We have identified an estrogen receptor of approximately 29 kDa apparent molecular weight in human sperm membranes by ligand and Western blot analysis, respectively, using peroxidase-conjugated E-2 and an antibody directed against the ligand binding region of the genomic receptor (alpha H222). Such receptor is functional since 17 beta E-2 induces a rapid and sustained increase of intracellular calcium concentrations ([Ca2+](i)) which is completely eliminated by preincubation with alpha H222. 17 beta E-2 effects on calcium are clearly mediated by a membrane receptor, as they are reproduced by the membrane-impermeable conjugate of the hormone BSA-E-2. Dose-response curve for this effect is biphasic with EC(50)s in the nanomolar and micromolar range. In addition to calcium increase, 17 beta E-2 stimulates tyrosine phosphorylation of several sperm proteins including the 29-kDa protein band. Preincubation of human sperm with 17 beta E-2 inhibits calcium and acrosome reaction increases in response to progesterone. We conclude that estrogens may play a role in the modulation of non-genomic action of progesterone (P) in human sperm during the process of fertilization. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.
Titolo: | A novel functional estrogen receptor on human sperm membrane interferes with progesterone effects. |
Autori di Ateneo: | |
Autori: | BALDI, ELISABETTA; LUCONI, MICHAELA; MURATORI, MONICA; FORTI, GIANNI |
Anno di registrazione: | 2000 |
Rivista: | |
Volume: | 161 |
Pagina iniziale: | 31 |
Pagina finale: | 35 |
Abstract: | We have identified an estrogen receptor of approximately 29 kDa apparent molecular weight in human sperm membranes by ligand and Western blot analysis, respectively, using peroxidase-conjugated E-2 and an antibody directed against the ligand binding region of the genomic receptor (alpha H222). Such receptor is functional since 17 beta E-2 induces a rapid and sustained increase of intracellular calcium concentrations ([Ca2+](i)) which is completely eliminated by preincubation with alpha H222. 17 beta E-2 effects on calcium are clearly mediated by a membrane receptor, as they are reproduced by the membrane-impermeable conjugate of the hormone BSA-E-2. Dose-response curve for this effect is biphasic with EC(50)s in the nanomolar and micromolar range. In addition to calcium increase, 17 beta E-2 stimulates tyrosine phosphorylation of several sperm proteins including the 29-kDa protein band. Preincubation of human sperm with 17 beta E-2 inhibits calcium and acrosome reaction increases in response to progesterone. We conclude that estrogens may play a role in the modulation of non-genomic action of progesterone (P) in human sperm during the process of fertilization. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved. |
Handle: | http://hdl.handle.net/2158/348 |
Appare nelle tipologie: | 1a - Articolo su rivista |
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Baldi MolCellEndocrinol2000.pdf | Versione finale referata | Open Access | Accesso pubblicoVisualizza/Apri |