title: Requirement for intron-encoded U22 small nucleolar RNA in 18S ribosomal RNA maturation.
abstract: The nucleoli of vertebrate cells contain a number of small RNAs that are generated by the processing of intron fragments of protein-coding gene transcripts. The host gene (UHG) for intro-encoded human U22 is unusual in that it specifies a polyadenylated but apparently noncoding RNA. Depletion of U22 from Xenopus oocytes by oligonucleotide-directed ribonuclease H targeting prevented the processing of 18S ribosomal RNA (rRNA) at both ends. The appearance of 18S rRNA was restored by injection of in vitro-synthesized U22 RNA. These results identify a cellular function for an intron-encoded small RNA.
authors.affiliation: Howard Hughes Medical Institute, Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, CT 06536.
authors.forename: K T
authors.initials: KT
authors.lastname: Tycowski
authors.forename: M D
authors.initials: MD
authors.lastname: Shu
authors.forename: J A
authors.initials: JA
authors.lastname: Steitz
mesh_terms: D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D002466:Cell Nucleolus / Q000737:chemistry*; D006801:Humans; D007438:Introns; D008969:Molecular Sequence Data; D015345:Oligonucleotide Probes; D009865:Oocytes / Q000378:metabolism; D012322:RNA Precursors / Q000378:metabolism*; D012323:RNA Processing, Post-Transcriptional; D015138:RNA, Nuclear / Q000737:chemistry / Q000235:genetics* / Q000502:physiology*; D012337:RNA, Ribosomal, 18S / Q000378:metabolism*; D012342:RNA, Small Nuclear / Q000737:chemistry / Q000235:genetics* / Q000502:physiology*; D014981:Xenopus
chemical_list: D015345:Oligonucleotide Probes; D012322:RNA Precursors; D015138:RNA, Nuclear; D012337:RNA, Ribosomal, 18S; D012342:RNA, Small Nuclear