
U1 snRNP 68K subunit
U1 snRNP 70K subunit
Size: 1.0mg
Source: Calf Thymus
Catalogue Number: ATR04-10
Product Information
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.
Clinical Indications
Mixed connective tissue diseases
Systemic Lupus Erythematosus
MSDS
References
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