title: Identification of two ATR-dependent phosphorylation sites on coronavirus nucleocapsid protein with nonessential functions in viral replication and infectivity in cultured cells.
abstract: Coronavirus encodes an extensively phosphorylated and highly basic nucleocapsid (N) protein. Previous studies have identified Ser190, Ser192, Thr378 and Ser379 as the phosphorylation sites for coronavirus infectious bronchitis virus (IBV) N protein. In this study, we show that phosphorylation at Thr378 and Ser379 sites is dependent on the ataxia-telangiectasia mutated (ATM) and Rad3-related (ATR), a kinase activated during IBV replication. Introduction of Ala substitutions at these two sites individually, in combination of the two and together with other two sites (Ser190 and Ser192) into an infectious IBV clone did not affect recovery of the recombinant viruses containing the mutations. A mutant virus (rIBV-Nm4) carrying the four Ala substitutions grew at a similar, if not better, growth rate as wild type virus. This study reveals a cellular kinase responsible for phosphorylation of a coronavirus N protein at two positions and the functional consequence of this modification on coronavirus replication.
authors.affiliation: Agricultural School, Yangtze University, 266 Jingmilu, Jingzhou City, Hubei Province 434025, China.
authors.forename: Shouguo
authors.initials: S
authors.lastname: Fang
authors.forename: Linghui
authors.initials: L
authors.lastname: Xu
authors.forename: Mei
authors.initials: M
authors.lastname: Huang
authors.forename: Frank
authors.initials: F
authors.lastname: Qisheng Li
authors.forename: D X
authors.initials: DX
authors.lastname: Liu
mesh_terms: D019943:Amino Acid Substitution; D000818:Animals; D002460:Cell Line; D002522:Chlorocebus aethiops; D000086462:Coronavirus Nucleocapsid Proteins; D004252:DNA Mutational Analysis; D001351:Infectious bronchitis virus / Q000378:metabolism / Q000502:physiology*; D016297:Mutagenesis, Site-Directed; D019590:Nucleocapsid Proteins / Q000378:metabolism*; D010766:Phosphorylation; D011499:Protein Processing, Post-Translational; D012694:Serine / Q000378:metabolism; D013912:Threonine / Q000378:metabolism; D014709:Vero Cells
chemical_list: D000086462:Coronavirus Nucleocapsid Proteins; D019590:Nucleocapsid Proteins; D013912:Threonine; D012694:Serine
keywords: ATR/Chk1 pathway; Coronavirus; N protein; Phosphorylation; Replication