Cellular stress alters the transcriptional properties of promoter-bound Mot1-TBP complexes
Cellular stress alters the transcriptional properties of promoter-bound Mot1-TBP complexes
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DOI：
10.1016/j.molcel.2004.05.003
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发表时间：
2004-05-21
期刊：
影响因子：
16
通讯作者：
Struhl, K
中科院分区：
文献类型：
--
作者：
Geisberg, JV;Struhl, K
Mot1与转录活性启动子相关，它直接以积极或消极的方式影响转录活性，具体取决于基因。通过连续染色质免疫沉淀确定，当细胞在正常条件下生长时，Mot1与TBP共同占据启动子，但不与TFIIB、TFIIA或POL II共同占据启动子。这强烈表明Mot1-TBP复合体在转录上是不活跃的，因此与转录活跃的TBP形式处于动态平衡。令人惊讶的是，在应对热休克和其他形式的环境胁迫时，Mot1与TFIIB和延伸能力强的POL II共同占据启动子，但不与TFIIA共同占据启动子。这表明功能性预引发复合体在体内可以含有Mot1而不是TFIIA。因此，Mot1-TBP复合体可以以受环境胁迫调节的活性和非活性形式存在。
Mot1 associates with transcriptionally active promoters, and it directly affects transcriptional activity in a positive or negative manner, depending on the gene. As determined by sequential chromatin immunoprecipitation, Mot1 co-occupies promoters with TBP, but not with TFIIB, TFIIA, or Pol II when cells are grown in normal conditions. This strongly suggests that the Mot1-TBP complex is transcriptionally inactive, and hence is in dynamic equilibrium with transcriptionally active forms of TBP. Surprisingly, in response to heat shock and other forms of environmental stress, Mot1 co-occupies promoters with TFIIB and elongation-competent Pol II, but not with TFIIA. This suggests that functional preinitiation complexes can contain Mot1 instead of TFIIA in vivo. Thus, Mot1-TBP complexes can exist in active and inactive forms that are regulated by environmental stress.