Serine/threonine kinase which plays an important role in the regulation of electrolyte homeostasis, cell signaling, survival and proliferation. Acts as an activator and inhibitor of sodium-coupled chloride cotransporters and potassium-coupled chloride cotransporters respectively. Phosphorylates WNK4. Regulates the phosphorylation of SLC12A1 and SLC12A2. Increases Ca(2+) influx mediated by TRPV5 and TRPV6 by enhancing their membrane expression level via a kinase-dependent pathway. Inhibits the activity of KCNJ1 by decreasing its expression at the cell membrane in a non-catalytic manner.; Isoform 1, isoform 2, isoform 3 and isoform 4 stimulate the activity of SLC12A1, SLC12A2 and SLC12A3 and inhibit the activity of SLC12A4, SLC12A5, SLC12A6 and SLC12A7. According to PubMed:19470686, isoform 1 inhibits the activity of SLC12A3.
