Protein kinase D2 Regulates Epithelial Sodium Channel Activity and Aldosterone Non-Genomic Responses in Renal Cortical Collecting Duct Cells

Publication date: Available online 11 December 2019Source: SteroidsAuthor(s): Warren Thomas, Ruth Dooley, Sinead Quinn, Manuel Yusef Robles, Brian J. HarveyAbstractProtein kinase D2 (PKD2) is a serine/ threonine protein kinase which plays an important role in vesicle fission at the trans-Golgi network (TGN) to coordinate subcellular trafficking with gene expression. We found that in the rat kidney, PKD2 is specifically expressed in collecting duct principal cells predominantly at the apical membrane and with lower basal expression in cytosolic compartments. When rats were maintained on a Na+ depleted diet (<0.87mmol Na+/kg) to increase plasma aldosterone levels, PKD2 became internalized to a cytoplasmic compartment. Treatment of murine M1 cortical collecting duct (M1-CCD) cells with aldosterone (10nM) promoted PKD2 co-localization with the trans-Golgi network within 30 min. PKD2 underwent autophosphorylation at Ser876 within 10 min of aldosterone treatment and remained phosphorylated (active) for at least 24 h. A stable PKD2 shRNA knock-down (PKD2 KD) M1-CCD cell line was developed to study the role of PKD2 in epithelial Na+ channel (ENaC) trafficking and transepithelial Na+ transport (SCC) in epithelial monolayers grown in Ussing chambers. The PKD2 KD cells developed transepithelial resistance with kinetics equivalent to wild-type cells, however the transepithelial voltage and Na+ current SCC were significantly elevated in PKD2 knock-down CCD.. The higher basal SCC was d...
Source: Steroids - Category: Drugs & Pharmacology Source Type: research