Biochemical analysis of distinct activation functions in p300 that enhance transcription initiation with chromatin templates

作     者：Kraus, WL Manning, ET Kadonaga, JT 

作者机构：Univ Calif San Diego Dept Biol La Jolla CA 92093 USA Univ Calif San Diego Ctr Mol Genet La Jolla CA 92093 USA 

出 版 物：《MOLECULAR AND CELLULAR BIOLOGY》 (分子生物学与细胞生物学)

年 卷 期：1999年第19卷第12期

页      面：8123-8135页

核心收录：

学科分类：0710[理学-生物学] 071010[理学-生物化学与分子生物学] 07[理学] 

基　　金：NIGMS NIH HHS [GM46995  R01 GM046995] Funding Source: Medline 

主　　题：乙酰基转移酶类/生物合成 乙酰基转移酶类/分离和提纯 乙酰基转移酶类/代谢 腺病毒E1A蛋白质类/代谢 氨基酸序列 染色质 E1A相关p300蛋白质 HeLa细胞 组蛋白酰基转移酶 分子序列数据 诱变 核蛋白质类/生物合成 核蛋白质类/分离和提纯 核蛋白质类/代谢 启动区 遗传 受体 雌激素/代谢 酿酒酵母蛋白质类 模板 遗传 反式激活因子类/生物合成 反式激活因子类/分离和提纯 反式激活因子类/代谢 转录 遗传 动物 人类 小鼠 

摘      要：To investigate the mechanisms of transcriptional enhancement by the p300 coactivator, we analyzed wildtype and mutant versions of p300 with a chromatin transcription system in vitro. Estrogen receptor, NF-kappa B p65 plus Sp1, and Gal4-VP16 were used as different sequence-specific activators. The CH3 domain (or E1A-binding region) was found to be essential for the function of each of the activators tested. The bromodomain was also observed to be generally important for p300 coactivator activity, though to a lesser extent than the CH3 domain/E1A-binding region. The acetyltransferase activity and the C-terminal region (containing the steroid receptor coactivator/p160-binding region and the glutamine-rich region) were each found to be important for activation by estrogen receptor but not for that by Gal4-VP16. The N-terminal region of p300, which had been previously found to interact with nuclear hormone receptors, was not seen to be required for any of the activators, including estrogen receptor. Single-round transcription experiments revealed that the functionally important subregions of p300 contribute to its ability to promote the assembly of transcription initiation complexes. In addition, the acetyltransferase activity of p300 was observed to be distinct from the broadly essential activation function of the CH3 domain/E1A-binding region. These results indicate that specific regions of p300 possess distinct activation functions that are differentially required to enhance the assembly of transcription initiation complexes. Interestingly, with the estrogen receptor, four distinct regions of p300 each have an essential role in the transcription activation process. These data exemplify a situation in which a network of multiple activation functions is required to achieve gene transcription.