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TZID:Europe/Paris
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BEGIN:VEVENT
UID:1-119@lptms.universite-paris-saclay.fr
DTSTART:20130419T140000Z
DTEND:20130419T140000Z
DTSTAMP:20130421T053955Z
URL:http://www.lptms.universite-paris-saclay.fr/seminars/physics-biology-i
 nterface-seminar-emanuele-helfer/
SUMMARY:Physics-Biology interface seminar: Emmanuèle Helfer - Amphi BLANDI
 N du LPS de la Faculté des Sciences d’Orsay (Bâtiment 510) - 19 Avr 13
  14:00
DESCRIPTION:Polymerization of actin branched networks controls the organiza
 tion of WASH domains at the surface of endosomes\nEmmanuèle Helfer (Labor
 atoire d'Enzymologie et de Biochimie Structurales - Gif-sur-Yvette)\nSorti
 ng of cargoes in endosomes occurs through their selective enrichment into 
 sorting platforms\, where transport intermediates are generated. The WASH 
 complex\, which is recruited from the cytosol to endosomes\, activates the
  Arp2/3 complex and hence actin polymerization onto such sorting platforms
 .\nHere\, we analyzed the role of actin polymerization in the physiology o
 f endosomal domains containing WASH using quantitative image analysis. Usi
 ng a novel colocalization method that is insensitive to the heterogeneity 
 of size and shape of endosomes\, we show that preventing the generation of
  branched actin networks induces endosomal accumulation of the WASH comple
 x. Moreover\, we found that actin depolymerization induces a dramatic decr
 ease in the recovery of endosomal WASH after photobleaching. These results
  suggest a built-in turnover\, where the actin network\, i.e. the product 
 of the WASH complex\, contributes to the dynamic cytosol/endosome exchange
  of the WASH complex. Our data also suggest a role of actin in the lateral
  compartmentalization of endosomes: discrete WASH domains coalesce upon ac
 tin depolymerization or Arp2/3 depletion. Thus\, branched actin networks a
 re involved in the regulation of WASH domain size.\nI will finally discuss
  the potential role of lipid repartitioning in these sorting platforms and
  of the ensuing line tension that could develop at the domain boundary. Th
 is may provide a dynamin-independent contribution to membrane scission.\n
LOCATION:Amphi BLANDIN du LPS de la Faculté des Sciences d’Orsay (Bâtim
 ent 510)\, 15 Rue Georges Clemenceau\, orsay\, France
GEO:48.698187;2.181768
X-APPLE-STRUCTURED-LOCATION;VALUE=URI;X-ADDRESS=15 Rue Georges Clemenceau\,
  orsay\, France;X-APPLE-RADIUS=100;X-TITLE=Amphi BLANDIN du LPS de la Facu
 lté des Sciences d’Orsay (Bâtiment 510):geo:48.698187,2.181768
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