title: The nonstructural protein 1 papain-like cysteine protease was necessary for porcine reproductive and respiratory syndrome virus nonstructural protein 1 to inhibit interferon-β induction.
abstract: Porcine reproductive and respiratory syndrome virus nonstructural protein 1 (nsp1) could be auto-cleaved into nsp1α and nsp1β, both of which had the papain-like cysteine protease activities. Previous studies have shown that porcine reproductive and respiratory syndrome virus nsp1 was an interferon (IFN) antagonist. However, the mechanism by which nsp1 inhibited IFN-β production was unclear. Here, we used site-directed mutagenesis that inactivated the papain-like cysteine protease activities of nsp1 to explore whether the papain-like cysteine protease activities were required for nsp1 to disrupt IFN-β production. The results showed that mutations that inactivated papain-like cysteine protease activity of nsp1α made nsp1 lose its IFN antagonism activity, whereas mutations that inactivated papain-like cysteine protease activity of nsp1β did not influence the IFN antagonism activity of nsp1. In conclusion, our present work indicated that the papain-like cysteine protease activity of nsp1α was necessary for nsp1 to inhibit IFN-β induction.
authors: Henan Provincial Key Laboratory of Animal Immunology, Henan Academy of Agricultural Sciences, Zhengzhou, China.
authors: Xibao
authors: X
authors: Shi
authors: Gaiping
authors: G
authors: Zhang
authors: Li
authors: L
authors: Wang
authors: Xuewu
authors: X
authors: Li
authors: Yubao
authors: Y
authors: Zhi
authors: Fangyu
authors: F
authors: Wang
authors: Jianming
authors: J
authors: Fan
authors: Ruiguang
authors: R
authors: Deng
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002460:Cell Line; D002522:Chlorocebus aethiops; D057056:Cysteine Proteases / Q000378:metabolism*; D050838:Interferon Regulatory Factor-3 / Q000378:metabolism; D016899:Interferon-beta / Q000037:antagonists & inhibitors*; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D010206:Papain / Q000737:chemistry* / Q000378:metabolism; D010766:Phosphorylation; D010957:Plasmids; D019316:Porcine respiratory and reproductive syndrome virus / Q000378:metabolism*; D017361:Viral Nonstructural Proteins / Q000737:chemistry / Q000378:metabolism*
chemical_list: D050838:Interferon Regulatory Factor-3; D017361:Viral Nonstructural Proteins; D016899:Interferon-beta; D057056:Cysteine Proteases; D010206:Papain