Sit4 genetically interacts with Vps27 to regulate mitochondrial function and lifespan in Saccharomyces cerevisiae

ABSTRACT: Sit4 is a PP2A-like Ser/Thr protein phosphatase implicated in the regulation of cellular processes important for cell survival during aging. We have previously shown that SIT4 deletion promotes vacuolar acidification, mitochondrial derepression and oxidative stress resistance, increasing yeast chronological lifespan. In this study, we performed a proteomic analysis of isolated vacuoles and yeast genetic interaction analysis to unravel how Sit4 influences vacuolar and mitochondrial function. By employing high-resolution mass spectrometry, we show that sit4Δ vacuolar membranes were enriched in Vps27 and Hse1, two proteins that are part of the endosomal sorting complex required for transport-0 complex. In addition, SIT4 exhibited a negative genetic interaction with VSP27, as sit4∆vps27∆ double mutants had a shortened lifespan compared to sit4∆ and vps27∆ single mutants. Our results also show that Vps27 did not increase sit4∆ lifespan by improving protein trafficking or vacuolar sorting pathways. However, Vps27 was critical for iron homeostasis and mitochondrial function in sit4∆ cells, as sit4∆vps27∆ double mutants exhibited high iron levels, impaired mitochondrial respiration and mitochondrial DNA (mtDNA) depletion. These findings show for the first-time a cross-talk between Sit4 and Vps27, providing new insights into the mechanisms governing chronological lifespan.

INSTRUMENT(S): Q Exactive

ORGANISM(S): Saccharomyces Cerevisiae (baker's Yeast)

SUBMITTER: Hugo Osorio  

LAB HEAD: Vítor Costa

PROVIDER: PXD048450 | Pride | 2024-05-24

REPOSITORIES: Pride