Self-generated concentrations of SNAREs and enzymes.

<p><b>Panel A:</b> Steady state concentration of cisternal SNARE vs the number of cisterna for: both the loss and the vesicular transport mechanisms are enacted (solid line), only the loss mechanism operates (dashed line), only vesicular transport occurs (dotted line). All concentrations are sampled immediately before the cisternal shift event, when the number of each cisterna is incremented by one. The definitions of parameters are given in <a href="http://www.ploscompbiol.org/article/info:doi/10.1371/journal.pcbi.1003125#s4" target="_blank">Methods</a>. Here and in all following plots it is assumed that and , i.e. all concentrations are expressed in the units of initial concentrations and the time is expressed in units of the cisternal maturation period. Solid line: and , dashed line: and , dotted line: and , for all curves . <b>Panel B:</b> Distribution of Golgi enzymes: <i>cis</i> (solid line), medial (dashed line) and <i>trans</i> (dotted line) established as a result of competition for incorporation into vesicles. Vesicular flux is controlled by the gradient of cisternal SNAREs shown by the solid line in the left panel, vesicles from the first cisterna can exit the Golgi and fuse with the ER. The parameters for the enzyme transport are , , , and .