PUBLICATION
Regulation of polymerase II transcription by 7SK snRNA: two distinct RNA elements direct P-TEFb and HEXIM1 binding
- Authors
- Egloff, S., Van Herreweghe, E., and Kiss, T.
- ID
- ZDB-PUB-090318-1
- Date
- 2006
- Source
- Molecular and cellular biology 26(2): 630-642 (Journal)
- Registered Authors
- Keywords
- none
- MeSH Terms
-
- 3' Flanking Region
- 5' Flanking Region
- Base Sequence
- Cell Line
- Conserved Sequence
- Humans
- Molecular Sequence Data
- Nucleic Acid Conformation
- Phosphorylation
- Positive Transcriptional Elongation Factor B/genetics
- Positive Transcriptional Elongation Factor B/metabolism*
- Protein Binding
- RNA Polymerase II/genetics
- RNA Polymerase II/metabolism*
- RNA, Small Nuclear/genetics*
- RNA-Binding Proteins/genetics
- RNA-Binding Proteins/metabolism*
- Transcriptional Activation*
- PubMed
- 16382153 Full text @ Mol. Cell. Biol.
Citation
Egloff, S., Van Herreweghe, E., and Kiss, T. (2006) Regulation of polymerase II transcription by 7SK snRNA: two distinct RNA elements direct P-TEFb and HEXIM1 binding. Molecular and cellular biology. 26(2):630-642.
Abstract
The positive transcription elongation factor b (P-TEFb), a complex of Cdk9 and cyclin T1/T2, stimulates transcription by phosphorylating RNA polymerase II. The 7SK small nuclear RNA, in cooperation with HEXIM1 protein, functions as a general polymerase II transcription regulator by sequestering P-TEFb into a large kinase-inactive 7SK/HEXIM1/P-TEFb complex. Here, determination and characterization of the functionally essential elements of human 7SK snRNA directing HEXIM1 and P-TEFb binding led to a new model for the assembly of the 7SK/HEXIM1/P-TEFb regulatory complex. We demonstrate that two structurally and functionally distinct protein binding elements located in the 5'- and 3'-terminal hairpins of 7SK support the in vivo recruitment of HEXIM1 and P-TEFb. Consistently, a minimal regulatory RNA composed of the 5' and 3' hairpins of 7SK can modulate polymerase II transcription in HeLa cells. HEXIM1 binds independently and specifically to the G24-C48/G60-C87 distal segment of the 5' hairpin of 7SK. Binding of HEXIM1 is a prerequisite for association of P-TEFb with the G302-C324 apical region of the 3' hairpin of 7SK that is highly reminiscent of the human immunodeficiency virus transactivation-responsive RNA.
Genes / Markers
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Orthology
Engineered Foreign Genes
Mapping