title: Small nucleolar RNAs encoded by introns of the human cell cycle regulatory gene RCC1.
abstract: Eukaryotic cells contain a large number of U small nuclear RNAs (U-snRNAs) involved in various RNA processing reactions in the nucleoplasm and nucleous. Most of the U-snRNAs have 5'-terminal caps added to the end of the primary transcript. Here we describe two variants of a snRNA, called U17, identified in human HeLa cells. U17 RNA may be involved in ribosome biogenesis since it is found in the nucleolus and sediments with 40S structures possibly representing nascent ribosomal subunits. U17 RNAs contain no cap but have a monophosphate at the 5'-terminus indicating that they are processed from longer precursors. The U17 RNAs are encoded within introns 1 and 2 of the single copy gene RCC1 which codes for an important cell cycle regulatory protein. In HeLa cell S-100 extract, U17 RNA is faithfully excised from a longer RNA transcript derived from the intron yielding 5'-monophosphorylated RNA. These data suggest that U17 RNAs are not independently transcribed but are processed out of the RCC1 pre-mRNA or out of the spliced introns.
authors.affiliation: Friedrich Miescher-Institut, Basel, Switzerland.
authors.forename: T
authors.initials: T
authors.lastname: Kiss
authors.forename: W
authors.initials: W
authors.lastname: Filipowicz
mesh_terms: D001483:Base Sequence; D005075:Biological Evolution; D002453:Cell Cycle / Q000235:genetics*; D018797:Cell Cycle Proteins; D002466:Cell Nucleolus / Q000378:metabolism; D017124:Conserved Sequence; D004268:DNA-Binding Proteins / Q000235:genetics*; D005809:Genes, Regulator; D020662:Guanine Nucleotide Exchange Factors; D006367:HeLa Cells; D006801:Humans; D007438:Introns; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000235:genetics*; D012322:RNA Precursors / Q000378:metabolism; D012342:RNA, Small Nuclear / Q000235:genetics*
chemical_list: D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; D020662:Guanine Nucleotide Exchange Factors; D009687:Nuclear Proteins; C062521:RCC1 protein, human; D012322:RNA Precursors; D012342:RNA, Small Nuclear