title: A novel PrP partner HS-1 associated protein X-1 (HAX-1) protected the cultured cells against the challenge of H₂O₂.
abstract: Prion protein (PrP) is a ubiquitous conserved glycoprotein predominantly expressed in neurons of the central nervous system (CNS). To elucidate on its cellular function, we performed a yeast two-hybrid screen within an adult human brain cDNA library for potential PrP-binding molecules. A novel protein, HS-1 associated protein X-1 (HAX-1), was identified to be able to bind with PrP strongly. The interaction between the two proteins has been further verified by glutathione-S-transferase (GST) pull-down and immunoprecipitation assays. The minimal binding regions were mapped to the segments of residues aa 91-163 for PrP(C) and residues aa 38-129 for HAX-1. Immunofluorescent assays of co-expressions of human PrP and HAX-1 in 293T and SHSY-5Y cells revealed marked co-localizations of those two proteins in cytoplasm. Moreover, the co-expression of HAX-1 and wild-type PrP (PG5) was found to enhance the cellular resistance to the challenge of H₂O₂. Contrarily, co-transfection of HAX-1 did not reverse but aggravated the cytotoxicities of the genetic CJD (gCJD) associated PrP mutants with nine- (PG9) and fourteen-octarepeats (PG14). Our data provide for the first time a new PrP-interacting partner that may play role in cell oxidative stress and anti-apoptosis physiologically and cell damage pathologically.
authors.affiliation: State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Chang-Bai Rd 155, Beijing 102206, People's Republic of China.
authors.forename: Yuan-Yuan
authors.initials: YY
authors.lastname: Jing
authors.forename: Xiao-Li
authors.initials: XL
authors.lastname: Li
authors.forename: Qi
authors.initials: Q
authors.lastname: Shi
authors.forename: Zhao-Yun
authors.initials: ZY
authors.lastname: Wang
authors.forename: Yan
authors.initials: Y
authors.lastname: Guo
authors.forename: Ming-Ming
authors.initials: MM
authors.lastname: Pan
authors.forename: Chan
authors.initials: C
authors.lastname: Tian
authors.forename: Shu-Ying
authors.initials: SY
authors.lastname: Zhu
authors.forename: Cao
authors.initials: C
authors.lastname: Chen
authors.forename: Han-Shi
authors.initials: HS
authors.lastname: Gong
authors.forename: Jun
authors.initials: J
authors.lastname: Han
authors.forename: Chen
authors.initials: C
authors.lastname: Gao
authors.forename: Xiao-Ping
authors.initials: XP
authors.lastname: Dong
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D002478:Cells, Cultured / Q000187:drug effects*; D005982:Glutathione Transferase / Q000235:genetics / Q000378:metabolism; D057809:HEK293 Cells / Q000187:drug effects; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D016877:Oxidants / Q000494:pharmacology*; D018384:Oxidative Stress; D017096:Prion Diseases / Q000473:pathology / Q000503:physiopathology; D011328:Prions / Q000235:genetics / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D020798:Two-Hybrid System Techniques
chemical_list: D048868:Adaptor Proteins, Signal Transducing; C104759:HAX1 protein, human; D016877:Oxidants; D011328:Prions; D011993:Recombinant Fusion Proteins; D006861:Hydrogen Peroxide; D005982:Glutathione Transferase