TY - JOUR
T1 - Distinct effects on the conformation of estrogen receptor α and β by both the antiestrogens ICI 164,384 and ICI 182,780 leading to opposite effects on receptor stability
AU - Van Den Bemd, Gert Jan C.M.
AU - Kuiper, George G.J.M.
AU - Pols, Huibert A.P.
AU - Van Leeuwen, Johannes P.T.M.
PY - 1999/7/22
Y1 - 1999/7/22
N2 - Tissue-specific effects of 17β-estradiol (E2) and synthetic estrogen receptor (ER) ligands on target gene regulation might, at least partly, be explained by a selective ligand-induced conformational change of their receptors (ERα and ERβ). In this study, the effects of E2 and the synthetic ER ligands tamoxifen (TAM), ICI 164,384, and ICI 182,780 on the conformation of ERα and ERβ were examined using limited proteolytic digestion analysis. We found that E2 induced a conformational change of ERα resulting in the protection of a 30-kDa product, whereas TAM protected a 28-kDa fragment. Strikingly, the ERα conformational change induced by both ICI 164,384 and ICI 182,780 did not result in protection but rather seems to induce a ligand concentration-dependent increase in proteolytic degradation of the 30- and 28-kDa products. Incubation of ERβ with E2 resulted in an increased protection of a 30-kDa fragment, whereas with TAM protection of a 29-kDa fragment was observed. In contrast to the situation with ERα, ICI 164,384 and ICI 182,780 incubation induced the protection in a manner similar to 30-kDa fragment E2. In addition, the ICI compounds also induced in a dose-dependent manner the preservation of a 32-kDa fragment. Our observations demonstrate that ICI 164,384 and ICI 182,780 have distinct effects on the conformation of ERα and ERβ, resulting in receptor subtype-selective opposite effects on receptor stability in vitro.
AB - Tissue-specific effects of 17β-estradiol (E2) and synthetic estrogen receptor (ER) ligands on target gene regulation might, at least partly, be explained by a selective ligand-induced conformational change of their receptors (ERα and ERβ). In this study, the effects of E2 and the synthetic ER ligands tamoxifen (TAM), ICI 164,384, and ICI 182,780 on the conformation of ERα and ERβ were examined using limited proteolytic digestion analysis. We found that E2 induced a conformational change of ERα resulting in the protection of a 30-kDa product, whereas TAM protected a 28-kDa fragment. Strikingly, the ERα conformational change induced by both ICI 164,384 and ICI 182,780 did not result in protection but rather seems to induce a ligand concentration-dependent increase in proteolytic degradation of the 30- and 28-kDa products. Incubation of ERβ with E2 resulted in an increased protection of a 30-kDa fragment, whereas with TAM protection of a 29-kDa fragment was observed. In contrast to the situation with ERα, ICI 164,384 and ICI 182,780 incubation induced the protection in a manner similar to 30-kDa fragment E2. In addition, the ICI compounds also induced in a dose-dependent manner the preservation of a 32-kDa fragment. Our observations demonstrate that ICI 164,384 and ICI 182,780 have distinct effects on the conformation of ERα and ERβ, resulting in receptor subtype-selective opposite effects on receptor stability in vitro.
UR - http://www.scopus.com/inward/record.url?scp=0033595102&partnerID=8YFLogxK
U2 - 10.1006/bbrc.1999.0864
DO - 10.1006/bbrc.1999.0864
M3 - Article
C2 - 10405313
AN - SCOPUS:0033595102
SN - 0006-291X
VL - 261
SP - 1
EP - 5
JO - Biochemical and Biophysical Research Communications
JF - Biochemical and Biophysical Research Communications
IS - 1
ER -