(N-acetylneuraminyl)-galactosylglucosylceramide N-acetylgalactosaminyltransferase activity https://github.com/geneontology/go-ontology/issues/30193 GM2 synthase activity MetaCyc:2.4.1.92-RXN GalNAc-T activity Reactome:R-HSA-8856223 UDP-N-acetyl-D-galactosamine:1-O-[O-(N-acetyl-alpha-neuraminosyl)-(2->3)-O-beta-D-galactopyranosyl-(1->4)-beta-D-glucopyranosyl]-ceramide 1,4-beta-N-acetyl-D-galactosaminyltransferase activity GO:0003947 UDP-N-acetyl-D-galactosamine:(N-acetylneuraminyl)-D-galactosyl-D-glucosylceramide N-acetyl-D-galactosaminyltransferase activity GM2/GD2-synthase activity EC:2.4.1.92 UDP acetylgalactosamine-(N-acetylneuraminyl)-D-galactosyl-D-glucosylceramide acetylgalactosaminyltransferase activity beta-1,4N-aetylgalactosaminyltransferase activity ganglioside GM3 acetylgalactosaminyltransferase activity molecular_function Catalysis of the reaction: UDP-N-acetyl-D-galactosamine + (N-acetylneuraminyl)-D-galactosyl-D-glucosylceramide = UDP + N-acetyl-D-galactosaminyl-(N-acetylneuraminyl)-D-galactosyl-D-glucosylceramide. uridine diphosphoacetylgalactosamine-ganglioside GM3 acetylgalactosaminyltransferase activity ganglioside GM2 synthase activity uridine diphosphoacetylgalactosamine-acetylneuraminylgalactosylglucosylceramide acetylgalactosaminyltransferase activity RHEA:12588 asialo-GM2 synthase activity uridine diphosphoacetylgalactosamine-hematoside acetylgalactosaminyltransferase activity UDP-N-acetylgalactosamine GM3 N-acetylgalactosaminyltransferase activity acetylgalactosaminyltransferase activity