Functional dissection of yeast Hir1p, a WD repeat-containing transcriptional corepressor.
Functional dissection of yeast Hir1p, a WD repeat-containing transcriptional corepressor.
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酵母 Hir1p（一种包含 WD 重复序列的转录辅阻遏物）的功能剖析。
DOI：
10.1093/genetics/148.2.657
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发表时间：
1998
期刊：
影响因子：
3.3
通讯作者：
Osley,MA
中科院分区：
文献类型：
--
作者：
DeSilva,H;Lee,K;Osley,MA
HIR 1基因产物需要抑制酿酒酵母中四个组蛋白基因位点中的三个的转录，并且像其对应物HIR 2蛋白一样，它作为转录辅抑制因子发挥作用。虽然Hir 1 p和Hir 2 p在酵母中是物理相关的，但当它被人工募集到组蛋白HTA 1启动子时，Hir 1 p能够独立于Hir 2 p发挥作用。HIR 1的缺失分析揭示了两个独立的抑制结构域：一个在其N末端，其中存在7个β-transducin或WD 40基序拷贝，第二个在剩余的C末端氨基酸中。在hir 1 Δ菌株中WD重复序列的过表达补充了其Hir−表型，而在野生型菌株中C末端的过表达导致了Hir−和Spt−表型。Hir 1 p的C末端在体内与Hir 2 p发生物理相互作用，并且两个Hir 1 p抑制结构域与全长Hir 1 p相互作用。此外，还发现Hir 1 p WD重复序列与SPT 4、SPT 5和SPT 6基因产物在功能上相互作用，这表明这些重复序列可能将Hir 1 p引导至不同的蛋白质复合物。
The HIR1 gene product is required to repress transcription of three of the four histone gene loci in Saccharomyces cerevisiae, and like its counterpart, the HIR2 protein, it functions as a transcriptional corepressor. Although Hir1p and Hir2p are physically associated in yeast, Hir1p is able to function independently of Hir2p when it is artificially recruited to the histone HTA1 promoter. A deletion analysis of HIR1 has revealed two separate repression domains: one in its N terminus, where seven copies of the β-transducin or WD40 motif reside, and the second in the remaining C-terminal amino acids. Overexpression of the WD repeats in a hir1Δ strain complemented its Hir−phenotype, while overexpression of the C terminus in a wild-type strain caused both Hir−and Spt−phenotypes. The Hir1p C terminus physically interacted in vivo with Hir2p, and both Hir1p repression domains interacted with full-length Hir1p. It was additionally found that the Hir1p WD repeats functionally interacted with the SPT4, SPT5, and SPT6 gene products, suggesting that these repeats may direct Hir1p to different protein complexes.