title: Phosphorylation of Beet black scorch virus coat protein by PKA is required for assembly and stability of virus particles.
abstract: Plant virus coat proteins (CPs) play a fundamental role in protection of genomic RNAs, virion assembly, and viral movement. Although phosphorylation of several CPs during virus infection have been reported, little information is available about CP phosphorylation of the spherical RNA plant viruses. Here, we demonstrate that the CP of Beet black scorch virus (BBSV), a member of the genus Necrovirus, can be phosphorylated at threonine-41 (T41) by cAMP-dependent protein kinase (PKA)-like kinase in vivo and in vitro. Mutant viruses containing a T41A non-phosphorylatable alanine substitution, and a T41E glutamic acid substitution to mimic threonine phosphorylation were able to replicate but were unable to move systemically in Nicotiana benthamiana. Interestingly, the T41A and T41E mutants generated unstable 17 nm virus-like particles that failed to package viral genomic (g) RNA, compared with wild-type BBSV with 30 nm virions during viral infection in N. benthamiana. Further analyses showed that the T41 mutations had little effect on the gRNA-binding activity of the CP. Therefore, we propose a model whereby CP phosphorylation plays an essential role in long-distance movement of BBSV that involves formation of stable virions.
authors.affiliation: State Key Laboratory of Agro-Biotechnology and Ministry of Agriculture Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing 100193, China.
authors.forename: Xiaofei
authors.initials: X
authors.lastname: Zhao
authors.affiliation: State Key Laboratory of Agro-Biotechnology and Ministry of Agriculture Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing 100193, China.
authors.forename: Xiaoling
authors.initials: X
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Agro-Biotechnology and Ministry of Agriculture Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing 100193, China.
authors.forename: Kai
authors.initials: K
authors.lastname: Dong
authors.affiliation: State Key Laboratory of Agro-Biotechnology and Ministry of Agriculture Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing 100193, China.
authors.forename: Yongliang
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Agro-Biotechnology and Ministry of Agriculture Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing 100193, China.
authors.forename: Yue
authors.initials: Y
authors.lastname: Hu
authors.affiliation: State Key Laboratory of Agro-Biotechnology and Ministry of Agriculture Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing 100193, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China.
authors.forename: Yanmei
authors.initials: Y
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Agro-Biotechnology and Ministry of Agriculture Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing 100193, China.
authors.forename: Xianbing
authors.initials: X
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Agro-Biotechnology and Ministry of Agriculture Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing 100193, China.
authors.forename: Chenggui
authors.initials: C
authors.lastname: Han
authors.affiliation: State Key Laboratory of Agro-Biotechnology and Ministry of Agriculture Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing 100193, China.
authors.forename: Jialin
authors.initials: J
authors.lastname: Yu
authors.affiliation: State Key Laboratory of Agro-Biotechnology and Ministry of Agriculture Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing 100193, China.
authors.forename: Dawei
authors.initials: D
authors.lastname: Li
mesh_terms: D000409:Alanine / Q000235:genetics / Q000378:metabolism; D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D027461:Beta vulgaris / Q000821:virology; D036022:Capsid Proteins / Q000235:genetics / Q000378:metabolism*; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism*; D015151:Immunoblotting; D046529:Microscopy, Electron, Transmission; D008969:Molecular Sequence Data; D009154:Mutation; D010766:Phosphorylation; D010935:Plant Diseases / Q000821:virology; D010942:Plant Viruses / Q000235:genetics / Q000378:metabolism / Q000472:pathogenicity; D017386:Sequence Homology, Amino Acid; D013912:Threonine / Q000235:genetics / Q000378:metabolism; D014026:Nicotiana / Q000821:virology; D014771:Virion / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D014774:Virulence / Q000235:genetics; D019065:Virus Assembly
chemical_list: D036022:Capsid Proteins; D013912:Threonine; D017868:Cyclic AMP-Dependent Protein Kinases; D000409:Alanine