Aquaporin 2: Not Just for Moving Water

• Authors: Jeff M Sands, Emory University
• Journal Title: Journal of the American Society of Nephrology
• Volume: Volume 23, Number 9
• Publisher: American Society of Nephrology | 2012-09, Pages 1443-1444
• Type of Work: Article | Post-print: After Peer Review
• Publisher DOI: http://doi.org/10.1681/ASN.2012060613
• Subjects: Health Sciences, General; Biology, Physiology

Abstract

Aquaporin 2 (AQP2) is widely recognized for its role in vasopressin-stimulated water transport across the collecting duct and hence in the production of concentrated urine. AQP2 is primarily expressed in the apical plasma membrane and subapical vesicles of the collecting duct, although it has also been detected in the basolateral plasma membrane. In response to vasopressin binding to the V2-vasopressin receptor, AQP2 is trafficked from the subapical vesicles to the apical plasma membrane; AQP2 is endocytosed and recycled into subapical vesicles when the vasopressin stimulus ends. Water exits collecting duct cells through AQP3 and APQ4, located in the basolateral plasma membrane, resulting in the transcellular reabsorption of water.