Remodeling of Membrane Shape and Topology by Curvature Elasticity and Membrane Tension

Lipid membranes routinely undergo protein-mediated morphological remodeling during vital processes such as cellular transport and division. These membrane remodeling proteins can be broadly classified into two categories: one that generates a spherical shape and another that generates a cylindrical shape. To gain physical insights into membrane shape transitions, it is important to investigate the stability of membranes in the presence of these two types of proteins. However, the existing membrane theory is mostly restricted to the class of membranes that interact with the sphere shape-generating proteins and possess isotropic symmetry. In this work, we use curvature elasticity of the lipid membranes to derive the stability criterion for membranes that interact with the cylindrical-shape-generating proteins that possess orthotropic symmetry. We derive the convexity condition followed by the stability criterion for a generalized form of strain energy that can entertain material heterogeneity. The proposed framework would allow for a rigorous analysis of a broader set of membrane–protein interactions during key cellular processes.

Download Full-text

Membrane Shape Remodeling by Protein Crowding

10.1101/2020.10.22.351130 ◽

2020 ◽

Author(s):

Susanne Liese ◽

Andreas Carlson

Keyword(s):

Spontaneous Curvature ◽

Steric Repulsion ◽

Membrane Tension ◽

Wide Range ◽

Associated Proteins ◽

Protein Crowding ◽

Membrane Shape ◽

Flat Membranes ◽

Spherical Vesicles ◽

Shape Changes

AbstractThe steric repulsion between proteins on biological membranes is one of the most generic mechanisms that cause membrane shape changes. We present a minimal model where a spontaneous curvature is induced by steric repulsion between membrane-associated proteins. Our results show that the interplay between the induced spontaneous curvature and the membrane tension determine the energy minimizing shapes, which describe the wide range of experimentally observed membrane shapes, i.e. flat membranes, spherical vesicles, elongated tubular protrusions, and pearling structures.

Download Full-text

Membrane tension and peripheral protein density mediate membrane shape transitions

Nature Communications ◽

10.1038/ncomms6974 ◽

2015 ◽

Vol 6 (1) ◽

Cited By ~ 105

Author(s):

Zheng Shi ◽

Tobias Baumgart

Keyword(s):

Membrane Tension ◽

Peripheral Protein ◽

Protein Density ◽

Membrane Shape ◽

Shape Transitions

Download Full-text

Protein-Induced Membrane Shape Instability: Dynamics and Membrane Tension Dependence

Biophysical Journal ◽

10.1016/j.bpj.2013.11.3907 ◽

2014 ◽

Vol 106 (2) ◽

pp. 706a

Author(s):

Zheng Shi ◽

Tobias Baumgart

Keyword(s):

Membrane Tension ◽

Induced Membrane ◽

Membrane Shape

Download Full-text

Piezo’s membrane footprint and its contribution to mechanosensitivity

eLife ◽

10.7554/elife.41968 ◽

2018 ◽

Vol 7 ◽

Cited By ~ 34

Author(s):

Christoph A Haselwandter ◽

Roderick MacKinnon

Keyword(s):

Cell Membrane ◽

Ion Channel ◽

Mechanical Stimulation ◽

Molecular Form ◽

Molecular Structures ◽

Specific Function ◽

Membrane Tension ◽

A Cell ◽

Membrane Shape ◽

Curved Membrane

Piezo1 is an ion channel that gates open when mechanical force is applied to a cell membrane, thus allowing cells to detect and respond to mechanical stimulation. Molecular structures of Piezo1 reveal a large ion channel with an unusually curved shape. This study analyzes how such a curved ion channel interacts energetically with the cell membrane. Through membrane mechanical calculations, we show that Piezo1 deforms the membrane shape outside the perimeter of the channel into a curved ‘membrane footprint’. This membrane footprint amplifies the sensitivity of Piezo1 to changes in membrane tension, rendering it exquisitely responsive. We assert that the shape of the Piezo channel is an elegant example of molecular form evolved to optimize a specific function, in this case tension sensitivity. Furthermore, the predicted influence of the membrane footprint on Piezo gating is consistent with the demonstrated importance of membrane-cytoskeletal attachments to Piezo gating.

Download Full-text