Event Date
MIC 291: Selected Topics in Microbiology
Work in Progress Seminars
Presented by Dyche Mullins, Ph.D., Professor and Chair of Cellular and Molecular Pharmacology, Howard Hughes Medical Institute Investigator, University of California, San Francisco School of Medicine
Dr. Mullins presents: "From Solution to Surface to Filament: Actin Network Assembly is a Romance of Many Dimensions”
About the seminar: Most actin filaments are created at membrane surfaces where their rapid assembly can generate pushing forces that support many cellular processes. Despite the biological importance of actin filament assembly in branched networks, we have long lacked realistic, quantitative models to describe how this process works in living cells or even within complex, reconstituted systems in vitro. A common assumption is that elongation of cellular actin filaments mirrors that of purified actin in vitro, where the major mode of filament elongation is rapid, diffusion-limited binding of soluble ATP-actin monomers and/or profilin-ATP-actin complexes to free barbed ends. At least three additional factors affect the rate of filament elongation in cells: (i) physical forces, (ii) the activity of actin polymerases, and (iii) the dissociation of profilin from barbed ends. Using a combination of in vitro biochemical and biophysical studies, together with cell biology, mathematical theory and numerical simulation, we can now accurately describe how membrane surfaces accelerate filament assembly via clustering of proteins that bind actin monomers and/or profilin-actin complexes.
Please contact Dr. Arthur Charles-Orszag (acharlesorszag@ucdavis.edu ) or Amanda Huang (amnhuang@ucdavis.edu ) for any questions.