title: Modulation of calcium signalling by the actin-binding protein cofilin.
abstract: Cofilin is a small protein that belongs to the family of actin-depolymerizing factors (ADF). The main cellular function of cofilin is to change cytoskeletal dynamics and thus to modulate cell motility and cytokinesis. We have recently demonstrated that the actin cytoskeleton is involved in the modulation of Ca(2+) signalling in starfish oocytes. To extend these observations, we have explored whether cofilin influences Ca(2+) signalling in the oocytes. Here we show that microinjection of the functionally active cofilin alters the Ca(2+) signalling mediated by the three major second messengers, InsP(3), NAADP, and cADPr. Cofilin intensifies the Ca(2+) signals induced by InsP(3) and NAADP, and delays those induced by cADPr. Furthermore, the injection of cofilin increases the Ca(2+) signals during hormone-induced oocyte maturation and fertilization. The results suggest that the dynamic regulation of F-actin by its binding proteins may play an important role in the modulation of intracellular Ca(2+) signalling.
authors.affiliation: Cell Signalling Laboratory, Stazione Zoologica Anton Dohrn Villa Comunale, I-80121 Naples, Italy.
authors.forename: Gilda A
authors.initials: GA
authors.lastname: Nusco
authors.forename: Jong Tai
authors.initials: JT
authors.lastname: Chun
authors.forename: Emanuela
authors.initials: E
authors.lastname: Ercolano
authors.forename: Dmitry
authors.initials: D
authors.lastname: Lim
authors.forename: Gianni
authors.initials: G
authors.lastname: Gragnaniello
authors.forename: Keiichiro
authors.initials: K
authors.lastname: Kyozuka
authors.forename: Luigia
authors.initials: L
authors.lastname: Santella
mesh_terms: D051339:Actin Depolymerizing Factors / Q000378:metabolism* / Q000494:pharmacology; D000199:Actins / Q000378:metabolism; D000818:Animals; D020013:Calcium Signaling / Q000187:drug effects; D036563:Cyclic ADP-Ribose / Q000378:metabolism; D007295:Inositol Phosphates / Q000378:metabolism; D009249:NADP / Q000031:analogs & derivatives / Q000378:metabolism; D009865:Oocytes / Q000378:metabolism; D013215:Starfish
chemical_list: D051339:Actin Depolymerizing Factors; D000199:Actins; D007295:Inositol Phosphates; D036563:Cyclic ADP-Ribose; D009249:NADP; C024376:NAADP; C058097:inositol 1,3,4-trisphosphate