Membrane potential and feedback dynamics regulate CatSper-mediated progesterone signaling in human sperm.

ABSTRACT: Activation of the sperm-specific Ca²⁺ channel CatSper by progesterone evokes rapid changes in intracellular Ca²⁺ in human sperm that are required for fertilization. However, the mechanisms regulating the progesterone-induced Ca²⁺ signals have remained elusive. Here, we used quantitative kinetic fluorimetry with fast voltage-sensitive fluorescent indicators to investigate how progesterone affects the membrane potential (V_m) of human sperm. Additionally, we employed the FAST^M technique to simultaneously record at millisecond time resolution changes in both V_m and intracellular Ca²⁺. We show that progesterone evokes a rapid pulse-like depolarization and repolarization. The depolarization is caused by Ca²⁺

SUBMITTER: Kierzek M 

PROVIDER: S-EPMC12458478 | biostudies-literature | 2025 Sep

REPOSITORIES: biostudies-literature