SCIENCE AT THE EDGE SEMINAR
QB/GEDD
Friday, February 18 at 11:30am
Room 1400 Biomedical and Physical Sciences Bldg.
Refreshments at 11:15
Joan Conaway
Stowers Institute for Medical Research, Kansas City, MO
The Mediator of RNA Polymerase II Transcription:
Links to Transcription Elongation and Leukemogenesis
Promoter proximal pausing by initiated RNA polymerase II (Pol II) and regulated release of paused polymerase into productive elongation has emerged as a major mechanism of transcription activation. Reactivation
of paused Pol II has been shown to correlate with recruitment of a so-called Super-Elongation Complex or SEC that contains the transcription elongation factors ELL/EAF and P-TEFb, as well as a collection of additional proteins encoded by genes involved in
translocations with the MLL gene in leukemia. Our lab has recently obtained evidence for a role of human Mediator in recruiting SEC and another ELL/EAF-containing complex to genes. I will present evidence that a conserved N-terminal domain in the Mediator
subunit Med26 provides docking sites for ELL/EAF, P-TEFb, and associated proteins as well as the general initiation factor TFIID. In addition, I will present evidence consistent with the model that Med26 may function as a molecular switch that interacts first
with the Pol II initiation complex through direct interactions with TFIID and then “exchanges” TFIID for complexes containing elongation factors ELL/EAF and P-TEFb to facilitate the transition of Pol II into the elongation stage of transcription.
Helen Geiger
Administrative Assistant
Quantitative Biology Graduate Program/
Gene Expression in Development & Disease
Michigan State University
502B Biochemistry Building
East Lansing, MI 48824
Phone: (517) 432-9895
Fax: (517) 353-9334
E-mail:
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Web: http://qbmi.msu.edu
http://www.bch.msu.edu/GEDD/index.htm