title: Calcium, calmodulin, and CaMKII requirement for initiation of centrosome duplication in Xenopus egg extracts.
abstract: Aberrant centrosome duplication is observed in many tumor cells and may contribute to genomic instability through the formation of multipolar mitotic spindles. Cyclin-dependent kinase 2 (Cdk2) is required for multiple rounds of centrosome duplication in Xenopus egg extracts but not for the initial round of replication. Egg extracts undergo periodic oscillations in the level of free calcium. We show here that chelation of calcium in egg extracts or specific inactivation of calcium/calmodulin-dependent protein kinase II (CaMKII) blocks even initial centrosome duplication, whereas inactivation of Cdk2 does not. Duplication can be restored to inhibited extracts by addition of CaMKII and calmodulin. These results indicate that calcium, calmodulin, and CaMKII are required for an essential step in initiation of centrosome duplication. Our data suggest that calcium oscillations in the cell cycle may be linked to centrosome duplication.
authors.affiliation: Howard Hughes Medical Institute and Department of Pharmacology, University of Colorado School of Medicine, Denver, CO 80262, USA.
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Matsumoto
authors.forename: James L
authors.initials: JL
authors.lastname: Maller
mesh_terms: D000818:Animals; D042846:CDC2-CDC28 Kinases; D002118:Calcium / Q000378:metabolism*; D020013:Calcium Signaling; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D002147:Calmodulin / Q000378:metabolism* / Q000494:pharmacology; D002457:Cell Extracts; D018385:Centrosome / Q000378:metabolism*; D002614:Chelating Agents / Q000494:pharmacology; D019927:Cyclin E; D051357:Cyclin-Dependent Kinase 2; D018844:Cyclin-Dependent Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D004533:Egtazic Acid / Q000031:analogs & derivatives* / Q000494:pharmacology; D004625:Embryo, Nonmammalian / Q000166:cytology / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005455:Fluorescent Antibody Technique; D006493:Heparin / Q000494:pharmacology; D008870:Microtubules / Q000378:metabolism / Q000648:ultrastructure; D010063:Ovum / Q000378:metabolism; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D016196:S Phase; D014981:Xenopus; D029867:Xenopus Proteins / Q000378:metabolism
chemical_list: D002147:Calmodulin; D002457:Cell Extracts; D002614:Chelating Agents; D019927:Cyclin E; D004791:Enzyme Inhibitors; D029867:Xenopus Proteins; D004533:Egtazic Acid; D006493:Heparin; D017346:Protein Serine-Threonine Kinases; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D042846:CDC2-CDC28 Kinases; C495891:Cdk2 protein, Xenopus; D051357:Cyclin-Dependent Kinase 2; D018844:Cyclin-Dependent Kinases; C025603:1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid; D002118:Calcium