Synaptophysin: a substrate for the protein tyrosine kinase pp60c-src in intact synaptic vesicles.
Expression of pp60c-src, the first well defined proto-oncogene product, is developmentally regulated and tissue-specific, with neuronal tissues displaying high amounts of the c-src encoded pp60c-src kinase activity. In the central nervous system pp60c-src is preferentially expressed in regions characterized by a high content of grey matter and elevated density of nerve terminals. In this study we show for the first time a direct interaction between pp60c-src and synaptophysin as a physiological target protein in neurons by demonstrating that endogenous pp60c-src is able to phosphorylate synaptophysin (p38). p38 is a major constituent of the synaptic vesicle membrane protein and is thought to play a key role in the exocytosis of small synaptic vesicles and possibly small clear vesicles in neuroendocrine cells.
Institute Med. Virology, University of Giessen, Federal Republic of Germany.
A
A
Barnekow
R
R
Jahn
M
M
Schartl
D000818:Animals; D000911:Antibodies, Monoclonal; D015153:Blotting, Western; D002458:Cell Fractionation; D066298:In Vitro Techniques; D008565:Membrane Proteins / Q000378:metabolism*; D008970:Molecular Weight; D009419:Nerve Tissue Proteins / Q000378:metabolism; D010446:Peptide Fragments / Q000032:analysis; D010750:Phosphoproteins / Q000378:metabolism; D010766:Phosphorylation; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D011518:Proto-Oncogene Proteins / Q000378:metabolism*; D016392:Proto-Oncogene Proteins pp60(c-src); D051381:Rats; D013572:Synaptic Vesicles / Q000378:metabolism*; D016708:Synaptophysin
D000911:Antibodies, Monoclonal; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; D010446:Peptide Fragments; D010750:Phosphoproteins; D011518:Proto-Oncogene Proteins; D016708:Synaptophysin; D011505:Protein-Tyrosine Kinases; D016392:Proto-Oncogene Proteins pp60(c-src)