Deep mutational scanning identifies sites in influenza nucleoprotein that affect viral inhibition by MxA

PLoS Pathogens

Jesse D. Bloom¹  Orr Ashenberg²  Michael B. Doud²  Jai Padmakumar² 

[1] Department of Genome Sciences, University of Washington, Seattle, WA, USA;Division of Basic Sciences and Computational Biology Program, Fred Hutchinson Cancer Research Center, Seattle, WA, USA

关键词: Microbial mutation;    Mutation detection;    Polymerases;    Influenza viruses;    Influenza;    Viral replication;    Influenza A virus;    Birds;   

DOI  :  10.1371/journal.ppat.1006288

学科分类：生物科学（综合）

来源: Public Library of Science

【 摘 要 】

The innate-immune restriction factor MxA inhibits influenza replication by targeting the viral nucleoprotein (NP). Human influenza virus is more resistant than avian influenza virus to inhibition by human MxA, and prior work has compared human and avian viral strains to identify amino-acid differences in NP that affect sensitivity to MxA. However, this strategy is limited to identifying sites in NP where mutations that affect MxA sensitivity have fixed during the small number of documented zoonotic transmissions of influenza to humans. Here we use an unbiased deep mutational scanning approach to quantify how all single amino-acid mutations to NP affect MxA sensitivity in the context of replication-competent virus. We both identify new sites in NP where mutations affect MxA resistance and re-identify mutations known to have increased MxA resistance during historical adaptations of influenza to humans. Most of the sites where mutations have the greatest effect are almost completely conserved across all influenza A viruses, and the amino acids at these sites confer relatively high resistance to MxA. These sites cluster in regions of NP that appear to be important for its recognition by MxA. Overall, our work systematically identifies the sites in influenza nucleoprotein where mutations affect sensitivity to MxA. We also demonstrate a powerful new strategy for identifying regions of viral proteins that affect inhibition by host factors.

【 授权许可】

CC BY