IDENTIFICATION AND CHARACTERIZATION OF HAP4 - A 3RD COMPONENT OF THE CCAAT-BOUND HAP2 HAP3 HETEROMER
IDENTIFICATION AND CHARACTERIZATION OF HAP4 - A 3RD COMPONENT OF THE CCAAT-BOUND HAP2 HAP3 HETEROMER
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DOI：
10.1101/gad.3.8.1166
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发表时间：
1989-08-01
影响因子：
10.5
通讯作者：
GUARENTE, L
中科院分区：
文献类型：
--
作者：
FORSBURG, SL;GUARENTE, L
酿酒酵母的 CYC1 基因受到 HAP2 和 HAP3 蛋白的正向调节，它们形成异聚复合物，与上游激活位点 UAS2 中的 CCAAT 盒结合，并激活不可发酵碳源中的转录。我们进行了遗传分析，以确定通过 UAS2 发挥作用的其他反式作用调节因子。我们提出了一个新基因座 HAP4 的鉴定和表征，该基因座被证明编码 UAS2 处 DNA 结合复合物的一个亚基。在 hap4 突变体中，体外未观察到 HAP2 和 HAP3 (HAP2/3) 的结合。 HAP4 基因通过碳源进行转录调节，表明它编码结合复合物的调节亚基。 HAP4 的序列显示出一个高酸性区域，删除后该区域会导致蛋白质失活。用 GAL4 的激活结构域替换该区域恢复了活性，表明它为结合的 HAP2/3/4 复合物提供了主要的激活结构域。
The CYC1 gene of Saccharomyces cerevisiae is positively regulated by the HAP2 and HAP3 proteins, which form a heteromeric complex that binds to a CCAAT box in the upstream activation site, UAS2, and which activate transcription in a nonfermentable carbon source. We carried out a genetic analysis to identify additional trans-acting regulatory factors exerting their effects through UAS2. We present the identification and characterization of a new locus, HAP4, which is shown to encode a subunit of the DNA-binding complex at UAS2. In the hap4 mutant, the binding of HAP2 and HAP3 (HAP2/3) is not observed in vitro. The HAP4 gene is regulated transcriptionally by a carbon source, suggesting that it encodes a regulatory subunit of the bound complex . The sequence of HAP4 show a highly acidic region, which inactivated the protein when deleted. Replacement of this region with the activation domain of GAL4 restored activity, suggesting that it provides the principal activation domain to the bound HAP2/3/4 complex.