Synthesis of β-Tubulin, Actin, and Other Proteins in Axons of Sympathetic Neurons in Compartmented Cultures

摘要: The proteins needed for growth and maintenance of the axon are generally believed to be synthesized in cell bodies delivered axons by anterograde transport. However, recent reports suggest that some can also within axons. We used [35S]methionine metabolic labeling investigate axonal protein synthesis compartmented cultures sympathetic neurons from newborn rats. Incubation distal 4 hr with resulted a highly specific pattern labeled on SDS-PAGE, prominent bands 43–55 kDa range. were not bodies, because they produced after had been removed. Two identified immunoprecipitation as actin β-tubulin. Axons <1% tubulin transported into axons, 75–85% inhibition cycloheximide puromycin failed inhibit elongation. Nonetheless, production major cytoskeleton suggests arises mechanisms likely has biological significance. One hypothetical scenario involves long vivo which losses turnover during transport may limit availability body In this case, significant fraction might supplied synthesis, could, therefore, play important roles maintenance, regeneration, sprouting.