TY - JOUR

T1 - Ceramide structure dictates glycosphingolipid nanodomain assembly and function

AU - Arumugam, Senthil

AU - Schmieder, Stefanie

AU - Pezeshkian, Weria

AU - Becken, Ulrike

AU - Wunder, Christian

AU - Chinnapen, Dan

AU - Ipsen, John Hjort

AU - Kenworthy, Anne K.

AU - Lencer, Wayne

AU - Mayor, Satyajit

AU - Johannes, Ludger

PY - 2021/6/16

Y1 - 2021/6/16

N2 - Gangliosides in the outer leaflet of the plasma membrane of eukaryotic cells are essential for many cellular functions and pathogenic interactions. How gangliosides are dynamically organized and how they respond to ligand binding is poorly understood. Using fluorescence anisotropy imaging of synthetic, fluorescently labeled GM1 gangliosides incorporated into the plasma membrane of living cells, we found that GM1 with a fully saturated C16:0 acyl chain, but not with unsaturated C16:1 acyl chain, is actively clustered into nanodomains, which depends on membrane cholesterol, phosphatidylserine and actin. The binding of cholera toxin B-subunit (CTxB) leads to enlarged membrane domains for both C16:0 and C16:1, owing to binding of multiple GM1 under a toxin, and clustering of CTxB. The structure of the ceramide acyl chain still affects these domains, as co-clustering with the glycosylphosphatidylinositol (GPI)-anchored protein CD59 occurs only when GM1 contains the fully saturated C16:0 acyl chain, and not C16:1. Thus, different ceramide species of GM1 gangliosides dictate their assembly into nanodomains and affect nanodomain structure and function, which likely underlies many endogenous cellular processes. Gangliosides such as GM1 present in the outer leaflet of the plasma membrane of eukaryotic cells are essential for many cellular functions and pathogenic interactions. Here the authors show that the acyl chain structure of GM1 determines the establishment of nanodomains when actively clustered by actin, which depended on membrane cholesterol and phosphatidylserine or superimposed by the GM1-binding bacterial cholera toxin.

AB - Gangliosides in the outer leaflet of the plasma membrane of eukaryotic cells are essential for many cellular functions and pathogenic interactions. How gangliosides are dynamically organized and how they respond to ligand binding is poorly understood. Using fluorescence anisotropy imaging of synthetic, fluorescently labeled GM1 gangliosides incorporated into the plasma membrane of living cells, we found that GM1 with a fully saturated C16:0 acyl chain, but not with unsaturated C16:1 acyl chain, is actively clustered into nanodomains, which depends on membrane cholesterol, phosphatidylserine and actin. The binding of cholera toxin B-subunit (CTxB) leads to enlarged membrane domains for both C16:0 and C16:1, owing to binding of multiple GM1 under a toxin, and clustering of CTxB. The structure of the ceramide acyl chain still affects these domains, as co-clustering with the glycosylphosphatidylinositol (GPI)-anchored protein CD59 occurs only when GM1 contains the fully saturated C16:0 acyl chain, and not C16:1. Thus, different ceramide species of GM1 gangliosides dictate their assembly into nanodomains and affect nanodomain structure and function, which likely underlies many endogenous cellular processes. Gangliosides such as GM1 present in the outer leaflet of the plasma membrane of eukaryotic cells are essential for many cellular functions and pathogenic interactions. Here the authors show that the acyl chain structure of GM1 determines the establishment of nanodomains when actively clustered by actin, which depended on membrane cholesterol and phosphatidylserine or superimposed by the GM1-binding bacterial cholera toxin.

KW - GPI-ANCHORED PROTEINS

KW - PLASMA-MEMBRANE

KW - CHOLERA-TOXIN

KW - MOLECULAR-DYNAMICS

KW - CORTICAL ACTIN

KW - PHASE-SEPARATION

KW - FORCE-FIELD

KW - RECEPTOR

KW - GM1

KW - ORGANIZATION

U2 - 10.1038/s41467-021-23961-9

DO - 10.1038/s41467-021-23961-9

M3 - Journal article

C2 - 34135326

VL - 12

JO - Nature Communications

JF - Nature Communications

SN - 2041-1723

IS - 1

M1 - 3675

ER -