Protein mediated membrane adhesion

Andreas Carlson,L Mahadevan

doi:10.1063/1.4919777

Andreas Carlson, L Mahadevan

Open Access

https://doi.org/10.1063/1.4919777

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Abstract

Adhesion in the context of mechanical attachment, signaling, and movement in cellular dynamics is mediated by the kinetic interactions between membrane-embedded proteins in an aqueous environment. Here, we present a minimal theoretical framework for the dynamics of membrane adhesion that accounts for the kinetics of protein binding, the elastic deformation of the membrane, and the hydrodynamics of squeeze flow in the membrane gap. We analyze the resulting equations using scaling estimates to characterize the spatiotemporal features of the adhesive patterning and corroborate them using numerical simulations. In addition to characterizing aspects of cellular dynamics, our results might also be applicable to a range of phenomena in physical chemistry and materials science where flow, deformation, and kinetics are coupled to each other in slender geometries.

Highlights

Intercellular adhesion is critical for the formation, development, and maintenance of any multicellular organism, for it allows cells to make physical contact to communicate information in both time and space
We complement these approaches and describe the time and length scales associated with passive protein patterning, with a focus on the regime limited by the viscous fluid flow in the synaptic cleft
The systems (1)-(4) describing the kinetics and elastohydrodynamics of membrane adhesion can be characterized in terms of the dimensionless numbers ε, Pe, B, and τ that determine the magnitude of advection, elasticity, and hydrodynamics, respectively

Summary

INTRODUCTION

Intercellular adhesion is critical for the formation, development, and maintenance of any multicellular organism, for it allows cells to make physical contact to communicate information in both time and space. Adhesive interactions are critically important for crawling cell movement, signaling, and recognition and enabled by the spatiotemporal patterning of the membrane embedded proteins.[1,2,3,4] Previous work has focused on understanding the important biophysics of intercellular interactions using models of adhesion statics,[5,6] diffusion,[7,8,9] membrane fluctuations, and stochastic protein kinetics.[10,11,12,13,14,15,16] We complement these approaches and describe the time and length scales associated with passive protein patterning, with a focus on the regime limited by the viscous fluid flow in the synaptic cleft We do this by deriving a physiochemical continuum model to couple membrane deformation, protein binding and clustering, and fluid flow in the membrane gap, and to analyze it in certain prototypical settings. These coupled processes ought to be of relevance in a range of settings outside cellular dynamics in such situations as transient mechanical adhesion, physical chemistry, and problems in materials science to each other in slender geometries

MATHEMATICAL FORMULATION

RESULTS

DISCUSSION