A small protein encoded by lncRNA PCBP1-AS1 promotes the replication of influenza virus via regulating the expression of proviral effectors
Ontology highlight
ABSTRACT: Many annotated long noncoding RNAs (lncRNAs) contain small open reading frames (sORFs), some of which have been demonstrated to encode small proteins or micropeptides with fundamental biological importance. While the small proteins or micropeptides hidden in lncRNA are gradually being revealed, their functions in influenza virus infection remain largely unexplored. Here, we identified and characterized a small 110-amino acid protein named PAESP that is encoded by the putative lncRNA PCBP1-AS1. We found that both PCBP1-AS1 and PAESP were upregulated by influenza virus infection as well as type I interferon treatment. Overexpression of PCBP1-AS1 or PAESP enhanced influenza virus replication. Conversely, knockdown of PCBP1-AS1 or knockout of PAESP inhibited viral production. In addition, loss-of-function experiment demonstrated that PAESP is essential for PCBP1-AS1 to facilitate influenza virus replication. More importantly, the overexpression of PAESP increases the mRNA level of several genes such as IFIT2 and IFIT3, which have been proved to be retasked by influenza virus from canonical antiviral factors into proviral effectors. Interestingly, when IFIT2 or IFIT3 expression was knocked down in PAESP-overexpressed cells, the virus titers significantly decreased compared to control cells. These findings reveal a novel lncRNA-derived small protein that is exploited by influenza virus and provide new insights into the virus-host regulatory network.
Project description:Many annotated long noncoding RNAs (lncRNAs) contain small open reading frames (sORFs), some of which have been demonstrated to encode small proteins or micropeptides with fundamental biological importance. While the small proteins or micropeptides hidden in lncRNA are gradually being revealed, their functions in influenza virus infection remain largely unexplored. Here, we identified and characterized a small 110-amino acid protein named PAESP that is encoded by the putative lncRNA PCBP1-AS1. We found that both PCBP1-AS1 and PAESP were upregulated by influenza virus infection as well as type I interferon treatment. Overexpression of PCBP1-AS1 or PAESP enhanced influenza virus replication. Conversely, knockdown of PCBP1-AS1 or knockout of PAESP inhibited viral production. In addition, loss-of-function experiment demonstrated that PAESP is essential for PCBP1-AS1 to facilitate influenza virus replication. More importantly, the overexpression of PAESP increases the mRNA level of several genes such as IFIT2 and IFIT3, which have been proved to be retasked by influenza virus from canonical antiviral factors into proviral effectors. Interestingly, when IFIT2 or IFIT3 expression was knocked down in PAESP-overexpressed cells, the virus titers significantly decreased compared to control cells. These findings reveal a novel lncRNA-derived small protein that is exploited by influenza virus and provide new insights into the virus-host regulatory network.
Project description:Many annotated long noncoding RNAs (lncRNAs) contain small open reading frames (sORFs), some of which have been demonstrated to encode small proteins or micropeptides with fundamental biological importance. However, the small proteins or micropeptides encoded by lncRNAs and their functions in viral infection remain largely unexplored. Here, we identified and characterized a small 110-amino acid protein named ORF6 encoded by the putative lncRNA PCBP1-AS1. Interestingly, both PCBP1-AS1 and ORF6 were significantly upregulated by influenza virus infection. Furthermore, we observed that they were markedly induced by type I interferon treatment. Overexpression of PCBP1-AS1 or ORF6 enhanced influenza virus replication. Conversely, knockdown of PCBP1-AS1 or knockout of ORF6 inhibited the viral production. In addition, loss-of-function experiment demonstrated that ORF6 is essential for PCBP1-AS1 to facilitate influenza virus replication. Importantly, the overexpression of ORF6 induced enhancement of autophagy by increasing the expression of ATG7, a gene encoding an essential effector enzyme for canonical autophagy. These findings reveal a lncRNA-derived small protein that is exploited by influenza virus, and provide new insights into the virus-host regulatory network.
Project description:Recognition of non-self nucleic acids, including cytoplasmic dsDNA, dsRNA, or mRNAs lacking proper 5' cap structures, is critical for the induction of innate immunity against viruses. Here, we demonstrate that short 5’ untranslated regions (UTRs), a characteristic of many viral mRNAs, can also serve as molecular pattern for innate immune recognition via the interferon-induced proteins, IFIT2 and IFIT3. The IFIT2-IFIT3 heterodimer, formed through an intricate domain swap structure, mediates viral mRNA 5' end recognition, translation inhibition, and ultimately antiviral activity. Critically, 5' UTR lengths <50 nucleotides are necessary and sufficient to sensitize an mRNA to translation inhibition by the IFIT2-IFIT3 complex. Thus, diverse viruses whose mRNAs contain short 5’ UTRs, such as vesicular stomatitis virus and parainfluenza virus 3, are sensitive to IFIT2-IFIT3-mediated antiviral activity. Our work reveals a new size-restricted pattern of nucleic acid innate immune recognition for the selective repression of viral replication.
Project description:A small protein encoded by lncRNA PCBP1-AS1 promotes the replication of influenza virus via regulating the expression of proviral effectors
Project description:A small protein encoded by lncRNA PCBP1-AS1 promotes the replication of influenza virus via regulating the expression of proviral effectors (Ribo-Seq)
Project description:Identification of a small protein encoded by PCBP1-AS1 that promotes replication of influenza virus via inducing enhancement of autophagy
Project description:Cells infected by influenza virus mount a large-scale antiviral response and most cells ultimately initiate cell-death pathways in an attempt to suppress viral replication. We performed a CRISPR/Cas9-knockout selection designed to identify host factors required for replication following viral entry. We identified a large class of presumptive antiviral factors that unexpectedly act as important pro-viral enhancers during influenza virus infection. One of these, IFIT2, is an interferon-stimulated gene with well-established antiviral activity but limited mechanistic understanding. As opposed to suppressing infection, we show here that IFIT2 is instead repurposed by influenza virus to promote viral gene expression. CLIP‐seq demonstrated that IFIT2 binds directly to viral and cellular mRNAs in AU‐rich regions, with bound cellular transcripts enriched in interferon‐stimulated mRNAs. Polysome and ribosome profiling revealed that IFIT2 prevents ribosome pausing on bound mRNAs. Together, the data link IFIT2 binding to enhanced translational efficiency for viral and cellular mRNAs and ultimately viral replication. Our findings establish a model for the normal function of IFIT2 as a protein that increases translation of cellular mRNAs to support antiviral responses and explain how influenza virus uses this same activity to redirect a classically antiviral protein into a pro-viral effector.
Project description:We recently identified a schizophrenia-associated upregulated long noncoding RNA (lncRNA) RP5-998N21.4 by transcriptomic analysis of monozygotic twins discordant for schizophrenia. Importantly, we found that genes coexpressed with RP5-998N21.4 were enriched in immune defense-related biological processes in twin subjects and in RP5-998N21.4-overexpressing (OE) SK-N-SH cell lines. We then identified two genes encoding interferon-induced protein with tetratricopeptide repeat (IFIT) 2 and 3, which play an important role in immune defense, as potential targets of RP5-998N21.4 by integrative analysis of RP5-998N21.4OE-induced differentially expressed genes (DEGs) in SK-N-SH cells and RP5-998N21.4-coexpressed schizophrenia-associated DEGs from twin subjects. We further demonstrated that RP5-998N21.4 positively regulates the transcription of IFIT2 and IFIT3 by binding to their promoter regions and affecting their histone modifications. In addition, as a general nuclear coactivator, RMB14 (encoding RNA binding motif protein 14) was identified to facilitate the regulatory role of RP5-998N21.4 in IFIT2 and IFIT3 transcription.
Project description:RNA-binding proteins participate in a complex array of post-transcriptional controls essential to cell-type specification and somatic development. Despite their detailed biochemical characterizations, the degree to which each RNA-binding protein impacts on mammalian embryonic development remains incompletely defined and the level of functional redundancy among subsets of these proteins remains open to question. The poly-(C) binding proteins, Pcbp's (aCPs, hnRNPEs), are encoded by a highly conserved and broadly expressed gene family. The two major Pcbp isoforms, Pcbp2 and Pcbp1, are robustly expressed in a wide range of tissues and exert both nuclear and cytoplasmic controls over gene expression. Here we report that Pcbp1-null embryos are rendered nonviable in the peri-implantation stage. In contrast, Pcbp2-null embryos survive until mid-gestation at which time they undergo a loss in viability associated with cardiovascular and hematopoietic abnormalities. Adult mice heterozygous for either Pcbp1 or Pcbp2 null alleles display a mild and non-disruptive growth defect. These data reveal that Pcbp1 and Pcbp2 are individually essential for mouse embryonic development and post-natal growth, reveal a non-redundant in vivo role for Pcpb2 in hematopoiesis, and provide direct evidence that Pcbp1, a retrotransposed derivative of Pcpb2, has evolved essential function(s) in the mammalian genome. mRNA-seq on fetal liver tissue from 12.5 days post coitum. 4 replicates of WT and 3 replicates of PCBP2 Knockout
Project description:The aim of this study was to construct a lncRNA-mRNA co-expression function network and analyze lncRNAs that might contribute to the pathogenesis of cervical cancer. Transcriptome analysis of 3 cervical cancer samples and 3 adjacent tissue samples was completed in this project.LncRNA-mRNA correlation analysis, enrichment of functions, qPCR, K-M survival, clinicopathology analysis, GSEA and immune infiltration analysis were implemented. Total of 67.600 GB of Clean Data (sequencing Data after quality control) was obtained. The average amount of Clean Data of each sample was 11.267 GB, the percentage of Q30 base was above 91.18%, and the GC content was between 45.46% and 47.18%.Reference species: human;Reference genomic version: GRCH38;Reference genome source: http://asia.ensembl.org/Homo_sapiens/Info/Index;The sequencing data of each sample after quality control was compared with the specified reference genome, and the matching rates ranged from 95.957% to 97.270%, and the unique matching rates ranged from 91.363% to 94.258%. Transcriptomic and lncRNA-mRNA correlation analysis revealed PCBP1-AS1 plays a key role as an independent prognostic factor in patients with cervical cancer.