Open AccessThe mammalian analogue of the yeast PRP8 splicing protein is present in the U4/5/6 small nuclear ribonucleoprotein particle and the spliceosome.
Author(s) -
Ann L. Pinto,
Joan A. Steitz
Publication year - 1989
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.86.22.8742
Subject(s) - snrnp , small nuclear ribonucleoprotein , spliceosome , rna splicing , ribonucleoprotein , heterogeneous ribonucleoprotein particle , protein splicing , immunoprecipitation , biology , nuclear protein , microbiology and biotechnology , rna binding protein , heterogeneous nuclear ribonucleoprotein , yeast , cell nucleus , biochemistry , rna , gene , nucleus , transcription factor
HeLa cell nuclear extracts contain a protein reactive with antibodies against PRP8, a polypeptide essential for pre-mRNA splicing in yeast and a specific component of the yeast U5 small nuclear ribonucleoprotein (snRNP) [Lossky, M., Anderson, G. J., Jackson, S. P. & Beggs, J. (1987) Cell 51, 1019-1026]. The mammalian protein appears as a doublet at approximately 200 kDa, smaller than the 260-kDa yeast protein, and possesses an Sm epitope as determined by immunoblotting. Its association with a snRNP of the Sm class other than U1 or U2 is indicated by its immunoprecipitation by anti-Sm and anti-trimethylguanosine antibodies but not by anti-(U1) or anti-(U2) RNP sera. Gradient fractionation of splicing extracts demonstrates that the 200-kDa protein is a component of the U4/5/6 snRNP complex and of U5 snRNPs. It is also present in affinity-purified spliceosomes.