Multidimensional Phase Diagrams for Multicomponent Systems Comprising Multivalent Proteins

Abstract

Phase transitions of multivalent protein and RNA molecules give rise to biomolecular condensates in living cells. A typical biomolecular condensate encompasses hundreds of distinct types of molecules. Each of the underlying protein/RNA molecules will likely have intrinsic phase behaviors that are governed by homotypic interactions. However, these intrinsic phase behaviors can also be modulated if there are obligate heterotypic interactions among the molecules of multicomponent condensates. The interplay between homotypic interactions and the network of heterotypic interactions will govern (i) the number of coexisting phases within condensates, (ii) reentrant features of the distinct phases, (iii) the compositions within these coexisting phases, and (iv) the emergence of modulated phases, which refers to new phases that emerge through a combination of heterotypic interactions and conformational transitions.