Protein-bound histidine, as well as protein-bound serine, residues are sites of phosphorylation in the synaptic plasma membrane.
When synaptic plasma membrane fragments are incubated with ATP in the presence of Mg2+, phosphate is transferred, not only to protein-bound serine, but also to protein-bound histidine. The phosphorylation of protein-bound serine is stimulated by cyclic AMP and has a Km for ATP of about 0.12 mM, both in the presence and absence of cyclic AMP. By contrast, the phosphorylation of protein-bound histidine is unaffected by cyclic AMP and does not follow Michaelis-Menton kinetics since a non-linear double reciprocal plot is given when activity is measured at various ATP concentrations.
D000255:Adenosine Triphosphate / Q000008:administration & dosage / Q000378:metabolism; D001665:Binding Sites; D000242:Cyclic AMP / Q000494:pharmacology; D006639:Histidine / Q000378:metabolism*; D066298:In Vitro Techniques; D007700:Kinetics; D008565:Membrane Proteins / Q000378:metabolism*; D010710:Phosphates / Q000378:metabolism*; D012694:Serine / Q000378:metabolism*; D013570:Synaptic Membranes / Q000378:metabolism*
D008565:Membrane Proteins; D010710:Phosphates; D012694:Serine; D006639:Histidine; D000255:Adenosine Triphosphate; D000242:Cyclic AMP