Phosphorylation of membrane-bound acetylcholine receptor by protein kinase C: characterization and subunit specificity
1990; American Chemical Society; Volume: 29; Issue: 28 Linguagem: Inglês
10.1021/bi00480a024
ISSN1943-295X
AutoresAnat Safran, Carlo Provenzano, Ronit Sagi‐Eisenberg, Sara Fuchs,
Tópico(s)Retinal Development and Disorders
ResumoAcetylcholine 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.
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