Binds to and modulates brain Na,K-ATPase subunits ATP1B1 and ATP1B3 and may thereby participate in the regulation of electrical excitability and synaptic transmission. May not display kinase activity. Also associates with the plasma membrane. Isoform 1 is present in all tissues examined. Isoform 2 is found in all tissues except skeletal muscle and very low levels in spleen. Both isoforms are widely expressed throughout the nervous system however levels of isoform 2 are higher in purified hippocampal and cortical neurons whereas glial cells express more isoform 1 than isoform 2. The protein kinase domain is predicted to be catalytically inactive. Belongs to the protein kinase superfamily. Intron retention.