FIGURE 2.

Separation of the linker compartments from the Golgi ribbon provides a landmark for the onset of mitosis and cell motility. At interphase the linker compartments, indicated with a single color (green) reside at the non-compact regions of the Golgi ribbon. (A) At late G2, the repositioning of the duplicated centrosomes is accompanied by the detachment of the linker compartments from the Golgi ribbon and their movement to the cell center along the radial array of centrosome-nucleated MTs (orange). As cells enter mitosis, the pericentrosomal compartments – BRC and ERC – expand and divide as the centrosomes mature, separate and move to form the spindle poles. At prometaphase, when the nuclear membrane breaks down, disassembly of the Golgi stacks (blue) gives rise to a vesicular “Golgi haze”, which together with the permanent compartments at the spindle poles contributes to the reassembly of the Golgi ribbon as cells exit mitosis (not shown). (B) The repolarization of the Golgi apparatus in motile cells is initiated by similar detachment of the linker compartments during the fragmentation of the Golgi ribbon. In this case, however, the joint reorientation of these compartments with the centrosome sets the stage for simultaneous reformation of the stacks and the Golgi ribbon on the other side of the nucleus facing the cell’s leading edge.