The Arp2/3 activator WASH controls the fission of endosomes through a large multiprotein complex.
The Arp2/3 complex generates branched actin networks when activated by Nucleation Promoting Factors (NPFs). Recently, the WASH family of NPFs has been identified, but its cellular role is unclear. Here, we show that WASH generates an actin network on a restricted domain of sorting and recycling endosomes. We found that WASH belongs to a multiprotein complex containing seven subunits, including the heterodimer of capping protein (CP). In vitro, the purified WASH complex activates Arp2/3-mediated actin nucleation and binds directly to liposomes. WASH also interacts with dynamin. WASH depletion gives rise to long membrane tubules pulled out from endosomes along microtubules, as does dynamin inhibition. Accordingly, WASH is required for efficient transferrin recycling. Together, these data suggest that the WASH molecular machine, integrating CP with a NPF, controls the fission of endosomes through an interplay between the forces generated by microtubule motors and actin polymerization.
Derivery
Emmanuel
E
Institut Curie, Centre de Recherche, 75248 Paris Cedex 05, France.
Sousa
Carla
C
Gautier
Jérémie J
JJ
Lombard
Bérangère
B
Loew
Damarys
D
Gautreau
Alexis
A
D051344:Actin Capping Proteins / Q000378:metabolism; D051377:Actin-Related Protein 2 / Q000378:metabolism*; D051378:Actin-Related Protein 3 / Q000378:metabolism*; D000199:Actins / Q000378:metabolism; D000818:Animals; D002460:Cell Line; D011992:Endosomes / Q000378:metabolism*; D006801:Humans; D051379:Mice; D008869:Microtubule-Associated Proteins / Q000235:genetics / Q000378:metabolism*; D055503:Protein Multimerization; D021381:Protein Transport
D051344:Actin Capping Proteins; D051377:Actin-Related Protein 2; D051378:Actin-Related Protein 3; D000199:Actins; C495927:Actr2 protein, mouse; C495929:Actr3 protein, mouse; D008869:Microtubule-Associated Proteins