Rapid actions of estrogens in GH3/B6 pituitary tumor cells via a plasma membrane version of estrogen receptor-α

Cheryl S. Watson, Andrea M. Norfleet, Todd C. Pappas, Bahiru Gametchu

Research output: Contribution to journalArticlepeer-review

153 Scopus citations


The focus of our work on rapid actions of estrogens has been on the immuno-identification of a membrane version of the estrogen receptor-α (mERα) and the correlation of the presence of this receptor to the rapid secretion of prolactin in pituitary tumor cells. We demonstrated the mERα by both fluorescence and immuno-enzyme-cytochemistry and with both conventional and confocal microscopy in the cell line GH3/B6 and its sublines. Its presence on cells (including recently subcloned ones) is very heterogenous, unlike the nuclear ERα, which is present in every cell. An impeded ligand (estradiol covalently linked to BSA) binds to mERα and elicits the same response. A total of eight antibodies to ERα recognize mERα, making it likely that the membrane and nuclear proteins are highly related. Immunoidentification techniques have also been used to identify mERα on the MCF-7 human breast cancer cell line. Estradiol at very low concentrations elicits prolactin release from GH3/B6 cells within a few minutes of application. This response is bimodal, with effective concentrations in both the picomolar and nanomolar ranges. Prolactin release is also elicited or inhibited by ERα-specific antibodies. The characteristics of mERα and the membrane receptor for glucocorticoids have many similarities, suggesting that this mode of subcellular location/function alternative might be used by other members of the gene family.

Original languageEnglish (US)
Pages (from-to)5-13
Number of pages9
Issue number1-2
StatePublished - 1999
Externally publishedYes


  • Breast cancer
  • Estrogen Membrane steroid receptor
  • Estrogen receptor-α
  • Prolactin release

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology
  • Endocrinology
  • Pharmacology
  • Clinical Biochemistry
  • Organic Chemistry


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