title: Small nuclear RNA U2 is base-paired to heterogeneous nuclear RNA.
abstract: Eukaryotic cells contain a set of low molecular weight nuclear RNA's. One of the more abundant of these is termed U2 RNA. The possibility that U2 RNA is hydrogen-bonded to complementary sequences in other nuclear RNA's was investigated. Cultured human (HeLa) cells were treated with a psoralen derivative that cross-links RNA chains that are base-paired with one another. High molecular weight heterogeneous nuclear RNA was isolated under denaturing conditions, and the psoralen cross-links were reversed. Electrophoresis of the released RNA and hybridization with a human cloned U2 DNA probe revealed that U2 is hydrogen-bonded to complementary sequences in heterogeneous nuclear RNA in vivo. In contrast, U2 RNA is not base-paired with nucleolar RNA, which contains the precursors of ribosomal RNA. The results suggest that U2 RNA participates in messenger RNA processing in the nucleus.
mesh_terms: D001482:Base Composition; D002466:Cell Nucleolus / Q000032:analysis; D003432:Cross-Linking Reagents / Q000494:pharmacology; D004274:DNA, Recombinant; D006367:HeLa Cells; D006801:Humans; D009693:Nucleic Acid Hybridization; D012313:RNA / Q000032:analysis*; D012332:RNA, Heterogeneous Nuclear / Q000032:analysis*; D012335:RNA, Ribosomal / Q000032:analysis; D012342:RNA, Small Nuclear; D014307:Trioxsalen / Q000031:analogs & derivatives / Q000494:pharmacology
chemical_list: D003432:Cross-Linking Reagents; D004274:DNA, Recombinant; D012332:RNA, Heterogeneous Nuclear; D012335:RNA, Ribosomal; D012342:RNA, Small Nuclear; D012313:RNA; C018822:aminomethyltrioxsalen; D014307:Trioxsalen