Dystonia-causing mutations in the transcription factor THAP1 disrupt HCFC1 cofactor recruitment and alter gene expression
Dystonia-causing mutations in the transcription factor THAP1 disrupt HCFC1 cofactor recruitment and alter gene expression
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DOI：
10.1093/hmg/ddx187
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发表时间：
2017-08-01
影响因子：
3.5
通讯作者：
Kaiser, Frank J.
中科院分区：
文献类型：
--
作者：
Hollstein, Ronja;Reiz, Benedikt;Kaiser, Frank J.
死亡相关蛋白1（THAP 1）是DYT 6肌张力障碍中突变的基因，编码一种转录因子。虽然N末端THAP结构域允许特异性DNA结合，但其他区域的功能相关性在很大程度上尚不清楚。C-末端含有一个4-氨基酸跨越宿主细胞因子1（HCFC 1）结合域（HBM），介导与HCFC 1的相互作用。有趣的是，在肌张力障碍患者中报告了影响HBM的三种突变（p.N136S、p.N136K、p.Y137C）。我们研究了这些突变对THAP 1与HCFC 1相互作用的影响，并证明所有三种突变都消除了HCFC 1-THAP 1复合物的形成。值得注意的是，在公开可用的全基因组ChIP数据中，在近3，500个负载THAP 1的染色质区域中发现了>90%的HCFC 1共定位。通过siRNA介导的HCFC 1的耗竭，我们检测到THAP 1表达的增加，表明HCFC 1对THAP 1具有共阻遏活性。定量ChIP对选定的启动子显示，没有突变显着降低DNA结合能力的THAP 1，而HCFC 1结合高度减少。我们的研究结果表明THAP 1介导的HCFC 1募集到THAP 1靶位点。值得注意的是，THAP 1中HBM内引起肌张力障碍的突变消除了这种相互作用。因此，我们证明了破坏THAP 1-HCFC 1复合物的形成是导致转录失调的肌张力障碍突变的另一种机制。
Thanatos-associated protein domain containing, apoptosis-associated protein 1 (THAP1), the gene mutated in DYT6 dystonia, encodes a transcription factor. While the N-terminal THAP domain allows for specific DNA-binding, the functional relevance of the other regions is largely unknown. The C-terminus contains a 4-amino-acid-spanning host cell factor 1 (HCFC1)-binding domain (HBM) that mediates the interaction with HCFC1. Interestingly, three mutations affecting the HBM (p.N136S, p.N136K, p.Y137C) have been reported in dystonia patients. We investigated the consequences of these mutations on the interaction of THAP1 with HCFC1 and demonstrated that all three mutations abolished HCFC1-THAP1 complex formation. Notably, HCFC1 co-localization was found in >90% of the almost 3,500 chromatin regions loaded with THAP1 in publicly available genome-wide ChIP data. By siRNA-mediated depletion of HCFC1, we detected an increase of THAP1 expression, indicating a co-repressor activity of HCFC1 for THAP1. Quantitative ChIP on selected promoters revealed that none of the mutations significantly decreased the DNA-binding ability of THAP1 while HCFC1 binding was highly reduced. Our findings indicate a THAP1-mediated recruitment of HCFC1 to THAP1 target sites. Of note, dystonia-causing mutations within the HBM in THAP1 abolished this interaction. Thus, we demonstrate disrupted THAP1-HCFC1 complex formation as another mechanism of dystonia-causing mutations leading to transcriptional dysregulation.