Saltzman A G, Weinmann R
Wistar Institute, Philadelphia, Pennsylvania 19104.
FASEB J. 1989 Apr;3(6):1723-33. doi: 10.1096/fasebj.3.6.2649403.
RNA polymerase II is a multisubunit enzyme involved in the transcription of protein encoding genes. Recently acquired knowledge of the transcription process and of the RNA polymerase molecule as well as the isolation of subunit clones have led to a better understanding of the enzyme's functional regulation. Specific transcription initiation occurs at promoter regions located upstream of the gene and requires a minimum of five basic factors in addition to the enzyme. Furthermore, proteins that bind to specific DNA elements within the promoter also regulate transcriptional activity. Additional factors are required for the elongation and, possibly, termination of transcription. Two elongation factors, SII and TFIIF, interact directly with the RNA polymerase II molecule. Functional domains of RNA polymerase II have been determined by analysis of genomic clones for the two largest subunits of the enzyme. For example, the 240-kDa largest subunit contains a highly phosphorylated carboxyl-terminal heptapeptide domain repeated 26-52 times that is absolutely required for transcription in vivo. Analysis of the polymerase molecule and its interaction with basic gene-specific transcription factors will aid in our studies of the control of gene expression.
RNA聚合酶II是一种参与蛋白质编码基因转录的多亚基酶。最近获得的关于转录过程和RNA聚合酶分子的知识，以及亚基克隆的分离，使人们对该酶的功能调节有了更好的理解。特异性转录起始发生在基因上游的启动子区域，除该酶外还至少需要五种基本因子。此外，与启动子内特定DNA元件结合的蛋白质也调节转录活性。转录的延伸和可能的终止还需要其他因子。两种延伸因子SII和TFIIF直接与RNA聚合酶II分子相互作用。RNA聚合酶II的功能结构域已通过对该酶两个最大亚基的基因组克隆分析得以确定。例如，240 kDa的最大亚基包含一个高度磷酸化的羧基末端七肽结构域，重复26 - 52次，这是体内转录绝对必需的。对聚合酶分子及其与基本基因特异性转录因子相互作用的分析将有助于我们对基因表达调控的研究。
