Standard Article

Protein Association with Membrane Rafts

  1. Michael Veit,
  2. Bastian Thaa

Published Online: 15 JUN 2011

DOI: 10.1002/9780470015902.a0023404

eLS

eLS

How to Cite

Veit, M. and Thaa, B. 2011. Protein Association with Membrane Rafts. eLS. .

Author Information

  1. Free University Berlin, Philippstraße, Berlin, Germany

Publication History

  1. Published Online: 15 JUN 2011

Abstract

Membrane rafts are very small and highly dynamic assemblies in cellular membranes enriched in cholesterol and sphingolipids. Some proteins can functionally associate with rafts: peripheral membrane proteins are incorporated into rafts depending on cues such as the presence of a glycosyl-phosphatidylinositol (GPI) anchor or S-acylation (palmitoylation); transmembrane proteins can partition into raft domains depending on specific features within their transmembrane domain. Raft association of membrane proteins was originally defined by their resistance to cold Triton X-100 extraction, which is however insufficient as the sole criterion – more sophisticated methodology such as fluorescence resonance energy transfer (FRET) has to be employed to determine whether and how a given protein interacts with raft structures.

Key Concepts:

  • Membrane rafts are small, dynamic clusters within biological membranes enriched in cholesterol and sphingolipids.

  • Rafts can be coalesced and stabilised to fulfil a biological function, for example, signal transduction or virus budding.

  • Some proteins are capable of partitioning into raft domains.

  • Raft-targeting features in proteins are glycosyl-phosphatidylinositol (GPI) anchors, S-acylation (palmitoylation) and structural motifs in the transmembrane domain.

  • Assessment of detergent-resistant membranes (DRM), the original biochemical method to analyse raft association of a protein, is artefact-prone and therefore not suitable to prove raft involvement in a biological process.

  • More sophisticated methodology such as fluorescence resonance energy transfer (FRET) is needed to decipher raft association of a protein.

Keywords:

  • membrane raft;
  • cholesterol;
  • sphingolipid;
  • glycosyl-phosphatidylinositol (GPI) anchor;
  • S-acylation/palmitoylation;
  • detergent-resistant membranes (DRM);
  • fluorescence microscopy;
  • fluorescence resonance energy transfer (FRET);
  • nanoscopy;
  • model membranes