The Paf1 complex transcriptionally regulates the mitochondrial-anchored protein Atg32 leading to activation of mitophagy.
Level 5 - mechanism / opinion, no new human data
Bench and cell biology research in yeast and mammalian cell systems
PubMed 31525119 · doi:10.1080/15548627.2019.1668228
What was done
Researchers used bioinformatics screening to identify transcriptional and epigenetic regulators of autophagy-related (ATG) genes. They tested the role of the polymerase-associated factor 1 complex (Paf1C) and its core subunits (Paf1 and Ctr9) in regulating general autophagy and mitophagy in yeast and mammalian cell models across different nutrient conditions, including glucose starvation, nitrogen starvation, and rapamycin exposure.
What was found
The abstract reports no numerical data or effect sizes. Qualitatively, Paf1C suppressed glucose starvation-induced autophagy without altering nitrogen starvation- or rapamycin-induced autophagy. Deletion of the genes encoding Paf1 and Ctr9 increased ATG32 and ATG11 expression and elevated mitophagy activity. Mechanistically, Paf1C bound the ATG32 promoter under glucose-rich conditions to repress transcription, whereas glucose starvation caused Paf1C dissociation and induced mitophagy.
Why it matters
This study defines Paf1C as a direct transcriptional regulator of mitochondrial quality control, identifying a molecular mechanism by which cells couple glucose availability to mitophagy initiation.
Limits
The abstract does not report quantitative effect sizes, replication numbers, or statistical metrics. The findings derive entirely from in vitro yeast and mammalian cell culture models and lack in vivo physiological data.
Cited by
- contradicts Yeast cells placed in a glucose medium shift from oxidative phosphorylation to glycolysis by destroying most of their mitochondria through mitophagy.