Enrichment of membrane curvature-sensing proteins from Escherichia coli using spherical supported lipid bilayers

In bacteria, certain shape-sensing proteins localize to differently curved membranes. During sporulation in Bacillus subtilis, the only convex (positively curved) surface in the cell is the forespore, an approximately spherical internal organelle. Previously, we demonstrated that SpoVM localizes to the forespore by preferentially adsorbing onto slightly convex membranes. Here, we used NMR and molecular dynamics simulations of SpoVM and a localization mutant (SpoVMP9A) to reveal that SpoVM’s atypical amphipathic α-helix inserts deeply into the membrane and interacts extensively with acyl chains to sense packing differences in differently curved membranes. Based on binding to spherical supported lipid bilayers and Monte Carlo simulations, we hypothesize that SpoVM’s membrane insertion, along with potential cooperative interactions with other SpoVM molecules in the lipid bilayer, drives its preferential localization onto slightly convex membranes. Such a mechanism, which is distinct from that used by high curvature-sensing proteins, may be widely conserved for the localization of proteins onto the surface of cellular organelles.

Download Full-text

Formation of supported lipid bilayers of Escherichia coli extracted lipids and their surface morphologies

Japanese Journal of Applied Physics ◽

10.7567/1347-4065/ab1b5f ◽

2019 ◽

Vol 58 (SI) ◽

pp. SIIB19 ◽

Cited By ~ 2

Author(s):

Yasuhiro Kakimoto ◽

Ryugo Tero

Keyword(s):

Escherichia Coli ◽

Lipid Bilayers ◽

Supported Lipid Bilayers ◽

Surface Morphologies

Download Full-text

Negative membrane curvature catalyzes nucleation of endosomal sorting complex required for transport (ESCRT)-III assembly

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1518765113 ◽

2015 ◽

Vol 112 (52) ◽

pp. 15892-15897 ◽

Cited By ~ 73

Author(s):

Il-Hyung Lee ◽

Hiroyuki Kai ◽

Lars-Anders Carlson ◽

Jay T. Groves ◽

James H. Hurley

Keyword(s):

Lipid Bilayers ◽

Multivesicular Body ◽

Membrane Curvature ◽

Supported Lipid Bilayers ◽

Nucleation Behavior ◽

Endosomal Sorting ◽

Superresolution Imaging ◽

Negatively Curved ◽

Curved Annulus ◽

Hiv 1

The endosomal sorting complexes required for transport (ESCRT) machinery functions in HIV-1 budding, cytokinesis, multivesicular body biogenesis, and other pathways, in the course of which it interacts with concave membrane necks and bud rims. To test the role of membrane shape in regulating ESCRT assembly, we nanofabricated templates for invaginated supported lipid bilayers. The assembly of the core ESCRT-III subunit CHMP4B/Snf7 is preferentially nucleated in the resulting 100-nm-deep membrane concavities. ESCRT-II and CHMP6 accelerate CHMP4B assembly by increasing the concentration of nucleation seeds. Superresolution imaging was used to visualize CHMP4B/Snf7 concentration in a negatively curved annulus at the rim of the invagination. Although Snf7 assemblies nucleate slowly on flat membranes, outward growth onto the flat membrane is efficiently nucleated at invaginations. The nucleation behavior provides a biophysical explanation for the timing of ESCRT-III recruitment and membrane scission in HIV-1 budding.

Download Full-text

Micron-scale plasma membrane curvature is recognized by the septin cytoskeleton

The Journal of Cell Biology ◽

10.1083/jcb.201512029 ◽

2016 ◽

Vol 213 (1) ◽

pp. 23-32 ◽

Cited By ~ 94

Author(s):

Andrew A. Bridges ◽

Maximilian S. Jentzsch ◽

Patrick W. Oakes ◽

Patricia Occhipinti ◽

Amy S. Gladfelter

Keyword(s):

Plasma Membrane ◽

Lipid Bilayers ◽

Fundamental Property ◽

Membrane Curvature ◽

Supported Lipid Bilayers ◽

Nanometer Scale ◽

Local Shape ◽

A Cell ◽

Developmental Conditions ◽

In Cells

Cells change shape in response to diverse environmental and developmental conditions, creating topologies with micron-scale features. Although individual proteins can sense nanometer-scale membrane curvature, it is unclear if a cell could also use nanometer-scale components to sense micron-scale contours, such as the cytokinetic furrow and base of neuronal branches. Septins are filament-forming proteins that serve as signaling platforms and are frequently associated with areas of the plasma membrane where there is micron-scale curvature, including the cytokinetic furrow and the base of cell protrusions. We report here that fungal and human septins are able to distinguish between different degrees of micron-scale curvature in cells. By preparing supported lipid bilayers on beads of different curvature, we reconstitute and measure the intrinsic septin curvature preference. We conclude that micron-scale curvature recognition is a fundamental property of the septin cytoskeleton that provides the cell with a mechanism to know its local shape.

Download Full-text

Formation and Characterization of Supported Lipid Bilayers Composed of Hydrogenated and Deuterated Escherichia coli Lipids

PLoS ONE ◽

10.1371/journal.pone.0144671 ◽

2015 ◽

Vol 10 (12) ◽

pp. e0144671 ◽

Cited By ~ 30

Author(s):

Tania Kjellerup Lind ◽

Hanna Wacklin ◽

Jürgen Schiller ◽

Martine Moulin ◽

Michael Haertlein ◽

...

Keyword(s):

Escherichia Coli ◽

Lipid Bilayers ◽

Supported Lipid Bilayers

Download Full-text

Influence of Brain Gangliosides on the Formation and Properties of Supported Lipid Bilayers for Binding Kinetics Studies

10.26434/chemrxiv.7505330 ◽

2018 ◽

Author(s):

Luke Jordan ◽

Nathan Wittenberg

Keyword(s):

Lipid Bilayers ◽

Binding Kinetics ◽

Supported Lipid Bilayers ◽

Dependent Manner ◽

Concentration Dependent Manner ◽

Supported Lipid Bilayer ◽

Head Groups ◽

Lipid Diffusion ◽

Kinetics Of ◽

Brain Gangliosides

This is a comprehensive study of the effects of the four major brain gangliosides (GM1, GD1b, GD1a, and GT1b) on the adsorption and rupture of phospholipid vesicles on SiO2 surfaces for the formation of supported lipid bilayer (SLB) membranes. Using quartz crystal microbalance with dissipation monitoring (QCM-D) we show that gangliosides GD1a and GT1b significantly slow the SLB formation process, whereas GM1 and GD1b have smaller effects. This is likely due to the net ganglioside charge as well as the positions of acidic sugar groups on ganglioside glycan head groups. Data is included that shows calcium can accelerate the formation of ganglioside-rich SLBs. Using fluorescence recovery after photobleaching (FRAP) we also show that the presence of gangliosides significantly reduces lipid diffusion coefficients in SLBs in a concentration-dependent manner. Finally, using QCM-D and GD1a-rich SLB membranes we measure the binding kinetics of an anti-GD1a antibody that has similarities to a monoclonal antibody that is a hallmark of a variant of Guillain-Barre syndrome.

Download Full-text