Model of the reciprocal regulatory mechanisms between dynamin and actin during CME.

<p>(A) During the early stages of CME dynamin has a transient association with the CCS which is modulated by the GTPase cycle (inset 1). As the CCS grows actin is recruited possibly generating auxiliary force to drive invagination. Dynamin regulates the rate of actin recruitment, in a mechanism that is dependent on it GTPase cycle (inset 2). The growth of dendritic actin networks around the clathrin bud form a scaffold that stabilizes dynamin and N-BAR proteins at the constricted neck of deeply invaginated CCS (inset 3). The coordinated recruitment of dynamin, actin, and N-BAR proteins promotes the efficient catalysis of membrane scission and the release the CCV into the lumen of the cell. The catalysis of scission also leads to the termination of actin polymerization and the breakdown the dendritic actin network. (B and C) Schematic of the dynamin/actin (B) and N-BAR/GAK recruitment profiles (C). We inferred (in absence of suitable measurements) where stages 1–3 (inset 1–3 from (A)) were relative to each profile.