[CANCELLED] FIP Seminar: Super-resolution light microscopy of the FtsZ ring in bacterial cell division
Wednesday, April 5, 2017
12:00 pm - 1:00 pm
Hudson Hall 125
Dr. Harold P. Erickson - Professor, Department of Cell Biology, Duke University
The bacterial tubulin homolog FtsZ forms a ring around the center of bacteria. At cytokinesis this Z ring constricts to pinch the bacterium in two. FtsZ assembles in vitro into protofilaments ~5 nm in diameter and 100-200 nm long. The Z ring is thought to be assembled from these pfs, but there are two conflicting models for how they are arranged. One model proposes that the pfs are attached by lateral bonds to make a ribbon 3-5 pfs wide. The other proposes that the pfs are more widely scattered on the membrane and mostly not in contact with each other. Several published PALM studies have reported the width of the Z ring to be from 70 to 110 nm wide. This favors the scattered model, because the ribbon model would only be 15-25 nm wide. I will review these published studies and suggest that their resolution is worse than they think. I will present new PALM data from our own collaboration with Drs. Cathy and Jim Galbraith, OHSU. Dr. Erickson's research has focused on cytoskeleton and extracellular matrix. His early cytoskeletal interest was microtubules, but when FtsZ was discovered to be a bacterial homolog of tubulin he began studying its assembly and role in bacterial cytokinesis. He has had a long interest in electron microscopy, and more recently an interest in super-resolution light microscopy.