A synthetic model of intra-Golgi traffic

We present a hypothesis on the mechanisms used by cells to transport cargo through the secretory system. We propose that at least three basic processes coordinately participate in membrane traffic: cisternal maturation-progression, controlled cargo diffusion along transient membrane continuities between different compartments, and a mostly retrograde vesicle-mediated transport. A 'synthetic' model based on the combination of these mechanisms can explain both the progression of supramolecular aggregates through the secretory pathway and the fast intra-Golgi transport of conventional cargoes. Analysis of the existing literature shows that the available data are consistent with the proposed model.