title: A tRNA methyltransferase paralog is important for ribosome stability and cell division in Trypanosoma brucei.
abstract: Most eukaryotic ribosomes contain 26/28S, 5S, and 5.8S large subunit ribosomal RNAs (LSU rRNAs) in addition to the 18S rRNA of the small subunit (SSU rRNA). However, in kinetoplastids, a group of organisms that include medically important members of the genus Trypanosoma and Leishmania, the 26/28S large subunit ribosomal RNA is uniquely composed of 6 rRNA fragments. In addition, recent studies have shown the presence of expansion segments in the large ribosomal subunit (60S) of Trypanosoma brucei. Given these differences in structure, processing and assembly, T. brucei ribosomes may require biogenesis factors not found in other organisms. Here, we show that one of two putative 3-methylcytidine methyltransferases, TbMTase37 (a homolog of human methyltransferase-like 6, METTL6), is important for ribosome stability in T. brucei. TbMTase37 localizes to the nucleolus and depletion of the protein results in accumulation of ribosomal particles lacking srRNA 4 and reduced levels of polysome associated ribosomes. We also find that TbMTase37 plays a role in cytokinesis, as loss of the protein leads to multi-flagellated and multi-nucleated cells.
authors.affiliation: Department of Microbiology and Center for RNA Biology, The Ohio State University, Columbus, Ohio 43210, USA.
authors.forename: Ian M C
authors.initials: IM
authors.lastname: Fleming
authors.affiliation: Department of Microbiology and Center for RNA Biology, The Ohio State University, Columbus, Ohio 43210, USA.
authors.forename: Zdeněk
authors.initials: Z
authors.lastname: Paris
authors.affiliation: Rieveschl Laboratories for Mass Spectrometry, Department of Chemistry, University of Cincinnati, Cincinnati, Ohio 45221, USA.
authors.forename: Kirk W
authors.initials: KW
authors.lastname: Gaston
authors.affiliation: Department of Microbiology and Center for RNA Biology, The Ohio State University, Columbus, Ohio 43210, USA.|Rieveschl Laboratories for Mass Spectrometry, Department of Chemistry, University of Cincinnati, Cincinnati, Ohio 45221, USA.
authors.forename: R
authors.initials: R
authors.lastname: Balakrishnan
authors.affiliation: Department of Microbiology and Center for RNA Biology, The Ohio State University, Columbus, Ohio 43210, USA.|Ohio State Biochemistry Program, The Ohio State University, Columbus, Ohio 43210, USA f.
authors.forename: Kurt
authors.initials: K
authors.lastname: Fredrick
authors.affiliation: Department of Microbiology and Center for RNA Biology, The Ohio State University, Columbus, Ohio 43210, USA.
authors.forename: Mary Anne T
authors.initials: MA
authors.lastname: Rubio
authors.affiliation: Department of Microbiology and Center for RNA Biology, The Ohio State University, Columbus, Ohio 43210, USA.|Ohio State Biochemistry Program, The Ohio State University, Columbus, Ohio 43210, USA f.
authors.forename: Juan D
authors.initials: JD
authors.lastname: Alfonzo
mesh_terms: D002455:Cell Division / Q000502:physiology*; D006801:Humans; D008780:Methyltransferases / Q000235:genetics / Q000378:metabolism*; D015800:Protozoan Proteins / Q000235:genetics / Q000378:metabolism*; D012270:Ribosomes / Q000235:genetics / Q000378:metabolism*; D014346:Trypanosoma brucei brucei / Q000235:genetics / Q000378:metabolism*
chemical_list: D015800:Protozoan Proteins; D008780:Methyltransferases