title: How curved membranes recruit amphipathic helices and protein anchoring motifs.
abstract: Lipids and several specialized proteins are thought to be able to sense the curvature of membranes (MC). Here we used quantitative fluorescence microscopy to measure curvature-selective binding of amphipathic motifs on single liposomes 50-700 nm in diameter. Our results revealed that sensing is predominantly mediated by a higher density of binding sites on curved membranes instead of higher affinity. We proposed a model based on curvature-induced defects in lipid packing that related these findings to lipid sorting and accurately predicted the existence of a new ubiquitous class of curvature sensors: membrane-anchored proteins. The fact that unrelated structural motifs such as alpha-helices and alkyl chains sense MC led us to propose that MC sensing is a generic property of curved membranes rather than a property of the anchoring molecules. We therefore anticipate that MC will promote the redistribution of proteins that are anchored in membranes through other types of hydrophobic moieties.
authors.affiliation: Bio-Nanotechnology Laboratory, Department of Neuroscience and Pharmacology & Nano-Science Center, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Nikos S
authors.initials: NS
authors.lastname: Hatzakis
authors.forename: Vikram K
authors.initials: VK
authors.lastname: Bhatia
authors.forename: Jannik
authors.initials: J
authors.lastname: Larsen
authors.forename: Kenneth L
authors.initials: KL
authors.lastname: Madsen
authors.forename: Pierre-Yves
authors.initials: PY
authors.lastname: Bolinger
authors.forename: Andreas H
authors.initials: AH
authors.lastname: Kunding
authors.forename: John
authors.initials: J
authors.lastname: Castillo
authors.forename: Ulrik
authors.initials: U
authors.lastname: Gether
authors.forename: Per
authors.initials: P
authors.lastname: Hedegård
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Stamou
mesh_terms: D019921:Biotinylation; D005452:Fluoresceins / Q000737:chemistry; D007700:Kinetics; D008051:Lipid Bilayers / Q000737:chemistry / Q000378:metabolism; D008081:Liposomes / Q000737:chemistry / Q000378:metabolism; D008563:Membrane Lipids / Q000737:chemistry*; D008565:Membrane Proteins / Q000737:chemistry*; D008566:Membranes / Q000378:metabolism / Q000648:ultrastructure*; D018613:Microscopy, Confocal; D008856:Microscopy, Fluorescence; D008958:Models, Molecular; D010455:Peptides / Q000737:chemistry
chemical_list: D005452:Fluoresceins; D008051:Lipid Bilayers; D008081:Liposomes; D008563:Membrane Lipids; D008565:Membrane Proteins; D010455:Peptides