Retrograde axonal transport of locally synthesized proteins, e.g., actin and heat shock protein 70, in regenerating adult frog sciatic sensory axons

The local synthesis and subsequent retrograde axonal transport of [³⁵S]methionine‐labelled proteins was studied in the in vitro regenerating adult frog sciatic sensory axons. By the use of a three compartment culture system, proteins in the outgrowth region were selectively labelled. After 2 days in culture a rise in TCA‐insoluble radioactivity was detected in the dorsal root ganglia, which could be prevented by the addition of viblastine or 2,4‐dinitrophenol to the nerve proximal to the crush site. Two‐dimensional polyacrylamide gel electrophoresis of ganglionic proteins revealed a pattern of 35 labelled polypeptides with apparent molecular masses (M_m) ranging from < 15 to 95 kDa and with isoelectric points (pI) ranging from 4.5 to 6.5. The major ones, representing about 75% of the activity in a gel, were of M_m/pI 47/5.4, 48/6.1,