List of Events

MRSEC SEMINARS-EVENTS

MRSEC Seminars are normally held at 4:00 p.m. in Abelson 229, unless otherwise noted. Find Abelson-Bass-Yalem building on the interactive map.

September 30, 2016
Room: Abelson 229
Time: 2:30 p.m.
Event: IRG 2
Speaker: Mat Chamberlain, Gelles Lab Grad Student
Title: 
Diversity of transcription elongation complexes from non-equilibrium binding of regulatory proteins
Abstract: In all organisms, the multi-subunit RNA polymerases (RNAPs) that synthesize messenger RNAs bind multiple accessory proteins to regulate elongation rate, transcriptional pausing, and termination.  However, the dynamics of regulatory protein association/dissociation and how different regulators influence one another’s function is unclear.  We used multi-wavelength single-molecule co-localization techniques to directly observe the association dynamics of the elongation regulators NusA and σ70 with E. coli RNAP in vitro. Contrary to previous proposals, NusA could repeatedly bind to and release from elongation complexes (EC) during synthesis of a single RNA.  However, elongation complexes that retained bound σ70 did not bind NusA and the RNAP-bound σ70 could be retained even in the presence of physiological (micromolar) concentrations of competing elongation factors NusA and/or NusG.  Factor occupancy of elongation complexes was non-equilibrium, with significant amounts of σ70ECs even in the absence of free σ70 because dynamics were dominated by slow σ70 dissociation from EC.  The data further demonstrate that same gene is transcribed by at least two different types of complexes with different elongation rates, pausing and termination propensity. These observations suggest that during cellular transcription different non-equilibrium dynamics dictates the composition of ECs whose different functional properties can cause traffic jams, altered pausing, and population shifting at intergenic transcriptional attenuators, all of which potentially allow fine-tuning of gene expression in bacterial cells.








October 14, 2016

Room: Abelson 229
Time: 2:30 p.m.
Event: IRG 1





October 28, 2016
Room: Abelson 229
Time: 2:30 p.m.
Event: IRG 2






October 31, 2016

Room: Abelson 307
Time: 9:30 a.m.
Event: MRSEC Executive Committee






November 11, 2016

Room: Abelson 229
Time: 2:30 p.m.
Event: IRG 1






November 18, 2016

Room: Shapiro Campus Center Multipurpose Room
Time: 11 a.m.
Event: MRSEC Retreat





November 21, 2016

Room: Abelson 307
Time: 9:30 a.m.
Event: MRSEC Executive Committee





November 22, 2016
Room: Abelson 229
Time: 4 p.m.
Event: IRG 2







December 9, 2016

Room: Abelson 229
Time: 2:30 p.m.
Event: IRG 1





December 19, 2016

Room: Abelson 307
Time: 9:30 a.m.
Event: MRSEC Executive Committee





December 20, 2016
Room: Abelson 229
Time: 4 p.m.
Event: IRG 2