Identification and characterization of the small nuclear ribonucleoprotein particle D' core protein.
The addition of urea to sodium dodecyl sulfate (SDS)-polyacrylamide gels has allowed the identification and characterization of the small nuclear ribonucleoprotein particle (snRNP) D' protein and has also improved resolution of the E, F, and G snRNP core proteins. In standard SDS-polyacrylamide gels, the D' and D snRNP core proteins comigrate at approximately 16 kilodaltons. The addition of urea to the separating gel caused the D' protein to shift to a slower electrophoretic mobility that is distinct from that of the D protein. The shift to a slower electrophoretic mobility in the presence of urea suggests that the D' protein has extensive secondary structure that is not totally disrupted by SDS alone. Both N-terminal sequencing and partial peptide maps indicate that the D and D' proteins are distinct gene products, and the sequence data have identified the faster moving of the two proteins as the previously cloned D protein (L. A. Rokeach, J. A. Haselby, and S. O. Hoch, Proc. Natl. Acad. Sci. USA 85:4832-4836, 1988). In the cytoplasm, the D protein is found primarily in the small-nuclear-RNA-free 6S protein complexes, while the D' protein is found primarily in the 20S protein complexes. Like the D protein, the D' protein is an autoantigen in patients with systemic lupus erythematosus and is recognized by some of the Sm class of autoimmune antisera.
Andersen
J
J
Department of Pathology, State University of New York, Stony Brook 11794-8081.
Feeney
R J
RJ
Zieve
G W
GW
D000818:Animals; D002467:Cell Nucleus / Q000378:metabolism; D015180:Electrophoresis, Gel, Two-Dimensional / Q000379:methods; D004591:Electrophoresis, Polyacrylamide Gel / Q000379:methods; D006168:Guinea Pigs; D006367:HeLa Cells / Q000378:metabolism; D006801:Humans; D007739:L Cells / Q000378:metabolism; D008715:Methionine / Q000378:metabolism; D008970:Molecular Weight; D010449:Peptide Mapping; D012261:Ribonucleoproteins / Q000096:biosynthesis / Q000302:isolation & purification*; D017411:Ribonucleoproteins, Small Nuclear; D014508:Urea
D012261:Ribonucleoproteins; D017411:Ribonucleoproteins, Small Nuclear; D014508:Urea; D008715:Methionine