SPT3 INTERACTS WITH TFIID TO ALLOW NORMAL TRANSCRIPTION IN SACCHAROMYCES-CEREVISIAE
SPT3 INTERACTS WITH TFIID TO ALLOW NORMAL TRANSCRIPTION IN SACCHAROMYCES-CEREVISIAE
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DOI：
10.1101/gad.6.7.1319
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发表时间：
1992-07-01
影响因子：
10.5
通讯作者：
WINSTON, F
中科院分区：
文献类型：
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作者：
EISENMANN, DM;ARNDT, KM;WINSTON, F
酿酒酵母基因SPT 15（编码TATA结合蛋白TFIID）中的突变已被证明会引起多效性表型并导致体内转录的变化。在这里，我们报告的一个这样的突变，spt 15 -21，这会导致一个单一的氨基酸取代TFIID的保守残基的克隆和分析。令人惊讶的是，spt 15 -21突变不影响TFIID的稳定性、其与DNA结合或支持体外基础转录的能力、或上游激活物在体内发挥功能的能力。为了进一步研究spt 15 -21缺陷，分离并分析了该突变的基因外抑制子。spt 15 -21的所有基因外抑制因子都是先前鉴定的SPT 3基因中的突变。这些spt 3突变对spt 15 -21的抑制是等位基因特异性的，表明TFIID和SPT 3相互作用，并且spt 15 -21以某种方式损害这种相互作用。与这些遗传数据一致，免疫共沉淀实验表明，TFIID和SPT 3蛋白在酵母提取物中是物理相关的。总而言之，这些结果表明SPT 3是TFIID相关蛋白，是TFIID在体内特定启动子处发挥作用所需的。
Mutations in the Saccharomyces cerevisiae gene SPT15, which encodes the TATA-binding protein TFIID, have been shown to cause pleiotropic phenotypes and to lead to changes in transcription in vivo. Here, we report the cloning and analysis of one such mutation, spt15-21, which causes a single-amino-acid substitution in a conserved residue of TFIID. Surprisingly, the spt15-21 mutation does not affect the stability of TFIID, its ability to bind to DNA or to support basal transcription in vitro, or the ability of an upstream activator to function in vivo. To study further the spt15-21 defect, extragenic suppressors of this mutation were isolated and analyzed. All of the extragenic suppressors of spt15-21 are mutations in the previously identified SPT3 gene. Suppression of spt15-21 by these spt3 mutations is allele-specific, suggesting that TFIID and SPT3 interact and that spt15-21 impairs this interaction in some way. Consistent with these genetic data, coimmunoprecipitation experiments demonstrate that the TFIID and SPT3 proteins are physically associated in yeast extracts. Taken together, these results suggest that SPT3 is a TFIID-associated protein, required for TFIID to function at particular promoters in vivo.