title: p53 and E2F-1 cooperate to mediate apoptosis.
abstract: The tumor-suppressor protein p53 appears to function at the G1 phase of the cell cycle as a checkpoint in response to DNA damage. Mutations in the p53 gene lead to an increased rate of genomic instability and tumorigenesis. The E2F-1 transcription factor is a protein partner of the retinoblastoma-susceptibility gene product, RB. E2F-1 appears to function as a positive regulator or signal for entry into S phase. To explore possible interactions of p53 and E2F-1 in the cell cycle, a human E2F-1 expression plasmid was introduced into a murine cell line containing a temperature-sensitive p53 allele which produces a p53 protein in the wild-type conformation at 32 degrees C and the mutant form at 37.5 degrees C. Coexpression of the wild-type p53 protein and E2F-1 in these cells resulted in a rapid loss of cell viability through a process of apoptosis. Thus, the cell cycle utilizes an interacting or communicative pathway between RB-E2F-1 and p53.
authors.affiliation: Department of Molecular Biology, Princeton University, NJ 08544-1014.
authors.forename: X
authors.initials: X
authors.lastname: Wu
authors.forename: A J
authors.initials: AJ
authors.lastname: Levine
mesh_terms: D017209:Apoptosis; D001483:Base Sequence; D002352:Carrier Proteins; D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins / Q000378:metabolism; D050684:E2F Transcription Factors; D050687:E2F1 Transcription Factor; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides / Q000737:chemistry; D011994:Recombinant Proteins; D056465:Retinoblastoma-Binding Protein 1; D050680:Transcription Factor DP1; D014157:Transcription Factors / Q000502:physiology*; D014162:Transfection; D016159:Tumor Suppressor Protein p53 / Q000502:physiology*
chemical_list: D002352:Carrier Proteins; D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; D050684:E2F Transcription Factors; D050687:E2F1 Transcription Factor; D009838:Oligodeoxyribonucleotides; D011994:Recombinant Proteins; D056465:Retinoblastoma-Binding Protein 1; D050680:Transcription Factor DP1; D014157:Transcription Factors; D016159:Tumor Suppressor Protein p53