Properties of overlapping EREs: synergistic activation of transcription and cooperative binding of ER.
We have designed a novel estrogen-responsive unit, overERE, which consists of two overlapping ERE separated by 5 bp (center-to-center). In gel retardation assays, this sequence forms a low-mobility complex that migrates like an estrogen receptor tetramer. The receptor-overERE complex was specific and was supershifted by anti-ER H222 antibodies. Dose response studies showed that the formation of the receptor tetramer-overERE complex was cooperative. Truncated receptors were used to assess the contribution of the receptor domains. Deletion of the E domain of the ER prevented the formation of an ER-tetramer complex, which reflects a novel function of this receptor domain. In transfection experiments, 17-beta-estradiol activated transcription from an overERE-containing promoter 4-6 times better than from an ERE-containing promoter. This synergistic effect was observed using either the natural hormone (17-beta-estradiol) or xenoestrogens (phenol red, chlordane). We conclude that two overlapping estrogen-responsive elements can elicit synergistic induction of transcription.
Massaad
C
C
INSERM Unité 99, Hôpital Henri Mondor, Créteil, France.
Coumoul
X
X
Sabbah
M
M
Garlatti
M
M
Redeuilh
G
G
Barouki
R
R
D001483:Base Sequence; D001943:Breast Neoplasms; D006528:Carcinoma, Hepatocellular; D002706:Chlordan / Q000494:pharmacology; D019281:Dimerization; D004357:Drug Synergism; D004591:Electrophoresis, Polyacrylamide Gel; D004965:Estrogen Antagonists / Q000494:pharmacology; D004967:Estrogens / Q000819:agonists / Q000494:pharmacology*; D017988:Gammaretrovirus / Q000235:genetics; D005807:Genes, Overlapping / Q000187:drug effects / Q000502:physiology*; D005822:Genetic Vectors / Q000494:pharmacology; D006801:Humans; D008969:Molecular Sequence Data; D010637:Phenolsulfonphthalein / Q000494:pharmacology; D011485:Protein Binding / Q000187:drug effects / Q000235:genetics; D017434:Protein Structure, Tertiary; D011960:Receptors, Estrogen / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D012045:Regulatory Sequences, Nucleic Acid / Q000502:physiology; D014158:Transcription, Genetic / Q000187:drug effects; D014407:Tumor Cells, Cultured; D015262:Xenobiotics / Q000494:pharmacology
D004965:Estrogen Antagonists; D004967:Estrogens; D011960:Receptors, Estrogen; D015262:Xenobiotics; D002706:Chlordan; D010637:Phenolsulfonphthalein