scholarly journals Cytoplasmic RNA sensors and their interplay with RNA-binding partners in innate antiviral response: Theme and variations

RNA ◽  
2022 ◽  
pp. rna.079016.121
Author(s):  
Chi-Ping Chan ◽  
Dong-Yan Jin

Sensing of pathogen-associated molecular patterns including viral RNA by innate immunity represents the first line of defense against viral infection. In addition to RIG-I-like receptors and NOD-like receptors, several other RNA sensors are known to mediate innate antiviral response in the cytoplasm. Double-stranded RNA-binding protein PACT interacts with prototypic RNA sensor RIG-I to facilitate its recognition of viral RNA and induction of host interferon response, but variations of this theme are seen when the functions of RNA sensors are modulated by other RNA-binding proteins to impinge on antiviral defense, proinflammatory cytokine production and cell death programs. Their discrete and coordinated actions are crucial to protect the host from infection. In this review, we will focus on cytoplasmic RNA sensors with an emphasis on their interplay with RNA-binding partners. Classical sensors such as RIG-I will be briefly reviewed. More attention will be brought to the new insights on how RNA-binding partners of RNA sensors modulate innate RNA sensing and how viruses perturb the functions of RNA-binding partners.

1999 ◽  
Vol 73 (1) ◽  
pp. 474-481 ◽  
Author(s):  
Tilman Heise ◽  
Luca G. Guidotti ◽  
Victoria J. Cavanaugh ◽  
Francis V. Chisari

ABSTRACT Hepatitis B virus (HBV) gene expression is downregulated in the liver of HBV transgenic mice by a posttranscriptional mechanism that is triggered by the local production of gamma interferon (IFN-γ) and tumor necrosis factor alpha (TNF-α) during intrahepatic inflammation (hepatitis). The molecular basis for this antiviral effect is unknown. In this study, we identified three HBV RNA-binding liver nuclear proteins (p45, p39, and p26) the relative abundance of which correlates with the abundance of HBV RNA in response to the induction of IFN-γ and TNF-α. All three proteins bind to a 91-bp element located at the 5′ end of a previously defined posttranscriptional regulatory element that is thought to mediate the nuclear export of HBV RNA. The presence of p45 correlates directly with the presence of HBV RNA, being detectable under baseline conditions when the viral RNA is abundant and undetectable when the viral RNA disappears in response to IFN-γ and TNF-α. In contrast, p26 is inversely related to HBV RNA, being detectable only when the viral RNA disappears following cytokine activation. Finally, p39 is constitutively expressed, and its abundance and mobility appear to be slightly increased by cytokine activation. These results suggest a model in which hepatocellular HBV RNA content might be controlled by the stabilizing and/or destabilizing influences of these RNA-binding proteins whose activity is regulated by cytokine-induced signaling pathways.


2021 ◽  
Vol 12 ◽  
Author(s):  
Yuying Ma ◽  
Xiaohui Wang ◽  
Weisheng Luo ◽  
Ji Xiao ◽  
Xiaowei Song ◽  
...  

cGAS, a DNA sensor in mammalian cells, catalyzes the generation of 2’-3’-cyclic AMP-GMP (cGAMP) once activated by the binding of free DNA. cGAMP can bind to STING, activating downstream TBK1-IRF-3 signaling to initiate the expression of type I interferons. Although cGAS has been considered a traditional DNA-binding protein, several lines of evidence suggest that cGAS is a potential RNA-binding protein (RBP), which is mainly supported by its interactions with RNAs, RBP partners, RNA/cGAS-phase-separations as well as its structural similarity with the dsRNA recognition receptor 2’-5’ oligoadenylate synthase. Moreover, two influential studies reported that the cGAS-like receptors (cGLRs) of fly Drosophila melanogaster sense RNA and control 3′-2′-cGAMP signaling. In this review, we summarize and discuss in depth recent studies that identified or implied cGAS as an RBP. We also comprehensively summarized current experimental methods and computational tools that can identify or predict RNAs that bind to cGAS. Based on these discussions, we appeal that the RNA-binding activity of cGAS cannot be ignored in the cGAS-mediated innate antiviral response. It will be important to identify RNAs that can bind and regulate the activity of cGAS in cells with or without virus infection. Our review provides novel insight into the regulation of cGAS by its RNA-binding activity and extends beyond its DNA-binding activity. Our review would be significant for understanding the precise modulation of cGAS activity, providing the foundation for the future development of drugs against cGAS-triggering autoimmune diseases such as Aicardi-Gourtières syndrome.


Author(s):  
Minzhe Zhang ◽  
Tao Wang ◽  
Guanghua Xiao ◽  
Yang Xie

Circular RNAs are a special type of RNAs which recently attracted a lot of research interest in studying its formation and function. RNA binding proteins (RBPs) that bind circRNAs are important in these processes but are relatively less studied. CLIP-Seq technology has been invented and applied to profile RBP-RNA interactions on the genome-wide scale. While mRNAs are usually the focus of CLIP-Seq experiments, RBP-circRNA interactions could also be identified through specialized analysis of CLIP-Seq datasets. However, many technical difficulties are involved in this process, such as the usually short read length of CLIP-Seq reads. In this study, we created a pipeline called Clirc specialized for profiling circRNAs in CLIP-Seq data and analyzing the characteristics of RBP- circRNAs interactions. In conclusion, this is one of the first few studies to investigate circRNAs and their binding partners through repurposing CLIP-Seq datasets to our knowledge, and we hope our work will become a valuable resource for future studies into the biogenesis and function of circRNAs. Clirc software is available at https://github.com/Minzhe/Clirc


Author(s):  
Ryan A. Flynn ◽  
Julia A. Belk ◽  
Yanyan Qi ◽  
Yuki Yasumoto ◽  
Cameron O. Schmitz ◽  
...  

AbstractSevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the cause of a pandemic with growing global mortality. There is an urgent need to understand the molecular pathways required for host infection and anti-viral immunity. Using comprehensive identification of RNA-binding proteins by mass spectrometry (ChIRP-MS), we identified 309 host proteins that bind the SARS-CoV-2 RNA during active infection. Integration of this data with viral ChIRP-MS data from three other positive-sense RNA viruses defined pan-viral and SARS-CoV-2-specific host interactions. Functional interrogation of these factors with a genome-wide CRISPR screen revealed that the vast majority of viral RNA-binding proteins protect the host from virus-induced cell death, and we identified known and novel anti-viral proteins that regulate SARS-CoV-2 pathogenicity. Finally, our RNA-centric approach demonstrated a physical connection between SARS-CoV-2 RNA and host mitochondria, which we validated with functional and electron microscopy data, providing new insights into a more general virus-specific protein logic for mitochondrial interactions. Altogether, these data provide a comprehensive catalogue of SARS-CoV-2 RNA-host protein interactions, which may inform future studies to understand the mechanisms of viral pathogenesis, as well as nominate host pathways that could be targeted for therapeutic benefit.Highlights· ChIRP-MS of SARS-CoV-2 RNA identifies a comprehensive viral RNA-host protein interaction network during infection across two species· Comparison to RNA-protein interaction networks with Zika virus, dengue virus, and rhinovirus identify SARS-CoV-2-specific and pan-viral RNA protein complexes and highlights distinct intracellular trafficking pathways· Intersection of ChIRP-MS and genome-wide CRISPR screens identify novel SARS-CoV-2-binding proteins with pro- and anti-viral function· Viral RNA-RNA and RNA-protein interactions reveal specific SARS-CoV-2-mediated mitochondrial dysfunction during infection


2007 ◽  
Vol 28 (2) ◽  
pp. 678-686 ◽  
Author(s):  
Raymond A. Lewis ◽  
James A. Gagnon ◽  
Kimberly L. Mowry

ABSTRACT Transport of specific mRNAs to defined regions within the cell cytoplasm is a fundamental mechanism for regulating cell and developmental polarity. In the Xenopus oocyte, Vg1 RNA is transported to the vegetal cytoplasm, where localized expression of the encoded protein is critical for embryonic polarity. The Vg1 localization pathway is directed by interactions between key motifs within Vg1 RNA and protein factors recognizing those RNA sequences. We have investigated how RNA-protein interactions could be modulated to trigger distinct steps in the localization pathway and found that the Vg1 RNP is remodeled during cytoplasmic RNA transport. Our results implicate two RNA-binding proteins with key roles in Vg1 RNA localization, PTB/hnRNP I and Vg1RBP/vera, in this process. We show that PTB/hnRNP I is required for remodeling of the interaction between Vg1 RNA and Vg1RBP/vera. Critically, mutations that block this remodeling event also eliminate vegetal localization of the RNA, suggesting that RNP remodeling is required for localization.


Acta Naturae ◽  
2017 ◽  
Vol 9 (2) ◽  
pp. 4-16 ◽  
Author(s):  
E. E. Alemasova ◽  
O. I. Lavrik

RNA-binding proteins (RBPs) regulate RNA metabolism, from synthesis to decay. When bound to RNA, RBPs act as guardians of the genome integrity at different levels, from DNA damage prevention to the post-transcriptional regulation of gene expression. Recently, RBPs have been shown to participate in DNA repair. This fact is of special interest as DNA repair pathways do not generally involve RNA. DNA damage in higher organisms triggers the formation of the RNA-like polymer - poly(ADP-ribose) (PAR). Nucleic acid-like properties allow PAR to recruit DNA- and RNA-binding proteins to the site of DNA damage. It is suggested that poly(ADP-ribose) and RBPs not only modulate the activities of DNA repair factors, but that they also play an important role in the formation of transient repairosome complexes in the nucleus. Cytoplasmic biomolecules are subjected to similar sorting during the formation of RNA assemblages by functionally related mRNAs and promiscuous RBPs. The Y-box-binding protein 1 (YB-1) is the major component of cytoplasmic RNA granules. Although YB-1 is a classic RNA-binding protein, it is now regarded as a non-canonical factor of DNA repair.


2011 ◽  
Vol 9 (4) ◽  
pp. 299-309 ◽  
Author(s):  
Kin-Hang Kok ◽  
Pak-Yin Lui ◽  
Ming-Him James Ng ◽  
Kam-Leung Siu ◽  
Shannon Wing Ngor Au ◽  
...  

mBio ◽  
2018 ◽  
Vol 9 (5) ◽  
Author(s):  
Jingru Fang ◽  
Colette Pietzsch ◽  
Palaniappan Ramanathan ◽  
Rodrigo I. Santos ◽  
Philipp A. Ilinykh ◽  
...  

ABSTRACTEbola virus (EBOV) genome and mRNAs contain long, structured regions that could hijack host RNA-binding proteins to facilitate infection. We performed RNA affinity chromatography coupled with mass spectrometry to identify host proteins that bind to EBOV RNAs and identified four high-confidence proviral host factors, including Staufen1 (STAU1), which specifically binds both 3′ and 5′ extracistronic regions of the EBOV genome. We confirmed that EBOV infection rate and production of infectious particles were significantly reduced in STAU1-depleted cells. STAU1 was recruited to sites of EBOV RNA synthesis upon infection and enhanced viral RNA synthesis. Furthermore, STAU1 interacts with EBOV nucleoprotein (NP), virion protein 30 (VP30), and VP35; the latter two bridge the viral polymerase to the NP-coated genome, forming the viral ribonucleoprotein (RNP) complex. Our data indicate that STAU1 plays a critical role in EBOV replication by coordinating interactions between the viral genome and RNA synthesis machinery.IMPORTANCEEbola virus (EBOV) is a negative-strand RNA virus with significant public health importance. Currently, no therapeutics are available for Ebola, which imposes an urgent need for a better understanding of EBOV biology. Here we dissected the virus-host interplay between EBOV and host RNA-binding proteins. We identified novel EBOV host factors, including Staufen1, which interacts with multiple viral factors and is required for efficient viral RNA synthesis.


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