title: ATPase activity and ATP-dependent conformational change in the co-chaperone HSP70/HSP90-organizing protein (HOP).
abstract: Co-chaperones help to maintain cellular homeostasis by modulating the activities of molecular chaperones involved in protein quality control. The HSP70/HSP90-organizing protein (HOP) is a co-chaperone that cooperates with HSP70 and HSP90 in catalysis of protein folding and maturation in the cytosol. We show here that HOP has ATP-binding activity comparable to that of HSP70/HSP90, and that HOP slowly hydrolyzes ATP. Analysis of deletion mutants revealed that the ATPase domain of HOP is in the N-terminal TPR1-DP1-TPR2A segment. In addition, HOP changes its conformation in the presence of ATP. These results indicate that HOP is a unique co-chaperone that undergoes an ATP-dependent conformational change.
authors.affiliation: From the Department of Life Science, Faculty and Graduate School of Engineering and Resource Science, Akita University, Akita 010-8502, Japan.
authors.forename: Soh
authors.initials: S
authors.lastname: Yamamoto
authors.forename: Ganesh Prasad
authors.initials: GP
authors.lastname: Subedi
authors.forename: Shinya
authors.initials: S
authors.lastname: Hanashima
authors.forename: Tadashi
authors.initials: T
authors.lastname: Satoh
authors.forename: Michiro
authors.initials: M
authors.lastname: Otaka
authors.forename: Hideki
authors.initials: H
authors.lastname: Wakui
authors.forename: Ken-ichi
authors.initials: K
authors.lastname: Sawada
authors.forename: Shin-ichi
authors.initials: S
authors.lastname: Yokota
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Yamaguchi
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kubota
authors.forename: Hideaki
authors.initials: H
authors.lastname: Itoh
mesh_terms: D000251:Adenosine Triphosphatases / Q000235:genetics / Q000378:metabolism*; D000255:Adenosine Triphosphate / Q000235:genetics / Q000378:metabolism*; D000595:Amino Acid Sequence; D018840:HSP70 Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism*; D018841:HSP90 Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism*; D006360:Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D006868:Hydrolysis; D017510:Protein Folding; D017434:Protein Structure, Tertiary; D017384:Sequence Deletion
chemical_list: D018840:HSP70 Heat-Shock Proteins; D018841:HSP90 Heat-Shock Proteins; D006360:Heat-Shock Proteins; C079373:STIP1 protein, human; D000255:Adenosine Triphosphate; D000251:Adenosine Triphosphatases
keywords: Heat Shock Protein; Hsp90; Molecular Chaperone; Protein Complexes; Protein Structure