Overexpression induces expression of sensor protein kdpD gene at low K(+) concentrations (0 and 250 uM, tested in M.smegatis). May interact with sensor protein KdpD. Probably also has a lipid-anchor at the mature N-terminus. Has been suggested to have 2 transmembrane domains (PubMed:12581360), but bioinformatic evidence does not support this. Modified by Lgt on Cys-35 with an S-linked diacylglycerol, signal peptide is removed by LspA, modified by Lnt with amide-linked fatty acid (By similarity).