title: MTase Domain of Dendrolimus punctatus cypovirus VP3 Mediates Virion Attachment and Interacts with Host ALP Protein.
abstract: Dendrolimus punctatus cypovirus(DpCPV) is an important pathogen ofD. punctatus, but little is known about the mechanisms of DpCPV infection. Here, we investigated the effects of VP3, VP4 and VP5 structural proteins on the viral invasion. Both the C-terminal of VP3 (methyltransferase (MTase) domain) and VP4 (A-spike) bound toSpodoptera exiguamidgut brush border membrane vesicles (BBMVs) in a dose-dependent manner, and the binding was inhibited by purified DpCPV virions. Importantly, anti-MTase and anti-VP4 antibodies inhibited viral binding toS. exiguaBBMVs. Using far-Western blots, a 65 kDa protein inBombyx moriBBMVs, identified as alkaline phosphatase protein (BmALP) by mass spectrometry, specifically interacted with DpCPV MTase. The interaction between MTase andBmALP was verified by co-immunoprecipitation in vitro. Pretreatment ofB. moriBBMVs with an anti-ALP antibody or incubation of DpCPV virions with prokaryotically expressedBmALP reduced viral attachment. Additionally,BmALP inhibited DpCPV infection inS. exigualarvae. Our data provide evidence that the MTase domain and A-spike function as viral attachment proteins during the DpCPV infection process, and ALP is the ligand that interacts with DpCPV via the MTase domain. These results augment our understanding of the mechanisms used by cypoviruses to enter their hosts.
authors.affiliation: Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, China. sul@wh.iov.cn.|University of Chinese Academy of Sciences, Beijing 100049, China. sul@wh.iov.cn.
authors.forename: Lan
authors.initials: L
authors.lastname: Su
authors.affiliation: Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, China. xucr@wh.iov.cn.|University of Chinese Academy of Sciences, Beijing 100049, China. xucr@wh.iov.cn.
authors.forename: Congrui
authors.initials: C
authors.lastname: Xu
authors.affiliation: Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, China. ccg083@126.com.
authors.forename: Chuangang
authors.initials: C
authors.lastname: Cheng
authors.affiliation: Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, China. cflei@wh.iov.cn.
authors.forename: Chengfeng
authors.initials: C
authors.lastname: Lei
authors.affiliation: Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, China. sunxl@wh.iov.cn.
authors.forename: Xiulian
authors.initials: X
authors.lastname: Sun
mesh_terms: D000469:Alkaline Phosphatase / Q000378:metabolism*; D000818:Animals; D012831:Bombyx / Q000201:enzymology*; D047468:Immunoprecipitation; D008780:Methyltransferases / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D012087:Reoviridae / Q000201:enzymology* / Q000235:genetics / Q000502:physiology*; D018411:Spodoptera / Q000821:virology; D015678:Viral Structural Proteins / Q000235:genetics / Q000378:metabolism*; D053585:Virus Attachment
chemical_list: D015678:Viral Structural Proteins; D008780:Methyltransferases; D000469:Alkaline Phosphatase
keywords: ALP; DpCPV; attachment proteins; viral entry