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: [log in to unmask]

Web: http://qbmi.msu.edu

http://www.bch.msu.edu/GEDD/index.htm