Reversible phosphorylation of histidine residues in vertebrate proteins.

Knowledge on kinases and phosphatases acting on serine, threonine and tyrosine residues of vertebrate proteins is huge. These enzymes are still under intensive investigation at present. This is in sharp contrast to what is known about kinases and phosphatases acting on histidine, arginine, lysine and aspartate residues in vertebrate proteins. It also is in contrast to extensive studies of histidine/aspartate phosphorylation in prokaryotes. This minireview briefly summarizes what we have learned about the reversible phosphorylation of histidine residues in mammals. It is described how the field developed during 40 years of science. The article especially highlights the discovery of the first protein histidine phosphatase from vertebrates. Having identified and characterized a protein histidine phosphatase provides at least one desperately required tool to handle and study phosphorylation and dephosphorylation of histidine residues in vertebrates in more detail. Recent evidence even suggests an involvement of histidine phosphorylation in signal transduction.