scholarly journals A Bioinformatics Analysis Reveals a Group of MocR Bacterial Transcriptional Regulators Linked to a Family of Genes Coding for Membrane Proteins

2016 ◽  
Vol 2016 ◽  
pp. 1-13 ◽  
Author(s):  
Teresa Milano ◽  
Sebastiana Angelaccio ◽  
Angela Tramonti ◽  
Martino Luigi Di Salvo ◽  
Roberto Contestabile ◽  
...  

The MocR bacterial transcriptional regulators are characterized by an N-terminal domain, 60 residues long on average, possessing the winged-helix-turn-helix (wHTH) architecture responsible for DNA recognition and binding, linked to a large C-terminal domain (350 residues on average) that is homologous to fold type-I pyridoxal 5′-phosphate (PLP) dependent enzymes like aspartate aminotransferase (AAT). These regulators are involved in the expression of genes taking part in several metabolic pathways directly or indirectly connected to PLP chemistry, many of which are still uncharacterized. A bioinformatics analysis is here reported that studied the features of a distinct group of MocR regulators predicted to be functionally linked to a family of homologous genes coding for integral membrane proteins of unknown function. This group occurs mainly in the Actinobacteria and Gammaproteobacteria phyla. An analysis of the multiple sequence alignments of their wHTH and AAT domains suggested the presence of specificity-determining positions (SDPs). Mapping of SDPs onto a homology model of the AAT domain hinted at possible structural/functional roles in effector recognition. Likewise, SDPs in wHTH domain suggested the basis of specificity of Transcription Factor Binding Site recognition. The results reported represent a framework for rational design of experiments and for bioinformatics analysis of other MocR subgroups.

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Elena N. Judd ◽  
Alison R. Gilchrist ◽  
Nicholas R. Meyerson ◽  
Sara L. Sawyer

Abstract Background The Type I interferon response is an important first-line defense against viruses. In turn, viruses antagonize (i.e., degrade, mis-localize, etc.) many proteins in interferon pathways. Thus, hosts and viruses are locked in an evolutionary arms race for dominance of the Type I interferon pathway. As a result, many genes in interferon pathways have experienced positive natural selection in favor of new allelic forms that can better recognize viruses or escape viral antagonists. Here, we performed a holistic analysis of selective pressures acting on genes in the Type I interferon family. We initially hypothesized that the genes responsible for inducing the production of interferon would be antagonized more heavily by viruses than genes that are turned on as a result of interferon. Our logic was that viruses would have greater effect if they worked upstream of the production of interferon molecules because, once interferon is produced, hundreds of interferon-stimulated proteins would activate and the virus would need to counteract them one-by-one. Results We curated multiple sequence alignments of primate orthologs for 131 genes active in interferon production and signaling (herein, “induction” genes), 100 interferon-stimulated genes, and 100 randomly chosen genes. We analyzed each multiple sequence alignment for the signatures of recurrent positive selection. Counter to our hypothesis, we found the interferon-stimulated genes, and not interferon induction genes, are evolving significantly more rapidly than a random set of genes. Interferon induction genes evolve in a way that is indistinguishable from a matched set of random genes (22% and 18% of genes bear signatures of positive selection, respectively). In contrast, interferon-stimulated genes evolve differently, with 33% of genes evolving under positive selection and containing a significantly higher fraction of codons that have experienced selection for recurrent replacement of the encoded amino acid. Conclusion Viruses may antagonize individual products of the interferon response more often than trying to neutralize the system altogether.


2019 ◽  
Vol 2 (1) ◽  
Author(s):  
François Ferron ◽  
Humberto J Debat ◽  
Ashleigh Shannon ◽  
Etienne Decroly ◽  
Bruno Canard

Abstract The order Nidovirales is a diverse group of (+)RNA viruses, classified together based on their common genome organisation and conserved replicative enzymes, despite drastic differences in size and complexity. One such difference pertains to the mechanisms and enzymes responsible for generation of the proposed viral 5′ RNA cap. Within the Coronaviridae family, two separate methytransferases (MTase), nsp14 and nsp16, perform the RNA-cap N7-guanine and 2′-OH methylation respectively for generation of the proposed m7GpppNm type I cap structure. For the majority of other families within the Nidovirales order, the presence, structure and key enzymes involved in 5′ capping are far less clear. These viruses either lack completely an RNA MTase signature sequence, or lack an N7-guanine methyltransferase signature sequence, obscuring our understanding about how RNA-caps are N7-methylated for these families. Here, we report the discovery of a putative Rossmann fold RNA methyltransferase in 10 Tobaniviridae members in Orf1a, an unusual genome locus for this gene. Multiple sequence alignments and structural analyses lead us to propose this novel gene as a typical RNA-cap N7-guanine MTase with substrate specificity and active-site organization similar to the canonical eukaryotic RNA-cap N7-guanine MTase.


2018 ◽  
Vol 19 (12) ◽  
pp. 3706 ◽  
Author(s):  
Jin-Shan Ran ◽  
Jie Jin ◽  
Xian-Xian Zhang ◽  
Ye Wang ◽  
Peng Ren ◽  
...  

Innate immunity is an essential line of defense against pathogen invasion which is gained at birth, and the mechanism involved is mainly to identify pathogen-associated molecular patterns through pattern recognition receptors. STING (stimulator of interferon genes) is a signal junction molecule that hosts the perception of viral nucleic acids and produces type I interferon response, which plays a crucial role in innate immunity. However, relatively few studies have investigated the molecular characterization, tissue distribution, and potential function of STING in chickens. In this study, we cloned the full-length cDNA of chicken STING that is composed of 1341 bp. Sequence analyses revealed that STING contains a 1140-bp open-reading frame that probably encodes a 379-amino acid protein. Multiple sequence alignments showed that the similarity of the chicken STING gene to other birds is higher than that of mammals. Real-time polymerase chain reaction (PCR) assays revealed that STING is highly expressed in the spleen, thymus and bursa of fabricious in chickens. Furthermore, we observed that STING expression was significantly upregulated both in vitro and in vivo following infection with Newcastle disease virus (NDV). STING expression was also significantly upregulated in chicken embryo fibroblasts upon stimulation with poly(I:C) or poly(dA:dT). Taken together, these findings suggest that STING plays an important role in antiviral signaling pathways in chickens.


Archaea ◽  
2006 ◽  
Vol 2 (1) ◽  
pp. 39-49 ◽  
Author(s):  
Michael Bose ◽  
David Slick ◽  
Mickey J. Sarto ◽  
Patrick Murphy ◽  
David Roberts ◽  
...  

Microbial genome sequencing projects have revealed an apparently wide distribution of SmtB/ArsR metal-responsive transcriptional regulators among prokaryotes. Using a position-dependent weight matrix approach, prokaryotic genome sequences were screened for SmtB/ArsR DNA binding sites using data derived from intergenic sequences upstream of orthologous genes encoding these regulators. Sixty SmtB/ArsR operators linked to metal detoxification genes, including nine among various archaeal species, are predicted among 230 annotated and draft prokaryotic genome sequences. Independent multiple sequence alignments of putative operator sites and corresponding winged helix-turn-helix motifs define sequence signatures for the DNA binding activity of this SmtB/ArsR subfamily. Prediction of an archaeal SmtB/ArsR based upon these signature sequences is confirmed using purifiedMethanosarcina acetivoransC2A protein and electrophoretic mobility shift assays. Tools used in this study have been incorporated into a web application, the Prokaryotic InterGenic Exploration Database (PIGED; http://bioinformatics.uwp.edu/~PIGED/home.htm), facilitating comparable studies. Use of this tool and establishment of orthology based on DNA binding signatures holds promise for deciphering potential cellular roles of various archaeal winged helix-turn-helix transcriptional regulators.


2020 ◽  
Vol 15 ◽  
Author(s):  
Mingxuan Yang ◽  
Liangtao Zhao ◽  
Xuchang Hu ◽  
Haijun Feng ◽  
Xuewen Kang

Background: Osteosarcoma (OS) is one of the most common primary malignant bone tumors in teenagers. Emerging studies demonstrated TWEAK and Fn14 were involved in regulating cancer cell differentiation, proliferation, apoptosis, migration and invasion. Objective: The present study identified differently expressed mRNAs and lncRNAs after anti-TWEAK treatment in OS cells using GSE41828. Methods: We identified 922 up-regulated mRNAs, 863 downregulated mRNAs, 29 up-regulated lncRNAs, and 58 down-regulated lncRNAs after anti-TWEAK treatment in OS cells. By constructing PPI networks, we identified several key proteins involved in anti-TWEAK treatment in OS cells, including MYC, IL6, CD44, ITGAM, STAT1, CCL5, FN1, PTEN, SPP1, TOP2A, and NCAM1. By constructing lncRNAs coexpression networks, we identified several key lncRNAs, including LINC00623, LINC00944, PSMB8-AS1, LOC101929787. Result: Bioinformatics analysis revealed DEGs after anti-TWEAK treatment in OS were involved in regulating type I interferon signaling pathway, immune response related pathways, telomere organization, chromatin silencing at rDNA, and DNA replication. Bioinformatics analysis revealed differently expressed lncRNAs after antiTWEAK treatment in OS were related to telomere organization, protein heterotetramerization, DNA replication, response to hypoxia, TNF signaling pathway, PI3K-Akt signaling pathway, Focal adhesion, Apoptosis, NF-kappa B signaling pathway, MAPK signaling pathway, FoxO signaling pathway. Conclusion: : This study provided useful information for understanding the mechanisms of TWEAK underlying OS progression and identifying novel therapeutic markers for OS.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Juan C. Muñoz-Escalante ◽  
Andreu Comas-García ◽  
Sofía Bernal-Silva ◽  
Daniel E. Noyola

AbstractRespiratory syncytial virus (RSV) is a major cause of respiratory infections and is classified in two main groups, RSV-A and RSV-B, with multiple genotypes within each of them. For RSV-B, more than 30 genotypes have been described, without consensus on their definition. The lack of genotype assignation criteria has a direct impact on viral evolution understanding, development of viral detection methods as well as vaccines design. Here we analyzed the totality of complete RSV-B G gene ectodomain sequences published in GenBank until September 2018 (n = 2190) including 478 complete genome sequences using maximum likelihood and Bayesian phylogenetic analyses, as well as intergenotypic and intragenotypic distance matrices, in order to generate a systematic genotype assignation. Individual RSV-B genes were also assessed using maximum likelihood phylogenetic analyses and multiple sequence alignments were used to identify molecular markers associated to specific genotypes. Analyses of the complete G gene ectodomain region, sequences clustering patterns, and the presence of molecular markers of each individual gene indicate that the 37 previously described genotypes can be classified into fifteen distinct genotypes: BA, BA-C, BA-CC, CB1-THB, GB1-GB4, GB6, JAB1-NZB2, SAB1, SAB2, SAB4, URU2 and a novel early circulating genotype characterized in the present study and designated GB0.


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