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PRODID:UW-Madison-Physics-Events
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SEQUENCE:0
UID:UW-Physics-Event-1151
DTSTART:20080508T150000Z
DURATION:PT1H0M0S
DTSTAMP:20260422T215803Z
LAST-MODIFIED:20080407T171711Z
LOCATION:5310 Chamberlin
SUMMARY:Force-Producing Machines in Living Cells\, R. G. Herb Condense
 d Matter Seminar\, Ben OShaughnessy\, Columbia University
DESCRIPTION:Living cells exert force in many basic processes. Forces c
 leave the mother cell into two daughters during cytokinesis in cell di
 vision\, enable rigidity sensing in cell growth and differentiation\, 
 apply traction during cell migration and stimulate extracellular matri
 x reorganization during wound healing. For these and many other purpos
 es cells assemble and operate complex multiprotein cytoskeletal machin
 es. I will discuss assembly and function of contractile cellular machi
 nes built from actin filaments\, force-producing myosin motor proteins
  and other components. (1) How are these machines assembled? We studie
 d the contractile cytokinetic ring in fission yeast using time-resolve
 d quantitative confocal microscopy and computer simulations. Assembly 
 occurs via a remarkably stochastic "search\, capture\, pull and releas
 e" mechanism whereby ~63 membrane-bound precursor nodes are condensed 
 into a continuous ring when node-bound myosins pull on transient formi
 n-nucleated node-node actin connectors. (2) How do the machines work? 
  We discuss stress fibers\, possibly the most accessible cellular cont
 ractile force-producing machines. We quantitatively modeled their kine
 tics as dramatically revealed by two recent experimental studies.
URL:https://www.physics.wisc.edu/events/?id=1151
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