title: Chaperonin TRiC assists the refolding of sperm-specific glyceraldehyde-3-phosphate dehydrogenase.
abstract: The cytosolic chaperonin TRiC was isolated from ovine testes using ultracentrifugation and heparin-Sepharose chromatography. The molecular mass of the obtained preparation was shown to exceed 900 kDa (by Blue Native PAGE). SDS-PAGE yielded a set of bands in the range of 50-60 kDa. Electron microscopy examination revealed ring-shaped complexes with the outer diameter of 15 nm and the inner diameter of approximately 6 nm. The results suggest that the purified chaperonin is an oligomeric complex composed of two 8-membered rings. The chaperonin TRiC was shown to assist an ATP-dependent refolding of recombinant forms of sperm-specific glyceraldehyde-3-phosphate dehydrogenase, an enzyme that is expressed only in precursor cells of the sperms in the seminiferous tubules of the testes. In contrast, TRiC did not influence the refolding of muscle isoform of glyceraldehyde-3-phosphate dehydrogenase and assisted the refolding of muscle lactate dehydrogenase by an ATP-independent mechanism. The obtained results suggest that TRiC is likely to be involved in the refolding of sperm-specific proteins.
authors: Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Leninskie Gory, Moscow, Russia. naletova@belozersky.msu.ru
authors: Irina N
authors: IN
authors: Naletova
authors: Kristina M
authors: KM
authors: Popova
authors: Mikhail A
authors: MA
authors: Eldarov
authors: Mikhail L
authors: ML
authors: Kuravsky
authors: Elena V
authors: EV
authors: Schmalhausen
authors: Irina A
authors: IA
authors: Sevostyanova
authors: Vladimir I
authors: VI
authors: Muronetz
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D018833:Chaperonins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases / Q000378:metabolism*; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D017510:Protein Folding; D021122:Protein Subunits / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D012333:RNA, Messenger / Q000032:analysis / Q000235:genetics; D011817:Rabbits; D016415:Sequence Alignment; D012756:Sheep; D013094:Spermatozoa / Q000201:enzymology* / Q000378:metabolism; D013737:Testis / Q000201:enzymology / Q000378:metabolism
chemical_list: D021122:Protein Subunits; D012333:RNA, Messenger; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases; D018833:Chaperonins