Subunit structure of guinea pig Ia.1 antigens.
Since their discovery in 1976, the guinea pig Ia.1 and Ia1,6 antigens were thought to be borne on a single protein species of approximately 26,000 m.w. This report demonstrates that the Ia.1 and Ia.1,6-bearing molecules are typical Ia.1 heterodimeric structures, consisting of acidic alpha-chain and basic beta-chain subunits. The mature Ia.1 and Ia.1,6 alpha-chains have an apparent size of 29,000 m.w., less than the 33,000 m.w. observed for the mature Ia.3,5 alpha-chain. Furthermore, pulse-chase studies and studies with tunicamycin demonstrate that the precursors of the Ia.1,6 alpha- and Ia.3,5 alpha-chains are clearly distinct. On the basis of their association with Ir genes and on their structural features, we conclude that the Ia.1 and Ia.1,6-bearing molecules are similar to other Ia antigens in subunit organization and biochemical properties.
D000818:Animals; D055598:Chemical Phenomena; D002621:Chemistry; D004591:Electrophoresis, Polyacrylamide Gel; D005802:Genes, MHC Class II; D006168:Guinea Pigs; D000949:Histocompatibility Antigens Class II / Q000276:immunology; D008198:Lymph Nodes / Q000166:cytology; D008214:Lymphocytes / Q000276:immunology; D008970:Molecular Weight; D014415:Tunicamycin / Q000494:pharmacology
D000949:Histocompatibility Antigens Class II; D014415:Tunicamycin