Cooperative protein transport in cellular organelles

TL;DR

This paper investigates how cooperative, recognition-based transport mechanisms enable eukaryotic cells to maintain distinct organelle identities and control material flux, offering functional advantages in protein processing.

Contribution

It demonstrates that cooperative transport based on molecular recognition sustains organelle differentiation and enhances protein maturation efficiency.

Findings

Cooperative transport maintains organelle identity.

Recognition-based transport increases transit time.

Chemical processing benefits from cooperative transport.

Abstract

Compartmentalization into biochemically distinct organelles constantly exchanging material is one of the hallmarks of eukaryotic cells. In the most naive picture of inter-organelle transport driven by concentration gradients, concentration differences between organelles should relax. We determine the conditions under which cooperative transport, i.e. based on molecular recognition, allows for the existence and maintenance of distinct organelle identities. Cooperative transport is also shown to control the flux of material transiting through a compartmentalized system, dramatically increasing the transit time under high incoming flux. By including chemical processing of the transported species, we show that this property provides a strong functional advantage to a system responsible for protein maturation and sorting.