Human sperm KSper is physiologically activated by intracellular pH alkalization and CatSper-mediated Ca²⁺ signaling.

ABSTRACT: The hyperpolarization of membrane potential (V_m) generated by the activation of the sperm-specific K⁺ channel (KSper) is considered as an important indicator for the evaluation of sperm-fertilizing capacity. However, owing to the relatively low pH sensitivity and low Ca²⁺ affinity of human KSper (hKSper), whether the changes of intracellular pH or cytosol Ca²⁺ ([Ca²⁺]_i) in response to physiological stimuli are sufficient to potentiate native hKSper is fairly obscure. Here, by utilizing quantitative V_m fluorometry and current-clamp recordings on human sperm, our results reliably demonstrated that physiologically relevant extracellular pH alkalization activated hKSper and evoked ∼20 mV hyperpolarization of V_m</

SUBMITTER: Kang H 

PROVIDER: S-EPMC12569824 | biostudies-literature | 2025 Sep

REPOSITORIES: biostudies-literature