  The dynamical organization of membrane-bound organelles along intracellular
transport pathways relies on vesicular exchange between organelles and on
biochemical maturation of the organelle content by specific enzymes. The
relative importance of each mechanism in controlling organelle dynamics remains
controversial, in particular for transport through the Golgi apparatus. Using a
stochastic model, we show that full maturation of membrane-bound compartments
can be seen as the stochastic escape from a steady-state in which export is
dominated by vesicular exchange. We show that full maturation can contribute a
significant fraction of the total out-flux for small organelles such as
endosomes and Golgi cisternae.
