title: Evidence for an association between U1 RNA and interspersed repeat single-copy RNAs in the cytoplasm of sea urchin eggs.
abstract: Psoralen crosslinking of RNA-RNA intermolecular duplexes in sea urchin egg extracts reveals that some maternal poly(A)+ RNA molecules are complexed with U1 RNA, a cofactor in somatic nuclear pre-mRNA splicing. Reaction of egg extracts with a monoclonal antibody specific for U1 snRNP selects, in addition to U1, RNAs that contain repeated sequences interspersed with single-copy elements. Antibody-selection experiments with nucleate and anucleate egg halves demonstrate that most of the U1 RNA-interspersed RNA complexes are cytoplasmic, as is the egg's store of total U1 snRNP. These results raise the possibility that maternal interspersed RNAs include unprocessed pre-messenger RNA molecules in arrested complexes with splicing cofactors.
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal; D000918:Antibody Specificity; D003593:Cytoplasm / Q000032:analysis; D010063:Ovum / Q000032:analysis*; D011061:Poly A / Q000276:immunology / Q000378:metabolism*; D012333:RNA, Messenger / Q000276:immunology / Q000378:metabolism*; D012342:RNA, Small Nuclear / Q000276:immunology / Q000378:metabolism*; D012091:Repetitive Sequences, Nucleic Acid; D012261:Ribonucleoproteins / Q000276:immunology; D017411:Ribonucleoproteins, Small Nuclear; D012617:Sea Urchins; D014307:Trioxsalen / Q000031:analogs & derivatives
chemical_list: D000911:Antibodies, Monoclonal; D012333:RNA, Messenger; D012342:RNA, Small Nuclear; D012261:Ribonucleoproteins; D017411:Ribonucleoproteins, Small Nuclear; D011061:Poly A; C018822:aminomethyltrioxsalen; D014307:Trioxsalen