Sava A, Barisone I, Di Mauro D, Fumagalli G, Sala C
Department of Medicine & Public Health, Section of Pharmacology, School of Medicine, University of Verona, Policlinico Borgo Roma, 37134 Verona, Italy.
Neurosci Lett. 2001 Nov 2;313(1-2):37-40. 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-epsilon subunit-containing AChRs already present in the membrane. Tyrosine phosphorylation of the receptor occurred on the beta 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.
肌肉烟碱型乙酰胆碱受体（AChR）的更新速率因突触发生和神经支配阶段的不同而有所差异。酪氨酸磷酸化可调节AChR的脱敏、与细胞骨架的相互作用以及在膜中的横向移动性。为了确定酪氨酸磷酸化是否也调节AChR的更新，体外培养的肌管被暴露于酪氨酸磷酸酶抑制剂过钒酸盐中。我们的数据表明，磷酸酪氨酸水平的短暂升高稳定了一部分AChR。这些作用仅限于膜中已存在的不含ε亚基的AChR。受体的酪氨酸磷酸化发生在β亚基上，是短暂的，并且稳定的分子不会被选择性地酪氨酸磷酸化。数据表明，调节肌肉细胞中的磷酸酪氨酸水平可提供控制AChR代谢稳定性的信号。
