Binding of hsp90-associated immunophilins to cytoplasmic dynein: Direct binding and in vivo evidence that the peptidylprolyl isomerase domain is a dynein interaction domain
Binding of hsp90-associated immunophilins to cytoplasmic dynein: Direct binding and in vivo evidence that the peptidylprolyl isomerase domain is a dynein interaction domain
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DOI：
10.1021/bi020399z
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发表时间：
2002-11-19
期刊：
影响因子：
2.9
通讯作者：
Pratt, WB
中科院分区：
文献类型：
--
作者：
Galigniana, MD;Harrell, JM;Pratt, WB
FKBP 52是一种类固醇受体相关的亲免素，其通过三肽重复序列（TPR）结构域与hsp 90结合。FKBP 52还显示通过其肽基脯氨酰异构酶（PPIase）结构域与细胞质动力蛋白直接或间接相互作用，所述细胞质动力蛋白是参与囊泡向细胞核的逆行运输的马达蛋白。通过显示FKBP 52的PPI酶结构域片段在3 T3细胞中的表达抑制绿色荧光蛋白-糖皮质激素受体嵌合体的地塞米松依赖性核转位，证明了PPI酶结构域在受体运动中的功能作用。在这里，我们表明，细胞质动力蛋白是共免疫吸附与其他两个TPR结构域的蛋白结合热休克蛋白90（亲环素CyP-40和蛋白磷酸酶PP 5）。这两种蛋白质都具有PPIase同源结构域，并且细胞质动力蛋白与每个蛋白质的共免疫吸附被FKBP 52的PPIase结构域片段阻断。使用纯化的蛋白质，我们表明，FKBP 52，PP 5，和PPIase结构域片段直接结合到细胞质动力蛋白的中间链。PP 5与细胞质动力蛋白和微管共定位，并且FKBP 52的PPIase结构域片段在3 T3细胞中的表达破坏了其细胞骨架定位。我们的结论是PPIase结构域的热休克蛋白90结合亲免蛋白直接与细胞质动力蛋白相互作用，这种相互作用与马达蛋白是负责微管定位的PP 5在体内。
FKBP52 is a steroid receptor-associated immunophilin that binds via a tetratricopeptide repeat (TPR) domain to hsp90. FKBP52 has also been shown to interact either directly or indirectly via its peptidylprolyl isomerase (PPIase) domain with cytoplasmic dynein, a motor protein involved in retrograde transport of vesicles toward the nucleus. The functional role for the PPIase domain in receptor movement was demonstrated by showing that expression of the PPIase domain fragment of FKBP52 in 3T3 cells inhibits dexamethasone-dependent nuclear translocation of a green fluorescent protein-glucocorticoid receptor chimera. Here, we show that cytoplasmic dynein is co-immunoadsorbed with two other TPR domain proteins that bind hsp90 (the cyclophilin CyP-40 and the protein phosphatase PP5). Both proteins possess PPIase homology domains, and co-immunoadsorption of cytoplasmic dynein with each is blocked by the PPIase domain fragment of FKBP52. Using purified proteins, we show that FKBP52, PP5, and the PPIase domain fragment bind directly to the intermediate chain of cytoplasmic dynein. PP5 colocalizes with both cytoplasmic dynein and microtubules, and expression of the PPIase domain fragment of FKBP52 in 3T3 cells disrupts its cytoskeletal localization. We conclude that the PPIase domains of the hsp90-binding immunophilins interact directly with cytoplasmic dynein and that this interaction with the motor protein is responsible for the microtubular localization of PP5 in vivo.