Multiple roles of the furrow deepening Ca2+ transient during cytokinesis in zebrafish embryos.
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.
Li
Wai Ming
WM
Department of Biology, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong.
Webb
Sarah E
SE
Chan
Ching Man
CM
Miller
Andrew L
AL
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*
D000199:Actins; D011993:Recombinant Fusion Proteins; D002118:Calcium