RNP-68K (Sm-Free) - 0.2mg

RNP-68K (Sm-Free) - 0.2mg

Regular price
Regular price
Sale price
Unit price
Sold out

U1 snRNP 68K subunit
U1 snRNP 70K subunit

Uniprot ID:  Q1RMR2
mRNA RefSeq:  NM_001076046
Protein RefSeq:  NP_001069514
Size: 0.2mg
Source: Calf Thymus
Catalogue Number: ATR04-02

Product Information

Anti-RNP antibodies were found in the sera of mixed connective tissue disease (MCTD) patients, and when these antibodies occur at high titre and in the absence of Sm, they are a good marker for MCTD. Such autoantibodies are also known to occur in the sera of patients with a range of other rheumatic diseases including progressive systemic sclerosis, rheumatoid arthritis, discoid lupus erythematosus, Sjögren's syndrome and various overlapping conditions.

The snRNPs are a group of nuclear particles comprised of several polypeptides associated with a small nuclear RNA molecule.  The most abundant snRNPs are involved in pre-mRNA-splicing. At least 13 different snRNAs have been identified in mammalian cells. Whereas autoantibodies directed against Sm are able to precipitate a wide range of snRNAs, RNP autoantibodies are only able to precipitate one particular type, referred to as U1snRNA. Anti-RNP antibodies react with the U1 snRNP-specific polypeptides (68K, A and C antigens) whereas anti-Sm antibodies react with polypeptides associated with U1, U2, U5 and U4/U6 snRNAs (B,B', D, E, F and G antigens).

Current methods for the detection of autoantibodies to RNP often require the simultaneous determination of reactivity to both RNP/Sm and Sm antigens. The reactivity with Sm is then subtracted from that with RNP/Sm, the difference being considered to be due to RNP-specific autoantibodies. The availability of RNP antigen in the absence of Sm would avoid the necessity for a dual assay to detect anti-RNP antibodies and assays have been reported using isolated U1-RNP specific subunits.

Since the 68K U1-RNP polypeptide constitutes the major MCTD RNP autoantigen, efforts to produce a recombinant RNP antigen have focused on this subunit, and not the U1-RNP specific subunits A and C which are known to share sequence homology and cross-reactivity with the Sm antigen B/B.


PDF-logo-dl RNP-68K (Sm-free) datasheet

Clinical Indications

Mixed connective tissue diseases
Systemic Lupus Erythematosus


PDF-logo-dl  Material Safety Data Sheet


Tan, E.M. & Kunkel, H.G. (1966) J. Immunol. 96, 464

Mattioli, M. & Reichlin, M. (1971) J. Immunol. 107, 1281

Sharp, G.C. et al. (1972) Am. J. Med. 52, 148

Sharp, G.C. et al. (1976) New Engl. J. Med. 295, 1149

Notman, D.D. et al. (1975) Ann. Intern. Med. 83, 464

Tan, E.M. et al. (1988) Clin. Immunol. Pathol. 47, 121

Tan, E.M. (1989) Adv. Immunol. 44, 93

van Venrooij, W.J. & Pruijn, G.J.M. (1995) Curr. OpinionImmunol. 7, 819

Guldner, H.H. (1986) Clin. Immunol. Immunopathol. 40, 532

Williams, D.G. et al. (1988) J. Immunol. Meth. 113, 25

Petersson, I. et al. (1984) J. Biol. Chem. 259, 5907

Reuter, R. et al. (1990) Eur. J. Immunol. 20, 437

Takeda, Y. et al. (1989) Clin. Immunol. Immunopathol. 50, 213

Williams, D.G. et al. (1988) J. Immunol. Meth. 113, 25

Combe, B. et al. (1989) Clin. Exp. Immunol. 75, 18

Francoeur, A.M. (1989) J. Clin. Immunol. 9, 256

Nyman, U. et al. (1990) Clin. Exp. Immunol. 81, 52

Ter-Borg, E.J. et al. (1991) J. Rheumatol. 18, 363

Frorath, B. et al. (1991) BioTechniques 11, 364

Habets, W.J. et al. (1989) Proc. Natl. Acad. Sci. USA 86, 4674

Theissen, H. et al. (1986) EMBO J. 5, 3209

Kawai, J. et al. (2001) Nature 409, 685