The Ca²⁺ channel CatSper is not activated by cAMP/PKA signaling but directly affected by chemicals used to probe the action of cAMP and PKA.

ABSTRACT: The sperm-specific Ca²⁺ channel CatSper (cation channel of sperm) controls the influx of Ca²⁺ into the flagellum and, thereby, the swimming behavior of sperm. A hallmark of human CatSper is its polymodal activation by membrane voltage, intracellular pH, and oviductal hormones. Whether CatSper is also activated by signaling pathways involving an increase of cAMP and ensuing activation of PKA is, however, a matter of controversy. To shed light on this question, we used kinetic ion-sensitive fluorometry, patch-clamp recordings, and optochemistry to study transmembrane Ca²⁺ flux and membrane currents in human sperm from healthy donors and from patients that lack functional CatSper channels. We found that human CatSper is neither activated by intracellular cAMP

SUBMITTER: Wang T 

PROVIDER: S-EPMC7504923 | biostudies-literature | 2020 Sep

REPOSITORIES: biostudies-literature