title: A plasma-membrane progesterone receptor in human sperm is switched on by increasing intracellular free calcium.
abstract: Recent studies have revealed the presence of an atypical progesterone receptor on the plasma membrane of a relatively small subpopulation of human sperm cells. In this study, we show that the receptor is present in many cells in a latent form and that the receptor function in these cells is switched on asynchronously by increasing intracellular free Ca2+ levels. Under physiological conditions, this process occurs during sperm capacitation, but it can be mimicked by a short sperm exposure to the Ca(2+)-mobilizing agent thapsigargin. These observations suggest a role of Ca2+ as a modulator of nongenomic steroid effects on the cell surface.
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Granada Faculty of Sciences, Spain.
authors.forename: C
authors.initials: C
authors.lastname: Mendoza
authors.forename: J
authors.initials: J
authors.lastname: Tesarik
mesh_terms: D001692:Biological Transport; D002118:Calcium / Q000378:metabolism*; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D016650:Fluorescein-5-isothiocyanate; D006801:Humans; D008297:Male; D011980:Receptors, Progesterone / Q000187:drug effects / Q000378:metabolism*; D013094:Spermatozoa / Q000187:drug effects / Q000378:metabolism*; D013729:Terpenes / Q000494:pharmacology; D019284:Thapsigargin
chemical_list: D011980:Receptors, Progesterone; D013729:Terpenes; D019284:Thapsigargin; D016650:Fluorescein-5-isothiocyanate; D002118:Calcium