Asymmetry between Activators and Deactivators in Functional Protein Networks

TL;DR

This paper investigates the roles of activators and deactivators in protein interaction networks, revealing a fundamental asymmetry where activators are synergistic and deactivators are competitive, through a minimal evolutionary model.

Contribution

It introduces a sequence-based mutational model to study the evolution of oscillatory protein networks, highlighting the asymmetric roles of activators and deactivators.

Findings

Activators tend to be synergistic in network dynamics.

Deactivators tend to be competitive in network dynamics.

Asymmetry between activators and deactivators is fundamental to network function.

Abstract

Are "turn-on" and "turn-off" functions in protein-protein interaction networks exact opposites of each other? To answer this question, we implement a minimal model for the evolution of functional protein-interaction networks using a sequence-based mutational algorithm, and apply the model to study neutral drift in networks that yield oscillatory dynamics. We study the roles of activators and deactivators, two core components of oscillatory protein interaction networks, and find a striking asymmetry in the roles of activating and deactivating proteins, where activating proteins tend to be synergistic and deactivating proteins tend to be competitive.