Gagnon KB, England R, Delpire E. A single binding motif is required for SPAK activation of the Na-K-2Cl cotransporter. Cellular physiology and biochemistry : international journal of experimental cellular physiology, biochemistry, and pharmacology. 20(20). 131-42. PMID: 17595523 [PubMed]
SPAK (Ste20p-related proline alanine-rich kinase) phosphorylates and activates NKCC1 (Na-K-2Cl cotransporter) in the presence of another serine/threonine kinase WNK4 (With No lysine (K)). However, whether or not the docking of SPAK to NKCC1 is a requirement for cotransporter activation has not been fully resolved.