Open AccessDiscrete spatio-temporal regulation of tyrosine phosphorylation directs influenza A virus M1 protein towards its function in virion assembly
Author(s) -
Angeles Mecate-Zambrano,
Swathi Sukumar,
Guiscard Seebohm,
Kevin Ciminski,
André Schreiber,
Darisuren Anhlan,
Lilo Greune,
Ludmilla Wixler,
S. Grothe,
Nora C. Stein,
M. Alexander Schmidt,
Klaus Langer,
Martin Schwemmle,
Ting Shi,
Stephan Ludwig,
Yvonne Boergeling
Publication year - 2020
Publication title -
plos pathogens
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.719
H-Index - 206
eISSN - 1553-7374
pISSN - 1553-7366
DOI - 10.1371/journal.ppat.1008775
Subject(s) - phosphorylation , biology , influenza a virus , viral replication , microbiology and biotechnology , viral matrix protein , tyrosine phosphorylation , viral structural protein , rna , virus , viral entry , virology , genetics , gene
Small RNA viruses only have a very limited coding capacity, thus most viral proteins have evolved to fulfill multiple functions. The highly conserved matrix protein 1 (M1) of influenza A viruses is a prime example for such a multifunctional protein, as it acts as a master regulator of virus replication whose different functions have to be tightly regulated. The underlying mechanisms, however, are still incompletely understood. Increasing evidence points towards an involvement of posttranslational modifications in the spatio-temporal regulation of M1 functions. Here, we analyzed the role of M1 tyrosine phosphorylation in genuine infection by using recombinant viruses expressing M1 phosphomutants. Presence of M1 Y132A led to significantly decreased viral replication compared to wildtype and M1 Y10F. Characterization of phosphorylation dynamics by mass spectrometry revealed the presence of Y132 phosphorylation in M1 incorporated into virions that is most likely mediated by membrane-associated Janus kinases late upon infection. Molecular dynamics simulations unraveled a potential phosphorylation-induced exposure of the positively charged linker domain between helices 4 and 5, supposably acting as interaction platform during viral assembly. Consistently, M1 Y132A showed a defect in lipid raft localization due to reduced interaction with viral HA protein resulting in a diminished structural stability of viral progeny and the formation of filamentous particles. Importantly, reduced M1-RNA binding affinity resulted in an inefficient viral genome incorporation and the production of non-infectious virions that interferes with virus pathogenicity in mice. This study advances our understanding of the importance of dynamic phosphorylation as a so far underestimated level of regulation of multifunctional viral proteins and emphasizes the potential feasibility of targeting posttranslational modifications of M1 as a novel antiviral intervention.