Phosphorylation Pathway

Protein phosphorylation is considered the most abundant post-translational modification in eukaryotes. Phosphorylation can occur on serine, threonine and tyrosine side chains (often called 'residues') through phosphoester bond formation, on histidine, lysine and arginine through phosphoramidate bonds, and on aspartic acid and glutamic acid through mixed anhydride linkages. Recent evidence confirms widespread histidine phosphorylation at both the 1 and 3 N-atoms of the imidazole ring. Recent work demonstrates widespread human protein phosphorylation on multiple non-canonical amino acids, including motifs containing phosphorylated histidine, aspartate, glutamate, cysteine, arginine and lysine in HeLa cell extracts.

Phosphorylation Pathway