Function in protein folding of TRiC, a cytosolic ring complex containing TCP-1 and structurally related subunits

J Frydman; E Nimmesgern; H Erdjument-Bromage; J S Wall; P Tempst; F U Hartl

doi:10.1002/j.1460-2075.1992.tb05582.x

Function in protein folding of TRiC, a cytosolic ring complex containing TCP-1 and structurally related subunits

EMBO J. 1992 Dec;11(13):4767-78. doi: 10.1002/j.1460-2075.1992.tb05582.x.

Authors

J Frydman¹, E Nimmesgern, H Erdjument-Bromage, J S Wall, P Tempst, F U Hartl

Affiliation

¹ Program in Cellular Biochemistry and Biophysics, Rockefeller Research Laboratories, Sloan-Kettering Institute, New York, NY 10021.

Abstract

T-complex polypeptide 1 (TCP-1) was analyzed as a potential chaperonin (GroEL/Hsp60) equivalent of the eukaryotic cytosol. We found TCP-1 to be part of a hetero-oligomeric 970 kDa complex containing several structurally related subunits of 52-65 kDa. These members of a new protein family are assembled into a TCP-1 ring complex (TRiC) which resembles the GroEL double ring. The main function of TRiC appears to be in chaperoning monomeric protein folding: TRiC binds unfolded polypeptides, thereby preventing their aggregation, and mediates the ATP-dependent renaturation of unfolded firefly luciferase and tubulin. At least in vitro, TRiC appears to function independently of a small co-chaperonin protein such as GroES. Folding of luciferase is mediated by TRiC but not by GroEL/ES. This suggests that the range of substrate proteins interacting productively with TRiC may differ from that of GroEL. We propose that TRiC mediates the folding of cytosolic proteins by a mechanism distinct from that of the chaperonins in specific aspects.

Publication types

Research Support, U.S. Gov't, P.H.S.

MeSH terms

Adenosine Triphosphatases / metabolism
Adenosine Triphosphate / metabolism
Amino Acid Sequence
Animals
Bacterial Proteins / chemistry
Cattle
Chaperonin 60
Chaperonins
Coleoptera / enzymology
Electrophoresis, Polyacrylamide Gel
Enzyme Activation
Heat-Shock Proteins / chemistry
Intracellular Signaling Peptides and Proteins*
Luciferases / chemistry
Luciferases / metabolism
Male
Microscopy, Electron, Scanning Transmission
Microtubule-Associated Proteins*
Molecular Sequence Data
Nuclear Proteins / chemistry*
Nuclear Proteins / metabolism
Protein Binding
Protein Folding*
Proteins / chemistry
Sequence Homology, Amino Acid
Tubulin / chemistry
Ubiquitin-Protein Ligases
t-Complex Genome Region

Substances

Bacterial Proteins
Chaperonin 60
Heat-Shock Proteins
Intracellular Signaling Peptides and Proteins
Microtubule-Associated Proteins
Nuclear Proteins
Proteins
Tubulin
Adenosine Triphosphate
Luciferases
PPP1R11 protein, human
Ubiquitin-Protein Ligases
Adenosine Triphosphatases
Chaperonins

Associated data

GENBANK/M12899