Role of ceramide in membrane protein organization investigated by combined AFM and FCS

Research output: Contribution to journalResearch articleContributedpeer-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 languageEnglish
Pages (from-to)1356-1364
Number of pages9
JournalBiochimica et Biophysica Acta - Biomembranes
Volume1778
Issue number5
Publication statusPublished - May 2008
Peer-reviewedYes

External IDs

PubMed 18346453

Keywords

ASJC Scopus subject areas

Keywords

  • Atomic force microscopy, Ceramide, Fluorescence correlations spectroscopy, GPI anchor, Liquid-ordered, Membrane protein, Raft

Library keywords