title: Evidence for the interaction of the regulatory protein Ki-1/57 with p53 and its interacting proteins.
abstract: Ki-1/57 is a cytoplasmic and nuclear phospho-protein of 57 kDa and interacts with the adaptor protein RACK1, the transcription factor MEF2C, and the chromatin remodeling factor CHD3, suggesting that it might be involved in the regulation of transcription. Here, we describe yeast two-hybrid studies that identified a total of 11 proteins interacting with Ki-1/57, all of which interact or are functionally associated with p53 or other members of the p53 family of proteins. We further found that Ki-1/57 is able to interact with p53 itself in the yeast two-hybrid system when the interaction was tested directly. This interaction could be confirmed by pull down assays with purified proteins in vitro and by reciprocal co-immunoprecipitation assays from the human Hodgkin analogous lymphoma cell line L540. Furthermore, we found that the phosphorylation of p53 by PKC abolishes its interaction with Ki-1/57 in vitro.
authors.affiliation: Centro de Biologia Molecular Estrutural, Laboratório Nacional de Luz Síncrotron, Rua Giuseppe Máximo Scolfaro 10.000, C.P. 6192, 13084-971 Campinas, SP, Brazil.
authors.forename: Flávia C
authors.initials: FC
authors.lastname: Nery
authors.forename: Edmilson
authors.initials: E
authors.lastname: Rui
authors.forename: Taís M
authors.initials: TM
authors.lastname: Kuniyoshi
authors.forename: Jörg
authors.initials: J
authors.lastname: Kobarg
mesh_terms: D000818:Animals; D002460:Cell Line; D002522:Chlorocebus aethiops; D004271:DNA, Fungal / Q000378:metabolism; D015971:Gene Expression Regulation, Enzymologic; D015966:Gene Expression Regulation, Fungal; D006801:Humans; D017730:Ki-1 Antigen / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D008970:Molecular Weight; D011485:Protein Binding; D011994:Recombinant Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic / Q000235:genetics; D015533:Transcriptional Activation / Q000235:genetics; D016159:Tumor Suppressor Protein p53 / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D020798:Two-Hybrid System Techniques; D001616:beta-Galactosidase / Q000378:metabolism
chemical_list: D004271:DNA, Fungal; D017730:Ki-1 Antigen; D011994:Recombinant Proteins; D016159:Tumor Suppressor Protein p53; D001616:beta-Galactosidase