FUNCTION IN PROTEIN FOLDING OF TRIC, A CYTOSOLIC RING COMPLEX CONTAINING TCP-1 AND STRUCTURALLY RELATED SUBUNITS
FUNCTION IN PROTEIN FOLDING OF TRIC, A CYTOSOLIC RING COMPLEX CONTAINING TCP-1 AND STRUCTURALLY RELATED SUBUNITS
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DOI：
10.1002/j.1460-2075.1992.tb05582.x
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发表时间：
1992-12-01
期刊：
影响因子：
11.4
通讯作者：
HARTL, FU
中科院分区：
文献类型：
--
作者：
FRYDMAN, J;NIMMESGERN, E;HARTL, FU
T-复合物多肽1（TCP-1）被分析为真核细胞质溶胶的潜在伴侣蛋白（GroEL/Hsp 60）等价物。我们发现TCP-1是一个异源寡聚970 kDa复合物的一部分，该复合物含有几个结构相关的52-65 kDa亚基。新蛋白质家族的这些成员组装成类似于GroEL双环的TCP-1环复合物（TRiC）。TRiC的主要功能似乎是陪伴单体蛋白质折叠：TRiC结合未折叠的多肽，从而防止其聚集，并介导未折叠的萤火虫荧光素酶和微管蛋白的ATP依赖性复性。至少在体外，TRiC似乎独立于小的辅伴侣蛋白如GroES发挥作用。荧光素酶的折叠由TRiC介导，但不由GroEL/ES介导。这表明与TRiC有效相互作用的底物蛋白的范围可能不同于GroEL。我们建议TRiC介导的折叠胞质蛋白质的机制不同的伴侣蛋白在特定方面。
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.