Cyclin B1/Cdk1 binds and phosphorylates Filamin A and regulates its ability to cross-link actin.
Substantial actin remodelling occurs prior to mitosis as cells alter their shape in preparation for cytokinesis. In mammalian cells, mitosis is initiated by a heterodimer of cyclin B1 and the cyclin dependent kinase 1 (Cdk1) serine/threonine kinase. In this report. we show that human cyclin B1 binds the actin cross-linking protein Filamin-A (FLNa). The proteins co-immunoprecipitate and co-localize in mitotic human cells. We find that cyclin B1/Cdk1 can phosphorylate FLNa in vitro and reduce its ability to gelate actin. We have also identified serine 1436 as one FLNa residue phosphorylated by cyclin B1/Cdk1 in vitro. Our results suggest a role for cyclin B1/Cdk1 in FLNa-dependent actin remodelling.
Cukier
I Howard
IH
Juravinski Cancer Centre and Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada.
Li
Yun
Y
Lee
Jonathan M
JM
D000199:Actins / Q000378:metabolism*; D000595:Amino Acid Sequence; D016203:CDC2 Protein Kinase / Q000378:metabolism*; D003285:Contractile Proteins / Q000032:analysis / Q000378:metabolism*; D019926:Cyclin B / Q000032:analysis / Q000378:metabolism*; D056744:Cyclin B1; D064448:Filamins; D006801:Humans; D008840:Microfilament Proteins / Q000032:analysis / Q000378:metabolism*; D008969:Molecular Sequence Data; D010766:Phosphorylation; D025941:Protein Interaction Mapping; D012694:Serine / Q000378:metabolism; D020798:Two-Hybrid System Techniques
D000199:Actins; C534699:CCNB1 protein, human; D003285:Contractile Proteins; D019926:Cyclin B; D056744:Cyclin B1; D064448:Filamins; D008840:Microfilament Proteins; D012694:Serine; D016203:CDC2 Protein Kinase