CHARACTERIZATION OF HIR1 AND HIR2, 2 GENES REQUIRED FOR REGULATION OF HISTONE GENE-TRANSCRIPTION IN SACCHAROMYCES-CEREVISIAE
CHARACTERIZATION OF HIR1 AND HIR2, 2 GENES REQUIRED FOR REGULATION OF HISTONE GENE-TRANSCRIPTION IN SACCHAROMYCES-CEREVISIAE
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DOI：
10.1128/mcb.13.1.28
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发表时间：
1993-01-01
影响因子：
5.3
通讯作者：
OSLEY, MA
中科院分区：
文献类型：
--
作者：
SHERWOOD, PW;TSANG, SVM;OSLEY, MA
HIR 1和HIR 2基因的产物在遗传学上被定义为S.啤酒。任何一个基因的突变都会影响四个组蛋白基因位点中三个的细胞周期调控;这些位点的转录发生在整个细胞周期中，并且不再因DNA复制的抑制而受到抑制。相同的突变也消除了组蛋白H2 A和H2 B对HTA 1-HTB 1基因座的自体调节。HIR 1和HIR 2基因已被分离，其在HTA 1-HTB 1基因座的转录调控中的作用已被表征。这两个基因都不编码必需蛋白，并且无效等位基因降低HTA 1-HTB 1转录。两个HIR基因在导致HTA 1基因阻遏或去阻遏的条件下组成型表达，并且两个基因都不调节另一个基因的表达。HIR 1基因的序列预测了一个88 kDa的蛋白质，该蛋白质具有在视网膜转导素的G（β）亚基和酵母转录抑制因子Tup 1中发现的三个重复基序。HIR 2基因的序列预测了98 kDa的蛋白质。两种基因产物都含有核靶向信号，并且Hir 2蛋白定位于细胞核中。
The products of the HIR1 and HIR2 genes have been defined genetically as repressors of histone gene transcription in S. cerevisiae. A mutation in either gene affects cell cycle regulation of three of the four histone gene loci; transcription of these loci occurs throughout the cell cycle and is no longer repressed in response to the inhibition of DNA replication. The same mutations also eliminate autogenous regulation of the HTA1-HTB1 locus by histones H2A and H2B. The HIR1 and HIR2 genes have been isolated, and their roles in the transcriptional regulation of the HTA1-HTB1 locus have been characterized. Neither gene encodes an essential protein, and null alleles derepress HTA1-HTB1 transcription. Both HIR genes are expressed constitutively under conditions that lead to repression or derepression of the HTA1 gene, and neither gene regulates the expression of the other. The sequence of the HIR1 gene predicts an 88-kDa protein with three repeats of a motif found in the G(beta) subunit of retinal transducin and in a yeast transcriptional repressor, Tup1. The sequence of the HIR2 gene predicts a protein of 98 kDa. Both gene products contain nuclear targeting signals, and the Hir2 protein is localized in the nucleus.