title: Modulation of the cellular distribution of human cytomegalovirus helicase by cellular factor Snapin.
abstract: Controlled regulation of genomic DNA synthesis is a universally conserved process for all herpesviruses, including human cytomegalovirus (HCMV), and plays a key role in viral pathogenesis, such as persistent infections. HCMV UL105 is believed to encode the helicase of the DNA replication machinery that needs to localize in the nuclei, the site of viral DNA synthesis. No host factors that interact with UL105 have been identified. In this study, we show that UL105 specifically interacts with Snapin, a human protein that is predominantly localized in the cytoplasm and associated with cellular vesicles. UL105 was found to interact with Snapin in both the yeast two-hybrid screen and coimmunoprecipitation experiments in HCMV-infected cells. The nuclear and cytoplasmic levels of UL105 were decreased and increased in cells overexpressing Snapin, respectively, while the levels of UL105 in the nuclei and cytoplasm were increased and decreased in cells in which the expression of Snapin was downregulated with anti-Snapin small interfering RNA (siRNA) molecules, respectively. Furthermore, viral DNA synthesis and progeny production were decreased in cells overexpressing Snapin and increased in the anti-Snapin siRNA-treated cells, respectively. Our results provide the first direct evidence to suggest that Snapin interacts with UL105 and alters its cellular distribution, leading to modulation of viral DNA synthesis and progeny production. Our study further suggests that modulation of the cellular distribution of viral helicase by Snapin may represent a possible mechanism for regulating HCMV genomic DNA synthesis, a key step during herpesvirus lytic and persistent infections.
authors.affiliation: State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, Hubei, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Luo
authors.forename: Jun
authors.initials: J
authors.lastname: Chen
authors.forename: Edward
authors.initials: E
authors.lastname: Yang
authors.forename: Ao
authors.initials: A
authors.lastname: Shen
authors.forename: Hao
authors.initials: H
authors.lastname: Gong
authors.forename: Zenglin
authors.initials: Z
authors.lastname: Pei
authors.forename: Gengfu
authors.initials: G
authors.lastname: Xiao
authors.forename: Songya
authors.initials: S
authors.lastname: Lu
authors.forename: Fenyong
authors.initials: F
authors.lastname: Liu
mesh_terms: D015153:Blotting, Western; D003587:Cytomegalovirus / Q000502:physiology*; D003586:Cytomegalovirus Infections / Q000378:metabolism* / Q000821:virology; D003593:Cytoplasm / Q000378:metabolism*; D004265:DNA Helicases / Q000378:metabolism*; D004261:DNA Replication; D004279:DNA, Viral / Q000235:genetics; D006801:Humans; D047468:Immunoprecipitation; D008856:Microscopy, Fluorescence; D009369:Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000821:virology; D034741:RNA, Small Interfering / Q000235:genetics; D014407:Tumor Cells, Cultured; D020798:Two-Hybrid System Techniques; D033921:Vesicular Transport Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D014779:Virus Replication
chemical_list: D004279:DNA, Viral; D034741:RNA, Small Interfering; C118519:SNAPIN protein, human; D033921:Vesicular Transport Proteins; D004265:DNA Helicases