Subcellular localization of mannose 6-phosphate glycoproteins in rat brain
| Autor: | David E. Sleat, Peter Lobel, Li Lin, Istvan Sohar, Robert Wattiaux, Ming Sing Hsu, Franz Dubois, Michel Jadot, John E. Pintar, Simone Wattiaux-De Coninck |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 1999 |
| Předmět: |
Male
Mannose Mannose 6-phosphate Biology Biochemistry chemistry.chemical_compound symbols.namesake Lysosome medicine Animals Rats Wistar Molecular Biology chemistry.chemical_classification Neurons Mannose 6-phosphate receptor Mannosephosphates Brain Biological Transport Cell Biology Golgi apparatus Subcellular localization Cell biology Rats medicine.anatomical_structure chemistry symbols Phosphorylation Glycoprotein Lysosomes |
| Zdroj: | The Journal of Biological Chemistry. 274(30):21104-21113 |
| ISSN: | 1083-351X 0021-9258 |
| Popis: | The intracellular transport of soluble lysosomal enzymes relies on the post-translational modification of N-linked oligosaccharides to generate mannose 6-phosphate (Man 6-P) residues. In most cell types the Man 6-P signal is rapidly removed after targeting of the precursor proteins from the Golgi to lysosomes via interactions with Man 6-phosphate receptors. However, in brain, the steady state proportion of lysosomal enzymes containing Man 6-P is considerably higher than in other tissues. As a first step toward understanding the mechanism and biological significance of this observation, we analyzed the subcellular localization of the rat brain Man 6-P glycoproteins by combining biochemical and morphological approaches. The brain Man 6-P glycoproteins are predominantly localized in neuronal lysosomes with no evidence for a steady state localization in nonlysosoreal or prelysosomal compartments. This contrasts with the clear endosome-like localization of the low steady state proportion of mannose-6-phosphorylated lysosomal enzymes in liver. It therefore seems likely that the observed high percentage of phosphorylated species in brain is a consequence of the accumulation of lysosomal enzymes in a neuronal lysosome that does not fully dephosphorylate the Man 6-P moieties. |
| Databáze: | OpenAIRE |
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