Abstract
The estrogen receptor (ER) appears to be down-regulated by its own ligand in some estrogen (E2)-responsive tissues as well as in cell lines such as MCF-7 and GH3. Surprisingly, we observed ER down-regulation in a newly constructed E2-responsive cell line (Rat1 + ER), in which expression of the coding region of the ER cDNA was driven by the Moloney murine leukemia virus long terminal repeat. We present evidence that the coding region of the ER cDNA, but not the Moloney murine leukemia virus long terminal repeat, possesses a sequence(s) necessary for ER down-regulation. The observed down-regulation occurs at ligand-binding and protein, as well as mRNA, levels. Marked decreases in both protein and mRNA levels were observed as early as 3 h after E2 treatment. Furthermore, maximal down-regulation occurred by 18-24 h with ligand-binding, and mRNA levels reached approximately 20% that of controls. ER down-regulation in Rat1 + ER cells is only partially inhibited by the presence of cycloheximide and therefore suggests a direct participation of the ER in this process. E2 does not appear to influence the stability of the ER transcript, which implies that negative regulation is occurring at the transcriptional level. Finally, since we can demonstrate ER binding to a portion of the cDNA sequence, we propose a mechanism whereby ER binding to its putative negative element leads to transcriptional repression of the upstream promoter.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 879-888 |
| Number of pages | 10 |
| Journal | Molecular Endocrinology |
| Volume | 7 |
| Issue number | 7 |
| DOIs | |
| State | Published - Jan 1 1993 |
| Externally published | Yes |
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ASJC Scopus subject areas
- Molecular Biology
- Endocrinology
Cite this
Involvement of the coding sequence for the estrogen receptor gene in autologous ligand-dependent down-regulation. / Kaneko, Kotaro J.; Furlow, John; Gorski, Jack.
In: Molecular Endocrinology, Vol. 7, No. 7, 01.01.1993, p. 879-888.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Involvement of the coding sequence for the estrogen receptor gene in autologous ligand-dependent down-regulation
AU - Kaneko, Kotaro J.
AU - Furlow, John
AU - Gorski, Jack
PY - 1993/1/1
Y1 - 1993/1/1
N2 - The estrogen receptor (ER) appears to be down-regulated by its own ligand in some estrogen (E2)-responsive tissues as well as in cell lines such as MCF-7 and GH3. Surprisingly, we observed ER down-regulation in a newly constructed E2-responsive cell line (Rat1 + ER), in which expression of the coding region of the ER cDNA was driven by the Moloney murine leukemia virus long terminal repeat. We present evidence that the coding region of the ER cDNA, but not the Moloney murine leukemia virus long terminal repeat, possesses a sequence(s) necessary for ER down-regulation. The observed down-regulation occurs at ligand-binding and protein, as well as mRNA, levels. Marked decreases in both protein and mRNA levels were observed as early as 3 h after E2 treatment. Furthermore, maximal down-regulation occurred by 18-24 h with ligand-binding, and mRNA levels reached approximately 20% that of controls. ER down-regulation in Rat1 + ER cells is only partially inhibited by the presence of cycloheximide and therefore suggests a direct participation of the ER in this process. E2 does not appear to influence the stability of the ER transcript, which implies that negative regulation is occurring at the transcriptional level. Finally, since we can demonstrate ER binding to a portion of the cDNA sequence, we propose a mechanism whereby ER binding to its putative negative element leads to transcriptional repression of the upstream promoter.
AB - The estrogen receptor (ER) appears to be down-regulated by its own ligand in some estrogen (E2)-responsive tissues as well as in cell lines such as MCF-7 and GH3. Surprisingly, we observed ER down-regulation in a newly constructed E2-responsive cell line (Rat1 + ER), in which expression of the coding region of the ER cDNA was driven by the Moloney murine leukemia virus long terminal repeat. We present evidence that the coding region of the ER cDNA, but not the Moloney murine leukemia virus long terminal repeat, possesses a sequence(s) necessary for ER down-regulation. The observed down-regulation occurs at ligand-binding and protein, as well as mRNA, levels. Marked decreases in both protein and mRNA levels were observed as early as 3 h after E2 treatment. Furthermore, maximal down-regulation occurred by 18-24 h with ligand-binding, and mRNA levels reached approximately 20% that of controls. ER down-regulation in Rat1 + ER cells is only partially inhibited by the presence of cycloheximide and therefore suggests a direct participation of the ER in this process. E2 does not appear to influence the stability of the ER transcript, which implies that negative regulation is occurring at the transcriptional level. Finally, since we can demonstrate ER binding to a portion of the cDNA sequence, we propose a mechanism whereby ER binding to its putative negative element leads to transcriptional repression of the upstream promoter.
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U2 - 10.1210/mend.7.7.8413312
DO - 10.1210/mend.7.7.8413312
M3 - Article
VL - 7
SP - 879
EP - 888
JO - Molecular Endocrinology
JF - Molecular Endocrinology
SN - 0888-8809
IS - 7
ER -