title: Disruption of the principal, progesterone-activated sperm Ca2+ channel in a CatSper2-deficient infertile patient.
abstract: The female steroid hormone progesterone regulates ovulation and supports pregnancy, but also controls human sperm function within the female reproductive tract. Progesterone causes elevation of sperm intracellular Ca(2+) leading to sperm hyperactivation, acrosome reaction, and perhaps chemotaxis toward the egg. Although it has been suggested that progesterone-dependent Ca(2+) influx into human spermatozoa is primarily mediated by cationic channel of sperm (CatSper), the principal flagellar Ca(2+) channel of sperm, conclusive loss-of-function genetic evidence for activation of CatSper by progesterone has yet to be provided. Moreover, it is not clear whether the responsiveness of CatSper to progesterone is an innate property of human spermatozoa or is acquired as the result of exposure to the seminal plasma. Here, by recording ionic currents from spermatozoa of an infertile CatSper-deficient patient, we demonstrate that CatSper is indeed the principal Ca(2+) channel of human spermatozoa, and that it is strongly potentiated by progesterone. In addition, by recording CatSper currents from human epididymal and testicular spermatozoa, we show that CatSper sensitivity to progesterone arises early in sperm development and increases gradually to a peak when spermatozoa are ejaculated. These results unambiguously establish an important role of CatSper channel in human sperm nongenomic progesterone signaling and demonstrate that the molecular mechanism responsible for activation of CatSper by progesterone arises early in sperm development concurrently with the CatSper channel itself.
authors.affiliation: Department of Urology, University of California, San Francisco, CA 94143, USA.
authors.forename: James F
authors.initials: JF
authors.lastname: Smith
authors.forename: Olga
authors.initials: O
authors.lastname: Syritsyna
authors.forename: Marc
authors.initials: M
authors.lastname: Fellous
authors.forename: Catherine
authors.initials: C
authors.lastname: Serres
authors.forename: Nadja
authors.initials: N
authors.lastname: Mannowetz
authors.forename: Yuriy
authors.initials: Y
authors.lastname: Kirichok
authors.forename: Polina V
authors.initials: PV
authors.lastname: Lishko
mesh_terms: D000328:Adult; D015220:Calcium Channels / Q000172:deficiency / Q000378:metabolism*; D004822:Epididymis / Q000378:metabolism; D006801:Humans; D007248:Infertility, Male / Q000503:physiopathology*; D008297:Male; D018408:Patch-Clamp Techniques; D011374:Progesterone / Q000494:pharmacology; D013094:Spermatozoa / Q000737:chemistry* / Q000502:physiology; D013737:Testis / Q000378:metabolism
chemical_list: C438823:CATSPER1 protein, human; D015220:Calcium Channels; D011374:Progesterone