MOLECULAR MECHANISMS IN THE DISASSEMBLY AND REASSEMBLY OF THE MAMMALIAN GOLGI-APPARATUS DURING M-PHASE

The mitotic disassembly and reassembly of the mammalian Golgi apparatu s is an ideal system to study the molecular mechanisms involved in bio genesis and maintenance of membranous organelles. As cells enter ill-p hase, Golgi stacks are converted into Golgi clusters of small membrane fragments, which are dispersed throughout the cytoplasmic space durin g metaphase. Disassembly is dependent on the action of cdc2-kinase and at least two distinct pathways contribute to the fragmentation: one i nvolves the budding of COP I-coated vesicles from Golgi cisternae, the other is a less well characterised COP I-independent pathway. During telophase, the Golgi fragments reassemble and fuse into a fully functi onal Golgi stack, using at least two distinct ATPase-mediated fusion p athways.