TY - JOUR
T1 - Glycolipid depletion using a ceramide analogue (PDMP) alters growth, adhesion, and membrane lipid organization in human A431 cells
AU - Barbour, Suzanne
AU - Edidin, Michael
AU - Felding‐Habermann, Brunhilde
AU - Taylor‐Norton, Janelle
AU - Radin, Norman S.
AU - Fenderson, Bruce A.
N1 - Copyright:
Copyright 2016 Elsevier B.V., All rights reserved.
PY - 1992/3
Y1 - 1992/3
N2 - Glycolipids were depleted from the membranes of human A431 cells using 1‐phenyl‐2‐decanoylamino‐3‐morpholino‐1‐propanol (PDMP), an inhibitor of glucosylceramide synthetase. After 6 days of culture in the presence of 5 μM D‐threo‐PDMP, glycolipid content was reduced to approximately 5% of control levels. By contrast, synthesis per cell of phosphatidylcholine, sphingomyelin, triglycerides, and glycoprotein was relatively unchanged in PDMP‐treated cells. In parallel with glycolipid depletion, PDMP‐treated cells exhibited a rapid loss of epithelial cell morphology, a reduced rate of cell growth, and inhibition of cell‐substrate adhesion. The effects of D‐threo‐PDMP on cell morphology and substrate adhesion were blocked by exogenous GM3 addition and were not observed with L‐threo‐PDMP (a relatively inactive enantiomer). Fluorescence photobleaching and recovery (FPR) was used to investigate the hypothesis that glycolipids influence cell behavior, in part, by changing the diffusion characteristics of membrane proteins and lipids. Diffusion coefficients and mobile fractions of two integral membrane proteins, the EGF receptor and a class I MHC antigen, did not differ significantly between control and PDMP‐treated cells. Diffusion coefficients of lipid probes, NBD‐PC and fluorescent GM1 ganglioside, were similarly unaffected by gly‐colipid depletion. However, lipid probes did show a significant increase in mobile fraction (the fraction of lipids that are free to diffuse) in PDMP‐treated cells. This increase was blocked by culturing cells in the presence of exogenous GM3 ganglioside. The results suggest that glycolipids play a role in the formation of lipid domains in A431 cell membranes. Glycolipid‐mediated changes in membrane lipid organization may influence receptor activation and transmembrane signaling, leading to changes in cell growth, morphology, and adhesion.
AB - Glycolipids were depleted from the membranes of human A431 cells using 1‐phenyl‐2‐decanoylamino‐3‐morpholino‐1‐propanol (PDMP), an inhibitor of glucosylceramide synthetase. After 6 days of culture in the presence of 5 μM D‐threo‐PDMP, glycolipid content was reduced to approximately 5% of control levels. By contrast, synthesis per cell of phosphatidylcholine, sphingomyelin, triglycerides, and glycoprotein was relatively unchanged in PDMP‐treated cells. In parallel with glycolipid depletion, PDMP‐treated cells exhibited a rapid loss of epithelial cell morphology, a reduced rate of cell growth, and inhibition of cell‐substrate adhesion. The effects of D‐threo‐PDMP on cell morphology and substrate adhesion were blocked by exogenous GM3 addition and were not observed with L‐threo‐PDMP (a relatively inactive enantiomer). Fluorescence photobleaching and recovery (FPR) was used to investigate the hypothesis that glycolipids influence cell behavior, in part, by changing the diffusion characteristics of membrane proteins and lipids. Diffusion coefficients and mobile fractions of two integral membrane proteins, the EGF receptor and a class I MHC antigen, did not differ significantly between control and PDMP‐treated cells. Diffusion coefficients of lipid probes, NBD‐PC and fluorescent GM1 ganglioside, were similarly unaffected by gly‐colipid depletion. However, lipid probes did show a significant increase in mobile fraction (the fraction of lipids that are free to diffuse) in PDMP‐treated cells. This increase was blocked by culturing cells in the presence of exogenous GM3 ganglioside. The results suggest that glycolipids play a role in the formation of lipid domains in A431 cell membranes. Glycolipid‐mediated changes in membrane lipid organization may influence receptor activation and transmembrane signaling, leading to changes in cell growth, morphology, and adhesion.
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U2 - 10.1002/jcp.1041500322
DO - 10.1002/jcp.1041500322
M3 - Article
C2 - 1537889
AN - SCOPUS:0026573630
SN - 0021-9541
VL - 150
SP - 610
EP - 619
JO - Journal of Cellular Physiology
JF - Journal of Cellular Physiology
IS - 3
ER -