Cytosolic chaperonin protects folding intermediates of Gbeta from aggregation by recognizing hydrophobic beta-strands.

ABSTRACT: Cytosolic chaperonin containing t-complex polypeptide 1 (CCT)/TRiC is a group II chaperonin that assists in the folding of newly synthesized proteins. It is a eukaryotic homologue of the bacterial group I chaperonin GroEL. In contrast to the well studied functions of GroEL, the substrate recognition mechanism of CCT/TRiC is poorly understood. Here, we established a system for analyzing CCT/TRiC functions by using a reconstituted protein synthesis by using recombinant elements system and show that CCT/TRiC strongly recognizes WD40 proteins particularly at hydrophobic beta-strands. Using the G protein beta subunit (Gbeta), a WD40 protein that is very rich in beta-sheets, as a model substrate, we found that CCT/TRiC prevents aggregation and assists in folding of Gbeta, whereas GroEL does not.

SUBMITTER: Kubota S 

PROVIDER: S-EPMC1482499 | biostudies-literature | 2006 May

REPOSITORIES: biostudies-literature