INHIBITION OF HEAT-SHOCK PROTEIN HSP90-PP60(V-SRC) HETEROPROTEIN COMPLEX-FORMATION BY BENZOQUINONE ANSAMYCINS - ESSENTIAL ROLE FOR STRESS PROTEINS IN ONCOGENIC TRANSFORMATION
INHIBITION OF HEAT-SHOCK PROTEIN HSP90-PP60(V-SRC) HETEROPROTEIN COMPLEX-FORMATION BY BENZOQUINONE ANSAMYCINS - ESSENTIAL ROLE FOR STRESS PROTEINS IN ONCOGENIC TRANSFORMATION
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DOI：
10.1073/pnas.91.18.8324
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发表时间：
1994-08-30
影响因子：
11.1
通讯作者：
NECKERS, LM
中科院分区：
文献类型：
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作者：
WHITESELL, L;MIMNAUGH, EG;NECKERS, LM
致癌酪氨酸激酶诱导细胞转化的分子机制尚不清楚。Herbimycin A，geldanamycin，和其他一些苯醌安莎霉素显示出一种不寻常的逆转酪氨酸激酶诱导的致癌转化的能力。作为研究v-src介导的转化的一种方法，我们检测了安莎霉素在转化细胞中的作用，发现药物诱导的逆转可以在不直接抑制src磷酸化活性的情况下实现。为了确定药物介导的逆转的激酶抑制以外的机制，我们制备了固相固定的格尔德霉素衍生物，并亲和沉淀与药物相互作用的分子靶点。在一系列细胞系中，固定化格尔德霉素以稳定且药理学特异性的方式结合主要类别热休克蛋白（HSP 90）的元件。与这些结合数据相一致，我们发现，可溶性格尔德霉素和除莠霉素A特异性抑制了先前描述的Src-HSP 90杂蛋白复合物的形成。一个相关的苯醌安莎霉素，未能恢复转化细胞没有抑制这种复合物的形成。这些结果表明，HSP参与多分子复合物的形成是src介导的转化所需的，并可提供药物调节的靶点。
The molecular mechanisms by which oncogenic tyrosine kinases induce cellular transformation are unclear. Herbimycin A, geldanamycin, and certain other benzoquinone ansamycins display an unusual capacity to revert tyrosine kinase-induced oncogenic transformation, As an approach to the study of v-src-mediated transformation, we examined ansamycin action in transformed cells and found that drug-induced reversion could be achieved without direct inhibition of src phosphorylating activity. To identify mechanisms other than kinase inhibition for drug-mediated reversion, we prepared a solid phase-immobilized geldanamycin derivative and affinity precipitated the molecular targets with which the drug interacted. In a range of cell lines, immobilized geldanamycin bound elements of a major class of heat shock protein (HSP90) in a stable and pharmacologically specific manner. Consistent with these binding data, we found that soluble geldanamycin and herbimycin A inhibited specifically the formation of a previously described src-HSP90 heteroprotein complex. A related benzoquinone ansamycin that failed to revert transformed cells did not inhibit the formation of this complex. These results demonstrate that HSP participation in multimolecular complex formation is required for src-mediated transformation and can provide a target for drug modulation.