Accumulation of high level of pp60c-srcN is an early event during GM3-antibody mediated differentiation of neuro-2a neuroblastoma cells.
Neuro-2a neuroblastoma cells, when differentiated via a cAMP-dependent pathway by treatment with anti-GM3 monoclonal antibody, accumulated a high level of pp60c-src protein and pp60c-src kinase activity just before the onset of neurite formation. The specific kinase activity of the accumulated c-src protein was found to be comparable to that of normal cerebellar neurons, but was about 6- to 8-fold higher than that of normal astrocytes. These results, and migrations of peptide fragments in the SDS-polyacrylamide gels after V8 proteolysis, strongly indicate the accumulation of the neuron-specific isoform of the c-src protein (pp60c-srcN) in the GM3 antibody-treated Neuro-2a cells. Similar high levels of pp60c-src protein and pp60c-src kinase activity were observed in the Neuro-2a cells differentiated via a cAMP-dependent pathway by treatment with dibutyryl cAMP, but not in the same cell line when differentiated via a cAMP-independent pathway with 5-bromo-2'-deoxyuridine. These results demonstrate that the accumulation of high levels of the neuron-specific isoform of the pp60c-src protein (pp60c-srcN) in the Neuro-2a neuroblastoma cells depends on the specific signal transduction pathway involved during the differentiation of these cells.
Chakraborty
M
M
Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06511.
Anderson
G M
GM
Chakraborty
A
A
Chatterjee
D
D
D000818:Animals; D000911:Antibodies, Monoclonal; D000912:Antibodies, Neoplasm; D002454:Cell Differentiation / Q000276:immunology; D000242:Cyclic AMP / Q000502:physiology; D005679:G(M3) Ganglioside / Q000276:immunology*; D051379:Mice; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D009447:Neuroblastoma; D009474:Neurons / Q000166:cytology / Q000276:immunology*; D016392:Proto-Oncogene Proteins pp60(c-src) / Q000378:metabolism*; D013997:Time Factors; D014407:Tumor Cells, Cultured
D000911:Antibodies, Monoclonal; D000912:Antibodies, Neoplasm; D005679:G(M3) Ganglioside; D009419:Nerve Tissue Proteins; D000242:Cyclic AMP; D016392:Proto-Oncogene Proteins pp60(c-src)