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Cell type specific localization of sphingomyelin biosynthesis
Author(s) -
Sadeghlar Farsaneh,
Sandhoff Konrad,
van Echten-Deckert Gerhild
Publication year - 2000
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(00)01818-4
Subject(s) - sphingomyelin , brefeldin a , golgi apparatus , biosynthesis , glycosphingolipid , ceramide , microbiology and biotechnology , ganglioside , biochemistry , sphingosine , glycolipid , chemistry , biology , cell , cholesterol , receptor , enzyme , apoptosis
We have studied the incorporation of [ 14 C]serine and of [ 3 H]sphingosine into sphingomyelin in the presence or absence of brefeldin A (BFA) in three different cell types. Administration of BFA (1 μg/ml) to fibroblasts for 24 h increased the incorporation of label into sphingomyelin 1.5–3 fold compared with untreated controls. In contrast, BFA strongly decreased sphingomyelin biosynthesis (4–5 fold) in cerebellar neurons as well as in neuroblastoma cells. The effect of BFA on glycosphingolipid formation, however, was similar in all three cell types studied: an increased labeling of the precursor glycolipids GlcCer, LacCer, GM3 and GD3 was paralleled by a decreased formation of complex gangliosides, GM1, GD1a, GT1b and GQ1b. Our data therefore suggest that in neuronal cells sphingomyelin synthesis, like the formation of complex gangliosides, is localized primarily distal to the BFA block, in a post‐Golgi compartment, most probably the trans ‐Golgi network, whereas in fibroblasts sphingomyelin biosynthesis is mainly localized prior to the BFA block, in the Golgi apparatus, as has been shown for LacCer, GlcCer, GM3 and GD3 synthases.