Regulation of potassium channel trafficking in the distal nephron

PURPOSE OF REVIEW: Potassium channels in the distal nephron are precisely controlled to regulate potassium secretion in accord with physiological demands. In recent years, it has become evident that membrane trafficking processes play a fundamental role. This short review highlights recent developments in elucidating the underlying mechanisms. RECENT FINDINGS: Novel sorting signals in the renal potassium channels, and the elusive intracellular trafficking machinery that read and act on these signals have recently been identified. These new discoveries reveal that independent signals sequentially interact with different intracellular sorting, retention and internalization machineries to appropriately ferry the channels to and from the apical and basolateral membrane domains in sufficient numbers to regulate potassium balance. SUMMARY: A new understanding of the basic mechanisms that control potassium channel density at polarized membrane domains has emerged, providing new insights into how potassium balance is achieved and how it goes awry in disease.