Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
34
pubmed:dateCreated
2005-8-22
pubmed:abstractText
The positive transcription elongation factor (P-TEFb) comprises a kinase, CDK9, and a Cyclin T1 or T2. Its activity is inhibited by association with the HEXIM1 or HEXIM2 protein bound to 7SK small nuclear RNA. HEXIM1 and HEXIM2 were found to form stable homo- and hetero-oligomers. Using yeast two-hybrid and transfection assays, we have now shown that the C-terminal domains of HEXIM proteins directly interact with each other. Hydrodynamic parameters measured by glycerol gradient ultracentrifugation and gel-permeation chromatography demonstrate that both purified recombinant and cellular HEXIM1 proteins form highly anisotropic particles. Chemical cross-links suggest that HEXIM1 proteins form dimers. The multimeric nature of HEXIM1 is maintained in P-TEFb.HEXIM1.7SK RNA complexes. Multiple P-TEFb modules are found in the inactive P-TEFb.HEXIM1.7SK complexes. It is proposed that 7SK RNA binding to a HEXIM1 multimer promotes the simultaneous recruitment and hence inactivation of multiple P-TEFb units.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/CCNT1 protein, human, http://linkedlifedata.com/resource/pubmed/chemical/Cross-Linking Reagents, http://linkedlifedata.com/resource/pubmed/chemical/Cyclin T, http://linkedlifedata.com/resource/pubmed/chemical/Cyclins, http://linkedlifedata.com/resource/pubmed/chemical/Glycerol, http://linkedlifedata.com/resource/pubmed/chemical/HEXIM1 protein, human, http://linkedlifedata.com/resource/pubmed/chemical/HEXIM2 protein, human, http://linkedlifedata.com/resource/pubmed/chemical/Positive Transcriptional..., http://linkedlifedata.com/resource/pubmed/chemical/RNA, http://linkedlifedata.com/resource/pubmed/chemical/RNA-Binding Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Recombinant Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Ribonucleoproteins, Small Nuclear
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
26
pubmed:volume
280
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
30619-29
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed-meshheading:15994294-Anisotropy, pubmed-meshheading:15994294-Centrifugation, Density Gradient, pubmed-meshheading:15994294-Cross-Linking Reagents, pubmed-meshheading:15994294-Cyclin T, pubmed-meshheading:15994294-Cyclins, pubmed-meshheading:15994294-Dimerization, pubmed-meshheading:15994294-Glycerol, pubmed-meshheading:15994294-HeLa Cells, pubmed-meshheading:15994294-Humans, pubmed-meshheading:15994294-Immunoprecipitation, pubmed-meshheading:15994294-Plasmids, pubmed-meshheading:15994294-Positive Transcriptional Elongation Factor B, pubmed-meshheading:15994294-Protein Binding, pubmed-meshheading:15994294-Protein Structure, Tertiary, pubmed-meshheading:15994294-RNA, pubmed-meshheading:15994294-RNA-Binding Proteins, pubmed-meshheading:15994294-Recombinant Proteins, pubmed-meshheading:15994294-Ribonucleoproteins, Small Nuclear, pubmed-meshheading:15994294-Transcription, Genetic, pubmed-meshheading:15994294-Two-Hybrid System Techniques, pubmed-meshheading:15994294-Ultracentrifugation
pubmed:year
2005
pubmed:articleTitle
Transcription-dependent association of multiple positive transcription elongation factor units to a HEXIM multimer.
pubmed:affiliation
Unite Mixte de Recherche 8541 CNRS, Ecole Normale Supérieure, Laboratoire de Régulation de l'Expression Génétique, 75230 Paris Cedex 05, France.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't