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MCEF, the newest member of the AF4 family of transcription factors involved in leukemia, is a positive transcription elongation factor-b-associated protein

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Journal of Biomedical Science

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 epitopetagged 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.

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Authors and Affiliations

  1. Departments of Biochemistry and Cell Biology, Baylor College of Medicine, Houston, Tex., USA

    Jun Qin

  2. Division of Clinical Virology, F68, Karolinska Institutet, Huddinge University Hospital, Stockholm, Sweden

    Mojgan H. Naghavi & Anders Vahlne

  3. Department of Chemistry, Biology and Chemical Engineering, Ryerson University, Toronto, Canada

    Mario Clemente Estable

  4. Laboratory of Biochemistry and Molecular Biology, The Rockefeller University, 10021, New York, NY, USA

    Mario Clemente Estable, Hiroyuki Kato, Hua Xiao & Robert G. Roeder

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  1. Mario Clemente Estable
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  2. Mojgan H. Naghavi
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  3. Hiroyuki Kato
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  4. Hua Xiao
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  5. Jun Qin
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  6. Anders Vahlne
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  7. Robert G. Roeder
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Estable, M.C., Naghavi, M.H., Kato, H. et al. MCEF, the newest member of the AF4 family of transcription factors involved in leukemia, is a positive transcription elongation factor-b-associated protein. J Biomed Sci 9, 234–245 (2002). https://doi.org/10.1007/BF02256070

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  • DOI: https://doi.org/10.1007/BF02256070

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