Download or read book Host RNA Degradation Pathways and Influenza A Virus Interplay written by Marion Declercq and published by . This book was released on 2019 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: RNA decay is a central cellular process as it regulates RNA stability and quality and thereby gene expression, which is essential to ensure proper cellular physiology and establishment of adapted responses to viral infection. Global takeover of gene expression machineries and rewiring of the cellular environment is key to the success of viral infection. Cellular proteome and viral replication are tightly connected and cellular RNA processing, stability, quality and decay accordingly influence the fate of the viral cycle. Growing evidence points towards the existence of a large interplay between eukaryotic RNA turnover machineries and viral proteins. Viruses not only evolved mechanisms to evade those RNA degradation pathways, but they also manipulate them to promote viral replication.Influenza A viruses (IAV) are major pathogens responsible for yearly epidemics and occasional pandemics. To complete their viral cycle, IAVs rely on many cellular proteins and establish a complex and highly coordinated interplay with the host proteome. Growing evidence supports the existence of a complex interplay between IAV viral proteins and RNA decay machineries. Unraveling such interplay is therefore essential to gain a better understanding of the IAV life cycle, required for the development of antiviral strategies. This led us to systematically screen interactions between viral proteins involved in IAV replication and a selected set of 75 cellular proteins carrying exoribonucleases activities or associated with RNA decay machineries. A total of 18 proteins were identified as interactors of at least one viral protein tested. Analysis of the interaction network highlighted a specific and preferential targeting of RNA degradation pathways by IAV proteins. Among validated interactors, a targeted RNAi screen identified nine factors as required for viral multiplication. We chose to focus on the 3'-5' exoribonuclease 1 (ERI1), found in our screen as an interactor of several components of the vRNPs (viral RiboNucleoProtein) (PB2, PB1 and NP). The ERI1 protein is a major player in the control of cellular gene expression as it is essential for the maturation and decay of histone mRNA, maturation of 5.8S rRNA and miRNA homeostasis in mammalian cells. Exploring the interplay between ERI1 and viral proteins during the course of IAV infection we found that i) ERI1 promotes viral transcription, and both of its activities - RNA binding and exonuclease - are required, ii) ERI1 interacts with viral proteins in an RNA dependent manner, iii) ERI1 interacts with the transcribing vRNPs, iv) viral proteins interact with a form of ERI1 that is associated to histone mRNA. Ultimately, our data point to a model where ERI1 associated to histone mRNA is co-opted by the transcribing viral polymerase, thereby promoting IAV multiplication, through a mechanism that remains to be precisely determined. Targeting of ERI1 by IAV is another example further supporting the intricate interplay between IAV and RNA decay machineries, used to rewire cellular gene expression in order to create a favorable environment for viral replication.