van Steensel B, Jenster G, Damm K, Brinkmann A O, van Driel R
E.C. Slater Institute, University of Amsterdam, The Netherlands.
J Cell Biochem. 1995 Mar;57(3):465-78. doi: 10.1002/jcb.240570312.
Steroid receptors have been reported to bind to the nuclear matrix. The nuclear matrix is operationally defined as the residual nuclear structure that remains after extraction of most of the chromatin and all soluble and loosely bound components. To obtain insight in the molecular mechanism of the interaction of steroid receptors with the nuclear matrix, we studied the binding of several deletion mutants of the human androgen receptor (hAR) and the human glucocorticoid receptor (hGR) to the nuclear matrix. Receptor binding was tested for two different nuclear matrix preparations: complete matrices, in which most matrix proteins are retained during the isolation procedure, and depleted matrices, which consist of only a subset of these proteins. The results show that the C-terminal domain of the hAR binds tightly to both depleted and complete matrices. In addition, at least one other domain of the hAR binds to complete matrices but not to depleted matrices. In contrast to the hAR, the hGR binds only to complete matrices. For this interaction both the DNA-binding domain and the C-terminal domain of the hGR are required, whereas the N-terminal domain is not. We conclude that specific protein domains of the hAR and the hGR are involved in binding to the nuclear matrix. In addition, our results indicate that the hAR and the hGR are attached to the nuclear matrix through different molecular interactions.
据报道，类固醇受体可与核基质结合。核基质在操作上被定义为在提取大部分染色质以及所有可溶性和松散结合成分后剩余的核结构。为深入了解类固醇受体与核基质相互作用的分子机制，我们研究了人雄激素受体（hAR）和人糖皮质激素受体（hGR）的几种缺失突变体与核基质的结合情况。针对两种不同的核基质制剂测试了受体结合：完整基质，即在分离过程中保留了大部分基质蛋白；以及耗尽基质，其仅由这些蛋白的一个子集组成。结果表明，hAR的C末端结构域与耗尽基质和完整基质都紧密结合。此外，hAR至少还有一个其他结构域与完整基质结合，但不与耗尽基质结合。与hAR不同，hGR仅与完整基质结合。对于这种相互作用，hGR的DNA结合结构域和C末端结构域都是必需的，而N末端结构域则不是。我们得出结论，hAR和hGR的特定蛋白质结构域参与了与核基质的结合。此外，我们的结果表明，hAR和hGR通过不同的分子相互作用附着于核基质。
