TY - JOUR
T1 - Involvement of estrogen receptor variant ER-α36, not GPR30, in nongenomic estrogen signaling
AU - Kang, Lianguo
AU - Zhang, Xintian
AU - Xie, Yan
AU - Tu, Yaping
AU - Wang, Dong
AU - Liu, Zhenming
AU - Wang, Zhao Yi
PY - 2010/4
Y1 - 2010/4
N2 - Accumulating evidence suggested that an orphan G protein-coupled receptor (GPR)30, mediates nongenomic responses to estrogen. The present study was performed to investigate the molecular mechanisms underlying GPR30 function.Wefound that knockdown of GPR30 expression in breast cancer SK-BR-3 cells down-regulated the expression levels of estrogen receptor (ER)-α36, a variant of ER-α. Introduction of a GPR30 expression vector into GPR30 nonexpressing cells induced endogenous ER-α36 expression, and cotransfection assay demonstrated that GPR30 activated the promoter activity of ER-α36 via an activator protein 1 binding site. Both 17β-estradiol (E2) and G1, a compound reported to be a selective GPR30 agonist, increased the phosphorylation levels of the MAPK/ERK1/2 in SK-BR-3 cells, which could be blocked by an anti-ER-α36-specific antibody against its ligand-binding domain. G1 induced activities mediated by ER-α36, such as transcription activation activity of a VP16-ER-α36 fusion protein and activation of the MAPK/ERK1/2 in ER-α36-expressing cells. ER-α36-expressing cells, but not the nonexpressing cells, displayed high-affinity, specific E2 and G1 binding, and E2- and G1-induced intracellular Ca2+ mobilization only in ER-α36 expressing cells. Taken together, our results demonstrated that previously reported activities of GPR30 in response to estrogen were through its ability to induce ER-α36 expression. The selective G protein-coupled receptor (GPR)30 agonist G1 actually interacts with ER-α36. Thus, the ER-α variant ER-α36, not GPR30, is involved in nongenomic estrogen signaling.
AB - Accumulating evidence suggested that an orphan G protein-coupled receptor (GPR)30, mediates nongenomic responses to estrogen. The present study was performed to investigate the molecular mechanisms underlying GPR30 function.Wefound that knockdown of GPR30 expression in breast cancer SK-BR-3 cells down-regulated the expression levels of estrogen receptor (ER)-α36, a variant of ER-α. Introduction of a GPR30 expression vector into GPR30 nonexpressing cells induced endogenous ER-α36 expression, and cotransfection assay demonstrated that GPR30 activated the promoter activity of ER-α36 via an activator protein 1 binding site. Both 17β-estradiol (E2) and G1, a compound reported to be a selective GPR30 agonist, increased the phosphorylation levels of the MAPK/ERK1/2 in SK-BR-3 cells, which could be blocked by an anti-ER-α36-specific antibody against its ligand-binding domain. G1 induced activities mediated by ER-α36, such as transcription activation activity of a VP16-ER-α36 fusion protein and activation of the MAPK/ERK1/2 in ER-α36-expressing cells. ER-α36-expressing cells, but not the nonexpressing cells, displayed high-affinity, specific E2 and G1 binding, and E2- and G1-induced intracellular Ca2+ mobilization only in ER-α36 expressing cells. Taken together, our results demonstrated that previously reported activities of GPR30 in response to estrogen were through its ability to induce ER-α36 expression. The selective G protein-coupled receptor (GPR)30 agonist G1 actually interacts with ER-α36. Thus, the ER-α variant ER-α36, not GPR30, is involved in nongenomic estrogen signaling.
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U2 - 10.1210/me.2009-0317
DO - 10.1210/me.2009-0317
M3 - Article
C2 - 20197310
AN - SCOPUS:77950407928
VL - 24
SP - 709
EP - 721
JO - Molecular Endocrinology
JF - Molecular Endocrinology
SN - 0888-8809
IS - 4
ER -