Hsp-90-mediated folding of the lymphoid cell kinase P56(lck1)
Hsp-90-mediated folding of the lymphoid cell kinase P56(lck1)
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DOI：
10.1021/bi961332c
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发表时间：
1996-10-15
期刊：
影响因子：
2.9
通讯作者：
Matts, RL
中科院分区：
文献类型：
--
作者：
Hartson, SD;Barrett, DJ;Matts, RL
多项证据表明，90-kDa 热休克蛋白 (hsp90) 家族的成员可能支持 src 激酶家族的各种同源物的折叠。在这项工作中，我们利用兔网织红细胞裂解物中的脉冲追踪分析来证明大多数新合成的 p56(lck) 分子都存在 hsp90 结合的中间体。 hsp90 结合药物格尔德霉素破坏了 p56lck 与 hsp90 的结合，阻止激酶表现出蛋白酶抗性构象，并导致激酶比活性降低。在追逐期间，对格尔德霉素抑制 hsp90 功能以及 hsp90 和 p56(lck) 之间物理相互作用的要求仍然存在。与在兔网织红细胞裂解物中观察到的效果一致，将格尔德霉素应用于成纤维细胞引起lck介导的转化的特异性逆转，同时伴随p56(lck)活性和蛋白质的丧失。然而，格尔德霉素对纯化的p56(lck)没有直接作用。也与 hsp90 和 p56(lck) 之间的功能联系一致，在 LSTRA 的细胞质部分而非膜部分中检测到这些蛋白质之间的物理相互作用。细胞。尽管 hsp90 在兔网织红细胞裂解物中的初始从头折叠和 p56(lck) 结构的重复支持中发挥作用，但 T 细胞细胞质中 hsp90 和 p56(lck) 之间复合物的特定出现表明 hsp90 在体内主要折叠 p56(lck) 的新生分子。
Several lines of evidence suggest that members of the 90-kDa family of heat shock proteins (hsp90) may support the folding of various homologues of the src kinase family. In this work, we utilized pulse-chase analyses in rabbit reticulocyte lysate to demonstrate that hsp90-bound intermediates existed for the majority of newly synthesized p56(lck) molecules. The hsp90-binding drug geldanamycin disrupted the association of p56lck with hsp90, prevented the kinase from demonstrating a protease-resistant conformation, and caused decreases in kinase specific activity. Requirements for geldanamycin-inhibitable hsp90 function and physical interactions between hsp90 and p56(lck) persisted during chase periods. Consistent with the effects observed in rabbit reticulocyte lysate, application of geldanamycin to fibroblasts caused specific reversion of lck-mediated transformation concomitant with loss of p56(lck) activity and protein. However, geldanamycin had no direct effect on purified p56(lck). Also consistent with functional linkages between hsp90 and p56(lck), physical interactions between these proteins were detected in cytoplasmic, but not membrane, fractions of LSTRA. cells. Although hsp90 functions in both the initial de novo folding and the reiterative support of p56(lck) structure in rabbit reticulocyte lysate, the specific occurrence of complexes between hsp90 and p56(lck) in the cytoplasm of T cells suggests that hsp90 primarily folds nascent molecules of p56(lck) in vivo.