Abstract
Positive transcription elongation factor-b (P-TEFb) contains CDK9 and cyclin T1. P-TEFb was affinity purified from a stably transfected cell line that expresses epitope-tagged CDK9, and proteins that appeared to be specifically bound were sequenced. In addition to CDK9, previously identified isoforms of cyclin T (including T1, T2A and T2B), HSP90 and CDC37, this analysis identified a novel protein named MCEF. Cloning of its cognate cDNA revealed that MCEF is the newest member of the AF4 family of transcription factors involved in acute lymphoblastic leukemia. MCEF RNA was expressed in all human tissues examined, and antisera directed against recombinant MCEF specifically immunoprecipitated P-TEFb. Ectopic expression of MCEF did not activate HIV-1 replication, and tethering of MCEF to a promoter did not activate transcription.
Original language | English (US) |
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Pages (from-to) | 234-245 |
Number of pages | 12 |
Journal | Journal of Biomedical Science |
Volume | 9 |
Issue number | 3 |
DOIs | |
State | Published - 2002 |
Funding
The authors thank M. Guermah, S. Malik and V. Palhan fbr advice throughout this work and S.M., M.G. and M. Teichmann tbr careful reading of the manuscript. M.C.E. is a Fellow of the Canadian Institutes of Health Research (formerly MRC). "['his work was supported by NIH grant AI37327-05 to R.G.R.
Keywords
- CDK9
- HIV
- Leukemia
- Positive transcription elongation factor-b
- Transcription
ASJC Scopus subject areas
- Biochemistry, medical
- Pharmacology (medical)
- Molecular Biology
- Clinical Biochemistry
- Endocrinology, Diabetes and Metabolism
- Cell Biology