title: Cysteine-rich secretory protein 4 is an inhibitor of transient receptor potential M8 with a role in establishing sperm function.
abstract: The cysteine-rich secretory proteins (CRISPs) are a group of four proteins in the mouse that are expressed abundantly in the male reproductive tract, and to a lesser extent in other tissues. Analysis of reptile CRISPs and mouse CRISP2 has shown that CRISPs can regulate cellular homeostasis via ion channels. With the exception of the ability of CRISP2 to regulate ryanodine receptors, the in vivo targets of mammalian CRISPs function are unknown. In this study, we have characterized the ion channel regulatory activity of epididymal CRISP4 using electrophysiology, cell assays, and mouse models. Through patch-clamping of testicular sperm, the CRISP4 CRISP domain was shown to inhibit the transient receptor potential (TRP) ion channel TRPM8. These data were confirmed using a stably transfected CHO cell line. TRPM8 is a major cold receptor in the body, but is found in other tissues, including the testis and on the tail and head of mouse and human sperm. Functional assays using sperm from wild-type mice showed that TRPM8 activation significantly reduced the number of sperm undergoing the progesterone-induced acrosome reaction following capacitation, and that this response was reversed by the coaddition of CRISP4. In accordance, sperm from Crisp4 null mice had a compromised ability to undergo to the progesterone-induced acrosome reaction. Collectively, these data identify CRISP4 as an endogenous regulator of TRPM8 with a role in normal sperm function.
authors.affiliation: Department of Anatomy and Developmental Biology, Monash University, VIC 3800, Australia.
authors.forename: Gerard M
authors.initials: GM
authors.lastname: Gibbs
authors.forename: Gerardo
authors.initials: G
authors.lastname: Orta
authors.forename: Thulasimala
authors.initials: T
authors.lastname: Reddy
authors.forename: Adam J
authors.initials: AJ
authors.lastname: Koppers
authors.forename: Pablo
authors.initials: P
authors.lastname: Martínez-López
authors.forename: José Luis
authors.initials: JL
authors.lastname: de la Vega-Beltràn
authors.forename: Jennifer C Y
authors.initials: JC
authors.lastname: Lo
authors.forename: Nicholas
authors.initials: N
authors.lastname: Veldhuis
authors.forename: Duangporn
authors.initials: D
authors.lastname: Jamsai
authors.forename: Peter
authors.initials: P
authors.lastname: McIntyre
authors.forename: Alberto
authors.initials: A
authors.lastname: Darszon
authors.forename: Moira K
authors.initials: MK
authors.lastname: O'Bryan
mesh_terms: D020101:Acrosome Reaction / Q000187:drug effects / Q000502:physiology*; D000818:Animals; D016466:CHO Cells; D006224:Cricetinae; D003412:Cricetulus; D006801:Humans; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D011374:Progesterone / Q000494:pharmacology; D011372:Progestins / Q000494:pharmacology; D029589:Seminal Plasma Proteins / Q000235:genetics / Q000378:metabolism*; D013094:Spermatozoa / Q000166:cytology / Q000378:metabolism*; D050053:TRPM Cation Channels / Q000235:genetics / Q000378:metabolism*
chemical_list: D011372:Progestins; D029589:Seminal Plasma Proteins; D050053:TRPM Cation Channels; C492297:TRPM8 protein, mouse; C503718:cysteine-rich secretory protein 4, mouse; D011374:Progesterone