Insights into Regulation of Transcription Elongation from Bacteriophage Lambda
Transcription elongation is a critical stage in the regulation of gene expression. In the first instance, the rate of elongation is modulated along genes by devices that coordinate the production of a transcript with its utilization by cellular processes. Perhaps the most dramatic regulation occurs at transcription pauses and termination sites, where elongation stops altogether until a controlling event intercedes; for example, a major such control point occurs in eukaryotic transcription close to the promoter. Bacteriophage lambda is the original model for elongation control; its genes N and Q specify transcription antiterminators that invoke expression of targeted sets of genes. The relative simplicity of the bacterial system allows fundamental and universal principles of transcription control to be discovered. The speaker will describe studies of lambda Q protein that illuminate the process of factor-induced pausing, the role of intrinsic sequences in transcription pausing, and the role of pausing and anti-pausing in antiterminator function.
About the speaker
Prof. Jeffrey Roberts received his PhD in Biophysics from Harvard University in 1970. He was a National Science Foundation postdoctoral fellow at the MRC Laboratory of Molecular Biology from 1970 to 1971. He returned to Harvard as a junior fellow of the Society of Fellows in 1971. He joined Cornell University in 1974, and is currently Robert J. Appel Professor of Molecular and Genetics.
Prof. Roberts conducts research in fundamental mechanisms of gene expression, continuing a tradition of studying simple microbiological models that derives from the origins of molecular biology and molecular genetics. His primary subject is the activity of transcription antiterminators, regulatory proteins that affect the ability of RNA polymerase to recognize transcription terminators. He also studies the nature of promoter recognition by initiation factors, in particular the mechanism by which sigma factors recognize and mediate melting of promoter sequences.
Prof. Roberts is a Member of the US National Academy of Sciences, and Fellow of the American Academy of Arts and Sciences and the American Academy of Microbiology.