Comparison of a 52-kDa phosphoprotein from synaptic plasma membranes related to long-term potentiation and the major coated vesicle phosphoprotein.
In the in vitro hippocampal slice preparation a short tetanus induces long-term potentiation (LTP) and an increase in the post hoc phosphorylation of a 52-kDa protein in synaptosomal plasma membranes (SPM) prepared from these slices. This 52-kDa SPM phosphoprotein closely resembles the predominant phosphoprotein in coated vesicles, pp50, with respect to the insensitivity of its phosphorylation to Ca2+/calmodulin and cyclic AMP. This resemblance prompted us to compare in rat brain the 52-kDa SPM protein with pp50 in isolated coated vesicles. Both proteins appear to be very similar on basis of the following criteria: relative molecular weight on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, peptide mapping, phospho-amino acid content, and isoelectric point. Since coated vesicles are thought to be involved in receptor-mediated endocytosis and membrane recycling, our data suggest that LTP-correlated changes in 52-kDa phosphorylation may reflect increased coated vesicle activity.
D000200:Action Potentials; D000818:Animals; D003034:Coated Pits, Cell-Membrane / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D008970:Molecular Weight; D010750:Phosphoproteins / Q000302:isolation & purification / Q000378:metabolism*; D010766:Phosphorylation; D051381:Rats; D013570:Synaptic Membranes / Q000378:metabolism*
D010750:Phosphoproteins