CMP-sialic acid, the sole sialosyl donor, is intra-axonally transported.
N-Acetyl-D-[6-3H]mannosamine was injected into the 9th dorsal root ganglion of Xenopus laevis and the intra-axonal transport of chloroform/methanol-soluble radioactivity was analyzed using thin-layer chromatography coupled with fluorography. Three radioactive groups were distinct in consecutive segments of the sciatic nerve. The first is due to N-acetyl-D-mannosamine itself which labels the nerve uniformly, but does not seem to migrate within axons. The second group, representing most probably CMP-sialic acid, migrates at about 8 mm/day at 15 degrees C. The third is a species of ganglioside uniquely present in the frog nerve, and this migrates at 1-3 mm/day. Our demonstration of the intra-axonal transport of CMP-sialic acid affords direct support to the contention that sialosylation of the ganglioside can occur in axon terminals.
Igarashi
M
M
Komiya
Y
Y
Kurokawa
M
M
D000818:Animals; D001370:Axonal Transport; D001369:Axons / Q000378:metabolism; D002250:Carbon Radioisotopes; D002855:Chromatography, Thin Layer; D003569:Cytidine Monophosphate N-Acetylneuraminic Acid / Q000302:isolation & purification / Q000378:metabolism*; D005260:Female; D005727:Ganglia, Spinal / Q000378:metabolism*; D006595:Hexosamines / Q000378:metabolism; D009439:Neuraminidase; D012584:Sciatic Nerve / Q000378:metabolism; D012794:Sialic Acids / Q000378:metabolism*; D014316:Tritium; D014981:Xenopus
D002250:Carbon Radioisotopes; D006595:Hexosamines; D012794:Sialic Acids; D014316:Tritium; D003569:Cytidine Monophosphate N-Acetylneuraminic Acid; D009439:Neuraminidase; C002022:N-acetylmannosamine