Membrane morphologies induced by mixtures of arc-shaped particles with opposite curvature

Abstract

Biological membranes are shaped by various proteins that either generate inward or outward membrane curvature. In this article, we investigate the membrane morphologies induced by mixtures of arc-shaped particles with coarse-grained modeling and simulations. The particles bind to the membranes either with their inward, concave side or their outward, convex side and, thus, generate membrane curvature of opposite sign. We find that small fractions of convex-binding particles can stabilize three-way junctions of membrane tubules, as suggested for the protein lunapark in the endoplasmic reticulum of cells. For comparable fractions of concave-binding and convex-binding particles, we observe lines of particles of the same type, and diverse membrane morphologies with grooves and bulges induced by these particle lines. The alignment and segregation of the particles is driven by indirect, membrane-mediated interactions.

A Review of Mechanics-Based Mesoscopic Membrane Remodelling Methods: Capturing Both the Physics and the Chemical Diversity

“…In most cases, the membrane is modeled as a discretized closed surface and proteins are either implicitly represented or introduced as inclusions [69][70][71][72] . We refer to some recent papers from Hiroshi Noguchi and co-workers [73][74][75] and Thomas Weikl and coworkers [76][77][78][79] . Noguchi et al use coarse-grained meshless membrane simulations 73,80 where the proteins are modelled as banana-shaped chains of beads and the membrane is modelled as a two-dimensional sheet of beads.…”

Membrane remodeling due to mixture of multiple types of curvature proteins

“…Though the sub-cellular processes of vesicular transports in mediated by multiple curvature proteins interacting in concert with each other, this aspect has not been studied very much in reconstitution experiments [20][21][22][23][24]. Also, a handful of theoretical and computational mesoscopic modeling work have provided important insights into the synergy between multiple scaffold proteins during membrane remodeling processes [25][26][27][28] but the studies are quite few in numbers and a more extensive exploration in this area is needed.…”

“…Though the sub-cellular processes of vesicular transports in mediated by multiple curvature proteins interacting in concert with each other, this aspect has not been studied very much in reconstitution experiments [20][21][22][23][24] . Also, a handful of theoretical and computational mesoscopic modeling work have provided important insights into the synergy between multiple sca↵old proteins during membrane remodeling processes [25][26][27][28] but the studies are quite few in numbers and a more extensive exploration in this area is needed. Also, lately role of flexible intrinsically disordered regions in sca↵olding proteins has been shown to be important 29,30 , which highlights the importance of considering the the e↵ective curvature of the sca↵old protein as a distribution rather than having one fixed curvature value.…”

“…Generally the membrane is presented as a discretized closed surface and proteins are implicit with the membrane or represented as inclusions. [31][32][33][34] In particular, we point the readers to papers from John Ipsen and co-workers, [35][36][37][38][39] Hiroshi Noguchi and co-workers, [40][41][42] Thomas Weikl and co-workers, [43][44][45][46] and the Mesoscopic Membrane with Proteins (MesM-P) model from Gregory Voth and co-workers. [47][48][49] Due to its smooth particle applied mechanics (SPAM) 50,51 based theoretically well-grounded framework, the MesM-P can provide phenomenological link between molecular interactions and macroscopic phenomena though the representation of particles is not in molecular detail and the membrane deformation studies are limited to one type of proteins.…”

“…Almost all of these work consider one protein type or a maximum of two proteins though these mesoscopic modeling work have provided important insights into the synergy between multiple scaffold proteins during membrane remodeling processes. 36,41,45,52,53 For example, membrane remodeling due to two opposite curvatures of proteins was studied recently 54 where the membrane is modelled as a triangulated surface and the proteins as arc-shaped particles. The model shows the membrane deformation due to two types of proteins with low or moderate scaffold curvatures.…”