Golgi localization of carbohydrate sulfotransferases is a determinant of L-selectin ligand biosynthesis.
Sulfation of endothelial glycoproteins by the sulfotransferase GlcNAc6ST-2 is a regulatory modification that promotes binding of the leukocyte adhesion molecule L-selectin. GlcNAc6ST-2 is a member of a family of related enzymes that act on similar carbohydrate substrates in vitro but discrete glycoproteins in vivo. We demonstrate that GlcNAc6ST-1, -2, and -3 have distinct Golgi distributions, with GlcNAc6ST-1 confined to the trans-Golgi network, GlcNAc6ST-3 confined to the early secretory pathway, and GlcNAc6ST-2 distributed throughout the Golgi. Their localization was correlated with preferred activity on either N-linked or O-linked glycoproteins. A chimera comprising the localization domain of GlcNAc6ST-1 fused to the catalytic domain of GlcNAc6ST-2 was confined to the trans-Golgi network and adopted the substrate preference of GlcNAc6ST-1. We propose a model in which Golgi enzyme localization and competition orchestrate the biosynthesis of L-selectin ligands.
de Graffenried
Christopher L
CL
Department of Chemistry, University of California, Berkeley, 94720, USA.
Bertozzi
Carolyn R
CR
D000595:Amino Acid Sequence; D000818:Animals; D016466:CHO Cells; D002240:Carbohydrate Sequence; D006224:Cricetinae; D006056:Golgi Apparatus / Q000201:enzymology*; D049452:Green Fluorescent Proteins; D006801:Humans; D066298:In Vitro Techniques; D019041:L-Selectin / Q000378:metabolism*; D008024:Ligands; D008164:Luminescent Proteins / Q000378:metabolism; D008954:Models, Biological; D008969:Molecular Sequence Data; D011134:Polysaccharides / Q000096:biosynthesis / Q000737:chemistry; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D013347:Subcellular Fractions / Q000201:enzymology; D013379:Substrate Specificity; D015238:Sulfotransferases / Q000235:genetics / Q000378:metabolism*; D000097811:Carbohydrate Sulfotransferases
D049452:Green Fluorescent Proteins; D019041:L-Selectin; D008024:Ligands; D008164:Luminescent Proteins; D011134:Polysaccharides; D011993:Recombinant Fusion Proteins; D015238:Sulfotransferases; D000097811:Carbohydrate Sulfotransferases