title: The role of viral protein Ac34 in nuclear relocation of subunits of the actin-related protein 2/3 complex.
abstract: The actin nucleator actin-related protein complex (Arp2/3) is composed of seven subunits: Arp2, Arp3, p40/ARPC1 (P40), p34/ARPC2 (P34), p21/ARPC3 (P21), p20/ARPC4 (P20), and p16/ARPC5 (P16). Arp2/3 plays crucial roles in a variety of cellular activities through regulation of actin polymerization. Autographa californica multiple nucleopolyhedrovirus (AcMNPV), one of the beststudied alphabaculoviruses, induces Arp2/3 nuclear relocation and mediates nuclear actin polymerization to assist in virus replication. We have demonstrated that Ac34, a viral late-gene product, induces translocation of the P40 subunit of Arp2/3 to the nucleus during AcMNPV infection. However, it remains unknown whether Ac34 could relocate other Arp2/3 subunits to the nucleus. In this study, the effects of the viral protein Ac34 on the distribution of these subunits were studied by an immunofluorescence assay. Arp2, P34, P21, and P20 cloned from Spodoptera frugiperda (Sf9) cells showed mainly cytoplasmic localization and were relocated to the nucleus in the presence of Ac34. In addition, Arp3 was localized in the cytoplasm in both the presence and absence of Ac34, and P16 showed whole-cell localization. In contrast to Sf9 cells, all subunits of mammalian Arp2/3 showed no nuclear relocation in the presence of Ac34. Co-immunoprecipitation analysis of the interaction between Ac34 and Arp2/3 subunits revealed that Ac34 bound to P40, P34, and P20 of Sf9 cells. However, none of the subunits of mammalian Arp2/3 interacted with Ac34, indicating that protein-protein interaction is essential for Ac34 to relocate Arp2/3 subunits to the nucleus.
authors.affiliation: State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, China.|University of Chinese Academy of Sciences, Beijing, 100049, China.
authors.forename: Jingfang
authors.initials: J
authors.lastname: Mu
authors.affiliation: State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, China.|University of Chinese Academy of Sciences, Beijing, 100049, China.
authors.forename: Yongli
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, China.|University of Chinese Academy of Sciences, Beijing, 100049, China.
authors.forename: Yangyang
authors.initials: Y
authors.lastname: Hu
authors.affiliation: State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, China.
authors.forename: Xue
authors.initials: X
authors.lastname: Hu
authors.affiliation: State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Zhou
authors.affiliation: State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, China. chenxw@wh.iov.cn.
authors.forename: Xinwen
authors.initials: X
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, China. wangyun@wh.iov.cn.
authors.forename: Yun
authors.initials: Y
authors.lastname: Wang
mesh_terms: D051377:Actin-Related Protein 2 / Q000378:metabolism; D051376:Actin-Related Protein 2-3 Complex / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D001483:Base Sequence; D036022:Capsid Proteins / Q000235:genetics / Q000378:metabolism; D002467:Cell Nucleus / Q000378:metabolism; D057809:HEK293 Cells; D006801:Humans; D017924:Nucleopolyhedroviruses / Q000235:genetics / Q000378:metabolism; D011485:Protein Binding; D054730:Protein Interaction Domains and Motifs; D014764:Viral Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
chemical_list: D051377:Actin-Related Protein 2; D051376:Actin-Related Protein 2-3 Complex; D036022:Capsid Proteins; D014764:Viral Proteins
keywords: Ac34; Arp2/3 complex; Autographa californica multiple nucleopolyhedrovirus (AcMNPV); nuclear relocation