Serine/threonine-protein kinase OSR1 is a member of the germinal centre kinase VI subfamily of the Ste20 (Sterile20)-related protein kinase family []. OSR1 (oxidative stress response 1) regulates downstream kinases in response to environmental stress []. It regulates the solute carrier 12 family of cation-chloride cotransporters which modulate ion homeostasis throughout the body [].