Lipid Rafts As a Membrane-Organizing Principle

Max Planck Institute for Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01307 Dresden, Germany.
Science (Impact Factor: 33.61). 01/2010; 327(5961):46-50. DOI: 10.1126/science.1174621
Source: PubMed


Cell membranes display a tremendous complexity of lipids and proteins designed to perform the functions cells require. To
coordinate these functions, the membrane is able to laterally segregate its constituents. This capability is based on dynamic
liquid-liquid immiscibility and underlies the raft concept of membrane subcompartmentalization. Lipid rafts are fluctuating
nanoscale assemblies of sphingolipid, cholesterol, and proteins that can be stabilized to coalesce, forming platforms that
function in membrane signaling and trafficking. Here we review the evidence for how this principle combines the potential
for sphingolipid-cholesterol self-assembly with protein specificity to selectively focus membrane bioactivity.

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    • "Cholesterol partitions into liquid-ordered/disordered phases to roughly the same extent, and this changes the properties of the lipid phases [31]. Other cell membrane lipids, such as sphingolipids, are also important in the formation of ordered membrane lipid domains [32]. Sphingomyelins and phosphatidylcholines constitute more than one-half of the plasma membrane phospholipids and form the main partners for cholesterol in some specialized lipid domains [33]. "

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    • "Nanoscale lipid clusters/domains have been studied quite substantially and shown to be biologically relevant [5] [6]. Meanwhile, the causes and consequences of the asymmetric transmembrane lipid distribution [4] are much less understood, yet clearly the asymmetric nature of lipid distribution is also biologically important given that cells spend considerable resources to maintain it. "
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    • "They are mostly located into membrane microdomains called lipid rafts that are enriched in GPIanchored proteins, glycosphingolipids and sterols (Rietveld et al., 1999; Lingwood and Simons, 2010). Although these proteins have been characterized as receptors in many different insect species for a large range of Bt Cry toxins, their role in the Bt toxins mode of action is still largely misunderstood (Vachon et al., 2012). "
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