Cooperative elastic stresses, the hydrophobic effect, and lipid tilt in membrane remodeling.
One of the fundamental properties of biological membranes is the high lateral integrity provided by the lipid bilayer, the structural core and the foundation of their barrier function. This tensile strength is due to the intrinsic properties of amphiphilic lipid molecules, which spontaneously self-assemble into a stable bilayer structure due to the hydrophobic effect. In the highly dynamic life of cellular membranes systems, however, this integrity has to be regularly compromised. One of the emerging puzzles is the mechanism of localized rupture of lipid monolayer, the formation of tiny hydrophobic patches and flipping of lipid tails between closely apposed monolayers. The energy cost of such processes is prohibitively high, unless cooperative deformations in a small membrane patch are carefully organized. Here we review the latest experimental and theoretical data on how such deformations can be conducted, specifically describing how elastic stresses yield tilting of lipids leading to cooperative restructuring of lipid monolayers. Proteins specializing in membrane remodeling assemble into closely packed circular complexes to arrange these deformations in time and space.
Frolov
Vadim A
VA
Unidad de Biofisica (Centro Mixto CSIC-UPV/EHU), Leioa 48940, Spain.
Zimmerberg
Joshua
J
D000818:Animals; D004548:Elasticity / Q000502:physiology*; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D008051:Lipid Bilayers / Q000737:chemistry / Q000378:metabolism; D050356:Lipid Metabolism / Q000502:physiology*; D008560:Membrane Fluidity / Q000502:physiology; D008563:Membrane Lipids / Q000378:metabolism* / Q000502:physiology; D008566:Membranes / Q000378:metabolism* / Q000502:physiology / Q000648:ultrastructure; D008954:Models, Biological; D013314:Stress, Mechanical; D013718:Tensile Strength / Q000502:physiology; D053835:Unilamellar Liposomes / Q000737:chemistry / Q000378:metabolism
D008051:Lipid Bilayers; D008563:Membrane Lipids; D053835:Unilamellar Liposomes