BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Talks.cam//talks.cam.ac.uk//
X-WR-CALNAME:Talks.cam
BEGIN:VEVENT
SUMMARY:Regulation of actin assembly and mechanotransduction in cell-matri
 x adhesion complexes: a biochemical study of the talin-vinculin complex - 
 Le Clainche\, C (CNRS (Centre National de la Recherche Scientifique))
DTSTART:20151201T110000Z
DTEND:20151201T123000Z
UID:TALK62773@talks.cam.ac.uk
CONTACT:42080
DESCRIPTION:Cell migration is involved in many physiological and pathologi
 cal processes. Force is produced by the growth and the contraction of the 
 actin cytoskeleton (1). To produce force in adherent cells\, these actin n
 etworks must be anchored to the extracellular matrix (ECM) by adhesion com
 plexes (1\,2). These structures contain transmembrane integrins that mecha
 nically couple the ECM to the intracellular actin cytoskeleton via actin b
 inding proteins (ABPs) (2). This system acts as a molecular clutch that co
 ntrols force transmission across adhesion complexes. This molecular clutch
  is a complex interface made of multiple layers of regulated protein-prote
 in interactions (2). The multiple activities of the ABPs present in these 
 structures play a critical role in the dynamics of this interface. In addi
 tion to the control of actin filament binding and polymerization (1-3)\, t
 hese proteins sense and respond to the force applied by the actomyosin cyt
 oskeleton to adjust the anchoring strength (4\,5). Our goal is to determin
 e the molecular mechanisms by which these ABPs cooperate to control the me
 chanical coupling between the actin cytoskeleton and cell-matrix adhesion 
 complexes.\n\nTo study these ABPs\, our laboratory combines the measuremen
 t of actin polymerisation kinetics using fluorescence spectroscopy\, singl
 e actin filament observations using TIRF microscopy and the reconstitution
  of actin-based mechanosensitive processes on micropatterned surfaces. Our
  model system is the mechanosensitive complex made of the two ABPs talin a
 nd vinculin.\n\nOur results showed that vinculin controls actin filament e
 longation (3). More recent results revealed that talin also regulates acti
 n polymerisation in response to integrin binding (unpublished data). In ad
 dition\, we have developed a microscopy assay with pure proteins in which 
 the self-assembly of actomyosin cables controls the association of vinculi
 n to a talin-micropatterned surface in a reversible manner (4\, 5). This i
 n vitro reconstitution revealed the mechanism by which a key mechanosensit
 ive molecular switch senses and controls the connection between adhesion c
 omplexes and the actomyosin cytoskeleton.\n
LOCATION:Seminar Room 2\, Newton Institute Gatehouse
END:VEVENT
END:VCALENDAR