Naslov
Membrane redistribution of gangliosides and glycosylphosphatidylinositol-anchored proteins under conditions of lipid raft isolation

Autori
Heffer-Lauc, Marija ; Lauc, Gordan ; Nimrichter, Leonardo ; Fromholt, Susan E. ; Schnaar, Ronald L.

Izvornik
Biochimica and biophysica acta. Molecular and cell biology of lipids (1388-1981) 1686 (2005), 3; 200-208

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
Microdomain; brain; myelin; ganglioside; Triton X-100

Sažetak
Sphingolipids, GPI-anchored proteins, and certain signaling molecules segregate from bulk membrane lipids into lateral domains termed lipid rafts, which are often isolated based on their insolubility in cold non-ionic detergents. During immunohistological studies of gangliosides, major sphingolipids of the brain, we found that cold Triton X-100 solubility is bidirectional, leading to histological redistribution from gray to white matter. When brain sections were treated with ≥ 0.25% Triton X-100 at 4° C, ganglioside GD1a, which is normally enriched in gray matter and depleted in white matter, redistributed into white matter tracts. Incubation of brain sections from knockout mice lacking GD1a with wild type sections in the presence of cold Triton X-100 resulted in GD1a redistribution from wild type gray matter to knockout white matter. GM1, which is normally enriched in white matter, remained in white-matter after cold detergent treatment and did not migrate to knockout mouse brain sections. However, when gray matter gangliosides were enzymatically converted into GM1 in situ, the newly formed GM1 transmigrated to knockout mouse brain sections in the presence of cold detergent. When purified GD1a was added to knockout mouse brain sections in the presence of cold Triton X-100 it preferentially incorporated into white matter tracts. These data demonstrate that brain white matter is a sink for gangliosides, which redistribute from gray matter in the presence of low concentrations of cold Triton X-100. A glycosylphosphatidylinositol (GPI) anchored protein, Thy-1, also transmigrated from wild type to Thy-1 knockout mouse brain sections in the presence of detergent at 4° C, although less efficiently than did gangliosides. These data raise technical challenges for using non-ionic detergents in certain histological protocols and for isolation of lipid rafts from brain tissue.

Izvorni jezik
Engleski

Znanstvena područja
Biologija, Temeljne medicinske znanosti

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