Ng Huck Hui, Robert François, Young Richard A, Struhl Kevin
Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115, USA.
Genes Dev. 2002 Apr 1;16(7):806-19. doi: 10.1101/gad.978902.
Genome-wide location analysis indicates that the yeast nucleosome-remodeling complex RSC has approximately 700 physiological targets and that the Rsc1 and Rsc2 isoforms of the complex behave indistinguishably. RSC is associated with numerous tRNA promoters, suggesting that the complex is recruited by the RNA polymerase III transcription machinery. At RNA polymerase II promoters, RSC specifically targets several gene classes, including histones, small nucleolar RNAs, the nitrogen discrimination pathway, nonfermentative carbohydrate metabolism, and mitochondrial function. At the histone HTA1/HTB1 promoter, RSC recruitment requires the Hir1 and Hir2 corepressors, and it is associated with transcriptional inactivity. In contrast, RSC binds to promoters involved in carbohydrate metabolism in response to transcriptional activation, but prior to association of the Pol II machinery. Therefore, the RSC complex is generally recruited to Pol III promoters and it is specifically recruited to Pol II promoters by transcriptional activators and repressors.
全基因组定位分析表明,酵母核小体重塑复合物RSC有大约700个生理靶点,且该复合物的Rsc1和Rsc2亚型表现无明显差异。RSC与众多tRNA启动子相关联,这表明该复合物是由RNA聚合酶III转录机制募集的。在RNA聚合酶II启动子处,RSC特异性靶向几类基因,包括组蛋白、小核仁RNA、氮代谢途径、非发酵性碳水化合物代谢和线粒体功能。在组蛋白HTA1/HTB1启动子处,RSC的募集需要Hir1和Hir2共抑制因子,且与转录无活性相关。相反,RSC响应转录激活而结合到参与碳水化合物代谢的启动子上,但在Pol II机制结合之前。因此,RSC复合物通常被募集到Pol III启动子上,并且通过转录激活因子和抑制因子被特异性募集到Pol II启动子上。