title: Accumulation of a form of p27(Kip1) not associated with Cdk-cyclin complexes in transforming growth factor-beta-arrested Mv1Lu cells.
abstract: The p27(Kip1) cyclin-dependent kinase inhibitor translocates in response to transforming growth factor-beta to a Cdk2-cyclin E complex inhibiting its catalytic activity, but the p27(Kip1) protein levels are unaffected [1]. We show here that transforming growth factor-beta induces the accumulation of a form of p27(Kip1) representing a subpopulation of total p27(Kip1) in growth-arrested Mv1Lu epithelial cells. The inducible p27(Kip1) is detectable only by a specific p27(Kip1) monoclonal antibody recognizing a native form of p27(Kip1). The increase in this subset of p27(Kip1) correlates with G(1) arrest and withdrawal of the cells from the cycle induced by transforming growth factor-beta, serum starvation, or contact inhibition. In contrast to the majority of p27(Kip1) in the cells, the transforming growth factor-beta-inducible p27(Kip1) is devoid of cyclin-dependent kinase/cyclin interactions. The results indicate that growth arresting treatments induce the accumulation of non-cyclin-dependent kinase-bound p27(Kip1), which may function as a reservoir for inhibition of Cdk2-cyclin E activities.
authors.affiliation: Department of Virology, University of Helsinki, Helsinki, FIN-00014, Finland.
authors.forename: M
authors.initials: M
authors.lastname: Taipale
authors.forename: E
authors.initials: E
authors.lastname: Tiihonen
authors.forename: A
authors.initials: A
authors.lastname: Heiskanen
authors.forename: M
authors.initials: M
authors.lastname: Laiho
mesh_terms: D016475:3T3 Cells; D000818:Animals; D000911:Antibodies, Monoclonal; D000918:Antibody Specificity; D042846:CDC2-CDC28 Kinases; D018797:Cell Cycle Proteins; D002467:Cell Nucleus / Q000201:enzymology; D019927:Cyclin E / Q000378:metabolism*; D051357:Cyclin-Dependent Kinase 2; D051358:Cyclin-Dependent Kinase 4; D051361:Cyclin-Dependent Kinase 6; D050760:Cyclin-Dependent Kinase Inhibitor p27; D018844:Cyclin-Dependent Kinases / Q000235:genetics / Q000378:metabolism*; D004847:Epithelial Cells / Q000166:cytology* / Q000201:enzymology; D016193:G1 Phase / Q000187:drug effects / Q000502:physiology; D015971:Gene Expression Regulation, Enzymologic; D006801:Humans; D051379:Mice; D008869:Microtubule-Associated Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D008907:Mink; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism*; D011518:Proto-Oncogene Proteins; D012333:RNA, Messenger / Q000032:analysis; D020545:Respiratory Mucosa / Q000166:cytology / Q000201:enzymology; D016196:S Phase / Q000187:drug effects / Q000502:physiology; D014162:Transfection; D016212:Transforming Growth Factor beta / Q000494:pharmacology*; D025521:Tumor Suppressor Proteins
chemical_list: D000911:Antibodies, Monoclonal; C493961:Cdkn1b protein, mouse; D018797:Cell Cycle Proteins; D019927:Cyclin E; D008869:Microtubule-Associated Proteins; D011518:Proto-Oncogene Proteins; D012333:RNA, Messenger; D016212:Transforming Growth Factor beta; D025521:Tumor Suppressor Proteins; D050760:Cyclin-Dependent Kinase Inhibitor p27; D017346:Protein Serine-Threonine Kinases; D042846:CDC2-CDC28 Kinases; C495894:CDK2 protein, human; C495900:CDK4 protein, human; C495911:CDK6 protein, human; C495893:Cdk2 protein, mouse; C495902:Cdk4 protein, mouse; C495912:Cdk6 protein, mouse; D051357:Cyclin-Dependent Kinase 2; D051358:Cyclin-Dependent Kinase 4; D051361:Cyclin-Dependent Kinase 6; D018844:Cyclin-Dependent Kinases