title: Elucidating the role of C/D snoRNA in rRNA processing and modification in Trypanosoma brucei.
abstract: Most eukaryotic C/D small nucleolar RNAs (snoRNAs) guide 2'-O methylation (Nm) on rRNA and are also involved in rRNA processing. The four core proteins that bind C/D snoRNA in Trypanosoma brucei are fibrillarin (NOP1), NOP56, NOP58, and SNU13. Silencing of NOP1 by RNA interference identified rRNA-processing and modification defects that caused lethality. Systematic mapping of 2'-O-methyls on rRNA revealed the existence of hypermethylation at certain positions of the rRNA in the bloodstream form of the parasites, suggesting that this modification may assist the parasites in coping with the major temperature changes during cycling between their insect and mammalian hosts. The rRNA-processing defects of NOP1-depleted cells suggest the involvement of C/D snoRNA in trypanosome-specific rRNA-processing events to generate the small rRNA fragments. MRP RNA, which is involved in rRNA processing, was identified in this study in one of the snoRNA gene clusters, suggesting that trypanosomes utilize a combination of unique C/D snoRNAs and conserved snoRNAs for rRNA processing.
authors.affiliation: The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 52900, Israel.
authors.forename: Sarit
authors.initials: S
authors.lastname: Barth
authors.forename: Boaz
authors.initials: B
authors.lastname: Shalem
authors.forename: Avraham
authors.initials: A
authors.lastname: Hury
authors.forename: Itai Dov
authors.initials: ID
authors.lastname: Tkacz
authors.forename: Xue-Hai
authors.initials: XH
authors.lastname: Liang
authors.forename: Shai
authors.initials: S
authors.lastname: Uliel
authors.forename: Inna
authors.initials: I
authors.lastname: Myslyuk
authors.forename: Tirza
authors.initials: T
authors.lastname: Doniger
authors.forename: Mali
authors.initials: M
authors.lastname: Salmon-Divon
authors.forename: Ron
authors.initials: R
authors.lastname: Unger
authors.forename: Shulamit
authors.initials: S
authors.lastname: Michaeli
mesh_terms: D000818:Animals; D017360:Arabidopsis / Q000235:genetics; D001483:Base Sequence; D015152:Blotting, Northern; D015153:Blotting, Western; D002868:Chromosomal Proteins, Non-Histone / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism; D019295:Computational Biology; D020868:Gene Silencing; D006801:Humans; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D016053:RNA, Protozoan / Q000378:metabolism*; D012335:RNA, Ribosomal / Q000378:metabolism*; D020537:RNA, Small Nucleolar / Q000502:physiology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012441:Saccharomyces cerevisiae / Q000235:genetics; D014346:Trypanosoma brucei brucei / Q000235:genetics*; D014352:Trypanosomiasis / Q000235:genetics
chemical_list: D002868:Chromosomal Proteins, Non-Histone; D016053:RNA, Protozoan; D012335:RNA, Ribosomal; D020537:RNA, Small Nucleolar; C047458:fibrillarin