title: Aggregation of Mod5 is affected by tRNA binding with implications for tRNA gene-mediated silencing.
abstract: Mod5 is a multifunctional protein that modifies a subset of tRNAs in the cytoplasm and is also required for an RNA-mediated form of transcriptional silencing. Previous in vivo studies have shown that the nuclear silencing function of Mod5 does not require that the causative tRNA gene encode a Mod5 substrate, although Mod5 is still required. However, previous data have not directly tested whether Mod5 can directly bind substrate and nonsubstrate RNAs. We herein demonstrate that Mod5 directly binds to both substrate and nonsubstrate RNAs, including a highly structured, non-tRNA sequence (5S-rRNA), consistent with previous in vivo data. Furthermore, we show that some RNAs drastically change the aggregation behavior of Mod5 with implications for tRNA gene-mediated silencing.
authors.affiliation: Biological Chemistry, University of Michigan, Ann Arbor, MI, USA.
authors.forename: David F
authors.initials: DF
authors.lastname: Read
authors.affiliation: Biological Chemistry, University of Michigan, Ann Arbor, MI, USA.
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Waller
authors.affiliation: Biological Chemistry, University of Michigan, Ann Arbor, MI, USA.|Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA.
authors.forename: Eric
authors.initials: E
authors.lastname: Tse
authors.affiliation: Biological Chemistry, University of Michigan, Ann Arbor, MI, USA.|Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA.
authors.forename: Daniel R
authors.initials: DR
authors.lastname: Southworth
authors.affiliation: Biological Chemistry, University of Michigan, Ann Arbor, MI, USA.|University of Colorado Denver/Anschutz Medical Campus, Aurora, CO, USA.
authors.forename: David R
authors.initials: DR
authors.lastname: Engelke
authors.affiliation: Biological Chemistry, University of Michigan, Ann Arbor, MI, USA.|Biology, Ball State University, Muncie, IN, USA.
authors.forename: Philip J
authors.initials: PJ
authors.lastname: Smaldino
mesh_terms: D019883:Alkyl and Aryl Transferases / Q000235:genetics / Q000378:metabolism*; D024202:Electrophoretic Mobility Shift Assay; D020868:Gene Silencing; D008856:Microscopy, Fluorescence; D011485:Protein Binding; D012343:RNA, Transfer / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D029701:Saccharomyces cerevisiae Proteins; D012343:RNA, Transfer; D019883:Alkyl and Aryl Transferases; C068392:MOD5 protein, S cerevisiae
keywords: Mod5; RNA binding; amyloid fiber; isopentenyl transferase; protein aggregation; tRNA modification