Protein histidine phosphatases in signal transduction and metabolism

Abstract

Knowledge about the function, structure, and interplay between protein histidine kinases and their response regulators in bacteria is overwhelming. The essential steps are phosphorylation of a histidine residue, phosphotransfer onto aspartate, and dephosphorylation of phosphoaspartate via sensor histidine kinases. Protein histidine phosphatases exist in bacteria as well. Knowledge of N-phosphorylation and dephosphorylation in vertebrates, on the other hand, is still limited. Although there has been unequivocal evidence of the presence of histidine kinases, histidine phosphatases, and N-phosphorylated proteins in mammals for decades, the information is scattered and the few and tiny pieces do not give a complete picture of the puzzle yet. This review on protein histidine phosphatases is intended to give short background information on the bacterial phosphohistidine signal transduction treasures. The major part, however, is directed at the dephosphorylation of phosphohistidine in vertebrate proteins and is culminated in the most recent discovery and cloning of the first protein histidine phosphatase from vertebrates.