Download Olivier THOUMINE Mechanical coupling between N

LABORATOIRE D’OPTIQUE ET BIOSCIENCES
Unité INSERM U1182 - UMR CNRS 7645 - Ecole Polytechnique
Ecole Polytechnique, 91128 Palaiseau cedex
Attention : horaires inhabituels
Jeudi 26 Mars 2015 à 10h30 (au lieu de 11h)
Ecole Polytechnique
Amphithéâtre Pierre CURIE
Olivier THOUMINE
Institut Interdisciplinaire de Neuroscience (IINS), Bordeaux
Mechanical coupling between N-cadherin adhesion and the
actin/myosin cytoskeleton in neuronal motility
To trigger cell motility, forces generated by the cytoskeleton must be transmitted physically to the
external environment through transmembrane adhesion molecules. One model put forward twenty
years ago to describe this process is the molecular clutch by which a modular interface of adaptor
proteins mediates a dynamic mechanical connection between the actin flow and cell adhesion
complexes. Recent optical imaging experiments have identified key clutch molecules linked to
specific chemical and mechanical signal transduction pathways, particularly regarding integrins in
migrating cells, IgCAMs in neuronal growth cones, and cadherins at intercellular junctions
(Giannone et al., Trends Cell Biol 2009).
In this talk, I will show examples of clutch-like mechanisms between the actin flow and N-cadherin
adhesions in neuronal motile structures. Two structures will be considered: i) growth cones
migrating on N-cadherin coated substrates, and ii) dendritic filopodia making cadherin-dependent
contacts with axons. In both cases, engagement of cadherin adhesions slow down the actin flow,
allowing migration and/or enlargement of the structure. I will show live imaging data (Single
Molecule Tracking, Fluorescence Recovery After Photobeaching) on actin, α-catenin, and Ncadherin molecules fused to fluorescent proteins and expressed in neurons. I will present ways to
quantify protein diffusion, flow, and turnover, as well as computer simulations to interpret the data
(Chazeau et al., Mol Biol Cell, 2015; Garcia et al., in revision).
Renseignements complémentaires
Antigoni ALEXANDROU – Tel : 01 69 33 50 04 - e.mail: [email protected]
http://www.lob.polytechnique.fr/seminaires.htm
Si vous souhaitez recevoir cette annonce par courrier électronique, écrivez à [email protected]