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Assembly of Myelin by Association of Proteolipid Protein with Cholesterol- and Galactosylceramide-Rich Membrane Domains
Myelin is a specialized membrane enriched in glycosphingolipids and cholesterol that contains a limited spectrum of proteins. We investigated the assembly of myelin components by oligodendrocytes and analyzed the role of lipid–protein interactions in this process. Proteolipid protein (PLP), the majo...
Autores principales: | , , , , |
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Formato: | Texto |
Lenguaje: | English |
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The Rockefeller University Press
2000
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2189802/ https://www.ncbi.nlm.nih.gov/pubmed/11018060 |
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author | Simons, Mikael Krämer, Eva-Maria Thiele, Christoph Stoffel, Wilhelm Trotter, Jacqueline |
author_facet | Simons, Mikael Krämer, Eva-Maria Thiele, Christoph Stoffel, Wilhelm Trotter, Jacqueline |
author_sort | Simons, Mikael |
collection | PubMed |
description | Myelin is a specialized membrane enriched in glycosphingolipids and cholesterol that contains a limited spectrum of proteins. We investigated the assembly of myelin components by oligodendrocytes and analyzed the role of lipid–protein interactions in this process. Proteolipid protein (PLP), the major myelin protein, was recovered from cultured oligodendrocytes from a low-density CHAPS-insoluble membrane fraction (CIMF) enriched in myelin lipids. PLP associated with the CIMF after leaving the endoplasmic reticulum but before exiting the Golgi apparatus, suggesting that myelin lipid and protein components assemble in the Golgi complex. The specific association of PLP with myelin lipids in CIMF was supported by the finding that it was efficiently cross-linked to photoactivable cholesterol, but not to phosphatidylcholine, which is underrepresented in both myelin and CIMF. Furthermore, depletion of cholesterol or inhibition of sphingolipid synthesis in oligodendrocytes abolished the association of PLP with CIMF. Thus, PLP may be recruited to myelin rafts, represented by CIMF, via lipid–protein interactions. In contrast to oligodendrocytes, after transfection in BHK cells, PLP is absent from isolated CIMF, suggesting that PLP requires specific lipids for raft association. In mice deficient in the enzyme ceramide galactosyl transferase, which cannot synthesize the main myelin glycosphingolipids, a large fraction of PLP no longer associates with rafts. Formation of a cholesterol- and galactosylceramide-rich membrane domain (myelin rafts) may be critical for the sorting of PLP and assembly of myelin in oligodendrocytes. |
format | Text |
id | pubmed-2189802 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2000 |
publisher | The Rockefeller University Press |
record_format | MEDLINE/PubMed |
spelling | pubmed-21898022008-05-01 Assembly of Myelin by Association of Proteolipid Protein with Cholesterol- and Galactosylceramide-Rich Membrane Domains Simons, Mikael Krämer, Eva-Maria Thiele, Christoph Stoffel, Wilhelm Trotter, Jacqueline J Cell Biol Original Article Myelin is a specialized membrane enriched in glycosphingolipids and cholesterol that contains a limited spectrum of proteins. We investigated the assembly of myelin components by oligodendrocytes and analyzed the role of lipid–protein interactions in this process. Proteolipid protein (PLP), the major myelin protein, was recovered from cultured oligodendrocytes from a low-density CHAPS-insoluble membrane fraction (CIMF) enriched in myelin lipids. PLP associated with the CIMF after leaving the endoplasmic reticulum but before exiting the Golgi apparatus, suggesting that myelin lipid and protein components assemble in the Golgi complex. The specific association of PLP with myelin lipids in CIMF was supported by the finding that it was efficiently cross-linked to photoactivable cholesterol, but not to phosphatidylcholine, which is underrepresented in both myelin and CIMF. Furthermore, depletion of cholesterol or inhibition of sphingolipid synthesis in oligodendrocytes abolished the association of PLP with CIMF. Thus, PLP may be recruited to myelin rafts, represented by CIMF, via lipid–protein interactions. In contrast to oligodendrocytes, after transfection in BHK cells, PLP is absent from isolated CIMF, suggesting that PLP requires specific lipids for raft association. In mice deficient in the enzyme ceramide galactosyl transferase, which cannot synthesize the main myelin glycosphingolipids, a large fraction of PLP no longer associates with rafts. Formation of a cholesterol- and galactosylceramide-rich membrane domain (myelin rafts) may be critical for the sorting of PLP and assembly of myelin in oligodendrocytes. The Rockefeller University Press 2000-10-02 /pmc/articles/PMC2189802/ /pubmed/11018060 Text en © 2000 The Rockefeller University Press This article is distributed under the terms of an Attribution–Noncommercial–Share Alike–No Mirror Sites license for the first six months after the publication date (see http://www.rupress.org/terms). After six months it is available under a Creative Commons License (Attribution–Noncommercial–Share Alike 4.0 Unported license, as described at http://creativecommons.org/licenses/by-nc-sa/4.0/). |
spellingShingle | Original Article Simons, Mikael Krämer, Eva-Maria Thiele, Christoph Stoffel, Wilhelm Trotter, Jacqueline Assembly of Myelin by Association of Proteolipid Protein with Cholesterol- and Galactosylceramide-Rich Membrane Domains |
title | Assembly of Myelin by Association of Proteolipid Protein with Cholesterol- and Galactosylceramide-Rich Membrane Domains |
title_full | Assembly of Myelin by Association of Proteolipid Protein with Cholesterol- and Galactosylceramide-Rich Membrane Domains |
title_fullStr | Assembly of Myelin by Association of Proteolipid Protein with Cholesterol- and Galactosylceramide-Rich Membrane Domains |
title_full_unstemmed | Assembly of Myelin by Association of Proteolipid Protein with Cholesterol- and Galactosylceramide-Rich Membrane Domains |
title_short | Assembly of Myelin by Association of Proteolipid Protein with Cholesterol- and Galactosylceramide-Rich Membrane Domains |
title_sort | assembly of myelin by association of proteolipid protein with cholesterol- and galactosylceramide-rich membrane domains |
topic | Original Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2189802/ https://www.ncbi.nlm.nih.gov/pubmed/11018060 |
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