Phosphorylation is one way that a cell carries out its tasks, activating proteins or altering their function by adding phosphoryl groups to individual amino acids. For lack of specific antibodies to study its role, the phosphorylation of one amino acid, histidine, is still insufficiently unstudied.Current technologies for the study of protein biochemistry and proteomics have been optimized for certain phosphorylated amino acids: phosphotyrosine, for instance, which could comprise only about 1% of the 200,000 known sites of phosphorylation. Phosphohistidine, meanwhile, may contribute up to 6% of eukaryotic phosphorylation. Clearly, there was a need to open up avenues of study for pHis with specific, monoclonal antibodies, which have now been developed by the Hunter Lab. By providing the ability to detect and evaluate new sites of protein phosphorylation, this work could bring new understanding of signal transduction pathways, and also find important applications in the detection of tumors and the search for new antibiotics.Image: LD-Histidine, by Bin im Garten (Own work) [CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons
