This gene encodes a member of the WNK family of serine-threonine protein kinases. The kinase is part of the tight junction complex in kidney cells, and regulates the balance between NaCl reabsorption and K(+) secretion. The kinase regulates the activities of several types of ion channels, cotransporters, and exchangers involved in electrolyte flux in epithelial cells. Mutations in this gene result in pseudohypoaldosteronism type IIB.