Pak1 Phosphorylation Enhances Cortactin-N-WASP Interaction in Clathrin-Caveolin-Independent Endocytosis.

Alexandre Grassart (1) , Vannary Meas-Yedid (2) , Alexandre Dufour (2) , Jean-Christophe Olivo-Marin (2) , Alice Dautry-Varsat (1) , Nathalie Sauvonnet (1)

1 Biologie des Interactions Cellulaires
2 AIQ - Analyse d'Images Quantitative

Growing evidence indicates that kinases are central to the regulation of endocytic pathways. Previously, we identified p21-activated kinase 1 (Pak1) as the first specific regulator of clathrin- and caveolae-independent endocytosis used by the interleukin 2 receptor subunit (IL-2R). Here, we address the mechanism by which Pak1 regulates IL-2Rbeta endocytosis. First, we show that Pak1 phosphorylates an activator of actin polymerization, cortactin, on its serine residues 405 and 418. Consistently, we observe a specific inhibition of IL-2Rbeta endocytosis when cells overexpress a cortactin, wherein these serine residues have been mutated. In addition, we show that the actin polymerization enhancer, neuronal Wiskott-Aldrich syndrome protein (N-WASP), is involved in IL-2Rbeta endocytosis. Strikingly, we find that Pak1 phosphorylation of cortactin on serine residues 405 and 418 increases its association with N-WASP. Thus, Pak1, by controlling the interaction between cortactin and N-WASP, could regulate the polymerization of actin during clathrin-independent endocytosis.

Domaines: Biologie cellulaire

Alexandre Grassart, Vannary Meas-Yedid, Alexandre Dufour, Jean-Christophe Olivo-Marin, Alice Dautry-Varsat, et al.. Pak1 Phosphorylation Enhances Cortactin-N-WASP Interaction in Clathrin-Caveolin-Independent Endocytosis.. Traffic, 2010, 11 (8), pp.1079-91. ⟨10.1111/j.1600-0854.2010.01075.x⟩. ⟨pasteur-00502612⟩