SPN1, a conserved gene identified by suppression of a postrecruitment-defective yeast TATA-binding protein mutant.
SPN1, a conserved gene identified by suppression of a postrecruitment-defective yeast TATA-binding protein mutant.
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SPN1，一种通过抑制招募后缺陷型酵母 TATA 结合蛋白突变体而鉴定的保守基因。
DOI：
10.1093/genetics/162.4.1605
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发表时间：
2002
期刊：
影响因子：
3.3
通讯作者：
Stargell,LaurieA
中科院分区：
文献类型：
--
作者：
Fischbeck,JulieA;Kraemer,SusanM;Stargell,LaurieA
尽管一些TBP突变体表现出招募后缺陷，但对TATA结合蛋白（TBP）在招募到TATA元件后的功能知之甚少。在这里，我们描述了招募后缺陷TBP等位基因的抑制基因筛选。抑制是通过先前未表征的酿酒酵母基因SPN1（抑制招募后功能基因编号1）的单点突变实现的。spn1是酵母的一个重要基因，在整个进化过程中高度保守。抑制突变inspn1在192位（spn1K192N）用天冬酰胺代替不变赖氨酸。espn1k192菌株能够抑制具有招募后缺陷的TBP等位基因，但不能抑制招募后胜任的TBP等位基因。此外，Spn1p在体内不稳定地与tfiid1结合。含有espn1k192等位基因的细胞表现出温度敏感的表型和激活转录的一些缺陷，而在突变背景下，组成型转录似乎相对强劲。与在募集后功能中的重要作用一致，来自cyc1启动子的转录在1k192n细胞中得到增强，该转录受到募集后机制的调节。此外，我们发现spn1是esptgene家族的成员，进一步支持了在转录过程中对espn1基因产物的功能需求。
Little is known about TATA-binding protein (TBP) functions after recruitment to the TATA element, although several TBP mutants display postrecruitment defects. Here we describe a genetic screen for suppressors of a postrecruitment-defective TBP allele. Suppression was achieved by a single point mutation in a previously uncharacterizedSaccharomyces cerevisiaegene,SPN1(suppressespostrecruitment functions genenumber1).SPN1is an essential yeast gene that is highly conserved throughout evolution. The suppressing mutation inSPN1substitutes an asparagine for an invariant lysine at position 192 (spn1K192N). Thespn1K192Nstrain is able to suppress additional alleles of TBP that possess postrecruitment defects, but not a TBP allele that is postrecruitment competent. In addition, Spn1p does not stably associate with TFIIDin vivo. Cells containing thespn1K192Nallele exhibit a temperature-sensitive phenotype and some defects in activated transcription, whereas constitutive transcription appears relatively robust in the mutant background. Consistent with an important role in postrecruitment functions, transcription from theCYC1promoter, which has been shown to be regulated by postrecruitment mechanisms, is enhanced inspn1K192Ncells. Moreover, we find thatSPN1is a member of theSPTgene family, further supporting a functional requirement for theSPN1gene product in transcriptional processes.