The Golgi grows up

Abstract

The Golgi apparatus of the cell has long baffled biologists, mainly because it is unclear how proteins are conveyed through it on their way to the cell surface. Some innovative microscopy may resolve the issue. Two models of Golgi network maturation can be found in cell biology textbooks: in the ‘traditional model’, vesicles containing cargo proteins travel from sac to sac on a production line, being modified along the way until they are secreted. Then there is the cisternal maturation model (cisternae are the flat disk-like membrane sacs that comprise the Golgi secretory system), which suggests that a single Golgi compartment develops with time, so that cargo proteins stay in one cisterna until ready to be packaged into transport vesicles and delivered to their final destination. Two independent groups have used sophisticated imaging techniques to show that in the yeast Saccharomyces cerevisiae, the proteins remain within a single cisterna before being secreted.