Electrochemical studies of human nAChR a7 subunit phosphorylation by kinases PKA, PKC and Src.

Nicotinic acetylcholine receptors (nAChR) are ion channels which regulate a numerous of neurotransmitters, including acetylcholine, norepinephrine, dopamine, serotonin and glutamate. These receptors are important targets for the study of a plethora of diseases such as Alzheimer's disease, schizophrenia, Parkinson's Disease, cancer, inflammation, etc. The α7 subunits are especially interesting in that they are commonly occurring and are critical sites of regulation. Herein we report the phosphorylation of the human nAChR α7 subunits, by the kinases PKA, PKC and Src, by both biochemical and electrochemical techniques along with the kinetics of each phosphorylation reaction. Phosphorylation was investigated through changes in current density as well as impedance and X-ray photo electron spectroscopy (XPS) and the kinetics were determined electrochemically using the surface Michaelis-Menten model. Our results clearly demonstrate the phosphorylation of the nAChR α7 and the invaluable strength of surface electrochemical techniques in the investigation of protein phosphorylation.