title: A complex consisting of pp60c-src/pp60c-srcN and a 38 kDa protein is highly enriched in growth cones from differentiated SH-SY5Y neuroblastoma cells.
abstract: Nerve growth cones of primary neurons are highly enriched in the proto-oncogene product pp60c-src. In order to investigate this molecule further in growing neuronal cells, growth cone and cell body fractions were prepared from human SH-SY5Y neuroblastoma cells differentiated neuronally in vitro under the influence of phorbol ester. The fractions were characterized ultrastructurally and by biochemical criteria. The neuronal (pp60c-srcN) and the fibroblastic (pp60c-src) forms of pp60src are slightly enriched and activated in the growth cones relative to the perikarya. Immunoprecipitates of pp60src from differentiated SH-SY5Y growth cones contain at least four phosphoproteins in addition to pp60src. One of these, pp38, migrates as a 100-140 kDa complex with pp60src under non-reducing conditions of gel electrophoresis. The pp38/pp60src complex is not easily detected in non-differentiated SH-SY5Y cells or perikarya of differentiated SH-SY5Y cells, but it is highly enriched in the growth cone preparation. These data suggest that growth-cone pp60src exists in a disulfide-linked oligomeric complex. The complex appears to be assembled only in the cell periphery and may be dependent upon neuronal differentiation.
authors.affiliation: Department of Pathology, University of Uppsala, University Hospital, Sweden.
authors.forename: G
authors.initials: G
authors.lastname: Meyerson
authors.forename: K H
authors.initials: KH
authors.lastname: Pfenninger
authors.forename: S
authors.initials: S
authors.lastname: Påhlman
mesh_terms: D002454:Cell Differentiation / Q000187:drug effects; D002458:Cell Fractionation; D006801:Humans; D008854:Microscopy, Electron; D008970:Molecular Weight; D009447:Neuroblastoma / Q000378:metabolism / Q000648:ultrastructure; D009474:Neurons / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D010750:Phosphoproteins / Q000302:isolation & purification / Q000378:metabolism*; D000090063:Proto-Oncogene Mas; D016392:Proto-Oncogene Proteins pp60(c-src) / Q000378:metabolism*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014407:Tumor Cells, Cultured / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure
chemical_list: C000715470:MAS1 protein, human; D010750:Phosphoproteins; D000090063:Proto-Oncogene Mas; D016392:Proto-Oncogene Proteins pp60(c-src); D013755:Tetradecanoylphorbol Acetate