RNA-free and ribonucleoprotein-associated influenza virus polymerases directly bind the serine-5 phosphorylated carboxyl-terminal domain of host RNA polymerase II

Journal article

Influenza viruses subvert the transcriptional machinery of their hosts to synthesise their own viral mRNA. Ongoing transcription by cellular RNA polymerase II (Pol II) is required for viral mRNA synthesis. By a process known as cap-snatching, the virus steals short 5ʹ capped RNA fragments from host capped RNAs and uses these to prime viral transcription. An interaction between the influenza A virus RNA polymerase and the C-terminal domain (CTD) of the large subunit of Pol II has been established, but the molecular details of this interaction remain unknown. We show here that influenza virus ribonucleoprotein (vRNP) complex binds to the CTD of transcriptionally engaged Pol II. Furthermore, we provide evidence that the viral polymerase binds directly to the serine-5 phosphorylated form of the Pol II CTD, both in the presence and absence of viral RNA, and show that this interaction is conserved in evolutionarily distant influenza viruses. We propose a model in which direct binding of the viral RNA polymerase in the context of vRNPs to Pol II early in infection facilitates cap-snatching, while we suggest that binding of free viral polymerase to Pol II late in infection may trigger Pol II degradation.

Authors: Fodor, E; Hengrung, N; Martinez-Alonso, M

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: American Society for Microbiology
• Journal: Journal of Virology
• Publication date: 2016-04-20
• Acceptance date: 2016-04-13
• DOI: 10.1128/JVI.00494-16
• EISSN: 1098-5514
• ISSN: 0022-538X