ISOLATION OF A HAMSTER CDNA HOMOLOGOUS TO THE MOUSE AND HUMAN CYCLIN KINASE INHIBITORY PROTEIN P27(KIP1)

We report here the isolation, cloning and sequencing of a hamster cDNA homologous to the mouse cyclin kinase inhibitory protein p27(Kip1). T he full length hamster cDNA sequence (p30(Kip1))(5) revealed 91% simil arity with the previously reported mouse and human cDNAs and coded for a protein of 198 amino acids, results which were very similar to that observed for the mouse and human protein. Western blotting analysis p erformed using a polyclonal antibody against a mouse cyclin kinase inh ibitory protein, p27(Kip1), revealed the presence of a strongly reacti ve protein band at 30 kDa (as opposed to 27 kDa in mouse and human cel ls) in cell lysate prepared from rat and hamster cells. Although the s ize of the cyclin kinase inhibitory protein cDNA transcript is similar in mouse and hamster it is likely that the differential mobility of t he hamster p30(Kip1) protein compared to the mouse and human p27(Kip1) protein could be due to post-translational modifications.