Fig. 1.

Summary of intracellular molecular mechanisms for aquaporin 2 (AQP2) regulation in renal collecting duct cells. Water permeability of collecting duct cells is regulated via AQP2 under various physiological and pathophysiological conditions through 2 mechanisms. Short-term regulation: trafficking between intracellular vesicles and plasma membrane is associated with posttranslational modification of AQP2 and vesicle-transporting systems dependent on cell signaling; long-term regulation: change of protein abundance is regulated by transcription and mRNA/protein stability. PTM, posttranslational modification.