Hip, a novel cochaperone involved in the eukaryotic hsc70/hsp40 reaction cycle
Hip, a novel cochaperone involved in the eukaryotic hsc70/hsp40 reaction cycle
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DOI：
10.1016/0092-8674(95)90099-3
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发表时间：
1995-11
期刊：
影响因子：
64.5
通讯作者：
Jörg Höfeld;Y. Minami;F. Hartl
中科院分区：
文献类型：
--
作者：
Jörg Höfeld;Y. Minami;F. Hartl
Hsc 70相互作用蛋白Hip是一种三肽重复序列蛋白，参与调节真核细胞70 kDa热休克同源物Hsc 70。一个Hip寡聚体结合至少两个Hsc 70分子的ATP酶结构域，依赖于Hsp 40对Hsc 70 ATP酶的激活。虽然水解仍然是ATP酶循环中的限速步骤，但Hip稳定了对底物蛋白具有高亲和力的Hsc 70的ADP状态。通过其自身的伴侣活性，Hip可能有助于Hsc 70与各种靶蛋白的相互作用。我们提出了一种机制，真核Hsc 70的调节，是不同于细菌Hsp 70。Hsc 70/Hsp 40/Hip系统显然不依赖于GrpE样核苷酸交换因子。
The Hsc70-interacting protein Hip, a tetratricopeptide repeat protein, participates in the regulation of the eukaryotic 70 kDa heat shock cognate Hsc70. One Hip oligomer binds the ATPase domains of at least two Hsc70 moleculesdependent on activation of the Hsc70 ATPase by Hsp40. While hydrolysis remains the ratelimiting step in the ATPase cycle, Hip stabilizes the ADP state of Hsc70 that has a high affinity for substrate protein. Through its own chaperone activity, Hip may contribute to the interaction of Hsc70 with various target proteins. We propose a mechanism for the regulation of eukaryotic Hsc70 that is distinct from that of bacterial Hsp70. The Hsc70/Hsp40/Hip system is apparently independent of a GrpE-like nucleotide exchange factor.