Curation of vasopressin-regulated phosphorylation sites in collecting duct

Vasopressin controls renal water excretion through actions to regulate aquaporin-2 (AQP2) trafficking, transcription and degradation. These actions are in part dependent on vasopressin-induced phosphorylation changes in collecting duct cells. Although most efforts have focused on phosphorylation of AQP2 itself, phosphoproteomic studies have identified many vasopressin-regulated phosphorylation sites in proteins other than AQP2. The goal of this bioinformatics-based review is to create a compendium of vasopressin-regulated phosphorylation sites with focus on those that are seen in both native rat inner medullary collecting ducts and cultured collecting duct cells from mouse (mpkCCD), arguing that these sites are the best candidates for roles in AQP2 regulation. This analysis identified 51 vasopressin-regulated phosphorylation sites in 45 proteins. We provide resource web pages at https://esbl.nhlbi.nih.gov/Databases/AVP-Phos/ and https://esbl.nhlbi.nih.gov/AVP-Network/, listing the phosphorylation sites and describing annotated functions of each of the vasopressin-targeted phosphoproteins. This document details the step-by-step process followed to identify the vasopressin-regulated phosphorylation sites that change in both mpkCCD cells and in native inner medullary collecting duct cells.