title: Identification of a novel regulatory sequence of actin nucleation promoting factor encoded by Autographa californica multiple nucleopolyhedrovirus.
abstract: Actin polymerization induced by nucleation promoting factors (NPFs) is one of the most fundamental biological processes in eukaryotic cells. NPFs contain a conserved output domain (VCA domain) near the C terminus, which interacts with and activates the cellular actin-related protein 2/3 complex (Arp2/3) to induce actin polymerization and a diverse regulatory domain near the N terminus. Autographa californica multiple nucleopolyhedrovirus (AcMNPV) nucleocapsid protein P78/83 is a virus-encoded NPF that contains a C-terminal VCA domain and induces actin polymerization in virus-infected cells. However, there is no similarity between the N terminus of P78/83 and that of other identified NPFs, suggesting that P78/83 may possess a unique regulatory mechanism. In this study, we identified a multifunctional regulatory sequence (MRS) located near the N terminus of P78/83 and determined that one of its functions is to serve as a degron to mediate P78/83 degradation in a proteasome-dependent manner. In AcMNPV-infected cells, the MRS also binds to another nucleocapsid protein, BV/ODV-C42, which stabilizes P78/83 and modulates the P78/83-Arp2/3 interaction to orchestrate actin polymerization. In addition, the MRS is also essential for the incorporation of P78/83 into the nucleocapsid, ensuring virion mobility powered by P78/83-induced actin polymerization. The triple functions of the MRS enable P78/83 to serve as an essential viral protein in the AcMNPV replication cycle, and the possible roles of the MRS in orchestrating the virus-induced actin polymerization and viral genome decapsidation are discussed.
authors.affiliation: From the State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, China, 430071, wangyun@wh.iov.cn.
authors.forename: Yun
authors.initials: Y
authors.lastname: Wang
authors.affiliation: From the State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, China, 430071, the University of Chinese Academy of Sciences, Beijing, China, 100049, and.
authors.forename: Yongli
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: the Central China Normal University, Wuhan, China, 430000.
authors.forename: Shili
authors.initials: S
authors.lastname: Han
authors.affiliation: From the State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, China, 430071.
authors.forename: Xue
authors.initials: X
authors.lastname: Hu
authors.affiliation: From the State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, China, 430071.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Zhou
authors.affiliation: From the State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, China, 430071, the University of Chinese Academy of Sciences, Beijing, China, 100049, and.
authors.forename: Jingfang
authors.initials: J
authors.lastname: Mu
authors.affiliation: From the State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, China, 430071.
authors.forename: Rongjuan
authors.initials: R
authors.lastname: Pei
authors.affiliation: From the State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, China, 430071.
authors.forename: Chunchen
authors.initials: C
authors.lastname: Wu
authors.affiliation: From the State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, China, 430071, chenxw@wh.iov.cn.
authors.forename: Xinwen
authors.initials: X
authors.lastname: Chen
mesh_terms: D051376:Actin-Related Protein 2-3 Complex / Q000378:metabolism; D000199:Actins / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D015153:Blotting, Western; D054884:Host-Pathogen Interactions; D019476:Insect Proteins / Q000378:metabolism; D008856:Microscopy, Fluorescence; D008957:Models, Genetic; D008969:Molecular Sequence Data; D009036:Moths / Q000821:virology; D019590:Nucleocapsid Proteins / Q000235:genetics* / Q000378:metabolism; D017924:Nucleopolyhedroviruses / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D058105:Polymerization; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism; D011485:Protein Binding; D012045:Regulatory Sequences, Nucleic Acid / Q000235:genetics*; D017386:Sequence Homology, Amino Acid; D061987:Sf9 Cells; D018411:Spodoptera; D014764:Viral Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D051376:Actin-Related Protein 2-3 Complex; D000199:Actins; D019476:Insect Proteins; D019590:Nucleocapsid Proteins; D014764:Viral Proteins; D046988:Proteasome Endopeptidase Complex
keywords: Actin; Arp2/3 Complex; DNA Viruses; Viral Protein; Virus Assembly