Modulation of nicotinic acetylcholine receptor turnover by tyrosine phosphorylation in rat myotubes

• Published in: Neuroscience letters Vol. 313; no. 1; pp. 37 - 40
• Main Authors: Sava, Anna, Barisone, Ilaria, Di Mauro, Debora, Fumagalli, Guido, Sala, Carlo
• Format: Journal Article
• Language: English
• Published: Shannon Elsevier Ireland Ltd 02-11-2001; Elsevier
• Subjects: Animals; Biological and medical sciences; Biotinylation; Bungarotoxins - metabolism; Bungarotoxins - pharmacology; Cells, Cultured; Cytoskeleton - metabolism; Enzyme Inhibitors - pharmacology; Fundamental and applied biological sciences. Psychology; Iodine Radioisotopes; Muscle Fibers, Skeletal - cytology; Muscle Fibers, Skeletal - metabolism; Myotubes; Neuromuscular junction; Neuromuscular Junction - metabolism; Nicotinic acetylcholine receptor; Pervanadate; Phosphorylation; Phosphotyrosine - metabolism; Protein Tyrosine Phosphatases - antagonists & inhibitors; Protein Tyrosine Phosphatases - metabolism; Radioligand Assay; Rats; Rats, Sprague-Dawley; Receptors, Nicotinic - metabolism; Striated muscle. Tendons; Turnover; Tyrosine - metabolism; Tyrosine phosphatases; Vanadates - pharmacology; Vertebrates: osteoarticular system, musculoskeletal system; Myotubes; Biotinylation; Pervanadate; Nicotinic acetylcholine receptor; Turnover; Tyrosine phosphatases; Neuromuscular junction; Tyrosine; Cholinergic receptor; Vertebrata; Phosphorylation; Mammalia; Rat; Rodentia; Myotube; Striated muscle; Nicotinic receptor
• ISSN: 0304-3940; 1872-7972
• DOI: 10.1016/S0304-3940(01)02244-3

The muscle nicotinic acetylcholine receptor (AChR) turns over at different rates depending on stage of synaptogenesis and innervation. Tyrosine phosphorylation modulates desensitization, interaction with cytoskeleton and lateral mobility in the membrane of AChR. To determine whether tyrosine phosphorylation also modulates the turnover of AChR, myotubes in vitro were exposed to the tyrosine phosphatase inhibitor pervanadate. Our data indicate that a transient increase of phosphotyrosine levels stabilized a fraction of AChRs. The effects were limited to the non-ε subunit-containing AChRs already present in the membrane. Tyrosine phosphorylation of the receptor occurred on the β subunit, was transient and stable molecules were not selectively tyrosine phosphorylated. The data indicate that modulation of phosphotyrosine levels in muscle cells provides signals to control AChR metabolic stability.