Enhancement of CIITA transcriptional function by ubiquitin
Enhancement of CIITA transcriptional function by ubiquitin
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DOI：
10.1038/ni985
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发表时间：
2003-11-01
影响因子：
30.5
通讯作者：
Ting, JPY
中科院分区：
文献类型：
--
作者：
Greer, SF;Zika, E;Ting, JPY
虽然越来越多的证据表明，在酵母中泛素化和单泛素化与转录之间存在直接联系，但这种联系尚未在高等真核生物中得到证实。在这里，我们表明，主要组织相容性复合体（MHC）II类反式激活因子（CIITA），这是需要表达的基因编码的MHC II类分子，是泛素化。这种泛素化增强了CIITA与MHC II类转录因子和MHC II类启动子的关联，导致反式激活功能和MHC II类mRNA表达的增加。CIITA泛素化的程度由组蛋白乙酰化酶（HAT）和脱乙酰化酶（HDAC）控制，表明由这些酶介导的关键细胞过程与调节转录有关。因此，泛素通过增强其在启动子处的组装来正向调节哺乳动物共激活因子。
Although increasing evidence indicates that there is a direct link between ubiquitination and mono-ubiquitination and transcription in yeast, this link has not been demonstrated in higher eukaryotes. Here we show that the major histocompatibility complex (MHC) class II transactivator (CIITA), which is required for expression of genes encoding MHC class II molecules, is ubiquitinated. This ubiquitination enhanced the association of CIITA with both MHC class II transcription factors and the MHC class II promoter, resulting in an increase in transactivation function and in the expression of MHC class II mRNA. The degree of CIITA ubiquitination was controlled by histone acetylases (HATs) and deacetylases (HDACs), indicating that the crucial cellular processes mediated by these enzymes are linked to regulate transcription. Thus, ubiquitin positively regulates a mammalian coactivator by enhancing its assembly at the promoter.