis for the engineering application of novel bacteria-algae symbiosis system in biogas slurry treatment and resource utilization.

Keywords: nutrient removal and recovery, leachate, anammox, Partial nitrification, Algae-bacteria interaction

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359 Effect of Probiotics and Vitamin B on Plasma Interferon-Gamma and Interleukin-6 Levels in Active Pulmonary Tuberculosis

Authors: Yulistiani Yulistiani, Zamrotul Izzah, Lintang Bismantara, Wenny Putri Nilamsari, Arif Bachtiar, Budi Suprapti

Abstract:

Interferon-gamma (IFN-γ) and interleukin-6 (IL-6) are pro-inflammatory cytokines, which have the protective immune response against Tuberculosis (TB). Indeed, pro-inflammatory cytokines Mycobacterium tuberculosis antigen-specific CD4+ and CD8+ T cells and NK cells increase the level of production of IFN-γ, a cytokine critical for augmenting the microbicidal activity of phagocytes. On the other hand, M. tuberculosis reduces the effects of IFN-γ by inhibiting the transcription of IFN-γ- responsive genes and by inducing the secretion of IL-6, which inhibits IFN-γ signaling. Probiotics Lactobacillus sp. and Bifidobacterium sp. were known to increase IFN-γ production in vivo, while vitamin B1, B6, and B12 worked on macrophages and releasing cytokines. Therefore, the present study was to evaluate the effect of probiotics and vitamin B supplement on changes of plasma cytokine levels in active pulmonary TB. From October to November 2016, twelve M. tuberculosis-infected patients starting anti-TB drugs were recruited, then divided into two groups. Seven patients were given a combination of probiotics and vitamin B, while five patients were in the control group. Plasma IFN-γ and IL-6 levels were measured by the ELISA kit before and a month after treatment. IFN-γ levels raised in four patients receiving the supplement (P = 0.743), while IL-6 increased in three patients in this group until day 30 of treatment (P = 0.298). Taken together, these results show the promising effect of probiotics and vitamin B on stimulation of IFN-γ and IL-6 production during intensive therapy of TB.

Keywords: interferon-gamma, interleukin-6, probiotic, tuberculosis

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358 Genome-Wide Functional Analysis of Phosphatase in Cryptococcus neoformans

Authors: Jae-Hyung Jin, Kyung-Tae Lee, Yee-Seul So, Eunji Jeong, Yeonseon Lee, Dongpil Lee, Dong-Gi Lee, Yong-Sun Bahn

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Cryptococcus neoformans causes cryptococcal meningoencephalitis mainly in immunocompromised patients as well as immunocompetent people. But therapeutic options are limited to treat cryptococcosis. Some signaling pathways including cyclic AMP pathway, MAPK pathway, and calcineurin pathway play a central role in the regulation of the growth, differentiation, and virulence of C. neoformans. To understand signaling networks regulating the virulence of C. neoformans, we selected the 114 putative phosphatase genes, one of the major components of signaling networks, in the genome of C. neoformans. We identified putative phosphatases based on annotation in C. neoformans var. grubii genome database provided by the Broad Institute and National Center for Biotechnology Information (NCBI) and performed a BLAST search of phosphatases of Saccharomyces cerevisiae, Aspergillus nidulans, Candida albicans and Fusarium graminearum to Cryptococcus neoformans. We classified putative phosphatases into 14 groups based on InterPro phosphatase domain annotation. Here, we constructed 170 signature-tagged gene-deletion strains through homologous recombination methods for 91 putative phosphatases. We examined their phenotypic traits under 30 different in vitro conditions, including growth, differentiation, stress response, antifungal resistance and virulence-factor production.

Keywords: human fungal pathogen, phosphatase, deletion library, functional genomics

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357 Modeling of CREB Pathway Induced Gene Induction: From Stimulation to Repression

Authors: K. Julia Rose Mary, Victor Arokia Doss

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Electrical and chemical stimulations up-regulate phosphorylaion of CREB, a transcriptional factor that induces its target gene production for memory consolidation and Late Long-Term Potentiation (L-LTP) in CA1 region of the hippocampus. L-LTP requires complex interactions among second-messenger signaling cascade molecules such as cAMP, CAMKII, CAMKIV, MAPK, RSK, PKA, all of which converge to phosphorylate CREB which along with CBP induces the transcription of target genes involved in memory consolidation. A differential equation based model for L-LTP representing stimulus-mediated activation of downstream mediators which confirms the steep, supralinear stimulus-response effects of activation and inhibition was used. The same was extended to accommodate the inhibitory effect of the Inducible cAMP Early Repressor (ICER). ICER is the natural inducible CREB antagonist represses CRE-Mediated gene transcription involved in long-term plasticity for learning and memory. After verifying the sensitivity and robustness of the model, we had simulated it with various empirical levels of repressor concentration to analyse their effect on the gene induction. The model appears to predict the regulatory dynamics of repression on the L-LTP and agrees with the experimental values. The flux data obtained in the simulations demonstrate various aspects of equilibrium between the gene induction and repression.

Keywords: CREB, L-LTP, mathematical modeling, simulation

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356 Melanoma Antigen Proteins Are Involved in DNA Damage Response

Authors: Olivier de Backer, Alexis Khelfi, Olivier Svensek, Axelle Nolmans, Dominique Desnoeck

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The SMC5-SMC6 complex helps replication and repair of DNA double-strand breaks. Nse1, Nse3 and Nse4 are non-SMC components of the complex in which Nse3 stimulates the E3 ubiquitin ligase activity of Nse1 and is required for recruiting the complex on DNA. In most eukaryotes, Nse3 is a single protein, but in eutherians (placental mammals), it belongs to a large family of proteins called MAGE (Melanoma antigen) that share a conserved domain of about 200 aa known as MHD (Mage homology domain). MAGE assembles specific RING and HECT ubiquitin ligases and determines new substrates for ubiquitination. The MHD is required for the interaction with the cognate E3 ligase. Some MAGEs (referred to as Type I) are exclusively expressed in germ cells of the testis but are often expressed ectopically in cancer cells as the result of epigenetic modifications. The 12 MAGE-A genes belong to this category. Serval MAGE-A proteins could promote tumorigenesis by targeting tumor suppressor proteins (including p53) for ubiquitination and degradation. We showed that depletion of MAGE-A proteins in melanoma cells results in impaired DNA damage response and increased double-strand breaks after exposure to camptothecin. Moreover, it was shown that other actors of the DNA Damage Response were impacted when cells were depleted of MAGEA proteins.

Keywords: DNA damage response, melanoma, camptothecin, new role, MAGEA

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