Ponticelli A S, Pardee T S, Struhl K
Department of Biochemistry, State University of New York at Buffalo, 14214.
Mol Cell Biol. 1995 Feb;15(2):983-8. doi: 10.1128/MCB.15.2.983.
Eukaryotic transcriptional activators have been classified on the basis of the characteristics of their activation domains. Acidic activation domains, such as those in the yeast GAL4 or GNC4 proteins and the herpes simplex virus activator VP16, stimulate RNA polymerase II transcription when introduced into a variety of eukaryotic cells. This species interchangeability demonstrates that the mechanism by which acidic activation domains function is highly conserved in the eukaryotic kingdom. To determine whether such a conservation of function exists for a different class of activation domain, we have tested whether the glutamine-rich activation domains of the human transcriptional activator Sp1 function in the yeast Saccharomyces cerevisiae. We report here that the glutamine-rich domains of Sp1 do not stimulate transcription in S. cerevisiae, even when accompanied by human TATA-box binding protein (TBP) or human-yeast TATA-box binding protein hybrids. Thus, in contrast to the case for acidic activation domains, the mechanism by which glutamine-rich domains stimulate transcription is not conserved between S. cerevisiae and humans.
真核转录激活因子已根据其激活结构域的特征进行了分类。酸性激活结构域，如酵母GAL4或GNC4蛋白以及单纯疱疹病毒激活因子VP16中的那些结构域，当被导入多种真核细胞时会刺激RNA聚合酶II转录。这种物种间的互换性表明酸性激活结构域发挥功能的机制在真核生物界中高度保守。为了确定对于另一类激活结构域是否存在这样的功能保守性，我们测试了人类转录激活因子Sp1富含谷氨酰胺的激活结构域在酿酒酵母中是否起作用。我们在此报告，即使伴有人类TATA框结合蛋白（TBP）或人 - 酵母TATA框结合蛋白杂种，Sp1富含谷氨酰胺的结构域在酿酒酵母中也不会刺激转录。因此，与酸性激活结构域的情况相反，富含谷氨酰胺的结构域刺激转录的机制在酿酒酵母和人类之间并不保守。
