Transcriptional regulation by p53. Functional interactions among multiple regulatory domains.
The tumor suppressor p53 protein possesses activities typical of eukaryotic transcriptional activators; p53 binds to specific DNA sequences and stimulates transcription of the target genes. By a series of deletion and domain-swapping studies, we report here that (i) p53 has two auxiliary domains, which have little effect on the DNA binding activity of its core domain but are capable of modulating its transactivation activity in a target site-dependent manner; (ii) p53 contains two cell-specific transcriptional inhibitory domains, I1 and I2, which are active in Saos-2 and HeLa cells but not in HepG2 and Hep3B cells; and (iii) I1 inhibits the activity of several structurally different activating regions. These results demonstrate that the apparent transcriptional activity of p53 is determined by collaborations among its regulatory domains, its target sites, and the cellular environment.
Hsu
Y S
YS
Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan.
Tang
F M
FM
Liu
W L
WL
Chuang
J Y
JY
Lai
M Y
MY
Lin
Y S
YS
D001483:Base Sequence; D004247:DNA / Q000378:metabolism; D004268:DNA-Binding Proteins; D005656:Fungal Proteins / Q000378:metabolism; D008969:Molecular Sequence Data; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D014158:Transcription, Genetic; D016159:Tumor Suppressor Protein p53 / Q000502:physiology*
D004268:DNA-Binding Proteins; D005656:Fungal Proteins; C052130:GAL4 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D016159:Tumor Suppressor Protein p53; D004247:DNA