The Golgi complex: perspectives and prospectives.

We now have considerable understanding of the role of the Golgi complex in the posttranslational modifications of membrane and secretory proteins and of lysosomal hydrolases. It is now also clear that the Golgi plays a key role in the intracellular packaging, addressing, and sorting of these classes of proteins to their final destinations on the secretory and endocytic pathways. While it has been proposed that vesicular budding and fusion underlie entry of proteins into the Golgi from the ER and subsequent movement among its cisternae and exit to their final stations, recent observations indicate that this model may need to be revised based on studies in living cells where vesicular-tubular structures appear to mediate membrane trafficking. This will be a major challenge for investigators in the coming years who will rely again on the use of morphologic techniques of the sort that started it all in 1898.