membrane shape transformation induced by …membrane shape transformation induced by banana-shaped...
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Membrane Shape Transformation Induced by Banana-Shaped Proteins
Shape deformations of biomembranes are controlled by various proteins. Many of theseproteins contain a binding module known as the BAR (Bin-Amphiphysin-Rvs) domain,which consists of a banana-shaped dimer. We have revealed anisotropic spontaneouscurvatures of banana-shaped domains induce assembly of the protein rods and changemembrane shapes using implicit-solvent meshless membrane simulations. The proteinrods cooperatively induce tubulation as well as formatin of percolated rod networks,striped bumps, polygonal tubes, and polyhedral vesicles [1-6].
Hiroshi NoguchiInstitute for Solid State Physics, University of Tokyo, Kashiwa, Chiba 277-8581, Japan
[1] H. Noguchi, EPL 108, 48001 (2014). [3] H. Noguchi, Sci. Rep. 6, 20935 (2016). [5] H. Noguchi and J.-B. Fournier, Soft Matter, 13, 4099 (2017).[2] H. Noguchi, J. Chem. Phys. 143, 243109 (2015). [4] H. Noguchi, Phys. Rev. E 93, 052404 (2016). [6] H. Noguchi, Soft Matter, 13, 7771 (2017).
BAR domain
McMahon & Gallop, Nature 438, 590 (2005).
φrod = 0.3 φrod = 0.4
tetrahedron
triangular prism0
0.5
1
5 10CrodRves
x
y
z
tri
dis
triangular hosohedron
elliptic disk
Formation of polyhedral vesicle
Membrane and Protein ModelsMembrane particles, which have orientationaldegrees of freedom, self-assemble to form one-layer membrane. A protein rod is modeled by alinear chain of membrane particles.No direct attractive interactions are takenbetween the rods. The rods are assembled bymembrane-mediated interactions.
1/Cside
1/Crod
Tubulation from Flat Membrane [3,6]
Csiderrod= -1
Percolated networks aretransiently formed at Cside< 0.
0
0.5
1
0 4000 8000t/τ
Csiderrod =
-1
0
1
0
0.5
1
Csiderrod = -1
0
1
3
4
-1 0 1Csiderrod
isolatetubulation
partial
network
Csiderrod= 1Tubulation via percolated network at high rod density φrod = 0.4
Acceleration of tubulation by addition of smallinclusions with isotropic spontaneous curvature
φrod = 0.1
straight clusterformation
budding
tubulation
random distribution
coexistence
Membrane Structures Induced byTwo Types of Protein Rods [5]
straightassembly
stripeassembly
Cr1rrod= 4Cr2= 0
Cr2rrod= -2 Cr2rrod= -3
Cr2rrod= -1
Two types of rods of opposite curavatures form straight andstripe bumps. Positive tension stabilizes stripe assembly.
surface tension
Rod Self-assembly on Vesicle [1-6]
rods of negativeside curvature
rods with isotropicinclusions two types of rods