Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720-3202, USA.
Mol Genet Genomics. 2010 Apr;283(4):365-80. doi: 10.1007/s00438-010-0523-x. Epub 2010 Feb 24.
The role of a highly conserved YEATS protein motif is explored in the context of the Taf14 protein of Saccharomyces cerevisiae. In S. cerevisiae, Taf14 is a protein physically associated with many critical multisubunit complexes including the general transcription factors TFIID and TFIIF, the chromatin remodeling complexes SWI/SNF, Ino80 and RSC, Mediator and the histone modification enzyme NuA3. Taf14 is a member of the YEATS superfamily, conserved from bacteria to eukaryotes and thought to have a transcription stimulatory activity. However, besides its ubiquitous presence and its links with transcription, little is known about Taf14's role in the nucleus. We use structure-function and mutational analysis to study the function of Taf14 and its well conserved N-terminal YEATS domain. We show here that the YEATS domain is not necessary for Taf14's association with these transcription and chromatin remodeling complexes, and that its presence in these complexes is dependent only on its C-terminal domain. Our results also indicate that Taf14's YEATS domain is not necessary for complementing the synthetic lethality between TAF14 and the general transcription factor TFIIS (encoded by DST1). Furthermore, we present evidence that the YEATS domain of Taf14 has a negative impact on cell growth: its absence enables cells to grow better than wild-type cells under stress conditions, like the microtubule destabilizing drug benomyl. Moreover, cells expressing solely the YEATS domain grow worser than cells expressing any other Taf14 construct tested, including the deletion mutant. Thus, this highly conserved domain should be considered part of a negative regulatory loop in cell growth.
在酿酒酵母的 Taf14 蛋白背景下,探索了高度保守的 YEATS 蛋白基序的作用。在酿酒酵母中,Taf14 是一种与许多关键多亚基复合物物理相关的蛋白质,包括一般转录因子 TFIID 和 TFIIF、染色质重塑复合物 SWI/SNF、Ino80 和 RSC、中介体和组蛋白修饰酶 NuA3。Taf14 是 YEATS 超家族的成员,从细菌到真核生物都保守,被认为具有转录刺激活性。然而,除了其普遍存在及其与转录的联系外,人们对 Taf14 在细胞核中的作用知之甚少。我们使用结构功能和突变分析来研究 Taf14 及其高度保守的 N 端 YEATS 结构域的功能。我们在这里表明,YEATS 结构域对于 Taf14 与这些转录和染色质重塑复合物的结合不是必需的,并且其在这些复合物中的存在仅取决于其 C 端结构域。我们的结果还表明,Taf14 的 YEATS 结构域对于补充 TAF14 和一般转录因子 TFIIS(由 DST1 编码)之间的合成致死性不是必需的。此外,我们提供的证据表明,Taf14 的 YEATS 结构域对细胞生长具有负面影响:其缺失使细胞在应激条件下(如微管不稳定药物苯并咪唑)比野生型细胞生长得更好。此外,仅表达 YEATS 结构域的细胞比表达任何其他测试的 Taf14 构建体(包括缺失突变体)的细胞生长更差。因此,这个高度保守的结构域应该被认为是细胞生长负反馈调节环的一部分。