Logo of pnasPNASInfo for AuthorsSubscriptionsAboutThis Article
Proc Natl Acad Sci U S A. Nov 1979; 76(11): 5495–5499.
PMCID: PMC411675

Antibodies to small nuclear RNAs complexed with proteins are produced by patients with systemic lupus erythematosus


Patients with systemic lupus erythematosus often possess antibodies against two nuclear antigens called Sm and RNP (ribonucleoprotein). We have established the molecular identity of these antigens by analyzing immune precipitates of nuclear extracts from mouse Ehrlich ascites cells labeled with 32P and 35S. Anti-Sm serum selectively precipitates six small nuclear RNA molecules (snRNAs); anti-RNP serum reacts with only two of these; and a third serum, characterized as mostly anti-RNP, precipitates a subset of three snRNA bands. Three of the six RNAs are identified by fingerprint analysis as the previously characterized and highly abundant nucleoplasmic snRNA species U1a (171 nucleotides), U1b, and U2 (196 nucleotides). The other three RNAs (U4, U5, and U6) likewise are uridine rich and contain modified nucleotides, but they are smaller, with lengths of about 145, 120, and 95 residues, respectively. Each of the six snRNAs is complexed with and apparently antigenic by virtue of association with specific proteins. All three sera precipitate an identical complement of seven different polypeptides ranging in molecular weight from 12,000 to 35,000; these proteins are abundant in nuclear extracts, but are neither histones nor the major polypeptides comprising the 30S heterogeneous nuclear RNP particles of mammalian nuclei. Our data argue that each of the six snRNAs exists in a separate small nuclear ribonucleoprotein (snRNP) complex with a total molecular weight of about 175,000. We find that human antisera also precipitate snRNAs from a wide range of vertebrate species and from arthropods. We discuss the antigenic snRNPs in relation to the published literature on snRNAs and nuclear RNPs and consider possible functions of snRNPs in nuclear processes.

Full text

Full text is available as a scanned copy of the original print version. Get a printable copy (PDF file) of the complete article (1.8M), or click on a page image below to browse page by page. Links to PubMed are also available for Selected References.

Images in this article

Click on the image to see a larger version.

Selected References

These references are in PubMed. This may not be the complete list of references from this article.
  • Notman DD, Kurata N, Tan EM. Profiles of antinuclear antibodies in systemic rheumatic diseases. Ann Intern Med. 1975 Oct;83(4):464–469. [PubMed]
  • Provost TT. Subsets in systemic lupus erythematosus. J Invest Dermatol. 1979 Mar;72(3):110–113. [PubMed]
  • Mattioli M, Reichlin M. Characterization of a soluble nuclear ribonucleoprotein antigen reactive with SLE sera. J Immunol. 1971 Nov;107(5):1281–1290. [PubMed]
  • Tan EM, Kunkel HG. Characteristics of a soluble nuclear antigen precipitating with sera of patients with systemic lupus erythematosus. J Immunol. 1966 Mar;96(3):464–471. [PubMed]
  • 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]
  • Kessler SW. Rapid isolation of antigens from cells with a staphylococcal protein A-antibody adsorbent: parameters of the interaction of antibody-antigen complexes with protein A. J Immunol. 1975 Dec;115(6):1617–1624. [PubMed]
  • Laemmli UK. Cleavage of structural proteins during the assembly of the head of bacteriophage T4. Nature. 1970 Aug 15;227(5259):680–685. [PubMed]
  • Silberklang M, Gillum AM, RajBhandary UL. Use of in vitro 32P labeling in the sequence analysis of nonradioactive tRNAs. Methods Enzymol. 1979;59:58–109. [PubMed]
  • Martin T, Billings P, Levey A, Ozarslan S, Quinlan T, Swift H, Urbas L. Some properties of RNA:protein complexes from the nucleus of eukaryotic cells. Cold Spring Harb Symp Quant Biol. 1974;38:921–932. [PubMed]
  • Zieve G, Penman S. Small RNA species of the HeLa cell: metabolism and subcellular localization. Cell. 1976 May;8(1):19–31. [PubMed]
  • Ro-Choi TS, Redy R, Henning D, Takano T, Taylor CW, Busch H. Nucleotide sequence of 4.5 S ribonucleic acid of Novikoff hepatoma cell nuclei. J Biol Chem. 1972 May 25;247(10):3205–3222. [PubMed]
  • Reddy R, Ro-Choi TS, Henning D, Busch H. Primary sequence of U-1 nuclear ribonucleic acid of Novikoff hepatoma ascites cells. J Biol Chem. 1974 Oct 25;249(20):6486–6494. [PubMed]
  • Shibata H, Ro-Choi TS, Reddy R, Choi YC, Henning D, Busch H. The primary nucleotide sequence of nuclear U-2 ribonucleic acid. The 5'-terminal portion of the molecule. J Biol Chem. 1975 May 25;250(10):3909–3920. [PubMed]
  • Forget BG, Weissman SM. Oligonucleotides produced by digestion of KB cell ribosomal 5 S ribonucleic acid with specific nucleases. J Biol Chem. 1968 Nov 10;243(21):5709–5723. [PubMed]
  • Ro-Choi TS, Reddy R, Henning D, Busch H. 5S RNA 3 , a new nucleus-specific 5S RNA. Biochem Biophys Res Commun. 1971 Aug 20;44(4):963–972. [PubMed]
  • Jelinek W, Leinwand L. Low molecular weight RNAs hydrogen-bonded to nuclear and cytoplasmic poly(A)-terminated RNA from cultured Chinese hamster ovary cells. Cell. 1978 Sep;15(1):205–214. [PubMed]
  • Douvas AS, Stumph WE, Reyes P, Tan EM. Isolation and characterization of nuclear ribonucleoprotein complexes using human anti-nuclear ribonucleoprotein antibodies. J Biol Chem. 1979 May 10;254(9):3608–3616. [PubMed]
  • Hellung-Larsen P, Frederiksen S. Occurrence and properties of low molecular weight RNA components from cells at different taxonomic levels. Comp Biochem Physiol B. 1977;58(3):273–281. [PubMed]
  • Raj NB, Ro-Choi TS, Busch H. Nuclear ribonucleoprotein complexes containing U1 and U2 RNA. Biochemistry. 1975 Oct 7;14(20):4380–4385. [PubMed]
  • Howard EF. Small nuclear RNA molecules in nuclear ribonucleoprotein complexes from mouse erythroleukemia cells. Biochemistry. 1978 Aug 8;17(16):3228–3236. [PubMed]
  • Mory Y, Gefter M. RNA synthesis in isolated nuclei: the use of mercurated nucleotides. Nucleic Acids Res. 1978 Oct;5(10):3899–3912. [PMC free article] [PubMed]
  • Bolden A, Aucker J, Weissbach A. Synthesis of herpes simplex virus, vaccinia virus, and adenovirus DNA in isolated HeLa cell nuclei. I. Effect of viral-specific antisera and phosphonoacetic acid. J Virol. 1975 Dec;16(6):1584–1592. [PMC free article] [PubMed]
  • Stark BC, Kole R, Bowman EJ, Altman S. Ribonuclease P: an enzyme with an essential RNA component. Proc Natl Acad Sci U S A. 1978 Aug;75(8):3717–3721. [PMC free article] [PubMed]
  • Catterall JF, O'Malley BW, Robertson MA, Staden R, Tanaka Y, Brownlee GG. Nucleotide sequence homology at 12 intron--exon junctions in the chick ovalbumin gene. Nature. 1978 Oct 12;275(5680):510–513. [PubMed]
  • Deimel B, Louis CH, Sekeris CE. The presence of small molecular weight RNAs in nuclear ribonucleoprotein particles carrying HnRNA. FEBS Lett. 1977 Jan 15;73(1):80–84. [PubMed]
  • Northemann W, Scheurlen M, Gross V, Heinrich PC. Circular dichroism of ribonucleoprotein complexes from rat liver nuclei. Biochem Biophys Res Commun. 1977 Jun 20;76(4):1130–1137. [PubMed]
  • Guimont-Ducamp C, Sri-Widada J, Jeanteur P. Occurrence of small molecular weight RNAs in Hela nuclear ribonucleoprotein particles containing HnRNA. Biochimie. 1977;59(8-9):755–758. [PubMed]
  • Karn J, Vidali G, Boffa LC, Allfrey VG. Characterization of the non-histone nuclear proteins associated with rapidly labeled heterogeneous nuclear RNA. J Biol Chem. 1977 Oct 25;252(20):7307–7322. [PubMed]
  • Beyer AL, Christensen ME, Walker BW, LeStourgeon WM. Identification and characterization of the packaging proteins of core 40S hnRNP particles. Cell. 1977 May;11(1):127–138. [PubMed]
  • Sharp GC, Irvin WS, May CM, Holman HR, McDuffie FC, Hess EV, Schmid FR. Association of antibodies to ribonucleoprotein and Sm antigens with mixed connective-tissue disease, systematic lupus erythematosus and other rheumatic diseases. N Engl J Med. 1976 Nov 18;295(21):1149–1154. [PubMed]
  • Reichlin M. Problems in differentiating SLE and mixed connective-tissue disease. N Engl J Med. 1976 Nov 18;295(21):1194–1195. [PubMed]
  • Parker MD. Ribonucleoprotein antibodies: frequency and clinical significance in systemic lupus erythematosus, scleroderma, and mixed connective tissue disease. J Lab Clin Med. 1973 Nov;82(5):769–775. [PubMed]
  • Pinnas JL, Northway JD, Tan EM. Antinucleolar antibodies in human sera. J Immunol. 1973 Oct;111(4):996–1004. [PubMed]
  • Eisenberg RA, Tan EM, Dixon FJ. Presence of anti-Sm reactivity in autoimmune mouse strains. J Exp Med. 1978 Feb 1;147(2):582–587. [PMC free article] [PubMed]

Articles from Proceedings of the National Academy of Sciences of the United States of America are provided here courtesy of National Academy of Sciences


Related citations in PubMed

See reviews...See all...

Cited by other articles in PMC

See all...


  • Cited in Books
    Cited in Books
    PubMed Central articles cited in books
  • MedGen
    Related information in MedGen
  • PubMed
    PubMed citations for these articles
  • Substance
    PubChem Substance links

Recent Activity

Your browsing activity is empty.

Activity recording is turned off.

Turn recording back on

See more...