title: Multiple roles of the furrow deepening Ca2+ transient during cytokinesis in zebrafish embryos.
abstract: The generation of a required series of localized Ca(2+) transients during cytokinesis in zebrafish embryos suggests that Ca(2+) plays a necessary role in regulating this process. Here, we report that cortical actin remodeling, characterized by the reorganization of the contractile band and the formation during furrow deepening of pericleavage F-actin enrichments (PAEs), requires a localized increase in intracellular Ca(2+), which is released from IP(3)-sensitive stores. We demonstrate that VAMP-2 vesicle fusion at the deepening furrow also requires Ca(2+) released via IP(3) receptors, as well as the presence of PAEs and the action of calpains. Finally, by expressing a dominant-negative form of the kinesin-like protein, kif23, we demonstrate that its recruitment to the furrow region is required for VAMP-2 vesicle transport; and via FRAP analysis, that kif23 localization is also Ca(2+)-dependent. Collectively, our data demonstrate that a localized increase in intracellular Ca(2+) is involved in regulating several key events during furrow deepening and subsequent apposition.
authors.affiliation: Department of Biology, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong.
authors.forename: Wai Ming
authors.initials: WM
authors.lastname: Li
authors.forename: Sarah E
authors.initials: SE
authors.lastname: Webb
authors.forename: Ching Man
authors.initials: CM
authors.lastname: Chan
authors.forename: Andrew L
authors.initials: AL
authors.lastname: Miller
mesh_terms: D000199:Actins / Q000378:metabolism; D000818:Animals; D002118:Calcium / Q000502:physiology*; D048749:Cytokinesis / Q000502:physiology*; D004625:Embryo, Nonmammalian / Q000166:cytology / Q000502:physiology*; D047108:Embryonic Development; D017930:Genes, Reporter; D007150:Immunohistochemistry; D007700:Kinetics; D010957:Plasmids; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D015027:Zebrafish / Q000196:embryology*
chemical_list: D000199:Actins; D011993:Recombinant Fusion Proteins; D002118:Calcium