Segregation of gangliosides GM1 and GD3 on cell membranes, isolated membrane rafts, and defined supported lipid monolayers.
Biol Chem
; 382(2): 241-50, 2001 Feb.
Article
in En
| MEDLINE
| ID: mdl-11308022
ABSTRACT
Lateral assemblies of sphingolipids, glycosphingolipids and cholesterol, termed rafts, are postulated to be present in biological membranes and to function in important cellular phenomena. We probed whether rafts are heterogeneous by determining the relative distribution of two gangliosides, GM1 and GD3, in artificial supported monolayers, in intact rat primary cerebellar granule neurones, and in membrane rafts isolated from rat cerebellum. Fluorescence resonance energy transfer (FRET) using fluorophore-labelled cholera toxin B subunit (which binds GM1) and mAb R24 (which binds GD3) revealed that GM1 spontaneously self-associates but does not co-cluster with GD3 in supported monolayers and on intact neurones. Cholera toxin and immunocytochemical labelling of isolated membrane rafts from rat cerebellum further demonstrated that GM1 does not co-localise with GD3. Furthermore, whereas the membrane raft resident proteins Lyn and caveolin both co-localise with GD3 in isolated membrane rafts, GM1 appears in separate and distinct aggregates. These data support prior reports that membrane rafts are heterogeneous, although the mechanisms for establishing and maintaining such heterogeneity remain to be determined.
Search on Google
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Cell Membrane
/
G(M1) Ganglioside
/
Gangliosides
/
Membrane Lipids
/
Neurons
Limits:
Animals
Language:
En
Journal:
Biol Chem
Journal subject:
BIOQUIMICA
Year:
2001
Document type:
Article
Affiliation country:
United States