Identification of a p130 domain mediating interactions with cyclin A/cdk 2 and cyclin E/cdk 2 complexes.
P130 shares structural and functional homology with pRb and p107. One property common to p107 and p130, but not to pRb, is the ability to stably interact with cyclin A/cdk2 and cyclin E/cdk2 complexes in vitro and in vivo. Using GST-p130 fusion proteins representing various regions of p130, baculovirus-produced cyclin A/cdk2 and cyclin E/cdk2 complexes were found to interact with residues within a part of p130 known as the spacer region. Cyclin E was able to bind the p130 spacer region in the presence or absence of cdk2 whereas cyclin A binding was dependent upon the presence of cdk2. The smallest p130 fusion protein sufficient to interact with cyclin A/cdk2 or cyclin E/cdk2 complexes contained p130 amino acids 652-698 and deletion of p130 amino acids 680-682 abolished binding to both of the cyclin/cdk2 complexes. When overexpressed in C33A cells, a p130 mutant containing a deletion of amino acids 620-697 was unable to form complexes with either cyclin A or cyclin E. This p130 mutant was at least as active as wild type p130 in suppressing the growth of G418 resistant colonies when overexpressed in C33A or SAOS-2 cells.
Lacy
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Institute for Molecular Biology and Biotechnology, McMaster University, Hamilton, Ontario, Canada.
Whyte
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D042846:CDC2-CDC28 Kinases; D051357:Cyclin-Dependent Kinase 2; D018844:Cyclin-Dependent Kinases / Q000378:metabolism*; D016213:Cyclins / Q000378:metabolism*; D006801:Humans; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism; D010446:Peptide Fragments / Q000378:metabolism; D010449:Peptide Mapping; D010750:Phosphoproteins / Q000235:genetics* / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D011506:Proteins; D011994:Recombinant Proteins / Q000378:metabolism; D050720:Retinoblastoma-Like Protein p107; D050717:Retinoblastoma-Like Protein p130; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D014407:Tumor Cells, Cultured
D016213:Cyclins; D009687:Nuclear Proteins; D010446:Peptide Fragments; D010750:Phosphoproteins; D011506:Proteins; C493844:RBL1 protein, human; C493837:RBL2 protein, human; D011994:Recombinant Proteins; D050720:Retinoblastoma-Like Protein p107; D050717:Retinoblastoma-Like Protein p130; D017346:Protein Serine-Threonine Kinases; D042846:CDC2-CDC28 Kinases; C495894:CDK2 protein, human; D051357:Cyclin-Dependent Kinase 2; D018844:Cyclin-Dependent Kinases