Aberrant interactions of transcriptional repressor proteins with the Huntington's disease gene product, huntingtin
Aberrant interactions of transcriptional repressor proteins with the Huntington's disease gene product, huntingtin
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DOI：
10.1093/hmg/8.9.1647
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发表时间：
1999-09-01
影响因子：
3.5
通讯作者：
Jones, AL
中科院分区：
文献类型：
--
作者：
Boutell, JM;Thomas, P;Jones, AL
我们利用酵母双杂交系统检测了亨廷顿蛋白（htt 171）的N端与核受体辅阻遏物（N-CoR）的C端区域的相互作用。这种相互作用是重复长度依赖性和特定的htt 171，辅阻遏物没有相互作用的重复携带一节的萎缩蛋白1，也没有与雄激素受体或聚谷氨酰胺单独。使用His标记的大肠杆菌表达的C-末端人类和大鼠共阻遏蛋白将全长亨廷顿蛋白从均质化的大鼠脑中拉出并在下拉测定中证实了这种相互作用。N-CoR抑制来自序列特异性配体激活受体的转录，如类维生素A X-甲状腺激素受体二聚体和其他核受体，包括Mad-Max受体二聚体。这种抑制的机制似乎是通过形成包括N-CoR、mSin 3和组蛋白脱乙酰酶的抑制蛋白复合物。我们使用N-CoR和mSin 3A抗体进行免疫组织化学研究，发现在亨廷顿病（HD）皮质和尾状核中，这些蛋白质的细胞定位仅为细胞质，而在对照脑中，它们定位于细胞核和细胞质中; mSin 3A免疫反应性也发生在亨廷顿蛋白阳性核内包涵体的子集中。阻遏蛋白在HD脑中的重新定位可能改变转录并参与疾病的病理学。
We detected an interaction of the N-terminus of huntingtin (htt171) with the C-terminal region of the nuclear receptor co-repressor (N-CoR) using the yeast two-hybrid system. This interaction was repeat length dependent and specific to htt171; the corepressor did not interact with the repeat carrying a section of atrophin 1 nor with the androgen receptor or polyglutamine alone. The interaction was confirmed using His-tagged Escherichia coli-expressed C-terminal human and rat co-repressor protein which pulled full-length huntingtin out of homogenized rat brain and in pull-down assays. The N-CoR represses transcription from sequence-specific ligand-activated receptors such as the retinoid X-thyroid hormone receptor dimers end other nuclear receptors including Mad-Max receptor dimers, The mechanism of this repression appears to be through the formation of a complex of repressor proteins including the N-CoR, mSin3 and histone deacetylases. We have used N-CoR and mSin3A antibodies in immunohistochemical studies and find that in Huntington's disease (HD) cortex and caudate, the cellular localization of these proteins is exclusively cytoplasmic whilst in control brain they are localized in the nucleus as well as the cytoplasm; mSin3A immunoreactivity also occurred in a subset of huntingtin positive intranuclear inclusions. The relocalization of repressor proteins in HD brain may alter transcription and be involved in the pathology of the disease.