The retina cell-surface N-acetylgalactosaminylphosphotransferase is anchored by a glycophosphatidylinositol.
A polypeptide with N-acetylgalactosaminylphosphotransferase (GalNAcPTase) activity is present at the cell surface in stable association with adhesion molecules of the cadherin family. Antibodies directed against the GalNAcPTase inhibit homophilic cadherin-mediated adhesion and cadherin-mediated neurite outgrowth. We have determined that the GalNAcPTase is anchored at the cell surface by a glycophosphatidylinositol linkage. Treatment of intact cells with phosphatidylinositol-specific phospholipase C (PI-PLC) releases active GalNAcPTase and abolishes the ability of anti-GalNAcPTAse antibodies to modulate cadherin-mediated adhesion or neurite outgrowth. Furthermore, GalNAcPTase released from cells by PI-PLC is recognized by anti-CRD antiserum and is radiolabeled in cells incubated with [14C]-ethanolamine.
Department of Biological Sciences, Clemson University, South Carolina 29631.
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Balsamo
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J
Lilien
D000818:Animals; D015820:Cadherins / Q000378:metabolism; D002448:Cell Adhesion; D002462:Cell Membrane / Q000201:enzymology*; D002642:Chick Embryo; D017261:Glycosylphosphatidylinositols / Q000276:immunology / Q000378:metabolism*; D015151:Immunoblotting; D007074:Immunoglobulin G / Q000276:immunology; D007163:Immunosorbent Techniques; D008970:Molecular Weight; D017350:N-Acetylgalactosaminyltransferases / Q000378:metabolism*; D016501:Neurites / Q000502:physiology; D043265:Phosphatidylinositol Diacylglycerol-Lyase; D054801:Phosphoinositide Phospholipase C; D010727:Phosphoric Diester Hydrolases / Q000494:pharmacology; D012160:Retina / Q000196:embryology / Q000201:enzymology* / Q000648:ultrastructure; D017855:Transferases (Other Substituted Phosphate Groups); D014643:Variant Surface Glycoproteins, Trypanosoma / Q000276:immunology
D015820:Cadherins; D017261:Glycosylphosphatidylinositols; D007074:Immunoglobulin G; D014643:Variant Surface Glycoproteins, Trypanosoma; D017350:N-Acetylgalactosaminyltransferases; D017855:Transferases (Other Substituted Phosphate Groups); C063044:UDP-N-acetylgalactosamine-N-acetylgalactosaminylphosphotransferase; D010727:Phosphoric Diester Hydrolases; D054801:Phosphoinositide Phospholipase C; D043265:Phosphatidylinositol Diacylglycerol-Lyase