Scinderin, a Ca2+-dependent actin filament severing protein that controls cortical actin network dynamics during secretion

Secretory vesicles are localized in specific compartments within neurosecre tory cells. These are different pools in which vesicles are in various stat es of releasability. The transit of vesicles between compartments is contro lled and regulated by Ca2+, scinderin and the cortical F-actin network. Cor tical F-actin disassembly is produced by the filament severing activity of scinderin. This Ca2+-dependent activity of scinderin together with its Ca2-independent actin nucleating activity, control cortical F-actin dynamics d uring the secretory cycle. A good understanding of the interaction of actin with scinderin and of the role of this protein in secretion has been provi ded by the analysis of the molecular structure of scinderin together with t he use of recombinant proteins corresponding to its different domains.