Nucleotide sugar transporters of the Golgi apparatus.

Glycosylation, sulfation and phosphorylation of proteins, proteoglycans and lipids occur in the lumen of the Golgi apparatus. The nucleotide substrates of these reactions must be first transported from the cytosol into the Golgi lumen by specific transporters. The topology and structure of these hydrophobic, multi-transmembrane-spanning proteins are beginning to be understood.