Every time a cell divides, the Golgi complex has to be assembled from scattered mini-stacks.  We have identified a specific function for the Golgi-derived microtubule array in this process (Nature Cell Biology 2009).

Golgi-derived microtubules cluster and organize Golgi mini-stacks (G-stage of Golgi assembly). At the same time, centrosomal microtubules  collect Golgi stacks in the cell center (C-stage of Golgi assembly). In CLASP-depleted cells that have no Golgi-derived microtubules, G-stage is absent.

When the G-stage is missing, Golgi organization is disturbed. Compare normally organized Golgi (left) to a partially scattered circular Golgi assembled by radial centrosomal microtubules in CLASP-depleted cells (right).

Polarity of post-Golgi trafficking cannot be maintained in cells that have a disorganized, circular Golgi. Compare normal polarized trafficking toward the cell front (left) to non-directional trafficking pattern in a CLASP-depleted cell (right).