Kuhlman T C, Cho H, Reinberg D, Hernandez N
Graduate Program in Molecular and Cellular Pharmacology, State University of New York at Stony Brook, Stony Brook, New York 11794, USA.
Mol Cell Biol. 1999 Mar;19(3):2130-41. doi: 10.1128/MCB.19.3.2130.
RNA polymerase II transcribes the mRNA-encoding genes and the majority of the small nuclear RNA (snRNA) genes. The formation of a minimal functional transcription initiation complex on a TATA-box-containing mRNA promoter has been well characterized and involves the ordered assembly of a number of general transcription factors (GTFs), all of which have been either cloned or purified to near homogeneity. In the human RNA polymerase II snRNA promoters, a single element, the proximal sequence element (PSE), is sufficient to direct basal levels of transcription in vitro. The PSE is recognized by the basal transcription complex SNAPc. SNAPc, which is not required for transcription from mRNA-type RNA polymerase II promoters such as the adenovirus type 2 major late (Ad2ML) promoter, is thought to recruit TATA binding protein (TBP) and nucleate the assembly of the snRNA transcription initiation complex, but little is known about which GTFs other than TBP are required. Here we show that the GTFs IIA, IIB, IIF, and IIE are required for efficient RNA polymerase II transcription from snRNA promoters. Thus, although the factors that recognize the core elements of RNA polymerase II mRNA and snRNA-type promoters differ, they mediate the recruitment of many common GTFs.
RNA聚合酶II转录编码mRNA的基因以及大多数小核RNA（snRNA）基因。在含TATA框的mRNA启动子上形成最小功能转录起始复合物的过程已得到充分表征，涉及多种通用转录因子（GTF）的有序组装，所有这些转录因子都已被克隆或纯化至近乎均一。在人类RNA聚合酶II的snRNA启动子中，单个元件，即近端序列元件（PSE），足以在体外指导基础水平的转录。PSE被基础转录复合物SNAPc识别。SNAPc对于从mRNA型RNA聚合酶II启动子（如腺病毒2型主要晚期（Ad2ML）启动子）进行转录不是必需的，它被认为可招募TATA结合蛋白（TBP）并启动snRNA转录起始复合物的组装，但对于除TBP之外还需要哪些GTF却知之甚少。在这里，我们表明GTF IIA、IIB、IIF和IIE是snRNA启动子高效进行RNA聚合酶II转录所必需的。因此，尽管识别RNA聚合酶II mRNA和snRNA型启动子核心元件的因子不同，但它们介导了许多常见GTF的招募。
