Ca²⁺-dependent K⁺ channels in exocrine salivary glands.

In the last 15 years, remarkable progress has been realized in identifying the genes that encode the ion-transporting proteins involved in exocrine gland function, including salivary glands. Among these proteins, Ca(2+)-dependent K(+) channels take part in key functions including membrane potential regulation, fluid movement and K(+) secretion in exocrine glands. Two K(+) channels have been identified in exocrine salivary glands: (1) a Ca(2+)-activated K(+) channel of intermediate single channel conductance encoded by the KCNN4 gene, and (2) a voltage- and Ca(2+)-dependent K(+) channel of large single channel conductance encoded by the KCNMA1 gene. This review focuses on the physiological roles of Ca(2+)-dependent K(+) channels in exocrine salivary glands. We also discuss interesting recent findings on the regulation of Ca(2+)-dependent K(+) channels by protein-protein interactions that may significantly impact exocrine gland physiology.