U4 and U6 small nuclear ribonucleoprotein particles. 1. Fractionation and characterization of snRNPs containing U4 and U6 RNAs.
The isolation of U4 and U6 small nuclear ribonucleoprotein particles (snRNP) was undertaken, since there has been no reliable method for their fractionation established. The procedure subjects a nuclear extract from HeLa cells to several types of ion exchange chromatography at moderate ionic strength, electrophoresis on agarose gels, transfer of the particles on DEAE cellulose paper, and elution with ammonium chloride. The purified U4 and U6 snRNPs contain U4 and U6 RNAs, respectively, and a set of six polypeptides, present in U4 RNPs and seven polypeptides in U6 snRNP particles. Five major proteins with molecular masses of 70, 64, 47, 40.5 and 24 kD are common to both assemblies. In addition U4 RNPs contain one polypeptide of 25.1 kD which is unique for this class of particles, while U6 RNPs possess two polypeptides with molecular masses of 31 and 18 kD which are not present in U1, U2 or U4 snRNPs. The U4 and U6 RNP particles thus fractionated retain their antigenicity as judged by their reaction with auto-antibodies from patients with lupus erythematosus.
Pironcheva
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Institute of Molecular Biology, Bulgarian Academy of Sciences, Sofia.
Todorov
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I
Russev
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G
D002846:Chromatography, Affinity; D002852:Chromatography, Ion Exchange; D006367:HeLa Cells / Q000032:analysis; D006801:Humans; D008970:Molecular Weight; D012342:RNA, Small Nuclear / Q000302:isolation & purification*; D012261:Ribonucleoproteins / Q000302:isolation & purification*; D017411:Ribonucleoproteins, Small Nuclear
D012342:RNA, Small Nuclear; D012261:Ribonucleoproteins; D017411:Ribonucleoproteins, Small Nuclear