The transcriptional activities of p53 and its homologue p51/p63: similarities and differences.
p51/p63 is a novel p53 homologue that has been shown to act as a transcriptional activator through the p53-binding sequence of the p21/WAF1 promoter and to induce apoptosis when it is expressed transiently in a human tumor cell line. We developed transcription assay systems for these two related genes in both Saccharomyces cerevisiae and mammalian cells and used them to investigate the functional similarities and differences of these genes. We found that p51/p63 trans-activated the previously identified p53 target genes, but the degree of the transactivation by p51/p63 differed from that by p53. These results suggest that the cellular signal on p51/p63 cross-talks partially but not completely with that of the p53 pathway.
Shimada
A
A
Department of Clinical Oncology, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan.
Kato
S
S
Enjo
K
K
Osada
M
M
Ikawa
Y
Y
Kohno
K
K
Obinata
M
M
Kanamaru
R
R
Ikawa
S
S
Ishioka
C
C
D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins / Q000235:genetics; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000502:physiology*; D015966:Gene Expression Regulation, Fungal; D015972:Gene Expression Regulation, Neoplastic; D017930:Genes, Reporter; D016147:Genes, Tumor Suppressor; D006801:Humans; D009687:Nuclear Proteins; D010750:Phosphoproteins; D011401:Promoter Regions, Genetic; D011518:Proto-Oncogene Proteins / Q000235:genetics; D019253:Proto-Oncogene Proteins c-bcl-2; D051736:Proto-Oncogene Proteins c-mdm2; D012441:Saccharomyces cerevisiae / Q000235:genetics; D015534:Trans-Activators; D014157:Transcription Factors; D014158:Transcription, Genetic; D015533:Transcriptional Activation; D014407:Tumor Cells, Cultured; D016159:Tumor Suppressor Protein p53 / Q000737:chemistry / Q000502:physiology*; D025521:Tumor Suppressor Proteins; D051028:bcl-2-Associated X Protein
C493956:CDKN1A protein, human; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins; D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D010750:Phosphoproteins; D011518:Proto-Oncogene Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; C115051:TP63 protein, human; D015534:Trans-Activators; D014157:Transcription Factors; D016159:Tumor Suppressor Protein p53; D025521:Tumor Suppressor Proteins; D051028:bcl-2-Associated X Protein; C497206:MDM2 protein, human; D051736:Proto-Oncogene Proteins c-mdm2