Tyrosine and serine phosphorylation of dystrophin and the 58-kDa protein in the postsynaptic membrane of Torpedo electric organ.
Dystrophin associates with a 58-kDa and an 87-kDa protein in the postsynaptic membrane of the Torpedo electric organ. We have previously shown that the 87-kDa protein is a major phosphotyrosine-containing protein in these membranes. Immunoprecipitation of the 87-kDa protein from phosphorylated postsynaptic membranes results in coimmunoprecipitation of additional phosphorproteins. These phosphorproteins are identified as dystrophin and the 58-kDa protein. Monoclonal antibodies to dystrophin and the 58-kDa protein immunoprecipitate phosphorylated forms of these proteins from postsynaptic membranes phosphorylated in vitro. Phosphoamino acid analysis reveals that dystrophin and the 58-kDa protein are phosphorylated on serine and tyrosine residues. In addition, both dystrophin and the 58-kDa protein are shown to be phosphorylated on tyrosine residues in vivo. These results suggest that the synaptic function of dystrophin and its associated proteins, the 58-kDa and 87-kDa proteins, may be modulated by tyrosine and serine protein phosphorylation.
Wagner
K R
KR
Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205-2185.
Huganir
R L
RL
D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D002458:Cell Fractionation; D002499:Centrifugation, Density Gradient; D016189:Dystrophin / Q000302:isolation & purification / Q000378:metabolism*; D004557:Electric Organ / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D008565:Membrane Proteins / Q000302:isolation & purification / Q000378:metabolism*; D008970:Molecular Weight; D010768:Phosphoserine / Q000032:analysis*; D019000:Phosphotyrosine; D013570:Synaptic Membranes / Q000378:metabolism; D014101:Torpedo; D014443:Tyrosine / Q000031:analogs & derivatives* / Q000032:analysis
D016189:Dystrophin; D008565:Membrane Proteins; D010768:Phosphoserine; D019000:Phosphotyrosine; D014443:Tyrosine; D000255:Adenosine Triphosphate