title: CP110 cooperates with two calcium-binding proteins to regulate cytokinesis and genome stability.
abstract: The centrosome is an integral component of the eukaryotic cell cycle machinery, yet very few centrosomal proteins have been fully characterized to date. We have undertaken a series of biochemical and RNA interference (RNAi) studies to elucidate a role for CP110 in the centrosome cycle. Using a combination of yeast two-hybrid screens and biochemical analyses, we report that CP110 interacts with two different Ca2+-binding proteins, calmodulin (CaM) and centrin, in vivo. In vitro binding experiments reveal a direct, robust interaction between CP110 and CaM and the existence of multiple high-affinity CaM-binding domains in CP110. Native CP110 exists in large (approximately 300 kDa to 3 MDa) complexes that contain both centrin and CaM. We investigated a role for CP110 in CaM-mediated events using RNAi and show that its depletion leads to a failure at a late stage of cytokinesis and the formation of binucleate cells, mirroring the defects resulting from ablation of either CaM or centrin function. Importantly, expression of a CP110 mutant unable to bind CaM also promotes cytokinesis failure and binucleate cell formation. Taken together, our data demonstrate a functional role for CaM binding to CP110 and suggest that CP110 cooperates with CaM and centrin to regulate progression through cytokinesis.
authors.affiliation: Department of Pathology, New York University School of Medicine, New York, NY 10016, USA.
authors.forename: William Y
authors.initials: WY
authors.lastname: Tsang
authors.forename: Alexander
authors.initials: A
authors.lastname: Spektor
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Luciano
authors.forename: Vahan B
authors.initials: VB
authors.lastname: Indjeian
authors.forename: Zhihong
authors.initials: Z
authors.lastname: Chen
authors.forename: Jeffery L
authors.initials: JL
authors.lastname: Salisbury
authors.forename: Irma
authors.initials: I
authors.lastname: Sánchez
authors.forename: Brian David
authors.initials: BD
authors.lastname: Dynlacht
mesh_terms: D002135:Calcium-Binding Proteins / Q000378:metabolism*; D002147:Calmodulin / Q000378:metabolism; D018797:Cell Cycle Proteins / Q000378:metabolism*; D048749:Cytokinesis; D015870:Gene Expression; D042822:Genomic Instability; D006367:HeLa Cells; D006801:Humans; D008869:Microtubule-Associated Proteins / Q000172:deficiency / Q000378:metabolism*; D008970:Molecular Weight; D046912:Multiprotein Complexes / Q000378:metabolism; D009154:Mutation / Q000235:genetics; D010641:Phenotype; D010750:Phosphoproteins / Q000172:deficiency / Q000378:metabolism*; D011123:Polyploidy; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D021381:Protein Transport; D034622:RNA Interference
chemical_list: C467559:CCP110 protein, human; D002135:Calcium-Binding Proteins; D002147:Calmodulin; D018797:Cell Cycle Proteins; D008869:Microtubule-Associated Proteins; D046912:Multiprotein Complexes; D010750:Phosphoproteins