Mutations in viral proteins can lead to the cold adaption of influenza A virus and the cold-adapted virus is an important vaccination instrument.Here,we identify a novel strain of influenza A virus with cold sensitivi...Mutations in viral proteins can lead to the cold adaption of influenza A virus and the cold-adapted virus is an important vaccination instrument.Here,we identify a novel strain of influenza A virus with cold sensitivity conferred by a mutation at a phosphorylation site within the nucleoprotein(NP).The highly conserved tyrosine 385 residue(Y385)of NP was identified as a phosphorylation site by mass spectrometry.The constructive NP phosphorylation mimicked by Y385 E mutation was fatal for virus replication,while the continuous Y385 dephosphorylation mimicked by Y385 F mutation had little impact on virus replication in vitro.Notably,the Y385 F virus showed much lower replicative capacity in turbinates of mice compared with the wild type virus.Moreover,the replication of Y385 F virus was significantly reduced in both A549 and MDCK cells grown at 33℃,when compared to that at 37℃.These results indicated that the Y385 F mutation led to cold sensitivity of virus.We further found that the cold sensitivity of Y385 F virus could be attributed to diminished NP oligomerization rather than any changes in intracellular localization.Taken together,these findings suggest that the phosphorylation of NP may be a critical factor that regulates the temperature sensitivity of influenza A virus.展开更多
基金supported by grants from the Strategic Priority Research Program of Chinese Academy of Sciences(XDB29010000)the National Natural Science Foundation of China(31630079,31972657,31672531)+2 种基金the National Key Research and Development Program of China(2016YFD0500206)the Mega-Project of Guangxi Natural Science Foundation(2015GXNSFEA139002)supported by Youth Innovation Promotion Association of CAS(2019091)。
文摘Mutations in viral proteins can lead to the cold adaption of influenza A virus and the cold-adapted virus is an important vaccination instrument.Here,we identify a novel strain of influenza A virus with cold sensitivity conferred by a mutation at a phosphorylation site within the nucleoprotein(NP).The highly conserved tyrosine 385 residue(Y385)of NP was identified as a phosphorylation site by mass spectrometry.The constructive NP phosphorylation mimicked by Y385 E mutation was fatal for virus replication,while the continuous Y385 dephosphorylation mimicked by Y385 F mutation had little impact on virus replication in vitro.Notably,the Y385 F virus showed much lower replicative capacity in turbinates of mice compared with the wild type virus.Moreover,the replication of Y385 F virus was significantly reduced in both A549 and MDCK cells grown at 33℃,when compared to that at 37℃.These results indicated that the Y385 F mutation led to cold sensitivity of virus.We further found that the cold sensitivity of Y385 F virus could be attributed to diminished NP oligomerization rather than any changes in intracellular localization.Taken together,these findings suggest that the phosphorylation of NP may be a critical factor that regulates the temperature sensitivity of influenza A virus.
