[HTML][HTML] Changes in membrane sphingolipid composition modulate dynamics and adhesion of integrin nanoclusters

C Eich, C Manzo, S Keijzer, GJ Bakker… - Scientific reports, 2016 - nature.com
C Eich, C Manzo, S Keijzer, GJ Bakker, I Reinieren-Beeren, MF García-Parajo, A Cambi
Scientific reports, 2016nature.com
Sphingolipids are essential constituents of the plasma membrane (PM) and play an
important role in signal transduction by modulating clustering and dynamics of membrane
receptors. Changes in lipid composition are therefore likely to influence receptor
organisation and function, but how this precisely occurs is difficult to address given the
intricacy of the PM lipid-network. Here, we combined biochemical assays and single
molecule dynamic approaches to demonstrate that the local lipid environment regulates …
Abstract
Sphingolipids are essential constituents of the plasma membrane (PM) and play an important role in signal transduction by modulating clustering and dynamics of membrane receptors. Changes in lipid composition are therefore likely to influence receptor organisation and function, but how this precisely occurs is difficult to address given the intricacy of the PM lipid-network. Here, we combined biochemical assays and single molecule dynamic approaches to demonstrate that the local lipid environment regulates adhesion of integrin receptors by impacting on their lateral mobility. Induction of sphingomyelinase (SMase) activity reduced sphingomyelin (SM) levels by conversion to ceramide (Cer), resulting in impaired integrin adhesion and reduced integrin mobility. Dual-colour imaging of cortical actin in combination with single molecule tracking of integrins showed that this reduced mobility results from increased coupling to the actin cytoskeleton brought about by Cer formation. As such, our data emphasizes a critical role for the PM local lipid composition in regulating the lateral mobility of integrins and their ability to dynamically increase receptor density for efficient ligand binding in the process of cell adhesion.
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