Sub-Golgi distribution in rat liver of CMP-NeuAc GM3- and CMP-NeuAc:GT1b alpha 2—-8sialyltransferases and comparison with the distribution of the other glycosyltransferase activities involved in ganglioside biosynthesis
| Autor: | M Trinchera, B Pirovano, Riccardo Ghidoni |
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| Rok vydání: | 1990 |
| Předmět: |
music.instrument
Ganglioside biology Chemistry Alpha (ethology) Cell Biology Golgi apparatus Biochemistry carbohydrates (lipids) Lactosylceramide chemistry.chemical_compound symbols.namesake Hexosyltransferases Biosynthesis Glycosyltransferase biology.protein symbols lipids (amino acids peptides and proteins) music Beta (finance) Molecular Biology |
| Zdroj: | Journal of Biological Chemistry. 265:18242-18247 |
| ISSN: | 0021-9258 |
| DOI: | 10.1016/s0021-9258(17)44744-2 |
| Popis: | Using a sucrose density gradient fractionation of a highly purified Golgi apparatus from rat liver, we determined the sub-Golgi distribution of CMP-NeuAc:GM3 ganglioside alpha 2----8sialyltransferase (GM3-SAT) and CMP-NeuAc:GT1b ganglioside alpha 2----8sialyltransferase (GT1b-SAT), in comparison with that of the other glycosyltransferase activities involved in ganglioside biosynthesis. While GM3-SAT was recovered in several density fractions, GT1b-SAT was mainly found on less dense sub-Golgi membranes; this indicates that these two activities are physically separate. Moreover, with regard to the monosialo pathway, CMP-NeuAc:lactosylceramide alpha 2----3sialyltransferase, UDP-GalNAc:GM3 ganglioside beta 1----4N-acetylgalactosaminyltransferase, UDP-Gal:GM2 ganglioside beta 1----3galactosyltransferase, and CMP-NeuAc:GM1 ganglioside alpha 2----3sialyltransferase were resolved from more dense to less dense fractions, respectively. In the disialo pathway, UDP-GalNAc:GD3 ganglioside beta 1----4N-acetylgalactosaminyltransferase, UDP-Gal:GD2 ganglioside beta 1----3galactosyltransferase and CMP-NeuAc:GD1b ganglioside alpha 2----3sialyltransferase co-distributed with the corresponding activities of the monosialo pathway. These last results indicate that many Golgi glycosyltransferases involved in ganglioside biosynthesis are localized in the order in which they act. |
| Databáze: | OpenAIRE |
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