Estrogen receptor acting in cis enhances WT and mutant p53 transactivation at canonical and noncanonical p53 target sequences.
p53 is a master regulatory, sequence-specific transcription factor that directly controls expression of over 100 genes in response to various stress signals. Transactivation is generally considered to occur through p53 binding to a consensus response element (RE) composed of two 5'-RRRCWWGYYY-3' decamers. Recently, studying the human angiogenesis-related gene FLT1 we discovered that p53 can mediate limited transactivation at a noncanonical 1/2 site and could synergize with the estrogen receptor (ER) acting in cis at a nearby ER 1/2 site. To address the generality of concerted transactivation by p53 and ER, the 1/2 site in the FLT1 promoter was replaced with a variety of 1/2 sites, as well as canonical weak and strong p53 REs of human target genes. The p53 transactivation of all tested sequences was greatly enhanced by ligand-activated ER acting in cis. Furthermore, enhanced transactivation extends to several cancer-associated p53 mutants with altered function, suggesting ER-dependent mutant p53 activity for at least some REs. The enhanced transactivation was also found with p63 and p73. We propose a general synergistic relationship between p53 family and ER master regulators in transactivation of p53 target canonical and noncanonical REs, which might be poorly responsive to p53 on their own. This relationship greatly expands the transcriptional master network regulated by p53 in terms of genes affected and levels of expression and has implications for the appearance and possible treatments of cancer.
Menendez
Daniel
D
Laboratory of Molecular Genetics, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA.
Inga
Alberto
A
Resnick
Michael A
MA
D001483:Base Sequence; D045744:Cell Line, Tumor; D047628:Estrogen Receptor alpha / Q000235:genetics / Q000378:metabolism*; D047629:Estrogen Receptor beta / Q000235:genetics / Q000378:metabolism*; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D009154:Mutation; D009369:Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000628:therapy; D011485:Protein Binding; D020218:Response Elements; D015533:Transcriptional Activation; D016159:Tumor Suppressor Protein p53 / Q000235:genetics / Q000378:metabolism*; D040281:Vascular Endothelial Growth Factor Receptor-1 / Q000235:genetics
C506487:ESR1 protein, human; D047628:Estrogen Receptor alpha; D047629:Estrogen Receptor beta; C495901:TP53 protein, human; D016159:Tumor Suppressor Protein p53; C501162:FLT1 protein, human; D040281:Vascular Endothelial Growth Factor Receptor-1