Decreasing mitochondrial RNA polymerase activity reverses biased inheritance of hypersuppressive mtDNA

PLoS Genet. 2021 Oct 19;17(10):e1009808. doi: 10.1371/journal.pgen.1009808. eCollection 2021 Oct.

Abstract

Faithful inheritance of mitochondrial DNA (mtDNA) is crucial for cellular respiration/oxidative phosphorylation and mitochondrial membrane potential. However, how mtDNA is transmitted to progeny is not fully understood. We utilized hypersuppressive mtDNA, a class of respiratory deficient Saccharomyces cerevisiae mtDNA that is preferentially inherited over wild-type mtDNA (rho+), to uncover the factors governing mtDNA inheritance. We found that some regions of rho+ mtDNA persisted while others were lost after a specific hypersuppressive takeover indicating that hypersuppressive preferential inheritance may partially be due to active destruction of rho+ mtDNA. From a multicopy suppression screen, we found that overexpression of putative mitochondrial RNA exonuclease PET127 reduced biased inheritance of a subset of hypersuppressive genomes. This suppression required PET127 binding to the mitochondrial RNA polymerase RPO41 but not PET127 exonuclease activity. A temperature-sensitive allele of RPO41 improved rho+ mtDNA inheritance over a specific hypersuppressive mtDNA at semi-permissive temperatures revealing a previously unknown role for rho+ transcription in promoting hypersuppressive mtDNA inheritance.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • DNA Replication / genetics
  • DNA, Fungal / genetics*
  • DNA, Mitochondrial / genetics*
  • DNA-Directed RNA Polymerases / genetics*
  • Genes, Fungal / genetics
  • Mitochondria / genetics*
  • RNA, Mitochondrial / genetics*
  • Replication Origin / genetics
  • Saccharomyces cerevisiae / genetics
  • Saccharomyces cerevisiae Proteins / genetics
  • Transcription, Genetic / genetics

Substances

  • DNA, Fungal
  • DNA, Mitochondrial
  • RNA, Mitochondrial
  • Saccharomyces cerevisiae Proteins
  • DNA-Directed RNA Polymerases

Associated data

  • Dryad/10.5061/dryad.547d7wm8v
  • Dryad/10.5061/dryad.cfxpnvx5z
  • Dryad/10.5061/dryad.cfxpnvx5z