title: Cloning and characterization of rat p27Kip1, a cyclin-dependent kinase inhibitor.
abstract: Cyclin-dependent kinase (Cdk) inhibitors play significant roles in the cell cycle control of various biological phenomena. To characterize the role of Cdk inhibitors in rat cells, we isolated a cDNA encoding rat p27Kip1, a 27-kDa Cdk inhibitor. The 1.04-kb cDNA of rat p27 contained an open reading frame of 197 amino acids that shared high homology with mammalian p27 and significant homology with mammalian p21Cip1 and p57Kip2. p27 mRNA was detected in most rat tissues and cell lines. The levels of p27 protein expression were similar in rat cell lines transformed by E1A and in normal cells. Rat p27 was able to interact with Cdk 2/4 and cyclin A/D in rat cells, but the amounts of rat p27 in Cdk2 complexes were different between transformed cells and normal cells. Thus, the formation of stable complexes of rat p27 may be modulated by E1A. Rat p27 protein could inhibit the increased Cdk2-associated kinase activity in transformed rat cells.
authors.affiliation: Department of Laboratory Medicine, Miyazaki Medical College, Kiyotake, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Nomura
authors.forename: Y
authors.initials: Y
authors.lastname: Sawada
authors.forename: K
authors.initials: K
authors.lastname: Fujinaga
authors.forename: S
authors.initials: S
authors.lastname: Ohtaki
mesh_terms: D017500:Adenovirus E1A Proteins / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D015152:Blotting, Northern; D015153:Blotting, Western; D042846:CDC2-CDC28 Kinases; D018797:Cell Cycle Proteins; D002460:Cell Line; D003001:Cloning, Molecular; D051357:Cyclin-Dependent Kinase 2; D050760:Cyclin-Dependent Kinase Inhibitor p27; D018844:Cyclin-Dependent Kinases / Q000037:antagonists & inhibitors* / Q000378:metabolism; D016213:Cyclins / Q000378:metabolism; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D004791:Enzyme Inhibitors / Q000737:chemistry; D005786:Gene Expression Regulation; D006801:Humans; D008869:Microtubule-Associated Proteins / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism / Q000494:pharmacology; D008969:Molecular Sequence Data; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors* / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017386:Sequence Homology, Amino Acid; D014170:Transformation, Genetic / Q000235:genetics; D025521:Tumor Suppressor Proteins
chemical_list: D017500:Adenovirus E1A Proteins; C493962:Cdkn1b protein, rat; D018797:Cell Cycle Proteins; D016213:Cyclins; D018076:DNA, Complementary; D004791:Enzyme Inhibitors; D008869:Microtubule-Associated Proteins; D012333:RNA, Messenger; D025521:Tumor Suppressor Proteins; D050760:Cyclin-Dependent Kinase Inhibitor p27; D017346:Protein Serine-Threonine Kinases; D042846:CDC2-CDC28 Kinases; C495894:CDK2 protein, human; C495892:Cdk2 protein, rat; D051357:Cyclin-Dependent Kinase 2; D018844:Cyclin-Dependent Kinases