Respiration and parturition affected by conditional overexpression of the Ca2+-activated K+ channel subunit, SK3

In:excitable cells, small-conductance Ca2+-activated potassium channels (SK channels) are responsible for the slow after-hyperpolarization that often follows an action potential. Three SK channel subunits have been molecularl y characterized. The SK3 gene was targeted by homologous recombination for the insertion of a gene switch that permitted experimental regulation of SK 3 expression while retaining normal SK3 promoter function. An absence of SK 3 did not-present overt phenotypic consequences. However, SK3 overexpressio n induced abnormal respiratory responses to hypoxia and compromised parturi tion. Both conditions were corrected by silencing the gene. The results imp licate SK3 channels as potential therapeutic targets for disorders such as sleep apnea Or sudden infant death syndrome and for regulating uterine cont ractions during labor.