title: Facilitated release of substrate protein from prefoldin by chaperonin.
abstract: Prefoldin is a chaperone that captures a protein-folding intermediate and transfers it to the group II chaperonin for correct folding. However, kinetics of interactions between prefoldin and substrate proteins have not been investigated. In this study, dissociation constants and dissociation rate constants of unfolded proteins with prefoldin were firstly measured using fluorescence microscopy. Our results suggest that binding and release of prefoldin from hyperthermophilic archaea with substrate proteins were in a dynamic equilibrium. Interestingly, the release of substrate proteins from prefoldin was facilitated when chaperonin was present, supporting a handoff mechanism of substrate proteins from prefoldin to the chaperonin.
authors.affiliation: Department of Physics, School of Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjyuku-ku, Tokyo 169-8555, Japan. zako@riken.jp
authors.forename: Tamotsu
authors.initials: T
authors.lastname: Zako
authors.forename: Ryo
authors.initials: R
authors.lastname: Iizuka
authors.forename: Mina
authors.initials: M
authors.lastname: Okochi
authors.forename: Tomoko
authors.initials: T
authors.lastname: Nomura
authors.forename: Taro
authors.initials: T
authors.lastname: Ueno
authors.forename: Hisashi
authors.initials: H
authors.lastname: Tadakuma
authors.forename: Masafumi
authors.initials: M
authors.lastname: Yohda
authors.forename: Takashi
authors.initials: T
authors.lastname: Funatsu
mesh_terms: D019843:Archaeal Proteins / Q000737:chemistry / Q000378:metabolism*; D018833:Chaperonins / Q000737:chemistry / Q000378:metabolism*; D002950:Citrate (si)-Synthase / Q000737:chemistry; D018832:Molecular Chaperones / Q000737:chemistry / Q000378:metabolism*; D043902:Pyrococcus horikoshii / Q000378:metabolism*; D013379:Substrate Specificity
chemical_list: D019843:Archaeal Proteins; D018832:Molecular Chaperones; C112806:prefoldin; D002950:Citrate (si)-Synthase; D018833:Chaperonins