Sequential association of nucleolar 7-2 RNA with two different autoantigens.
Anti-Th serum from a patient with systemic lupus erythematosus immunoprecipitates from both human and mouse cell extracts small ribonucleoproteins containing 7-2 RNA, 8-2 RNA, and the Ro RNAs. Human 7-2 RNA, which must be complexed with protein to be antigenic, is about 300 nucleotides long and has mostly pG at its 5' end. A related 7-2 RNA, precipitated by anti-La antibody, gives identical Tl and pancreatic RNase fingerprints, but has more pppG at its 5' end. La 7-2 RNA is, therefore, likely to be a precursor of Th 7-2 RNA. The synthesis of 7-2 RNA in isolated nuclei exhibits a pattern of sensitivity to alpha-amanitin that is characteristic for RNA polymerase III transcription. Thus, 7-2 RNA can be added to the list of mammalian RNA polymerase III transcripts that initially bind the La protein and then become incorporated into other types of antigenic RNP particles.
D000818:Animals; D000936:Antigen-Antibody Complex; D000941:Antigens / Q000276:immunology*; D001324:Autoantigens / Q000276:immunology*; D002466:Cell Nucleolus / Q000032:analysis*; D004591:Electrophoresis, Polyacrylamide Gel; D006367:HeLa Cells / Q000032:analysis; D006801:Humans; D007106:Immune Sera; D007942:Leukemia, Experimental / Q000032:analysis*; D008180:Lupus Erythematosus, Systemic / Q000276:immunology*; D051379:Mice; D008970:Molecular Weight; D012313:RNA / Q000032:analysis*; D012334:RNA, Neoplasm / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification*; D012342:RNA, Small Nuclear
D000936:Antigen-Antibody Complex; D000941:Antigens; D001324:Autoantigens; D007106:Immune Sera; D012334:RNA, Neoplasm; D012342:RNA, Small Nuclear; D012313:RNA