ISSN:
1471-4159
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Medicine
Notes:
Abstract: The ninth dorsal root ganglion of adult Xenopus laevis was labeled with N-acetyl-D-[6-3H]mannosamine, and intraaxonal migration of gangliosides was examined by analysis of the chloroform/methanol extract of each of 5-mm consecutive nerve segments by TLC coupled with fluorography. A unique disialoganglioside (GD1α), which amounted to up to 83% of the total ganglioside in this nerve, migrated at 1–2 mm/day at 15°C. This contrasts with the rapid transport of other ganglioside species previously reported in the optic systems of goldfish, rabbits, chickens, and rats. Fluorographic analysis also revealed a trichloro-acetic acid-soluble substance migrating at a velocity of 8 mm/day at 15°C. The substance was considered to be CMP-sialic acid on the basis of observations that it comigrates with authentic CMP-N-acetylneuraminic acid in TLC developed with two different solvent systems, it is very labile to weak acid but resistant to neuraminidase from Vibriocholerae, it is converted to N-acetylmannosamine when treated first with weak acid and subsequently with N-acetyl-neuraminic acid aldolase, and it has a β-sialosyl group in its structure. Because CMP-sialic acid is believed to be the sole sialosyl donor in the cells, its migration in axons toward terminals, together with the previous demonstration of sialyl-transferase activity in the synaptosomal plasma membrane, strongly supports the possibility that sialosylation of gangliosides and probably of other sialoglycoproteins is not confined to the Golgi apparatus, but can also occur after the compounds are committed to axonal transport.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1471-4159.1986.tb13080.x
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