THE 56-59-KILODALTON PROTEIN IDENTIFIED IN UNTRANSFORMED STEROID-RECEPTOR COMPLEXES IS A UNIQUE PROTEIN THAT EXISTS IN CYTOSOL IN A COMPLEX WITH BOTH THE 70-KILODALTON AND 90-KILODALTON HEAT-SHOCK PROTEINS
THE 56-59-KILODALTON PROTEIN IDENTIFIED IN UNTRANSFORMED STEROID-RECEPTOR COMPLEXES IS A UNIQUE PROTEIN THAT EXISTS IN CYTOSOL IN A COMPLEX WITH BOTH THE 70-KILODALTON AND 90-KILODALTON HEAT-SHOCK PROTEINS
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DOI：
10.1021/bi00473a021
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发表时间：
1990-05-29
期刊：
影响因子：
2.9
通讯作者：
PRATT, WB
中科院分区：
文献类型：
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作者：
SANCHEZ, ER;FABER, LE;PRATT, WB
先前已经表明，兔子宫和肝细胞质中的9 S、未转化的孕酮、雌激素、雄激素和糖皮质激素受体复合物含有59-kDa蛋白[Tai，P.K.，Maeda，Y.，Nakao，K.，Wakim，N.G.，杜林，J.L.，和Faber，L. E.（1986）Biochemistry 25，5269-5275]。在这项工作中，我们表明，单克隆抗体KN 382/EC 1提出了对兔59 kDa的蛋白反应与9 S，未转化的糖皮质激素受体复合物从人IM-9淋巴细胞，但不与4S盐转化的受体制备的胞质溶胶。EC 1抗体识别的人蛋白质是一种中等丰度的56 kDa蛋白质（p56），通过间接免疫荧光法主要位于细胞质中。二维凝胶电泳分析表明，p56蛋白至少有6种同晶型。N-末端测序（20个氨基酸）表明p56是一种独特的人类蛋白质。当p56从IM-9细胞胞质溶胶中被免疫吸附时，70-和90-kDa的热休克蛋白以免疫特异性的方式被共吸附。两种热休克蛋白都不直接与EC 1抗体反应。我们的结论是，p56存在于细胞质中的高阶复合物含有热休克蛋白70和热休克蛋白90，这两者又被发现与未转化的类固醇受体。
It has previously been shown that 9S, untransformed progestin, estrogen, androgen, and glucocorticoid receptor complexes in rabbit uterine and liver cytosols contain a 59-kDa protein [Tai, P.K., Maeda, Y., Nakao, K., Wakim, N.G., Duhring, J.L., and Faber, L.E. (1986) Biochemistry 25, 5269-5275]. In this work we show that the monoclonal antibody KN 382/EC1 raised against the rabbit 59-kDa protein reacts with 9S, untransformed glucocorticoid receptor complexes in cytosol prepared from human IM-9 lymphocytes but not with 4S salt-transformed receptors. The human protein recognized by the EC1 antibody is a 56-kDa protein (p56) of moderate abundance located predominantly in the cytoplasm by indirect immunofluorescence. There are at least six isomorphs of p56 by two-dimensionsl gel analysis. N-Terminal sequencing (20 amino acids) shows that p56 is a unique human protein. When p56 is immunoadsorbed from IM-9 cell cytosol, both the 70- and 90-kDa heat shock proteins are coadsorbed in an immune-specific manner. Neither heat shock protein reacts directly with the EC1 antibody. We conclude that p56 exists in cytosol in a higher order complex containing hsp70 and hsp90, both of which in turn have been found to be associated with untransformed steroid receptors.