一部分TAF（II）是SAGA复合物的组成成分，对于核小体乙酰化和转录激活是必需的。

A subset of TAF(II)s are integral components of the SAGA complex required for nucleosome acetylation and transcriptional stimulation.

作者信息

Grant P A, Schieltz D, Pray-Grant M G, Steger D J, Reese J C, Yates J R, Workman J L

机构信息

Howard Hughes Medical Institute, Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park 16802-4500, USA.

出版信息

Cell. 1998 Jul 10;94(1):45-53. doi: 10.1016/s0092-8674(00)81220-9.

DOI:10.1016/s0092-8674(00)81220-9

PMID:9674426

Abstract

A number of transcriptional coactivator proteins have been identified as histone acetyltransferase (HAT) proteins, providing a direct molecular basis for the coupling of histone acetylation and transcriptional activation. The yeast Spt-Ada-Gcn5-acetyltransferase (SAGA) complex requires the coactivator protein Gcn5 for HAT activity. Identification of protein subunits by mass spectrometry and immunoblotting revealed that the TATA binding protein-associated factors (TAF(II)s) TAF(II)90, -68/61, -60, -25/23, and -20/17 are integral components of this complex. In addition, TAF(II)68 was required for both SAGA-dependent nucleosomal HAT activity and transcriptional activation from chromatin templates in vitro. These results illustrate a role for certain TAF(II) proteins in the regulation of gene expression at the level of chromatin modification that is distinct from the TFIID complex and TAF(II)145.

摘要

许多转录共激活蛋白已被鉴定为组蛋白乙酰转移酶（HAT）蛋白，为组蛋白乙酰化与转录激活的偶联提供了直接的分子基础。酵母Spt-Ada-Gcn5-乙酰转移酶（SAGA）复合物的HAT活性需要共激活蛋白Gcn5。通过质谱和免疫印迹鉴定蛋白质亚基表明，TATA结合蛋白相关因子（TAF(II)s）TAF(II)90、-68/61、-60、-25/23和-20/17是该复合物的组成成分。此外，TAF(II)68对于体外依赖SAGA的核小体HAT活性和染色质模板的转录激活都是必需的。这些结果说明了某些TAF(II)蛋白在染色质修饰水平上对基因表达调控的作用，这与TFIID复合物和TAF(II)145不同。