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Biophysics of Proteins at Surfaces: Assembly, Activation, Signaling
Thursday Speaker Abstracts
Control of Protein Adsorption and Protein-induced Membrane Deformation by
Phospholipid Unsaturation
Bruno Antonny
.
CNRS and Université de Nice Sophia Antipolis, Valbonne, France.
Membrane bound organelles differ by their shape and lipid composition. Gradients of
phospholipids with different fatty acid profiles are observed along the secretory pathway
(endoplasmic reticulum > Golgi > plasma membrane) and in differentiated structures (e. g.
axons). Using a combination of biochemical and biophysical measurements, of cell biology
observations and of molecular dynamics simulations, we are exploring the role of phospholipid
unsaturation on the physicochemical properties of cellular membranes. Our work reveals that
membrane curvature and lipids with monounsaturated acyl chains cooperate for the formation of
large lipid packing defects that can be recognized by peripheral proteins with bulky hydrophobic
residues. In contrast, polyunsaturated phospholipids dampen the effect of membrane curvature
on large lipid packing defects, owing to their ability to adopt various bent conformations. As a
result, membrane fission is facilitated. These findings give a rationale for the high levels of
monounsaturated phospholipids in membranes with biosynthetic functions (endoplasmic
reticulum) and the high levels of polyunsaturated phospholipids in membranes undergoing very
fast shape changes (synaptic vesicles).
References:
Pinot M, Vanni S, Pagnotta S, Lacas-Gervais S, Payet LA, Ferreira T, Gautier R, Goud B,
Antonny B, Barelli H (2014). Polyunsaturated phospholipids facilitate membrane deformation
and fission by endocytic proteins.
Science
345, 693-7.
Vanni S, Hirose H, Barelli H, Antonny B, Gautier R (2014). A sub-nanometre view of how
membrane curvature and composition modulate lipid packing and protein recruitment.
Nat
Commun
5, 4916.
Antonny B, Vanni S, Shindou H, Ferreira T (2015). From zero to six double bounds:
phospholipid unsaturation and organelle functions.
Trends in Cell Biol
in press.