Skip to main content
NCBI home page
The Journal of Experimental Medicine logoLink to The Journal of Experimental Medicine
. 1988 May 1;167(5):1560–1571. doi: 10.1084/jem.167.5.1560

A 52-kD protein is a novel component of the SS-A/Ro antigenic particle

PMCID: PMC2188933  PMID: 3367095

Abstract

Anti-SS-A/Ro autoantibodies are found in the sera of patients with Sjogren's syndrome (SS) and SLE. In the course of analyzing 61 SS patients for their autoantibody profiles, we found that 42 were positive for anti-SS-A by double diffusion in agarose and demonstrated precipitin lines identical to that produced by a prototype anti-SS-A serum. Further analysis of these SS-A antibody-positive sera by Western blotting of cell extracts revealed that 21 sera reacted with two proteins of 60 and 52 kD, 13 sera reacted with 52-kD protein, two detected only 60 kD, while six were nonreactive. Affinity-purified anti- 60-kD and anti-52-kD antibodies reacted exclusively with their corresponding antigens. Partial proteolysis of these proteins did not reveal common degradation fragments. Thus the 52- and 60-kD proteins were found to be antigenically and apparently structurally distinct from each other. They were also distinct from 48-kD SS-B/La protein. In immunoprecipitation using labeled cell extracts, affinity-purified anti- 52-kD antibodies brought down the 52-kD protein as well as the 60-kD band. In [32P]orthophosphate-labeled HeLa cell extract both antibodies precipitated the same spectrum of small RNAs (hYl-5). In indirect immunofluorescence, anti-52-kD and anti-60-kD antibodies immunolocalized in similar subcellular structures and showed similar punctate nuclear staining patterns. Western blot analysis revealed that both proteins were present in lymphocytic as well as epithelial human cell lines tested. The data above define a new antigen of 52 kD which is another component of the SS-A particle and is associated in complex formation with the previously reported 60-kD protein.

Full Text

The Full Text of this article is available as a PDF (820.7 KB).

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Alspaugh M. A., Tan E. M. Antibodies to cellular antigens in Sjögren's syndrome. J Clin Invest. 1975 May;55(5):1067–1073. doi: 10.1172/JCI108007. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Bachmann M., Mayet W. J., Schröder H. C., Pfeifer K., Meyer zum Büschenfelde K. H., Müller W. E. Identification of the Ro and La antigens in the endoribonuclease VII--ribonucleoprotein complex. Biochem J. 1987 Apr 1;243(1):189–194. doi: 10.1042/bj2430189. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Chan E. K., Francoeur A. M., Tan E. M. Epitopes, structural domains, and asymmetry of amino acid residues in SS-B/La nuclear protein. J Immunol. 1986 May 15;136(10):3744–3749. [PubMed] [Google Scholar]
  4. Christian C. L., Elkon K. B. Autoantibodies to intracellular proteins. Clinical and biologic significance. Am J Med. 1986 Jan;80(1):53–61. doi: 10.1016/0002-9343(86)90048-3. [DOI] [PubMed] [Google Scholar]
  5. Clark G., Reichlin M., Tomasi T. B., Jr Characterization of a soluble cytoplasmic antigen reactive with sera from patients with systemic lupus erythmatosus. J Immunol. 1969 Jan;102(1):117–122. [PubMed] [Google Scholar]
  6. Cleveland D. W., Fischer S. G., Kirschner M. W., Laemmli U. K. Peptide mapping by limited proteolysis in sodium dodecyl sulfate and analysis by gel electrophoresis. J Biol Chem. 1977 Feb 10;252(3):1102–1106. [PubMed] [Google Scholar]
  7. Deng J. S., Sontheimer R. D., Gilliam J. N. Molecular characteristics of SS-B/La and SS-A/Ro cellular antigens. J Invest Dermatol. 1985 Feb;84(2):86–90. doi: 10.1111/1523-1747.ep12274950. [DOI] [PubMed] [Google Scholar]
  8. Eisenberg R. A. Association between the Ro and La antigenic determinants: immunodiffusion analysis of human spleen extract. J Immunol. 1985 Sep;135(3):1707–1713. [PubMed] [Google Scholar]
  9. Elkon K. B., Culhane L. Partial immunochemical characterization of the Ro and La proteins using antibodies from patients with the sicca syndrome and lupus erythematosus. J Immunol. 1984 May;132(5):2350–2356. [PubMed] [Google Scholar]
  10. Elkon K. B., Jankowski P. W. Fine specificities of autoantibodies directed against the Ro, La, Sm, RNP, and Jo-1 proteins defined by two-dimensional gel electrophoresis and immunoblotting. J Immunol. 1985 Jun;134(6):3819–3824. [PubMed] [Google Scholar]
  11. Fox R. I., Robinson C. A., Curd J. G., Kozin F., Howell F. V. Sjögren's syndrome. Proposed criteria for classification. Arthritis Rheum. 1986 May;29(5):577–585. doi: 10.1002/art.1780290501. [DOI] [PubMed] [Google Scholar]
  12. Francoeur A. M., Mathews M. B. Interaction between VA RNA and the lupus antigen La: formation of a ribonucleoprotein particle in vitro. Proc Natl Acad Sci U S A. 1982 Nov;79(22):6772–6776. doi: 10.1073/pnas.79.22.6772. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Guldner H. H., Lakomek H. J., Bautz F. A. Identification of human Sm and (U1) RNP antigens by immunoblotting. J Immunol Methods. 1983 Nov 11;64(1-2):45–59. doi: 10.1016/0022-1759(83)90383-6. [DOI] [PubMed] [Google Scholar]
  14. Harmon C. E., Deng J. S., Peebles C. L., Tan E. M. The importance of tissue substrate in the SS-A/Ro antigen-antibody system. Arthritis Rheum. 1984 Feb;27(2):166–173. doi: 10.1002/art.1780270207. [DOI] [PubMed] [Google Scholar]
  15. Hendrick J. P., Wolin S. L., Rinke J., Lerner M. R., Steitz J. A. Ro small cytoplasmic ribonucleoproteins are a subclass of La ribonucleoproteins: further characterization of the Ro and La small ribonucleoproteins from uninfected mammalian cells. Mol Cell Biol. 1981 Dec;1(12):1138–1149. doi: 10.1128/mcb.1.12.1138. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Herrera-Esparza R., Halim H. Y., Provost T. T., Diaz L. A. A sensitive and specific assay to detect Ro(SS-A) and La(SS-B) antibodies. J Invest Dermatol. 1986 Mar;86(3):217–221. doi: 10.1111/1523-1747.ep12285159. [DOI] [PubMed] [Google Scholar]
  17. Laemmli U. K. Cleavage of structural proteins during the assembly of the head of bacteriophage T4. Nature. 1970 Aug 15;227(5259):680–685. doi: 10.1038/227680a0. [DOI] [PubMed] [Google Scholar]
  18. 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]
  19. Lieu T. S., Jiang M., Steigerwald J. C., Tan E. M. Identification of the SS-A/Ro intracellular antigen with autoimmune sera. J Immunol Methods. 1984 Jul 6;71(2):217–228. doi: 10.1016/0022-1759(84)90068-1. [DOI] [PubMed] [Google Scholar]
  20. Mattioli M., Reichlin M. Heterogeneity of RNA protein antigens reactive with sera of patients with systemic lupus erythematosus. Description of a cytoplasmic nonribosomal antigen. Arthritis Rheum. 1974 Jul-Aug;17(4):421–429. doi: 10.1002/art.1780170413. [DOI] [PubMed] [Google Scholar]
  21. Olmsted J. B. Affinity purification of antibodies from diazotized paper blots of heterogeneous protein samples. J Biol Chem. 1981 Dec 10;256(23):11955–11957. [PubMed] [Google Scholar]
  22. Reeves W. H., Fisher D. E., Lahita R. G., Kunkel H. G. Autoimmune sera reactive with Sm antigen contain high levels of RNP-like antibodies. J Clin Invest. 1985 Feb;75(2):580–587. doi: 10.1172/JCI111734. [DOI] [PMC free article] [PubMed] [Google Scholar]
  23. 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]
  24. Towbin H., Staehelin T., Gordon J. Electrophoretic transfer of proteins from polyacrylamide gels to nitrocellulose sheets: procedure and some applications. Proc Natl Acad Sci U S A. 1979 Sep;76(9):4350–4354. doi: 10.1073/pnas.76.9.4350. [DOI] [PMC free article] [PubMed] [Google Scholar]
  25. Venables P. J., Smith P. R., Maini R. N. Purification and characterization of the Sjögren's syndrome A and B antigens. Clin Exp Immunol. 1983 Dec;54(3):731–738. [PMC free article] [PubMed] [Google Scholar]
  26. Wolin S. L., Steitz J. A. Genes for two small cytoplasmic Ro RNAs are adjacent and appear to be single-copy in the human genome. Cell. 1983 Mar;32(3):735–744. doi: 10.1016/0092-8674(83)90059-4. [DOI] [PubMed] [Google Scholar]
  27. Wolin S. L., Steitz J. A. The Ro small cytoplasmic ribonucleoproteins: identification of the antigenic protein and its binding site on the Ro RNAs. Proc Natl Acad Sci U S A. 1984 Apr;81(7):1996–2000. doi: 10.1073/pnas.81.7.1996. [DOI] [PMC free article] [PubMed] [Google Scholar]
  28. Yamagata H., Harley J. B., Reichlin M. Molecular properties of the Ro/SSA antigen and enzyme-linked immunosorbent assay for quantitation of antibody. J Clin Invest. 1984 Aug;74(2):625–633. doi: 10.1172/JCI111460. [DOI] [PMC free article] [PubMed] [Google Scholar]

Articles from The Journal of Experimental Medicine are provided here courtesy of The Rockefeller University Press

RESOURCES