Dom34 Links Translation to Protein O-mannosylation

PLoS Genet. 2016 Oct 21;12(10):e1006395. doi: 10.1371/journal.pgen.1006395. eCollection 2016 Oct.

Abstract

In eukaryotes, Dom34 upregulates translation by securing levels of activatable ribosomal subunits. We found that in the yeast Saccharomyces cerevisiae and the human fungal pathogen Candida albicans, Dom34 interacts genetically with Pmt1, a major isoform of protein O-mannosyltransferase. In C. albicans, lack of Dom34 exacerbated defective phenotypes of pmt1 mutants, while they were ameliorated by Dom34 overproduction that enhanced Pmt1 protein but not PMT1 transcript levels. Translational effects of Dom34 required the 5'-UTR of the PMT1 transcript, which bound recombinant Dom34 directly at a CA/AC-rich sequence and regulated in vitro translation. Polysomal profiling revealed that Dom34 stimulates general translation moderately, but that it is especially required for translation of transcripts encoding Pmt isoforms 1, 4 and 6. Because defective protein N- or O-glycosylation upregulates transcription of PMT genes, it appears that Dom34-mediated specific translational upregulation of the PMT transcripts optimizes cellular responses to glycostress. Its translational function as an RNA binding protein acting at the 5'-UTR of specific transcripts adds another facet to the known ribosome-releasing functions of Dom34 at the 3'-UTR of transcripts.

MeSH terms

  • Candida albicans / genetics*
  • Candida albicans / growth & development
  • Cell Cycle Proteins / biosynthesis
  • Cell Cycle Proteins / genetics*
  • Endoribonucleases / biosynthesis
  • Endoribonucleases / genetics*
  • Glycosylation
  • Humans
  • Mannosyltransferases / genetics*
  • Oligonucleotides / genetics
  • Phenotype
  • Protein Biosynthesis / genetics*
  • Protein Isoforms / biosynthesis
  • Protein Isoforms / genetics
  • Ribosomes / genetics
  • Ribosomes / metabolism
  • Saccharomyces cerevisiae / genetics*
  • Saccharomyces cerevisiae Proteins / biosynthesis
  • Saccharomyces cerevisiae Proteins / genetics*

Substances

  • Cell Cycle Proteins
  • Oligonucleotides
  • Protein Isoforms
  • Saccharomyces cerevisiae Proteins
  • Mannosyltransferases
  • protein O-mannosyltransferase
  • Dom34 protein, S cerevisiae
  • Endoribonucleases

Grants and funding

Funded by the Deutsche Forschungsgemeinschaft (SPP1160), the Manchot Graduate School Molecules of Infection (MOI II) and ERA-NET Pathogenomics project “Glycoshield” to JFE and by the Spanish Ministerio de Ciencia e Innovación (BFU2013-48643-C3-3-P) to PA. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.