STE20/SPS1-related proline-alanine-rich protein kinase

UniProtKB accession:  Q9Z1W9

Grouped By:  Matching UniProtKB accession

UniProtKB description:  Effector serine/threonine-protein kinase component of the WNK-SPAK/OSR1 kinase cascade, which is involved in various processes, such as ion transport, response to hypertonic stress and blood pressure (PubMed:16382158, PubMed:17488636, PubMed:19633012, PubMed:21486947). Specifically recognizes and binds proteins with a RFXV motif (PubMed:14563843). Acts downstream of WNK kinases (WNK1, WNK2, WNK3 or WNK4): following activation by WNK kinases, catalyzes phosphorylation of ion cotransporters, such as SLC12A1/NKCC2, SLC12A2/NKCC1, SLC12A3/NCC, SLC12A5/KCC2 or SLC12A6/KCC3, regulating their activity (PubMed:14563843, PubMed:16382158, PubMed:17488636, PubMed:19633012, PubMed:21486947). Mediates regulatory volume increase in response to hyperosmotic stress by catalyzing phosphorylation of ion cotransporters SLC12A1/NKCC2, SLC12A2/NKCC1 and SLC12A6/KCC3 downstream of WNK1 and WNK3 kinases (By similarity). Phosphorylation of Na-K-Cl cotransporters SLC12A2/NKCC1 and SLC12A2/NKCC1 promote their activation and ion influx; simultaneously, phosphorylation of K-Cl cotransporters SLC12A5/KCC2 and SLC12A6/KCC3 inhibit their activity, blocking ion efflux (By similarity). Acts as a regulator of NaCl reabsorption in the distal nephron by mediating phosphorylation and activation of the thiazide-sensitive Na-Cl cotransporter SLC12A3/NCC in distal convoluted tubule cells of kidney downstream of WNK4 (PubMed:17488636, PubMed:19633012, PubMed:21486947). Mediates the inhibition of SLC4A4, SLC26A6 as well as CFTR activities (PubMed:21317537, PubMed:23542070). Phosphorylates RELT (PubMed:16530727).