scholarly journals Polo-Like Kinase 1 Inhibits the Activity of Positive Transcription Elongation Factor of RNA Pol II b (P-TEFb)

PLoS ONE ◽  
2013 ◽  
Vol 8 (8) ◽  
pp. e72289 ◽  
Author(s):  
Liangzhen Jiang ◽  
Yan Huang ◽  
Min Deng ◽  
Ting Liu ◽  
Wenbin Lai ◽  
...  
Keyword(s):  
Transcription Elongation ◽  
Elongation Factor ◽  
Rna Pol Ii ◽  
Pol Ii ◽  
Positive Transcription Elongation Factor ◽  
Transcription Elongation Factor

scholarly journals Positive Transcription Elongation Factor b Phosphorylates hSPT5 and RNA Polymerase II Carboxyl-terminal Domain Independently of Cyclin-dependent Kinase-activating Kinase

2001 ◽  
Vol 276 (15) ◽  
pp. 12317-12323 ◽  
Author(s):  
Jae B. Kim ◽  
Phillip A. Sharp
Keyword(s):  
Human Immunodeficiency Virus ◽  
Rna Polymerase ◽  
Elongation Factor ◽  
Rna Pol Ii ◽  
Factor B ◽  
Pol Ii ◽  
Positive Transcription Elongation Factor ◽  
Transcription Elongation Factor ◽  
Immunodeficiency Virus ◽  
Carboxyl Terminal

The CDK9-cyclin T kinase complex, positive transcription elongation factor b (P-TEFb), stimulates the process of elongation of RNA polymerase (Pol) II during transcription of human immunodeficiency virus. P-TEFb associates with the human immunodeficiency virus Tat protein and with the transactivation response element to form a specific complex, thereby mediating efficient elongation. Here, we show that P-TEFb preferentially phosphorylates hSPT5 as compared with the carboxyl-terminal domain of RNA Pol IIin vitro. Phosphorylation of hSPT5 by P-TEFb occurred on threonine and serine residues in its carboxyl-terminal repeat domains. In addition, we provide several lines of evidence that P-TEFb is a CDK-activating kinase (CAK)-independent kinase. For example, CDK9 was not phosphorylated by CAK, whereas CDK2-cyclin A kinase activity was dramatically enhanced by CAK. Therefore, it is likely that P-TEFb participates in regulation of elongation by RNA Pol II by phosphorylation of its substrates, hSPT5 and the CTD of RNA Pol II, in a CAK-independent manner.

scholarly journals JMJD6 cleaves MePCE to release positive transcription elongation factor b (P-TEFb) in higher eukaryotes

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Schuyler Lee ◽  
Haolin Liu ◽  
Ryan Hill ◽  
Chunjing Chen ◽  
Xia Hong ◽  
...  
Keyword(s):  
Rna Polymerase Ii ◽  
Transcription Elongation ◽  
Elongation Factor ◽  
Factor B ◽  
Pol Ii ◽  
Positive Transcription Elongation Factor ◽  
Transcription Elongation Factor ◽  
Higher Eukaryotes

More than 30% of genes in higher eukaryotes are regulated by promoter-proximal pausing of RNA polymerase II (Pol II). Phosphorylation of Pol II CTD by positive transcription elongation factor b (P-TEFb) is a necessary precursor event that enables productive transcription elongation. The exact mechanism on how the sequestered P-TEFb is released from the 7SK snRNP complex and recruited to Pol II CTD remains unknown. In this report, we utilize mouse and human models to reveal methylphosphate capping enzyme (MePCE), a core component of the 7SK snRNP complex, as the cognate substrate for Jumonji domain-containing 6 (JMJD6)’s novel proteolytic function. Our evidences consist of a crystal structure of JMJD6 bound to methyl-arginine, enzymatic assays of JMJD6 cleaving MePCE in vivo and in vitro, binding assays, and downstream effects of Jmjd6 knockout and overexpression on Pol II CTD phosphorylation. We propose that JMJD6 assists bromodomain containing 4 (BRD4) to recruit P-TEFb to Pol II CTD by disrupting the 7SK snRNP complex.

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