PDF(Pubmed)
Abstract：
The recognition of core promoter sequences by the general transcription factor TFIID is the first step in the process of RNA polymerase II (Pol II) transcription initiation. Metazoan holo-TFIID is composed of the TATA binding protein (TBP) and of 13 TBP associated factors (TAFs). Inducible Taf7 knock out (KO) results in the formation of a Taf7-less TFIID complex, while Taf10 KO leads to serious defects within the TFIID assembly pathway. Either TAF7 or TAF10 depletions correlate with the detected TAF occupancy changes at promoters, and with the distinct phenotype severities observed in mouse embryonic stem cells or mouse embryos. Surprisingly however, under either Taf7 or Taf10 deletion conditions, TBP is still associated to the chromatin, and no major changes are observed in nascent Pol II transcription. Thus, partially assembled TFIID complexes can sustain Pol II transcription initiation, but cannot replace holo-TFIID over several cell divisions and/or development.
摘要：
一般转录因子TFIID对核心启动子序列的识别是RNA聚合酶II（PolII）转录起始过程中的第一步。后生完整-TFIID由TATA结合蛋白（TBP）和13种TBP相关因子（TAF）组成。诱导型Taf7敲除（KO）导致形成无Taf7的TFIID复合物，而Taf10KO导致TFIID组装途径内的严重缺陷。TAF7或TAF10耗尽与启动子处检测到的TAF占用变化相关，在小鼠胚胎干细胞或小鼠胚胎中观察到明显的表型严重性。然而令人惊讶的是,在Taf7或Taf10删除条件下，TBP仍然与染色质有关，在新生的PolII转录中未观察到重大变化。因此，部分组装的TFIID复合物可以维持PolII转录起始，但不能取代holo-TFIID在几个细胞分裂和/或发展。
