scholarly journals STAT2/IRF9 directs a prolonged ISGF3-like transcriptional response and antiviral activity in the absence of STAT1

2015 ◽  
Vol 466 (3) ◽  
pp. 511-524 ◽  
Author(s):  
Katarzyna Blaszczyk ◽  
Adam Olejnik ◽  
Hanna Nowicka ◽  
Lilla Ozgyin ◽  
Yi-Ling Chen ◽  
...  

Evidence is accumulating for the existence of a signal transducer and activator of transcription 2 (STAT2)/interferon regulatory factor 9 (IRF9)-dependent, STAT1-independent interferon alpha (IFNα) signalling pathway. However, no detailed insight exists into the genome-wide transcriptional regulation and the biological implications of STAT2/IRF9-dependent IFNα signalling as compared with interferon-stimulated gene factor 3 (ISGF3). In STAT1-defeicient U3C cells stably overexpressing human STAT2 (hST2-U3C) and STAT1-deficient murine embryonic fibroblast cells stably overexpressing mouse STAT2 (mST2-MS1KO) we observed that the IFNα-induced expression of 2′-5′-oligoadenylate synthase 2 (OAS2) and interferon-induced protein with tetratricopeptide repeats 1 (Ifit1) correlated with the kinetics of STAT2 phosphorylation, and the presence of a STAT2/IRF9 complex requiring STAT2 phosphorylation and the STAT2 transactivation domain. Subsequent microarray analysis of IFNα-treated wild-type (WT) and STAT1 KO cells overexpressing STAT2 extended our observations and identified ∼120 known antiviral ISRE-containing interferon-stimulated genes (ISGs) commonly up-regulated by STAT2/IRF9 and ISGF3. The STAT2/IRF9-directed expression profile of these IFN-stimulated genes (ISGs) was prolonged as compared with the early and transient response mediated by ISGF3. In addition, we identified a group of ‘STAT2/IRF9-specific’ ISGs, whose response to IFNα was ISGF3-independent. Finally, STAT2/IRF9 was able to trigger an antiviral response upon encephalomyocarditis virus (EMCV) and vesicular stomatitis Indiana virus (VSV). Our results further prove that IFNα-activated STAT2/IRF9 induces a prolonged ISGF3-like transcriptome and generates an antiviral response in the absence of STAT1. Moreover, the existence of ‘STAT2/IRF9-specific’ target genes predicts a novel role of STAT2 in IFNα signalling.

Cells ◽  
2019 ◽  
Vol 8 (8) ◽  
pp. 919 ◽  
Author(s):  
Mélissa K. Mariani ◽  
Pouria Dasmeh ◽  
Audray Fortin ◽  
Elise Caron ◽  
Mario Kalamujic ◽  
...  

Interferon (IFN) β and Tumor Necrosis Factor (TNF) are key players in immunity against viruses. Compelling evidence has shown that the antiviral and inflammatory transcriptional response induced by IFNβ is reprogrammed by crosstalk with TNF. IFNβ mainly induces interferon-stimulated genes by the Janus kinase (JAK)/signal transducer and activator of transcription (STAT) pathway involving the canonical ISGF3 transcriptional complex, composed of STAT1, STAT2, and IRF9. The signaling pathways engaged downstream of the combination of IFNβ and TNF remain elusive, but previous observations suggested the existence of a response independent of STAT1. Here, using genome-wide transcriptional analysis by RNASeq, we observed a broad antiviral and immunoregulatory response initiated in the absence of STAT1 upon IFNβ and TNF costimulation. Additional stratification of this transcriptional response revealed that STAT2 and IRF9 mediate the expression of a wide spectrum of genes. While a subset of genes was regulated by the concerted action of STAT2 and IRF9, other gene sets were independently regulated by STAT2 or IRF9. Collectively, our data supports a model in which STAT2 and IRF9 act through non-canonical parallel pathways to regulate distinct pool of antiviral and immunoregulatory genes in conditions with elevated levels of both IFNβ and TNF.


2009 ◽  
Vol 83 (9) ◽  
pp. 4412-4422 ◽  
Author(s):  
Juliet M. Morrison ◽  
Vincent R. Racaniello

ABSTRACT The Picornaviridae family comprises a diverse group of small RNA viruses that cause a variety of human and animal diseases. Some of these viruses are known to induce cleavage of components of the innate immune system and to inhibit steps in the interferon pathway that lead to the production of type I interferon. There has been no study of the effect of picornaviral infection on the events that occur after interferons have been produced. To determine whether members of the Enterovirus genus can antagonize the antiviral activity of interferon-stimulated genes (ISGs), we pretreated cells with alpha interferon (IFN-α) and then infected the cells with poliovirus type 1, 2, or 3; enterovirus type 70; or human rhinovirus type 16. We found that these viruses were able to replicate in IFN-α-pretreated cells but that replication of vesicular stomatitis virus, a Rhabdovirus, and encephalomyocarditis virus (EMCV), a picornavirus of the Cardiovirus genus, was completely inhibited. Although EMCV is sensitive to IFN-α, coinfection of cells with poliovirus and EMCV leads to EMCV replication in IFN-α-pretreated cells. The enteroviral 2A proteinase (2Apro) is essential for replication in cells pretreated with interferon, because amino acid changes in this protein render poliovirus sensitive to IFN-α. The addition of the poliovirus 2Apro gene to the EMCV genome allowed EMCV to replicate in IFN-α-pretreated cells. These results support an inhibitory role for 2Apro in the most downstream event in interferon signaling, the antiviral activities of ISGs.


2007 ◽  
Vol 18 (11) ◽  
pp. 4528-4542 ◽  
Author(s):  
Cheng-Jun Hu ◽  
Aneesa Sataur ◽  
Liyi Wang ◽  
Hongqing Chen ◽  
M. Celeste Simon

The basic helix-loop-helix-Per-ARNT-Sim–proteins hypoxia-inducible factor (HIF)-1α and HIF-2α are the principal regulators of the hypoxic transcriptional response. Although highly related, they can activate distinct target genes. In this study, the protein domain and molecular mechanism important for HIF target gene specificity are determined. We demonstrate that although HIF-2α is unable to activate multiple endogenous HIF-1α–specific target genes (e.g., glycolytic enzymes), HIF-2α still binds to their promoters in vivo and activates reporter genes derived from such targets. In addition, comparative analysis of the N-terminal DNA binding and dimerization domains of HIF-1α and HIF-2α does not reveal any significant differences between the two proteins. Importantly, replacement of the N-terminal transactivation domain (N-TAD) (but not the DNA binding domain, dimerization domain, or C-terminal transactivation domain [C-TAD]) of HIF-2α with the analogous region of HIF-1α is sufficient to convert HIF-2α into a protein with HIF-1α functional specificity. Nevertheless, both the N-TAD and C-TAD are important for optimal HIF transcriptional activity. Additional experiments indicate that the ETS transcription factor ELK is required for HIF-2α to activate specific target genes such as Cited-2, EPO, and PAI-1. These results demonstrate that the HIF-α TADs, particularly the N-TADs, confer HIF target gene specificity, by interacting with additional transcriptional cofactors.


2013 ◽  
Vol 24 (3) ◽  
pp. 351-360 ◽  
Author(s):  
Conchi Estarás ◽  
Raquel Fueyo ◽  
Naiara Akizu ◽  
Sergi Beltrán ◽  
Marian A. Martínez-Balbás

JMJD3 H3K27me3 demethylase plays an important role in the transcriptional response to different signaling pathways; however, the mechanism by which it facilitates transcription has been unclear. Here we show that JMJD3 regulates transcription of transforming growth factor β (TGFβ)–responsive genes by promoting RNA polymerase II (RNAPII) progression along the gene bodies. Using chromatin immunoprecipitation followed by sequencing experiments, we show that, upon TGFβ treatment, JMJD3 and elongating RNAPII colocalize extensively along the intragenic regions of TGFβ target genes. According to these data, genome-wide analysis shows that JMJD3-dependent TGFβ target genes are enriched in H3K27me3 before TGFβ signaling pathway activation. Further molecular analyses demonstrate that JMJD3 demethylates H3K27me3 along the gene bodies, paving the way for the RNAPII progression. Overall these findings uncover the mechanism by which JMJD3 facilitates transcriptional activation.


2021 ◽  
Vol 9 (8) ◽  
pp. 1570
Author(s):  
Chien-Hsun Huang ◽  
Chih-Chieh Chen ◽  
Yu-Chun Lin ◽  
Chia-Hsuan Chen ◽  
Ai-Yun Lee ◽  
...  

The current taxonomy of the Lactiplantibacillus plantarum group comprises of 17 closely related species that are indistinguishable from each other by using commonly used 16S rRNA gene sequencing. In this study, a whole-genome-based analysis was carried out for exploring the highly distinguished target genes whose interspecific sequence identity is significantly less than those of 16S rRNA or conventional housekeeping genes. In silico analyses of 774 core genes by the cano-wgMLST_BacCompare analytics platform indicated that csbB, morA, murI, mutL, ntpJ, rutB, trmK, ydaF, and yhhX genes were the most promising candidates. Subsequently, the mutL gene was selected, and the discrimination power was further evaluated using Sanger sequencing. Among the type strains, mutL exhibited a clearly superior sequence identity (61.6–85.6%; average: 66.6%) to the 16S rRNA gene (96.7–100%; average: 98.4%) and the conventional phylogenetic marker genes (e.g., dnaJ, dnaK, pheS, recA, and rpoA), respectively, which could be used to separat tested strains into various species clusters. Consequently, species-specific primers were developed for fast and accurate identification of L. pentosus, L. argentoratensis, L. plantarum, and L. paraplantarum. During this study, one strain (BCRC 06B0048, L. pentosus) exhibited not only relatively low mutL sequence identities (97.0%) but also a low digital DNA–DNA hybridization value (78.1%) with the type strain DSM 20314T, signifying that it exhibits potential for reclassification as a novel subspecies. Our data demonstrate that mutL can be a genome-wide target for identifying and classifying the L. plantarum group species and for differentiating novel taxa from known species.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Samina Shabbir ◽  
Prerona Boruah ◽  
Lingli Xie ◽  
Muhammad Fakhar-e-Alam Kulyar ◽  
Mohsin Nawaz ◽  
...  

AbstractOvary development is an important determinant of the procreative capacity of female animals. Here, we performed genome-wide sequencing of long non-coding RNAs (lncRNAs) and mRNAs on ovaries of 1, 3 and 8 months old Hu sheep to assess their expression profiles and roles in ovarian development. We identified 37,309 lncRNAs, 45,404 messenger RNAs (mRNAs) and 330 novel micro RNAs (miRNAs) from the transcriptomic analysis. Six thousand, seven hundred and sixteen (6716) mRNAs and 1972 lncRNAs were significantly and differentially expressed in ovaries of 1 month and 3 months old Hu sheep (H1 vs H3). These mRNAs and target genes of lncRNAs were primarily enriched in the TGF-β and PI3K-Akt signalling pathways which are closely associated with ovarian follicular development and steroid hormone biosynthesis regulation. We identified MSTRG.162061.1, MSTRG.222844.7, MSTRG.335777.1, MSTRG.334059.16, MSTRG.188947.6 and MSTRG.24344.3 as vital genes in ovary development by regulating CTNNB1, CCNA2, CDK2, CDC20, CDK1 and EGFR expressions. A total of 2903 mRNAs and 636 lncRNAs were differentially expressed in 3 and 8 months old ovaries of Hu sheep (H3 vs H8); and were predominantly enriched in PI3K-Akt, progesterone-mediated oocyte maturation, estrogen metabolism, ovulation from the ovarian follicle and oogenesis pathways. These lncRNAs were also found to regulate FGF7, PRLR, PTK2, AMH and INHBA expressions during follicular development. Our result indicates the identified genes participate in the development of the final stages of follicles and ovary development in Hu sheep.


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