Keaveney M, Struhl K
Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115, USA.
Mol Cell. 1998 May;1(6):917-24. doi: 10.1016/s1097-2765(00)80091-x.
Eukaryotic transcriptional activators bind to enhancer elements and stimulate the RNA polymerase II (pol II) machinery via functionally autonomous activation domains. In yeast cells, the normal requirement for an activation domain can be bypassed by artificially connecting an enhancer-bound protein to a component of the pol II machinery. This observation suggests, but does not necessarily indicate, that the physiological role of activation domains is to recruit the pol II apparatus to promoters. Here, we show that transcriptional stimulation does not occur when the activation domain is physically disconnected from the enhancer-bound protein and transferred to components of the pol II machinery. The observation that autonomous activation domains are functional when connected to enhancer-bound proteins but not to components of the pol II machinery strongly argues that recruitment is the predominant mechanism for transcriptional activation in yeast.
真核转录激活因子与增强子元件结合，并通过功能自主的激活结构域刺激RNA聚合酶II（Pol II）机制。在酵母细胞中，通过人工将与增强子结合的蛋白质连接到Pol II机制的一个组件上，可以绕过对激活结构域的正常需求。这一观察结果表明，但不一定表明，激活结构域的生理作用是将Pol II装置招募到启动子上。在这里，我们表明，当激活结构域与增强子结合蛋白物理分离并转移到Pol II机制的组件上时，转录刺激不会发生。当自主激活结构域与增强子结合蛋白连接时具有功能，但与Pol II机制的组件连接时则没有功能，这一观察结果有力地证明，招募是酵母中转录激活的主要机制。
