RELATIVE CONTRIBUTIONS OF MCM1 AND STE12 TO TRANSCRIPTIONAL ACTIVATION OF A-SPECIFIC AND ALPHA-SPECIFIC GENES FROM SACCHAROMYCES-CEREVISIAE
RELATIVE CONTRIBUTIONS OF MCM1 AND STE12 TO TRANSCRIPTIONAL ACTIVATION OF A-SPECIFIC AND ALPHA-SPECIFIC GENES FROM SACCHAROMYCES-CEREVISIAE
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DOI：
10.1007/bf00259671
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发表时间：
1991-06-01
期刊：
影响因子：
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通讯作者：
SPRAGUE, GF
中科院分区：
文献类型：
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作者：
HWANGSHUM, JJ;HAGEN, DC;SPRAGUE, GF
我们通过使用 STE2 5'-非编码区的 367 bp 片段驱动报告基因 lacZ 基因的表达，检查了 MCM1 和 STE12 对 a 特异性 STE2 基因转录的相对贡献。 MCM1结合位点的突变破坏了MCM1。 α-2 介导的α细胞抑制并显着降低细胞中的表达。细胞暴露于信息素会高度刺激残余表达。同样，STE12 功能的丧失减少了野生型 STE2 片段驱动的 lacZ 表达。在 MCM1 和 STE12 功能均缺失的情况下，没有观察到残留表达。因此，STE2 片段似乎包含两种不同的上游激活序列 (UAS)，一种负责未受信息素刺激的细胞中的大部分表达，另一种负责在信息素刺激后表达增加。为了进一步支持这一观点，化学合成的 STE2 MCM1 结合位点具有 UAS 活性，但该活性既不受信息素刺激，也没有在 ste12 突变体中降低。尽管α特异性基因的转录也需要MCM1和STE12，但这些基因与α特异性基因的不同之处在于它们具有单一的、依赖MCM1的UAS系统。来自 α 特异性 STE3 基因的最小 26 bp UAS 的活性既受到信息素的刺激，又在 ste12 突变体中降低。这些数据表明，α 特异性基因 STE12 和 MCM1 通过单个 UAS 发挥作用。
We have examined the relative contributions of MCM1 and STE12 to the transcription of the a-specific STE2 gene by using a 367 bp fragment from the STE2 5'-noncoding region to drive expression of a reporter lacZ gene. Mutation of the MCM1 binding site destroyed MCM1 . alpha-2-mediated repression in alpha-cells and dramatically reduced expression in a cells. The residual expression was highly stimulated by exposure of cells to pheromone. Likewise, the loss of STE12 function reduced lacZ expression driven by the wild-type STE2 fragment. In the absence of both MCM1 and STE12 functions, no residual expression was observed. Thus, the STE2 fragment appears to contain two distinct upstream activation sequences (UASs), one that is responsible for the majority of expression in cells not stimulated by pheromone, and one that is responsible for increased expression upon pheromone stimulation. In further support of this idea, a chemically synthesized version of the STE2 MCM1 binding site had UAS activity, but the activity was neither stimulated by pheromone nor reduced in ste12 mutants. Although transcription of alpha-specific genes also requires both MCM1 and STE12, these genes differ from a-specific genes in that they have a single, MCM1-dependent UAS system. The activity of the minimal 26 bp UAS from the alpha-specific STE3 gene was both stimulated by pheromone and reduced in ste12 mutants. These data suggest that at alpha-specific genes STE12 and MCM1 exert their effects through a single UAS.