SPAK, phosphorylated (Ser373), OSR1, phosphorylated (Ser325) (STE20/SPS1-related Proline-alanine-rich Protein Kinase, Ste-20-related Kinase, DCHT, Serine/Threonine-protein Kinase 39, STK39/ Serine/Threonine-protein Kinase OSR1, Oxidative Stress-responsive 1 Protein, OXSR1, KIAA1101) (APC)

As members of the (sterile 20)-like kinase family, the oxidative-stress-responsive kinase 1 (OSR1) and the SPS1-related proline/alanine-rich kinase (SPAK) serve as key enzymes in a signaling cascade, which mediate the activity of Na+/K+/2Cl- cotransporters (NKCCs) in response to osmotic stress. Both kinases have a conserved carboxy-terminal (CCT) domain, which are 79% identical to each other at the sequence level, and are also highly conserved in orthologues of these enzymes in Caenorhabditis elegans, Drosophila, and Xenopus. The CCT domain reflects no similarity to sequences found in other proteins. This domain is known to recognize and interact with a unique peptide (Arg-Phe-Xaa-Val) motif, which is present in OSRT1- and SPAK-activating kinases (with-no-lysine-kinase 1 (WNK1 and WNK4) and also in STE20 kinase family substrates (NKCC1 and NKCC2). It is reported that phosphorylation of a Ser/Thr residue preceding the (Arg-Phe-Xaa-Val) motif results in steric clash, and subsequent dissociation from the CCT domain. Furthermore, patients suffering from Gordon syndrome carry mutated WNK1 and WNK4 genes.||Applications:|Suitable for use in Western Blot. Other applications not tested.||Recommended Dilutions:|Western Blot: 0.5ug/ml |Optimal dilutions to be determined by the researcher.||Positive Control: |Hypotonic-stimulated HEK293 cells untreated and lambda phosphatase-treated.||Storage and Stability:|Store product at 4°C in the dark. DO NOT FREEZE! Stable at 4°C for 12 months after receipt as an undiluted liquid. Dilute required amount only prior to immediate use. Further dilutions can be made in assay buffer. Caution: APC conjugates are sensitive to light. For maximum recovery of product, centrifuge the original vial prior to removing the cap. ||Note: Applications are based on unconjugated antibody.