RRC ID 58218
Author Shetty M, Noguchi C, Wilson S, Martinez E, Shiozaki K, Sell C, Mell JC, Noguchi E.
Title Maf1-dependent transcriptional regulation of tRNAs prevents genomic instability and is associated with extended lifespan.
Journal Aging Cell
Abstract Maf1 is the master repressor of RNA polymerase III responsible for transcription of tRNAs and 5S rRNAs. Maf1 is negatively regulated via phosphorylation by the mTOR pathway, which governs protein synthesis, growth control, and lifespan regulation in response to nutrient availability. Inhibiting the mTOR pathway extends lifespan in various organisms. However, the downstream effectors for the regulation of cell homeostasis that are critical to lifespan extension remain elusive. Here we show that fission yeast Maf1 is required for lifespan extension. Maf1's function in tRNA repression is inhibited by mTOR-dependent phosphorylation, whereas Maf1 is activated via dephosphorylation by protein phosphatase complexes, PP4 and PP2A. Mutational analysis reveals that Maf1 phosphorylation status influences lifespan, which is correlated with elevated tRNA and protein synthesis levels in maf1∆ cells. However, mTOR downregulation, which negates protein synthesis, fails to rescue the short lifespan of maf1∆ cells, suggesting that elevated protein synthesis is not a cause of lifespan shortening in maf1∆ cells. Interestingly, maf1∆ cells accumulate DNA damage represented by formation of Rad52 DNA damage foci and Rad52 recruitment at tRNA genes. Loss of the Rad52 DNA repair protein further exacerbates the shortened lifespan of maf1∆ cells. Strikingly, PP4 deletion alleviates DNA damage and rescues the short lifespan of maf1∆ cells even though tRNA synthesis is increased in this condition, suggesting that elevated DNA damage is the major cause of lifespan shortening in maf1∆ cells. We propose that Maf1-dependent inhibition of tRNA synthesis controls fission yeast lifespan by preventing genomic instability that arises at tRNA genes.
Volume 19(2)
Pages e13068
Published 2020-2-1
DOI 10.1111/acel.13068
PMID 31833215
PMC PMC6996946
MeSH Chromatin Immunoprecipitation DNA Damage / genetics Gene Expression Regulation, Fungal* Genomic Instability / genetics* Glucose / metabolism Mechanistic Target of Rapamycin Complex 1 / genetics Mechanistic Target of Rapamycin Complex 1 / metabolism* Phosphoprotein Phosphatases / genetics Phosphoprotein Phosphatases / metabolism Phosphorylation Protein Biosynthesis / genetics Protein Biosynthesis / physiology Protein Phosphatase 2 / genetics Protein Phosphatase 2 / metabolism RNA, Transfer / biosynthesis RNA, Transfer / genetics* RNA, Transfer / metabolism Rad52 DNA Repair and Recombination Protein / genetics Rad52 DNA Repair and Recombination Protein / metabolism Repressor Proteins / genetics Repressor Proteins / metabolism* Schizosaccharomyces / genetics* Schizosaccharomyces / metabolism Schizosaccharomyces / physiology Schizosaccharomyces pombe Proteins / genetics Schizosaccharomyces pombe Proteins / metabolism*
IF 7.238
Times Cited 2
Yeast FY9908 FY9910 FY21019