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Transport of proteolipid protein to the plasma membrane does not depend on glycosphingolipid cotransport in oligodendrocyte cultures
Author(s) -
van der Haar Marjan E.,
Visser H. Willy,
de Vries Hans,
Hoekstra Dick
Publication year - 1998
Publication title -
journal of neuroscience research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.72
H-Index - 160
eISSN - 1097-4547
pISSN - 0360-4012
DOI - 10.1002/(sici)1097-4547(19980201)51:3<371::aid-jnr10>3.0.co;2-a
Subject(s) - biochemistry , oligodendrocyte , glycosphingolipid , myelin proteolipid protein , chinese hamster ovary cell , ceramide , cotransporter , chemistry , myelin , microbiology and biotechnology , biology , sodium , receptor , myelin basic protein , apoptosis , organic chemistry , neuroscience , central nervous system
The possibility that transport of proteolipid protein (PLP) from its site of synthesis to the plasma membrane is dependent on cotransport with (sulfo)galacto‐cerebrosides was investigated in primary cultured oligodendrocytes and Chinese hamster ovary (CHO) cells expressing PLP. Sulfation was inhibited by growing oligodendrocytes in the presence of a competitive inhibitor of this process, sodium chlorate. Under these circumstances, sulfatide synthesis was inhibited by 85%. Nevertheless, PLP was still delivered to the plasma membrane in quantitative amounts. Furthermore, when PLP was expressed in CHO cells, which normally synthesize very low amounts of galactosyl ceramide (GalCer) and no sulfatide, PLP was transported to the plasma membrane. Moreover, in CHO cells coexpressing PLP and ceramide galactosyl transferase, PLP cell surface labeling was unaltered. Noting that it has been demonstrated that proteins destined for the apical surface of epithelial cells colocalize with glycolipid‐enriched microdomains, we isolated detergent‐insoluble membrane complexes from cultured oligodendrocytes. We found, however, that most of the PLP is present in the detergent‐soluble fraction and, furthermore, that PLP could not be chased into or out of the insoluble fraction. Taken together, these data make it very likely that in oligodendrocytes PLP transport takes place irrespective of the presence of glycosphingolipids GalCer and sulfatide. J. Neurosci. Res. 51:371–381, 1998. © 1998 Wiley‐Liss, Inc.