Safran A, Provenzano C, Sagi-Eisenberg R, Fuchs S
Department of Chemical Immunology, Weizmann Institute of Science, Rehovot, Israel.
Biochemistry. 1990 Jul 17;29(28):6730-4. doi: 10.1021/bi00480a024.
Acetylcholine receptor (AChR) from Torpedo electric organ in its membrane-bound or solubilized form is phosphorylated by the Ca2+/phospholipid-dependent protein kinase (PKC). The subunit specificity for PKC is different from that observed for cAMP-dependent protein kinase (PKA). Whereas PKC phosphorylates predominantly the delta subunit and the phosphorylation of the gamma subunit by this enzyme is very low, PKA phosphorylates both subunits to a similar high extent. We have extended our phosphorylation studies to a synthetic peptide from the gamma subunit, corresponding to residues 346-359, which contains a consensus PKA phosphorylation site. This synthetic peptide is phosphorylated by both PKA and PKC, suggesting that in the intact receptor both kinases may phosphorylate the gamma subunit at a similar site, as has been previously demonstrated by us for the delta subunit [Safran, A., et al. (1987) J. Biol. Chem. 262, 10506-10510]. The diverse pattern of phosphorylation of AChR by PKA and PKC may play a role in the regulation of its function.
来自电鳐电器官的膜结合型或可溶型乙酰胆碱受体（AChR）可被Ca2+/磷脂依赖性蛋白激酶（PKC）磷酸化。PKC的亚基特异性与环磷酸腺苷依赖性蛋白激酶（PKA）所观察到的不同。PKC主要使δ亚基磷酸化，而该酶对γ亚基的磷酸化程度很低，PKA则使两个亚基磷酸化的程度相似且都很高。我们已将磷酸化研究扩展至γ亚基的一段合成肽，其对应于346 - 359位残基，该合成肽含有一个PKA磷酸化共有位点。此合成肽可被PKA和PKC磷酸化，这表明在完整受体中，两种激酶可能在相似位点使γ亚基磷酸化，正如我们之前对δ亚基所证实的那样[萨夫兰，A.等人（1987年）《生物化学杂志》262卷，10506 - 10510页]。PKA和PKC对AChR的不同磷酸化模式可能在其功能调节中起作用。
