A Golgi retention signal in a membrane-spanning domain of coronavirus E1 protein

The Golgi complex plays a central role in the processing and sorting ofnewly synthesized proteins (reviewed in reference 9) . Its characteristic morphology (stacks of flattened saccular membranes) and central location (peri-or juxta nuclear) in the cell may be important for these functions. Four Golgi subcompartments have been defined functionally: cis-, medial-, trans-, and trans-Golgi network . Newly synthesized proteins are thought to move vectorially through the Golgi complex subcompartments via vesicular transport, from the cis-to the trans-side ofthe stack . Endogenous Golgi proteins such as the glycosyltransferases and glycosidases that are involved in the processing of asparagine-linked oligosaccharides are each enriched in a specific subcompartment (8) . It has been suggested that this arrangement allows sequential and orderly processing of glycoproteins as they are vectorially transported through the Golgi complex .