Melamed Philippa
Department of Biological Sciences, 14 Science Drive 4, National University of Singapore, Singapore 117543.
Trends Endocrinol Metab. 2008 Jan;19(1):25-31. doi: 10.1016/j.tem.2007.10.008. Epub 2007 Dec 26.
The roles of chromatin modifications in transcription have been studied extensively; however, there remains a dearth of information explaining how extracellular signals induce changes in chromatin at a specific gene locus. The gonadotropins provide an example of genes that undergo significant fluctuations in their expression, and are regulated by gonadotropin-releasing hormone (GnRH) through a membrane-bound receptor. GnRH displaces histone deacetylases (HDACs) from gonadotropin genes in immature mouse gonadotropes, and some of the pathways have been elucidated. This GnRH effect likely comprises a mechanism involved in altering reproductive potential and provides a model for studying the regulation of derepression. This paper reviews the role of HDACs in repression of the gonadotropin genes and the mechanisms through which GnRH overcomes their actions.
染色质修饰在转录过程中的作用已得到广泛研究；然而，关于细胞外信号如何在特定基因位点诱导染色质变化的信息仍然匮乏。促性腺激素就是一个例子，其基因表达会发生显著波动，并通过膜结合受体受促性腺激素释放激素（GnRH）调控。在未成熟小鼠促性腺细胞中，GnRH会将组蛋白去乙酰化酶（HDACs）从促性腺激素基因上置换下来，并且其中一些途径已得到阐明。这种GnRH效应可能包含一种改变生殖潜能的机制，并为研究去抑制调控提供了一个模型。本文综述了HDACs在促性腺激素基因抑制中的作用以及GnRH克服其作用的机制。
