Roles of the actin-binding proteins in intracellular Ca2+   signalling.
Starfish oocytes undergo massive intracellular Ca2+ signalling during meiotic maturation and fertilization. Although the igniting stimulus of Ca2+ mobilization may differ in different cell contexts, its final leverage is usually the Ca2+-releasing second messengers such as InsP3, cADPr and NAADP. The general scheme of intracellular Ca2+ release is that the corresponding receptors for these molecules serve as ion channels to release free Ca2+ from its internal stores such as the lumen of the endoplasmic reticulum. However, a growing body of evidence has suggested that intracellular Ca2+ release can be strongly modulated by the actin cytoskeleton. Although it is known that Ca2+ contributes to remodelling of the actin cytoskeleton, whether the actin cytoskeleton modulates Ca2+ signalling in return has not been much explored. An emerging candidate to answer to this reciprocal causality of Ca2+ and the actin cytoskeleton may be actin-binding proteins. In this review, we discuss how the actin cytoskeleton may fit into the known mechanisms of intracellular Ca2+ release, and propose two models to explain the experimental data.
Chun
J T
JT
Stazione Zoologica Anton Dohrn, Napoli, Italy.
Santella
L
L
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D020013:Calcium Signaling / Q000502:physiology*; D004721:Endoplasmic Reticulum / Q000502:physiology; D008840:Microfilament Proteins / Q000502:physiology*; D009865:Oocytes / Q000502:physiology; D013215:Starfish / Q000502:physiology
D008840:Microfilament Proteins; D002118:Calcium