Nonequilibrium mechanisms underlying de novo biogenesis of Golgi cisternae

TL;DR

This paper develops simplified models to understand how Golgi cisternae form de novo through the interplay of molecular transport and chemical maturation, providing new quantitative tools for experimental discrimination.

Contribution

It introduces analytically tractable minimalist models that combine transport and chemical progression to explain Golgi cisternae biogenesis, along with new measures for model discrimination.

Findings

Models can reproduce de novo cisternae formation.

Quantitative measures distinguish transport mechanisms.

Predictions are testable via live-cell imaging.

Abstract

A central issue in cell biology is the physico-chemical basis of organelle biogenesis in intracellular trafficking pathways, its most impressive manifestation being the biogenesis of Golgi cisternae. At a basic level, such morphologically and chemically distinct compartments should arise from an interplay between the molecular transport and chemical maturation. Here, we formulate analytically tractable, minimalist models, that incorporate this interplay between transport and chemical progression in physical space, and explore the conditions for de novo biogenesis of distinct cisternae. We propose new quantitative measures that can discriminate between the various models of transport in a qualitative manner- this includes measures of the dynamics in steady state and the dynamical response to perturbations of the kind amenable to live-cell imaging.