POSITIVE REGULATION OF GENERAL TRANSCRIPTION FACTOR SIII BY A TAILED UBIQUITIN HOMOLOG
POSITIVE REGULATION OF GENERAL TRANSCRIPTION FACTOR SIII BY A TAILED UBIQUITIN HOMOLOG
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DOI：
10.1073/pnas.92.16.7172
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发表时间：
1995-08-01
影响因子：
11.1
通讯作者：
CONAWAY, JW
中科院分区：
文献类型：
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作者：
GARRETT, KP;ASO, T;CONAWAY, JW
通用转录因子SIII是一种由110 kDa(P110)、18 kDa(P18)和15 kDa(P15)亚基组成的杂三聚体，通过抑制DNA模板上多个位置的聚合酶的短暂停顿来提高RNA聚合酶II的转录催化速率。在这里，我们报道了SIII p18亚基的分子克隆和生化特性，该亚基被发现是泛素同源(UBH)基因家族的成员，具有SIII正调控亚基的功能。P18是由一个84个残基的N端UBH结构域和34个残基的C端尾融合而成的118个氨基酸组成的蛋白质。机制研究表明，p18在SIIIp110和p15亚基所固有的基础水平上激活SIII转录活性。综上所述，这些发现确立了p18在调节RNA聚合酶II延伸复合体的活性中的作用，并揭示了UBH结构域蛋白在转录调节中的功能。
General transcription factor SIII, a heterotrimer composed of 110-kDa (p110), 18-kDa (p18), and 15-kDa (p15) subunits, increases the catalytic rate of transcribing RNA polymerase II by suppressing transient pausing by polymerase at multiple sites on DNA templates. Here we report molecular cloning and biochemical characterization of the SIII p18 subunit, which is found to be a member of the ubiquitin homology (UbH) gene family and functions as a positive regulatory subunit of SIII. p18 is a 118-amino acid protein composed of an 84-residue N-terminal UbH domain fused to a 34-residue C-terminal tail. Mechanistic studies indicate that p18 activates SIII transcriptional activity above a basal Level inherent in the SIII p110 and p15 subunits. Taken together, these findings establish a role for p18 in regulating the activity of the RNA polymerase II elongation complex, and they bring to light a function for a UbH domain protein in transcriptional regulation.