RNA 聚合酶 III 从类型 3 启动子转录起始
中文名称
通路描述
具有动物特异性类型的 3 个启动子，以人类 U6 启动子为例，招募一种称为 snRNA 激活蛋白复合物（SNAPc）（Sadowski et al., 1993）、PSE 结合蛋白（PBP）（Waldschmidt et al., 1991）或 PSE 转录因子（PTF）（Murphy et al., 1992）的复合物。该复合物包含五种亚基，并结合 PSE。类型 3 启动子还通过 SNAPc 与 Brf2-TFIIIB 的蛋白质 - 蛋白质接触以及 Brf2-TFIIIB 的 TBP 组分与 TATA 框的直接结合，招募 RNA 聚合酶 III。类型 3 启动子的下游元件（DSE），它增强核心启动子的转录，几乎总是包含八聚体序列和 SPH 元件（也称为 NONOCT 元件）（Cheung et al., 1993; Danzeiser et al., 1993; Kunkel et al., 1996; Myslinski et al., 1992）。八聚体序列招募 POU 结构域蛋白 Oct-1（Herr et al., 1988; Sturm et al., 1988），SPH 元件招募一种称为 Staf 或 SPH 结合因子（SBF）的锌指蛋白，该蛋白已从人类克隆（Myslinski et al., 1998; Rincon et al., 1998）。
英文描述
RNA Polymerase III Transcription Initiation From Type 3 Promoter The metazoan-specific type 3 promoters, which are exemplified by the human U6 promoter, recruit a complex variously called the snRNA activating protein complex (SNAPc) (Sadowski et al., 1993), the PSE binding protein (PBP) (Waldschmidt et al., 1991), or the PSE transcription factor (PTF) (Murphy et al., 1992). The complex contains five types of subunits and binds to the PSE. Type 3 promoters also recruit Brf2-TFIIIB through a combination of protein-protein contacts with SNAPc and a direct association of the TBP component of Brf2-TFIIIB with the TATA box. This then allows RNA polymerase III to join the complex.The down stream element (DSE) of type 3 promoters, which enhances transcription from the core promoter, almost invariably contains an octamer sequence and an SPH element (also called NONOCT element)(Cheung et al., 1993; Danzeiser et al., 1993; Kunkel et al., 1996; Myslinski et al., 1992). The octamer sequence recruits the POU domain protein Oct-1 (Herr et al., 1988; Sturm et al., 1988), and the SPH element recruits a zinc finger protein known as Staf or SPH binding factor (SBF), which has been cloned from humans (Myslinski et al., 1998; Rincon et al., 1998).
所含基因
28 个基因