Weake Vikki M, Swanson Selene K, Mushegian Arcady, Florens Laurence, Washburn Michael P, Abmayr Susan M, Workman Jerry L
Stowers Institute for Medical Research, Kansas City, Missouri 64110, USA.
Genes Dev. 2009 Dec 15;23(24):2818-23. doi: 10.1101/gad.1846409.
The histone acetyltransferase complex SAGA is well characterized as a coactivator complex in yeast. In this study of Drosophila SAGA (dSAGA), we describe three novel components that include an ortholog of Spt20, a potential ortholog of Sgf73/ATXN7, and a novel histone fold protein, SAF6 (SAGA factor-like TAF6). SAF6, which binds directly to TAF9, functions analogously in dSAGA to TAF6/TAF6L in the yeast and human SAGA complexes, respectively. Moreover, TAF6 in flies is restricted to TFIID. Mutations in saf6 disrupt SAGA-regulated gene expression without disrupting acetylated or ubiquitinated histone levels. Thus, SAF6 is essential for SAGA coactivator function independent of the enzymatic activities of the complex.
组蛋白乙酰转移酶复合物SAGA在酵母中作为共激活因子复合物已得到充分表征。在对果蝇SAGA（dSAGA）的这项研究中，我们描述了三个新组分，包括Spt20的一个直系同源物、Sgf73/ATXN7的一个潜在直系同源物，以及一种新的组蛋白折叠蛋白SAF6（SAGA因子样TAF6）。SAF6直接与TAF9结合，在dSAGA中的功能分别类似于酵母和人类SAGA复合物中的TAF6/TAF6L。此外，果蝇中的TAF6仅限于TFIID。saf6中的突变会破坏SAGA调控的基因表达，而不会破坏乙酰化或泛素化组蛋白水平。因此，SAF6对于SAGA共激活因子功能至关重要，且独立于该复合物的酶活性。
