Vasopressin and the regulation of aquaporin-2

Abstract

Water excretion is regulated in large part through the regulation of the osmotic water permeability of the renal collecting duct epithelium. The water permeability is controlled by vasopressin through regulation of the water channel, aquaporin-2 (AQP2). Two processes contribute: 1) regulation of AQP2 trafficking to the apical plasma membrane; and 2) regulation of the total amount of the AQP2 protein in the cells. Regulation of AQP2 abundance is defective in several water balance disorders including many polyuric disorders and the syndrome of inappropriate antidiuresis (SIADH). Here we review vasopressin signaling in the renal collecting duct that is relevant to the two modes of water permeability regulation.

Role of aquaporins in saliva secretion

“…Phosphorylation-dependent trafficking of AQP5 in SGs remains poorly understood as compared to that of its most closely sequencerelated family member AQP2 in the kidney 26 . AQP5 shares homologous structural and amino acid features with AQP2, namely in the carboxyterminus domain, the latter being involved in AQP2 cellular trafficking and apical membrane targeting in the kidney 26 .…”

“…AQP5 shares homologous structural and amino acid features with AQP2, namely in the carboxyterminus domain, the latter being involved in AQP2 cellular trafficking and apical membrane targeting in the kidney 26 . Targeting of AQP5 to the apical membrane of epithelial cells seemingly result from the presence of a specific targeting signal present in the C-terminal part of the protein 27 .…”

Arginine Vasopressin Promotes Redistribution of Adhesion Junction Protein E-Cadherin in Kidney Epithelial Cells

“…[11][12][13][14] Higher serum level of copeptin was also detected in kidney transplant recipients who have accelerated renal function decline. 12 From currently available literatures, it is clear that vasopressin (VP) regulates water reabsorption by a®ecting cellular distribution of a water channel protein aquaporin 2 in kidney epithelial cells; 7,[16][17][18] however, whether VP a®ects other cellular proteins that are responsible for maintaining cell polarity of kidney tubules, and as a consequence, contributes to the kidney diseases progression is unclear.…”

Negative feedback from CaSR signaling to aquaporin-2 sensitizes vasopressin to extracellular Ca2+

“…Vasopressin-elicited water reabsorption is mediated by the cAMPdependent trafficking of vesicles containing the water channel aquaporin-2 (AQP2) into the apical membrane of collecting ducts (Nedvetsky et al, 2009;Wilson et al, 2013). We have previously provided evidence that high concentrations of luminal Ca 2+ in the renal collecting duct attenuate short-term vasopressin-induced AQP2 trafficking through Ca 2+ -sensing receptor (CaSR) activation (Procino et al, 2012(Procino et al, , 2004(Procino et al, , 2008.…”