Department of Molecular and Medical Genetics, Oregon Health and Science University, Oregon 97239, USA.
Oregon Stem Cell Center, Oregon Health and Science University, Oregon 97239, USA.
Genes Dev. 2018 Nov 1;32(21-22):1398-1419. doi: 10.1101/gad.314377.118. Epub 2018 Oct 26.
The transcription factor MYC (also c-Myc) induces histone modification, chromatin remodeling, and the release of paused RNA polymerase to broadly regulate transcription. MYC is subject to a series of post-translational modifications that affect its stability and oncogenic activity, but how these control MYC's function on the genome is largely unknown. Recent work demonstrates an intimate connection between nuclear compartmentalization and gene regulation. Here, we report that Ser62 phosphorylation and PIN1-mediated isomerization of MYC dynamically regulate the spatial distribution of MYC in the nucleus, promoting its association with the inner basket of the nuclear pore in response to proliferative signals, where it recruits the histone acetyltransferase GCN5 to bind and regulate local gene acetylation and expression. We demonstrate that PIN1-mediated localization of MYC to the nuclear pore regulates MYC target genes responsive to mitogen stimulation that are involved in proliferation and migration pathways. These changes are also present at the chromatin level, with an increase in open regulatory elements in response to stimulation that is PIN1-dependent and associated with MYC chromatin binding. Taken together, our study indicates that post-translational modification of MYC controls its spatial activity to optimally regulate gene expression in response to extrinsic signals in normal and diseased states.
转录因子MYC(也称为c-Myc)可诱导组蛋白修饰、染色质重塑以及释放暂停的RNA聚合酶,从而广泛调控转录。MYC会经历一系列影响其稳定性和致癌活性的翻译后修饰,但这些修饰如何在基因组上控制MYC的功能在很大程度上尚不清楚。最近的研究表明核区室化与基因调控之间存在密切联系。在此,我们报告MYC的Ser62磷酸化和PIN1介导的异构化动态调节MYC在细胞核中的空间分布,响应增殖信号促进其与核孔内篮的结合,在该处它招募组蛋白乙酰转移酶GCN5来结合并调节局部基因的乙酰化和表达。我们证明PIN1介导的MYC定位于核孔调节了对有丝分裂原刺激有反应的MYC靶基因,这些基因参与增殖和迁移途径。这些变化在染色质水平也存在,响应刺激时开放调节元件增加,这是PIN1依赖性的且与MYC染色质结合相关。综上所述,我们的研究表明MYC的翻译后修饰控制其空间活性,以在正常和疾病状态下响应外在信号来最佳地调节基因表达。