Fraction of imported mitochondrial proteins that are degraded after import in logarithmically growing yeast

Range 6 - 12 %
Organism Budding yeast Saccharomyces cerevisiae
Reference Gonczarowska-Jorge H, Zahedi RP, Sickmann A. The proteome of baker's yeast mitochondria. Mitochondrion. 2017 Mar33: 15-21. doi: 10.1016/j.mito.2016.08.007. p.18 right column top paragraphPubMed ID27535110
Primary Source Augustin S et al., Characterization of peptides released from mitochondria: evidence for constant proteolysis and peptide efflux. J Biol Chem. 2005 Jan 28 280(4):2691-9. DOI: 10.1074/jbc.M410609200PubMed ID15556950
Comments P.18 right column top paragraph: "Besides proteases that play a role in protein import such as Icp55, MPP or Oct1, maintaining mitochondrial homeostasis requires a dedicated protein turnover machinery. This is particularly relevant as the components of the respiratory chain are encoded by both the mitochondrial and the nuclear genome. Imbalanced regulation may result in protein accumulation to avoid wrong complex stoichiometries. Moreover, the production of reactive oxygen species (ROS) renders especially IMM (inner mitochondrial membrane) proteins susceptible to undergo oxidative damage (Baker et al., 2011). Indeed, it is estimated that in logarithmically growing yeast 6–12% of imported mitochondrial proteins are degraded after import (primary source). Consequently, mitochondria possesses their own protein turnover machinery, composed of proteases and chaperones, responsible to maintain homeostasis especially under stress conditions (Baker et al., 2011, Pellegrino et al., 2013)."
Entered by Uri M
ID 113492