Sorting of newly synthesized galactosphingolipids to the two surface domains of epithelial cells
| Autor: | van der Bijl, Petra, van Meer, G., Lopes-Cardozo, M., Biochemie van Membranen, Dep Scheikunde |
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| Přispěvatelé: | Biochemie van Membranen, Dep Scheikunde |
| Rok vydání: | 1996 |
| Předmět: |
Ceramide
Galactosylceramides Biology Glucosylceramides Models Biological Epithelium Cell membrane chemistry.chemical_compound symbols.namesake Dogs Cell polarity medicine Animals Humans Cells Cultured Fluorescent Dyes Vesicle Cell Membrane Fatty Acids Cell Polarity Epithelial Cells Articles Cell Biology Glycosphingolipid Golgi apparatus Sphingolipid Cell Compartmentation Cell biology medicine.anatomical_structure chemistry symbols lipids (amino acids peptides and proteins) Sphingomyelin |
| Zdroj: | Journal of Cell Biology, 132(5), 813. Rockefeller University Press The Journal of Cell Biology |
| ISSN: | 1540-8140 0021-9525 |
| DOI: | 10.1083/jcb.132.5.813 |
| Popis: | The high concentration of glycosphingolipids on the apical surface of epithelial cells may be generated by selective transport from their site of synthesis to the cell surface. Previously, we showed that canine kidney MDCK and human intestinal Caco-2 cells converted a ceramide carrying the short fluorescent fatty acid C6-NBD to glucosylceramide (GlcCer) and sphingomyelin (SM), and that GlcCer was preferentially transported to the apical surface as compared to SM. Here, we address the point that not all glycosphingolipid classes are apically enriched in epithelia. We show that a ceramide containing the 2-hydroxy fatty acid C6OH was preferentially converted by MDCK and Caco-2 cells to galactosylceramide (GalCer) and its derivatives galabiosylceramide (Ga2Cer) and sulfatide (SGalCer) as compared to SM and GlcCer--all endogenous lipid classes of these cells. Transport to the apical and basolateral cell surface was monitored by a BSA-depletion assay. In MDCK cells, GalCer reached the cell surface with two- to sixfold lower apical/basolateral polarity than GlcCer. Remarkably, in Caco-2 cells GalCer and GlcCer displayed the same apical/basolateral polarity, but it was sixfold lower for lipids with a C6OH chain than for C6-NBD lipids. Therefore, the sorting of a sphingolipid appears to depend on lipid structure and cell type. We propose that the different ratios of gluco- and galactosphingolipid synthesis in the various epithelial tissues govern lipid sorting in the membrane of the trans Golgi network by dictating the composition of the domains from where vesicles bud to the apical and basolateral cell surface. |
| Databáze: | OpenAIRE |
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