Balance between transcription and RNA degradation is vital for Saccharomyces cerevisiae mitochondria: reduced transcription rescues the phenotype of deficient RNA degradation.
The Saccharomyces cerevisiae SUV3 gene encodes the helicase component of the mitochondrial degradosome (mtEXO), the principal 3'-to-5' exoribonuclease of yeast mitochondria responsible for RNA turnover and surveillance. Inactivation of SUV3 (suv3Delta) causes multiple defects related to overaccumulation of aberrant transcripts and precursors, leading to a disruption of mitochondrial gene expression and loss of respiratory function. We isolated spontaneous suppressors that partially restore mitochondrial function in suv3Delta strains devoid of mitochondrial introns and found that they correspond to partial loss-of-function mutations in genes encoding the two subunits of the mitochondrial RNA polymerase (Rpo41p and Mtf1p) that severely reduce the transcription rate in mitochondria. These results show that reducing the transcription rate rescues defects in RNA turnover and demonstrates directly the vital importance of maintaining the balance between RNA synthesis and degradation.
Rogowska
Agata T
AT
Department of Genetics, Warsaw University, 02-106 Warsaw, Poland.
Puchta
Olga
O
Czarnecka
Anna M
AM
Kaniak
Aneta
A
Stepien
Piotr P
PP
Golik
Pawel
P
D000483:Alleles; D019943:Amino Acid Substitution / Q000235:genetics; D002467:Cell Nucleus / Q000378:metabolism; D019069:Cell Respiration; D053487:DEAD-box RNA Helicases; D012321:DNA-Directed RNA Polymerases / Q000235:genetics / Q000378:metabolism; D017353:Gene Deletion; D016681:Genome, Fungal / Q000235:genetics; D007438:Introns / Q000235:genetics; D008928:Mitochondria / Q000235:genetics* / Q000378:metabolism*; D024101:Mitochondrial Proteins; D010641:Phenotype; D020365:RNA Helicases / Q000235:genetics; D020871:RNA Stability; D012331:RNA, Fungal / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000166:cytology* / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism; D013489:Suppression, Genetic / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic / Q000235:genetics*
C071720:MTF1 protein, S cerevisiae; D024101:Mitochondrial Proteins; D012331:RNA, Fungal; D012333:RNA, Messenger; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D012321:DNA-Directed RNA Polymerases; C487996:RPO41 protein, S cerevisiae; C075918:SUV3 protein, S cerevisiae; D053487:DEAD-box RNA Helicases; D020365:RNA Helicases