WNK4 (WNK Lysine Deficient Protein Kinase 4) 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 WNK4 result in pseudohypoaldosteronism type IIB.
