Ia-associated invariant chain is fatty acylated before addition of sialic acid.
The murine invariant chain (Ii) was found to incorporate radioactive palmitic acid. This binding of fatty acid inhibits the formation of interchain S-S bonds, probably because the cysteine residue in the transmembrane region of the Ii chain is palmitylated. The inhibition of fatty acylation by cerulenin blocks further posttranslational maturation of the invariant chain as shown by two-dimensional gel electrophoresis of Ii immunoprecipitates. In particular, the addition of sialic acid residues is blocked. Thus, it appears that fatty acylation is essential for carbohydrate processing of the Ii chain.
D000215:Acylation; D000818:Animals; D000911:Antibodies, Monoclonal; D000944:Antigens, Differentiation, B-Lymphocyte; D002569:Cerulenin / Q000494:pharmacology; D003545:Cysteine; D004220:Disulfides; D000949:Histocompatibility Antigens Class II / Q000302:isolation & purification*; D008223:Lymphoma / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D019158:N-Acetylneuraminic Acid; D009439:Neuraminidase; D019308:Palmitic Acid; D010169:Palmitic Acids / Q000378:metabolism; D010954:Plasmacytoma / Q000276:immunology; D011485:Protein Binding; D012794:Sialic Acids; D014415:Tunicamycin / Q000494:pharmacology
D000911:Antibodies, Monoclonal; D000944:Antigens, Differentiation, B-Lymphocyte; D004220:Disulfides; D000949:Histocompatibility Antigens Class II; D010169:Palmitic Acids; D012794:Sialic Acids; C045084:invariant chain; D014415:Tunicamycin; D002569:Cerulenin; D019308:Palmitic Acid; D009439:Neuraminidase; D019158:N-Acetylneuraminic Acid; D003545:Cysteine