SUPT5H O00267

转录延伸因子SPT5 (hSPT5) (DRB敏感性诱导因子160 kDa亚基) (DSIF p160) (DRB敏感性诱导因子大亚基) (DSIF大亚基) (Tat共激活因子1蛋白) (Tat-CT1蛋白)

功能描述

DRB敏感性诱导因子复合物（DSIF复合物）的组分，该复合物通过RNA polymerase II调节mRNA加工和转录延伸(PubMed:10075709, PubMed:10199401, PubMed:10421630, PubMed:10757782, PubMed:10912001, PubMed:11112772, PubMed:11553615, PubMed:12653964, PubMed:12718890, PubMed:15136722, PubMed:15380072, PubMed:9450929, PubMed:9857195)。DSIF通过刺激RNGTT/CAP1A的mRNA鸟苷酸转移酶活性，正向调节mRNA加帽(PubMed:10075709, PubMed:10421630, PubMed:10757782, PubMed:10912001, PubMed:11112772, PubMed:11553615, PubMed:12653964, PubMed:12718890, PubMed:15136722, PubMed:15380072, PubMed:9450929, PubMed:9857195)。DSIF还与负延伸因子复合物（NELF复合物）协同作用，增强启动子近端位点的转录暂停(PubMed:10075709, PubMed:10199401, PubMed:10757782, PubMed:10912001, PubMed:11112772, PubMed:11553615, PubMed:12653964, PubMed:12718890, PubMed:15136722, PubMed:15380072, PubMed:9450929, PubMed:9857195)。转录暂停可能促进具有延伸能力的RNA polymerase II复合物的组装(PubMed:10075709, PubMed:10199401, PubMed:10421630, PubMed:10757782, PubMed:10912001, PubMed:11112772, PubMed:11553615, PubMed:12653964, PubMed:12718890, PubMed:15136722, PubMed:15380072, PubMed:9450929, PubMed:9857195)。DSIF和NELF通过抑制转录延伸因子TFIIS/S-II来促进暂停(PubMed:16214896)。TFIIS/S-II在转录暂停位点结合RNA polymerase II，并刺激该酶微弱的内在核酸酶活性(PubMed:16214896)。RNA polymerase II对受阻转录本的切割促进从新的3'末端恢复转录，并可能允许反复尝试转录通过天然暂停位点(PubMed:16214896)。在CDK9磷酸化后，DSIF也可以正向调节转录延伸(PubMed:16427012)。HIV-1核转录激活因子Tat有效激活转录延伸所必需(PubMed:10393184, PubMed:10454543, PubMed:11809800, PubMed:9514752)。DSIF作用于抑制源自HIV-1 LTR的转录本的转录暂停，并阻断HIV-1转录本在终止子序列处的过早释放(PubMed:11112772, PubMed:14701750)。 {ECO:0000269|PubMed:10075709, ECO:0000269|PubMed:10199401, ECO:0000269|PubMed:10393184, ECO:0000269|PubMed:10421630, ECO:0000269|PubMed:10454543, ECO:0000269|PubMed:10757782, ECO:0000269|PubMed:10912001, ECO:0000269|PubMed:11112772, ECO:0000269|PubMed:11553615, ECO:0000269|PubMed:11809800, ECO:0000269|PubMed:12653964, ECO:0000269|PubMed:12718890, ECO:0000269|PubMed:14701750, ECO:0000269|PubMed:15136722, ECO:0000269|PubMed:15380072, ECO:0000269|PubMed:16214896, ECO:0000269|PubMed:16427012, ECO:0000269|PubMed:9450929, ECO:0000269|PubMed:9514752, ECO:0000269|PubMed:9857195}.

组织特异性

Ubiquitously expressed.

亚细胞定位

Nucleus