Self-assembly of biomolecular condensates with shared components

TL;DR

This paper presents a minimal model demonstrating that sharing components among biomolecular condensates enables the formation of a large, predictable number of distinct droplets, revealing principles of cellular organization.

Contribution

It introduces a model showing superlinear growth in condensate diversity with shared components and provides a way to predict maximum condensates without detailed interaction data.

Findings

Number of condensates grows superlinearly with species when sharing components

Maximum number of condensates can be predicted without detailed interactions

Simulations confirm the physical rules are broadly applicable

Abstract

Biomolecular condensates self-assemble when proteins and nucleic acids spontaneously demix to form droplets within the crowded intracellular milieu. This simple mechanism underlies the formation of a wide variety of membraneless compartments in living cells. To understand how multiple condensates with distinct compositions can self-assemble in such a heterogeneous system, we study a minimal model in which we can "program" the pairwise interactions among hundreds of species. We show that the number of distinct condensates that can be reliably assembled grows superlinearly with the number of species in the mixture when the condensates are allowed to share components. Furthermore, we show that we can predict the maximum number of distinct condensates in a mixture without knowing the details of the pairwise interactions. Simulations of condensate growth confirm these predictions and suggest that the physical rules governing the achievable complexity of condensate-mediated spatial organization are broadly applicable to biomolecular mixtures.