Role of ceramide in membrane protein organization investigated by combined AFM and FCS
Research output: Contribution to journal › Research article › Contributed › peer-review
Contributors
Abstract
Ceramide-induced alterations in the lateral organization of membrane proteins can be involved in several biological contexts, ranging from apoptosis to viral infections. In order to investigate such alterations in a simple model, we used a combined approach of atomic force microscopy, scanning fluorescence correlation spectroscopy and confocal fluorescence imaging to study the partitioning of different membrane components in sphingomyelin/dioleoyl-phosphatidylcholine/cholesterol/ceramide supported bilayers. Such model membranes exhibit coexistence of liquid-disordered, liquid-ordered (raft-like) and ceramide-rich lipid phases. Our results show that components with poor affinity toward the liquid-ordered phase, such as several fluorescent lipid analogues or the synaptic protein Synaptobrevin 2, are excluded from ceramide-rich domains. Conversely, we show for the first time that the raft-associated protein placental alkaline phosphatase (GPI-PLAP) and the ganglioside GM1 are enriched in such domains, while exhibiting a strong decrease in lateral diffusion. Analogue modulation of the local concentration and dynamics of membrane proteins/receptors by ceramide can be of crucial importance for the biological functions of cell membranes.
Details
Original language | English |
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Pages (from-to) | 1356-1364 |
Number of pages | 9 |
Journal | Biochimica et Biophysica Acta - Biomembranes |
Volume | 1778 |
Issue number | 5 |
Publication status | Published - May 2008 |
Peer-reviewed | Yes |
External IDs
PubMed | 18346453 |
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Keywords
ASJC Scopus subject areas
Keywords
- Atomic force microscopy, Ceramide, Fluorescence correlations spectroscopy, GPI anchor, Liquid-ordered, Membrane protein, Raft