Eukaryotic cytosolic chaperonin contains t-complex polypeptide 1 and seven related subunits.
We have characterized the cytosolic chaperonin from both rabbit reticulocyte lysate and bovine testis. The heteromeric complex contains eight subunits. Partial amino acid sequence data reveal that one of these is t-complex polypeptide 1 (TCP-1), while the other seven are TCP-1-related polypeptides, implicating the existence of a multigene family of TCP-1 homologues. We provide evidence that TCP-1 ring complex from bovine testis can facilitate the folding of both actin and tubulin, although, as in the case of chaperonin from reticulocyte lysate, two cofactors are required for the generation of properly folded tubulin. An additional molecule of TCP-1 may associate with the chaperonin depending on the purification procedure used. We propose that a highly conserved region in these polypeptides and in other chaperonins of the cpn60 chaperone family participates in ATP binding.
Rommelaere
H
H
Laboratory of Physiological Chemistry, University Ghent, Belgium.
Van Troys
M
M
Gao
Y
Y
Melki
R
R
Cowan
N J
NJ
Vandekerckhove
J
J
Ampe
C
C
D000199:Actins / Q000737:chemistry / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D002417:Cattle; D056404:Chaperonin Containing TCP-1; D018833:Chaperonins; D003600:Cytosol / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000032:analysis; D047908:Intracellular Signaling Peptides and Proteins; D046911:Macromolecular Substances; D008297:Male; D008869:Microtubule-Associated Proteins; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000032:analysis* / Q000302:isolation & purification; D010446:Peptide Fragments / Q000737:chemistry / Q000302:isolation & purification; D017510:Protein Folding; D011506:Proteins / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D011817:Rabbits; D012156:Reticulocytes / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D013737:Testis / Q000378:metabolism*; D014404:Tubulin / Q000737:chemistry / Q000378:metabolism; D044767:Ubiquitin-Protein Ligases; D056427:t-Complex Genome Region
D000199:Actins; D004268:DNA-Binding Proteins; D047908:Intracellular Signaling Peptides and Proteins; D046911:Macromolecular Substances; D008869:Microtubule-Associated Proteins; D009687:Nuclear Proteins; D010446:Peptide Fragments; D011506:Proteins; D014404:Tubulin; C116196:PPP1R11 protein, human; D044767:Ubiquitin-Protein Ligases; D056404:Chaperonin Containing TCP-1; D018833:Chaperonins