CIP4 coordinates with phospholipids and actin-associated proteins to localize to the protruding edge and produce actin ribs and veils

• DOI: 10.1242/jcs.117473
• Publication Date: 2013-04-10T02:19:09Z
• Authors: Witchuda Saengsawang; Kendra L. Taylor; Derek C. Lumbard; Kelly Mitok; Amanda Price; Lauren Pietila; Timothy M. Gomez; Erik W. Dent
• Keywords: Lamellipodium; Filopodia; Formins; Pseudopodia; Cytochalasin D; CDC42; Actin remodeling; MDia1

CIP4, a member of the F-BAR family proteins, plays important roles in variety cellular events by regulating both membrane and actin dynamics. In many cell types CIP4 functions vesicle formation, endocytosis tubulation. However, recent data indicate that is also involved protrusion some types, including cancer cells (lamellipodia invadopodia) neurons (ribbed lamellipodia veils). neurons, localizes specifically to extending protrusions limit neurite outgrowth early development. The mechanism which protruding edge induces lamellipodial/veil rib formation not known. Here we show localization dependent on phospholipid content plasma underlying organization filaments. Inhibiting phosphatidylinositol 3,4,5-trisphosphate (PIP3) production decreases at membrane. Rac1/WAVE1, rather than Cdc42/N-WASP. Capping filaments with low concentrations cytochalasin D or overexpressing capping protein dramatically edge, while inactivating Arp2/3 drives edge. We demonstrate dynamically co-localizes Ena/VASP DAAM1, two proteins known induce unbranched filament arrays play neuronal Together, this first study an depends architecture phospholipids developing neurons.