title: The protamine-like DNA-binding protein P6.9 epigenetically up-regulates Autographa californica multiple nucleopolyhedrovirus gene transcription in the late infection phase.
abstract: Protamines are a group of highly basic proteins first discovered in spermatozoon that allow for denser packaging of DNA than histones and will result in down-regulation of gene transcription[1]. It is well recognized that the Autographa californica multicapsid nucleopolyhedrovirus (AcMNPV) encodes P6.9, a protamine-like protein that forms the viral subnucleosome through binding to the viral genome[29]. Previous research demonstrates that P6.9 is essential for viral nucleocapsid assembly, while it has no influence on viral genome replication[31]. In the present study, the role of P6.9 in viral gene transcription regulation is characterized. In contrast to protamines or other protamine-like proteins that usually down-regulate gene transcription, P6.9 appears to up-regulate viral gene transcription at 12-24 hours post infection (hpi), whereas it is non-essential for the basal level of viral gene transcription. Fluorescence microscopy reveals the P6.9's co-localization with DNA is temporally and spatially synchronized with P6.9's impact on viral gene transcription, indicating the P6.9-DNA association contributes to transcription regulation. Chromatin fractionation assay further reveals an unexpected co-existence of P6.9 and host RNA polymerase II in the same transcriptionally active chromatin fraction at 24 hpi, which may probably contribute to viral gene transcription up-regulation in the late infection phase.
authors.affiliation: Key Laboratory of Agricultural & Environmental Microbiology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Peng
authors.forename: Kun
authors.initials: K
authors.lastname: Li
authors.forename: Rong-juan
authors.initials: RJ
authors.lastname: Pei
authors.forename: Chun-chen
authors.initials: CC
authors.lastname: Wu
authors.forename: Chang-yong
authors.initials: CY
authors.lastname: Liang
authors.forename: Yun
authors.initials: Y
authors.lastname: Wang
authors.forename: Xin-wen
authors.initials: XW
authors.lastname: Chen
mesh_terms: D000818:Animals; D002460:Cell Line; D047369:Chromatin Immunoprecipitation; D004279:DNA, Viral / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism*; D044127:Epigenesis, Genetic; D015967:Gene Expression Regulation, Viral; D008856:Microscopy, Fluorescence; D017924:Nucleopolyhedroviruses / Q000235:genetics / Q000254:growth & development / Q000502:physiology*; D011479:Protamines / Q000378:metabolism; D011485:Protein Binding; D018411:Spodoptera; D014158:Transcription, Genetic; D014764:Viral Proteins / Q000378:metabolism*; D014779:Virus Replication
chemical_list: D004279:DNA, Viral; D004268:DNA-Binding Proteins; D011479:Protamines; D014764:Viral Proteins