Abstract
Antibodies directed against small nuclear ribonucleoprotein ( snRNP ) particles are found in the Sm and RNP autoimmune sera from numerous patients with systemic lupus erythematosus (SLE) and mixed connective tissue disease (MCTD). These two reactivities differ in disease distribution as well as antigen specificity. Although sera from both of these autoimmune syndromes contain snRNP reactive antibodies, distinction in antigen binding specificity have been difficult to define because of the particulate nature of the snRNP antigen. To overcome this problem, while retaining the antigen in a native state, cells were pulse-labeled with [35S]methionine for 8 min to generate radioactive snRNP proteins in forms reflecting incomplete de novo particle assembly. Immunoprecipitation of snRNP antigen prepared in this manner revealed clearly distinct patterns of Sm and RNP immunorecognition . While Sm sera precipitated all eight labeled snRNP proteins, RNP antibodies precipitated only two of the eight. However, a brief pulse followed by periods of cold chase demonstrated that RNP sera can eventually coprecipitate all components of the complete particle. In addition to antibodies to the other six snRNP peptides, all Sm sera tested have been found to contain the RNP-like reactivity with snRNP proteins A and C. RNP reactivity with these two components is of particular interest because these proteins are unique in the metabolism of snRNPs. Defining and distinguishing the precise peptides recognized by Sm and RNP antibodies has helped to clarify the biochemical basis of the standard laboratory tests for these antigen reactivities.
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Selected References
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- Bonner W. M., Laskey R. A. A film detection method for tritium-labelled proteins and nucleic acids in polyacrylamide gels. Eur J Biochem. 1974 Jul 1;46(1):83–88. doi: 10.1111/j.1432-1033.1974.tb03599.x. [DOI] [PubMed] [Google Scholar]
- Conner G. E., Nelson D., Wisniewolski R., Lahita R. G., Blobel G., Kunkel H. G. Protein antigens of the RNA-protein complexes detected by anti-SM and anti-RNP antibodies found in serum of patients with systemic lupus erythematosus and related disorders. J Exp Med. 1982 Nov 1;156(5):1475–1485. doi: 10.1084/jem.156.5.1475. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Douvas A. S., Stumph W. E., Reyes P., Tan E. M. Isolation and characterization of nuclear ribonucleoprotein complexes using human anti-nuclear ribonucleoprotein antibodies. J Biol Chem. 1979 May 10;254(9):3608–3616. [PubMed] [Google Scholar]
- Erickson A. H., Blobel G. Cell-free translation of messenger RNA in a wheat germ system. Methods Enzymol. 1983;96:38–50. doi: 10.1016/s0076-6879(83)96007-x. [DOI] [PubMed] [Google Scholar]
- Fisher D. E., Conner G. E., Reeves W. H., Blobel G., Kunkel H. G. Synthesis and assembly of human small nuclear ribonucleoproteins generated by cell-free translation. Proc Natl Acad Sci U S A. 1983 Oct;80(20):6356–6360. doi: 10.1073/pnas.80.20.6356. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Fisher P. A., Berrios M., Blobel G. Isolation and characterization of a proteinaceous subnuclear fraction composed of nuclear matrix, peripheral lamina, and nuclear pore complexes from embryos of Drosophila melanogaster. J Cell Biol. 1982 Mar;92(3):674–686. doi: 10.1083/jcb.92.3.674. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Habets W. J., de Rooij D. J., Salden M. H., Verhagen A. P., van Eekelen C. A., van de Putte L. B., van Venrooij W. J. Antibodies against distinct nuclear matrix proteins are characteristic for mixed connective tissue disease. Clin Exp Immunol. 1983 Oct;54(1):265–276. [PMC free article] [PubMed] [Google Scholar]
- Hinterberger M., Pettersson I., Steitz J. A. Isolation of small nuclear ribonucleoproteins containing U1, U2, U4, U5, and U6 RNAs. J Biol Chem. 1983 Feb 25;258(4):2604–2613. [PubMed] [Google Scholar]
- Kinlaw C. S., Dusing-Swartz S. K., Berget S. M. Human U1 and U2 small nuclear ribonucleoproteins contain common and unique polypeptides. Mol Cell Biol. 1982 Oct;2(10):1159–1166. doi: 10.1128/mcb.2.10.1159. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kinlaw C. S., Robberson B. L., Berget S. M. Fractionation and characterization of human small nuclear ribonucleoproteins containing U1 and U2 RNAs. J Biol Chem. 1983 Jun 10;258(11):7181–7189. [PubMed] [Google Scholar]
- Lerner M. R., Boyle J. A., Mount S. M., Wolin S. L., Steitz J. A. Are snRNPs involved in splicing? Nature. 1980 Jan 10;283(5743):220–224. doi: 10.1038/283220a0. [DOI] [PubMed] [Google Scholar]
- Lerner M. R., Steitz J. A. Antibodies to small nuclear RNAs complexed with proteins are produced by patients with systemic lupus erythematosus. Proc Natl Acad Sci U S A. 1979 Nov;76(11):5495–5499. doi: 10.1073/pnas.76.11.5495. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Matter L., Schopfer K., Wilhelm J. A., Nyffenegger T., Parisot R. F., De Robertis E. M. Molecular characterization of ribonucleoprotein antigens bound by antinuclear antibodies. A diagnostic evaluation. Arthritis Rheum. 1982 Nov;25(11):1278–1283. doi: 10.1002/art.1780251102. [DOI] [PubMed] [Google Scholar]
- Mattioli M., Reichlin M. Characterization of a soluble nuclear ribonucleoprotein antigen reactive with SLE sera. J Immunol. 1971 Nov;107(5):1281–1290. [PubMed] [Google Scholar]
- Mattioli M., Reichlin M. Physical association of two nuclear antigens and mutual occurrence of their antibodies: the relationship of the SM and RNAprotein (MO) systems in SLE sera. J Immunol. 1973 May;110(5):1318–1324. [PubMed] [Google Scholar]
- Rogers J., Wall R. A mechanism for RNA splicing. Proc Natl Acad Sci U S A. 1980 Apr;77(4):1877–1879. doi: 10.1073/pnas.77.4.1877. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Sharp G. C., Irvin W. S., Tan E. M., Gould R. G., Holman H. R. Mixed connective tissue disease--an apparently distinct rheumatic disease syndrome associated with a specific antibody to an extractable nuclear antigen (ENA). Am J Med. 1972 Feb;52(2):148–159. doi: 10.1016/0002-9343(72)90064-2. [DOI] [PubMed] [Google Scholar]
- Takano M., Golden S. S., Sharp G. C., Agris P. F. Molecular relationships between two nuclear antigens, ribonucleoprotein and Sm: purification of active antigens and their biochemical characterization. Biochemistry. 1981 Oct 13;20(21):5929–5936. doi: 10.1021/bi00524a001. [DOI] [PubMed] [Google Scholar]
- Tan E. M. Autoantibodies to nuclear antigens (ANA): their immunobiology and medicine. Adv Immunol. 1982;33:167–240. doi: 10.1016/s0065-2776(08)60836-6. [DOI] [PubMed] [Google Scholar]
- Tan E. M., Christian C., Holman H. R., Homma M., Kunkel H. G., Reichlin M., Sharp G. C., Ziff M., Barnett E. V. Anti-tissue antibodies in rheumatic disease: standardization and nomenclature. Arthritis Rheum. 1977 Sep-Oct;20(7):1419–1420. doi: 10.1002/art.1780200718. [DOI] [PubMed] [Google Scholar]
- Tan E. M., Kunkel H. G. Characteristics of a soluble nuclear antigen precipitating with sera of patients with systemic lupus erythematosus. J Immunol. 1966 Mar;96(3):464–471. [PubMed] [Google Scholar]
- White P. J., Hoch S. O. Definition of the antigenic polypeptides in the Sm and RNP ribonucleoprotein complexes. Biochem Biophys Res Commun. 1981 Sep 16;102(1):365–371. doi: 10.1016/0006-291x(81)91530-8. [DOI] [PubMed] [Google Scholar]
- Wieben E. D., Madore S. J., Pederson T. Protein binding sites are conserved in U1 small nuclear RNA from insects and mammals. Proc Natl Acad Sci U S A. 1983 Mar;80(5):1217–1220. doi: 10.1073/pnas.80.5.1217. [DOI] [PMC free article] [PubMed] [Google Scholar]