title: Contribution of the C-Terminal Region of a Group II Chaperonin to its Interaction with Prefoldin and Substrate Transfer.
abstract: Prefoldin is a molecular chaperone that captures an unfolded protein substrate and transfers it to a group II chaperonin. Previous studies have shown that the interaction sites for prefoldin are located in the helical protrusions of group II chaperonins. However, it does not exclude the possibility of the existence of other interaction sites. In this study, we constructed C-terminal truncation mutants of a group II chaperonin and examined the effects of these mutations on the chaperone's function and interaction with prefoldin. Whereas the mutants with up to 6 aa truncation from the C-terminus retained more than 90% chaperone activities for protecting citrate synthase from thermal aggregation and refolding of green fluorescent protein and isopropylmalate dehydrogenase, the truncation mutants showed decreased affinities for prefoldin. Consequently, the truncation mutants showed reduced transfer efficiency of the denatured substrate protein from prefoldin and subsequent chaperonin-dependent refolding. The results clearly show that the C-terminal region of group II chaperonins contributes to their interactions with prefoldin, the transfer of the substrate protein from prefoldin and its refolding.
authors.affiliation: Bioengineering Laboratory, RIKEN Institute, Saitama, Japan.
authors.forename: Tamotsu
authors.initials: T
authors.lastname: Zako
authors.affiliation: Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, Tokyo, Japan; Department of Chemical Engineering, University of Indonesia, Depok, Indonesia.
authors.forename: Muhamad
authors.initials: M
authors.lastname: Sahlan
authors.affiliation: Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, Tokyo, Japan.
authors.forename: Sayaka
authors.initials: S
authors.lastname: Fujii
authors.affiliation: Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, Tokyo, Japan.
authors.forename: Yohei Y
authors.initials: YY
authors.lastname: Yamamoto
authors.affiliation: Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, Tokyo, Japan.
authors.forename: Phan The
authors.initials: PT
authors.lastname: Tai
authors.affiliation: Bioengineering Laboratory, RIKEN Institute, Saitama, Japan; Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, Tokyo, Japan.
authors.forename: Kotaro
authors.initials: K
authors.lastname: Sakai
authors.affiliation: Bioengineering Laboratory, RIKEN Institute, Saitama, Japan.
authors.forename: Mizuo
authors.initials: M
authors.lastname: Maeda
authors.affiliation: Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, Tokyo, Japan. Electronic address: yohda@cc.tuat.ac.jp.
authors.forename: Masafumi
authors.initials: M
authors.lastname: Yohda
mesh_terms: D002950:Citrate (si)-Synthase / Q000378:metabolism; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D056385:Group II Chaperonins / Q000235:genetics / Q000378:metabolism*; D018832:Molecular Chaperones / Q000235:genetics / Q000378:metabolism*; D009154:Mutation / Q000235:genetics; D066329:Protein Aggregates / Q000235:genetics; D011485:Protein Binding / Q000235:genetics; D011489:Protein Denaturation; D017510:Protein Folding
chemical_list: D018832:Molecular Chaperones; D066329:Protein Aggregates; C112806:prefoldin; D049452:Green Fluorescent Proteins; D002950:Citrate (si)-Synthase; D056385:Group II Chaperonins
keywords: Chaperone; Chaperonin; Prefoldin; Protein folding; Protein interaction