title: Roles of nucleic acid substrates and cofactors in the vhs protein activity of pseudorabies virus.
abstract: Pseudorabies virus (PrV) belongs to the α-herpesvirinae of which human simplex virus (HSV) is the prototype virus. One of the hallmarks of HSV infection is shutoff of protein synthesis that is mediated by various viral proteins including vhs (virion host shutoff), which is encoded by the UL41 gene. However, the function of PrV vhs is poorly understood. Due to the low sequence similarity (39.3%) between the HSV and PrV UL41 proteins, vhs might not share the same biochemistry characteristics. The purpose of this study was to characterize the nuclease activity of the PrV vhs protein with respect to substrate specificity, its requirements in terms of cofactors, and the protein regions, as well as key amino acids, which contribute to vhs activity. Our results indicated that, similar to HSV vhs, PrV vhs is able to degrade ssRNA and mRNA. However, PrV vhs also targeted rRNA for degradation, which is novel compared to the HSV-1 vhs. Activity assays indicated that Mg(2+) alone enhances RNA degradation mediated by PrV vhs, while K(+) and ATP are not sufficient to induce activity. Finally, we demonstrated that each of the four highly conserved functional boxes of PrV vhs contributes to RNA degradation and that, in particular, residues 152, 169, 171, 172, 173 343, 345, 352 and 356, which are conserved among α-herpesviruses, are key amino acids needed for PrV vhs ribonuclease activity.
authors.affiliation: Graduate Institute of Microbiology and Public Health, College of Veterinary Medicine, National Chung Hsing University, 250 Kou Kuang Road, Taichung, 402, Taiwan. mar55665566@yahoo.com.tw.
authors.forename: Ya-Fen
authors.initials: YF
authors.lastname: Liu
authors.affiliation: Graduate Institute of Microbiology and Public Health, College of Veterinary Medicine, National Chung Hsing University, 250 Kou Kuang Road, Taichung, 402, Taiwan. peiyun0822@gmail.com.
authors.forename: Pei-Yun
authors.initials: PY
authors.lastname: Tsai
authors.affiliation: Graduate Institute of Microbiology and Public Health, College of Veterinary Medicine, National Chung Hsing University, 250 Kou Kuang Road, Taichung, 402, Taiwan. ftpfax@gmail.com.|Department of Beauty Science, MeiHo University, Neipu, Pingtung County, Taiwan. ftpfax@gmail.com.
authors.forename: Fong-Yuan
authors.initials: FY
authors.lastname: Lin
authors.affiliation: Graduate Institute of Microbiology and Public Health, College of Veterinary Medicine, National Chung Hsing University, 250 Kou Kuang Road, Taichung, 402, Taiwan. fgtrytr@yahoo.com.tw.
authors.forename: Kuan-Hsun
authors.initials: KH
authors.lastname: Lin
authors.affiliation: Department of Veterinary Medicine, College of Veterinary Medicine, National Chung Hsing University, Taichung, Taiwan. tjchang@dragon.nchu.edu.tw.
authors.forename: Tien-Jye
authors.initials: TJ
authors.lastname: Chang
authors.affiliation: Department of Veterinary Medicine, College of Veterinary Medicine, National Chung Hsing University, Taichung, Taiwan. d9138001@asia.edu.tw.
authors.forename: Hui-Wen
authors.initials: HW
authors.lastname: Lin
authors.affiliation: Department of Veterinary Medicine, College of Veterinary Medicine, National Chung Hsing University, Taichung, Taiwan. songkhlac@gmail.com.
authors.forename: Songkhla
authors.initials: S
authors.lastname: Chulakasian
authors.affiliation: Graduate Institute of Microbiology and Public Health, College of Veterinary Medicine, National Chung Hsing University, 250 Kou Kuang Road, Taichung, 402, Taiwan. wlhsu@dragon.nchu.edu.tw.
authors.forename: Wei-Li
authors.initials: WL
authors.lastname: Hsu
mesh_terms: D000818:Animals; D057809:HEK293 Cells; D011558:Herpesvirus 1, Suid / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D011557:Pseudorabies / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics* / Q000378:metabolism; D012335:RNA, Ribosomal / Q000235:genetics* / Q000378:metabolism; D034741:RNA, Small Interfering / Q000235:genetics* / Q000378:metabolism; D014764:Viral Proteins / Q000235:genetics* / Q000378:metabolism
chemical_list: D012333:RNA, Messenger; D012335:RNA, Ribosomal; D034741:RNA, Small Interfering; D014764:Viral Proteins