The GM1 Ganglioside Forms GM1-Rich Gel Phase Microdomains within Lipid Rafts

Biochemical studies have suggested that certain synaptic proteins associate with lipid rafts to perform key functions within the synapse. However, variability in biochemical preparations raises questions as to which synaptic proteins actually associate with lipid rafts. In the present study, we use both electron microscopy and biochemistry to investigate AMPA (α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid) receptor localization in synaptic membrane subfractions prepared in two different ways, by Triton X-100 detergent treatment or without detergent by sonication at high pH. Immunogold electron microscopy shows that a detergent-resistant synaptosomal membrane subfraction consists of empty vesicles 0.1–1.0 μm in diameter. A subpopulation of these vesicles labelled for glycosphingolipid GM1 ganglioside, a marker of lipid rafts, and 46% of the labelled vesicles also labelled for the AMPA receptor subunit GluR2. This co-segregation into specific vesicles does not depend on effects of detergent because a similar distribution of label was found in vesicles isolated without the use of detergent. Our results suggest that AMPA receptors localize within specific regions of synaptic membranes rich in GM1 ganglioside.

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Formation of Toxic Aβ(1–40) Fibrils on GM1 Ganglioside-Containing Membranes Mimicking Lipid Rafts: Polymorphisms in Aβ(1–40) Fibrils

Journal of Molecular Biology ◽

10.1016/j.jmb.2008.07.072 ◽

2008 ◽

Vol 382 (4) ◽

pp. 1066-1074 ◽

Cited By ~ 74

Author(s):

Takuma Okada ◽

Keisuke Ikeda ◽

Masaki Wakabayashi ◽

Mariko Ogawa ◽

Katsumi Matsuzaki

Keyword(s):

Lipid Rafts ◽

Gm1 Ganglioside

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Sphingolipid-Enriched Microdomains in the Plasma Membrane of Saccharomyces Cerevisiae: Ergosterol-Free «Lipid Rafts» in the Gel Phase

Biophysical Journal ◽

10.1016/j.bpj.2011.11.175 ◽

2012 ◽

Vol 102 (3) ◽

pp. 27a

Author(s):

Francisco Aresta-Branco ◽

André M. Cordeiro ◽

H. Susana Marinho ◽

Luísa Cyrne ◽

Fernando Antunes ◽

...

Keyword(s):

Saccharomyces Cerevisiae ◽

Plasma Membrane ◽

Lipid Rafts ◽

Free Lipid ◽

Gel Phase

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Influence of gel-phase microdomains and lipid rafts in lipid monolayers on the electron transfer of a lipophilic redox probe: dioctadecylviologen

Physical Chemistry Chemical Physics ◽

10.1039/c0cp01928c ◽

2011 ◽

Vol 13 (9) ◽

pp. 3917 ◽

Cited By ~ 3

Author(s):

Lucia Becucci ◽

Elisabetta Lottini ◽

Rolando Guidelli

Keyword(s):

Electron Transfer ◽

Lipid Rafts ◽

Lipid Monolayers ◽

Redox Probe ◽

Gel Phase

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Cutting Edge: Optical Microspectrophotometry Supports the Existence of Gel Phase Lipid Rafts at the Lamellipodium of Neutrophils: Apparent Role in Calcium Signaling

The Journal of Immunology ◽

10.4049/jimmunol.172.8.4681 ◽

2004 ◽

Vol 172 (8) ◽

pp. 4681-4685 ◽

Cited By ~ 51

Author(s):

Andrei L. Kindzelskii ◽

Robert G. Sitrin ◽

Howard R. Petty

Keyword(s):

Calcium Signaling ◽

Lipid Rafts ◽

Cutting Edge ◽

Gel Phase

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Caveolin-1, galectin-3 and lipid raft domains in cancer cell signalling

Essays in Biochemistry ◽

10.1042/bse0570189 ◽

2015 ◽

Vol 57 ◽

pp. 189-201 ◽

Cited By ~ 13

Author(s):

Jay Shankar ◽

Cecile Boscher ◽

Ivan R. Nabi

Keyword(s):

Plasma Membrane ◽

Lipid Rafts ◽

Cancer Cell ◽

Cellular Response ◽

Spatial Organization ◽

Essential Feature ◽

Cell Signalling ◽

Coated Pits ◽

Signalling Molecules ◽

Raft Domains

Spatial organization of the plasma membrane is an essential feature of the cellular response to external stimuli. Receptor organization at the cell surface mediates transmission of extracellular stimuli to intracellular signalling molecules and effectors that impact various cellular processes including cell differentiation, metabolism, growth, migration and apoptosis. Membrane domains include morphologically distinct plasma membrane invaginations such as clathrin-coated pits and caveolae, but also less well-defined domains such as lipid rafts and the galectin lattice. In the present chapter, we will discuss interaction between caveolae, lipid rafts and the galectin lattice in the control of cancer cell signalling.

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Spatial control of actin-based motility through plasmalemmal PtdIns(4,5)P2-rich raft assemblies.

Biochemical Society Symposium ◽

10.1042/bss0720119 ◽

2005 ◽

Vol 72 ◽

pp. 119-127 ◽

Cited By ~ 19

Author(s):

Tamara Golub ◽

Caroni Pico

Keyword(s):

Protein Kinase ◽

Cell Surface ◽

Actin Cytoskeleton ◽

Lipid Rafts ◽

Patch Clustering ◽

Pkc Protein Kinase C ◽

Membrane Bound ◽

And Function ◽

Cytoskeleton Dynamics ◽

Syndrome Protein

The interactions of cells with their environment involve regulated actin-based motility at defined positions along the cell surface. Sphingolipid- and cholesterol-dependent microdomains (rafts) order proteins at biological membranes, and have been implicated in most signalling processes at the cell surface. Many membrane-bound components that regulate actin cytoskeleton dynamics and cell-surface motility associate with PtdIns(4,5)P2-rich lipid rafts. Although raft integrity is not required for substrate-directed cell spreading, or to initiate signalling for motility, it is a prerequisite for sustained and organized motility. Plasmalemmal rafts redistribute rapidly in response to signals, triggering motility. This process involves the removal of rafts from sites that are not interacting with the substrate, apparently through endocytosis, and a local accumulation at sites of integrin-mediated substrate interactions. PtdIns(4,5)P2-rich lipid rafts can assemble into patches in a process depending on PtdIns(4,5)P2, Cdc42 (cell-division control 42), N-WASP (neural Wiskott-Aldrich syndrome protein) and actin cytoskeleton dynamics. The raft patches are sites of signal-induced actin assembly, and their accumulation locally promotes sustained motility. The patches capture microtubules, which promote patch clustering through PKA (protein kinase A), to steer motility. Raft accumulation at the cell surface, and its coupling to motility are influenced greatly by the expression of intrinsic raft-associated components that associate with the cytosolic leaflet of lipid rafts. Among them, GAP43 (growth-associated protein 43)-like proteins interact with PtdIns(4,5)P2 in a Ca2+/calmodulin and PKC (protein kinase C)-regulated manner, and function as intrinsic determinants of motility and anatomical plasticity. Plasmalemmal PtdIns(4,5)P2-rich raft assemblies thus provide powerful organizational principles for tight spatial and temporal control of signalling in motility.

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