OTUB1 contributes to the stability and function of Influenza A virus NS2
Journal
PLOS Pathogens
Journal Volume
20
Journal Issue
5
Start Page
e1012279
ISSN
1553-7374
Date Issued
2024-05-30
Author(s)
Yu-Jyun Li
Chi-Yuan Chen
Yu-Shen Kuo
Yi-Wen Huang
Rei-Lin Kuo
Jeng-How Yang
Chih-Ho Lai
Shin-Ru Shih
Ya-Fang Chiu
Abstract
The influenza A virus (IAV) consists of 8 single-stranded, negative-sense viral RNA (vRNA) segments. After infection, vRNA is transcribed, replicated, and wrapped by viral nucleoprotein (NP) to form viral ribonucleoprotein (vRNP). The transcription, replication, and nuclear export of the viral genome are regulated by the IAV protein, NS2, which is translated from spliced mRNA transcribed from viral NS vRNA. This splicing is inefficient, explaining why NS2 is present in low abundance after IAV infection. The levels of NS2 and its subsequent accumulation are thought to influence viral RNA replication and vRNP nuclear export. Here we show that NS2 is ubiquitinated at the K64 and K88 residues by K48-linked and K63-linked polyubiquitin (polyUb) chains, leading to the degradation of NS2 by the proteasome. Additionally, we show that a host deubiquitinase, OTUB1, can remove polyUb chains conjugated to NS2, thereby stabilizing NS2. Accordingly, knock down of OTUB1 by siRNA reduces the nuclear export of vRNP, and reduces the overall production of IAV. These results collectively demonstrate that the levels of NS2 in IAV-infected cells are regulated by a ubiquitination-deubiquitination system involving OTUB1 that is necessary for optimal IAV replication.
SDGs
Publisher
Public Library of Science (PLoS)
Type
journal article