Section of Molecular Biology, University of California at San Diego, La Jolla, California 92093, USA.
Genes Dev. 2010 Sep 15;24(18):2013-8. doi: 10.1101/gad.1951110. Epub 2010 Aug 27.
The TCT motif (polypyrimidine initiator) encompasses the transcription start site of nearly all ribosomal protein genes in Drosophila and mammals. The TCT motif is required for transcription of ribosomal protein gene promoters. The TCT element resembles the Inr (initiator), but is not recognized by TFIID and cannot function in lieu of an Inr. However, a single T-to-A substitution converts the TCT element into a functionally active Inr. Thus, the TCT motif is a novel transcriptional element that is distinct from the Inr. These findings reveal a specialized TCT-based transcription system that is directed toward the synthesis of ribosomal proteins.
TCT 基序（多嘧啶起始子）包含了果蝇和哺乳动物中几乎所有核糖体蛋白基因的转录起始位点。TCT 基序是核糖体蛋白基因启动子转录所必需的。TCT 元件类似于 Inr（起始子），但不被 TFIID 识别，不能替代 Inr 发挥作用。然而，单个 T 到 A 的替换将 TCT 元件转化为具有功能活性的 Inr。因此，TCT 基序是一种与 Inr 不同的新型转录元件。这些发现揭示了一种专门针对核糖体蛋白合成的基于 TCT 的转录系统。
