WNK Lysine Deficient Protein Kinase 1 (WNK1)

The WNK1 protein is composed of 2382 amino acids. The protein contains a small N-terminal domain followed by the kinase domain and a long C-terminal tail. The kinase domain has some similarity to the MEKK protein kinase family.The protein appears to be part of the ERK5 MAP kinase pathway upstream of MEKK2 / MEKK3 and to function as a tetramer. It selectively binds to and phosphorylates synaptotagmin 2 (SYT2) within its calcium binding C2 domains. It activates the serum- and glucocorticoid-inducible protein kinase SGK1, leading to activation of the epithelial sodium channel. It along with WNK4 stimulates clathrin-dependent endocytosis of renal outer medullar potassium 1 (ROMK1). It (and WNK4) interactes with intersectin (ITSN1, ITSN2).