Autoantibodies to the U2 small nuclear ribonucleoprotein in a patient with scleroderma-polymyositis overlap syndrome.

Abstract

Autoantibodies directed against the U2 small nuclear ribonucleoprotein (snRNP) have been found in the serum of a patient with scleroderma-polymyositis overlap syndrome. This specificity, called anti-(U2)-RNP, is distinct from all previously described autoantibodies, including those that precipitate related snRNPs: anti-Sm antibodies, which react with the entire set of U1, U2, U4, U5, and U6 snRNPs, and anti-(U1)RNP antibodies, which recognize only U1 snRNPs. From HeLa cell extracts, anti-(U2)RNP immunoprecipitates predominantly one 32P-labeled RNA species, identified as U2 small nuclear RNA, and six [35S]methionine-labeled protein bands, A' (Mr = 32,000), B (Mr = 28,000), D (Mr = 16,000), E (Mr = 13,000), F (Mr = 12,000), and G (Mr = 11,000). Protein blot analysis reveals that the A' protein carries (U2)RNP antigenic determinant(s) and therefore represents a polypeptide unique to the U2 snRNP; the B protein associated with U2 snRNPs may also be unique. Like U1 and the other Sm snRNPs, U2 snRNPs occupy a nuclear, non-nucleolar location and are antigenically conserved from insects to man. An antibody specific for the U2 snRNP will be useful in deciphering the function of this particle.

• Authors: T Mimori, M Hinterberger, I Pettersson, J A Steitz
• Journal: The Journal of biological chemistry (J Biol Chem) Vol. 259 Issue 1 Pg. 560-5 (Jan 10 1984) ISSN: 0021-9258 [Print] United States
• PMID: 6231285 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Autoantibodies
• Ribonucleoproteins
• Ribonucleoproteins, Small Nuclear

Topics

• Autoantibodies (analysis)
• Female
• Fluorescent Antibody Technique
• HeLa Cells (immunology)
• Humans
• Immunodiffusion
• Myositis (complications)
• Ribonucleoproteins (immunology)
• Ribonucleoproteins, Small Nuclear
• Scleroderma, Systemic (complications, immunology)