Depletion of thiol reducing capacity impairs cytosolic but not mitochondrial iron-sulfur protein assembly machineries

Publication date: February 2019Source: Biochimica et Biophysica Acta (BBA) - Molecular Cell Research, Volume 1866, Issue 2Author(s): Joseph J. Braymer, Martin Stümpfig, Stefanie Thelen, Ulrich Mühlenhoff, Roland LillAbstractIron‑sulfur (Fe/S) clusters are versatile inorganic cofactors that play central roles in essential cellular functions, from respiration to genome stability.>30 proteins involved in Fe/S protein biogenesis in eukaryotes are known, many of which bind clusters via cysteine residues. This opens up the possibility that the thiol-reducing glutaredoxin and thioredoxin systems are required at both the Fe/S biogenesis and target protein level to counteract thiol oxidation. To address the possible interplay of thiol redox chemistry and Fe/S protein biogenesis, we have characterized the status of the mitochondrial (ISC) and cytosolic (CIA) Fe/S protein assembly machineries in Saccharomyces cerevisiae mutants in which the three partially redundant glutathione (Glr1) and thioredoxin (Trr1 and Trr2) oxidoreductases have been inactivated in either mitochondria, cytosol, or both compartments. Cells devoid of mitochondrial oxidoreductases maintained a functional mitochondrial ISC machinery and showed no altered iron homeostasis despite a non-functional complex II of the respiratory chain due to redox-specific defects. In cells that lack either cytosolic or total cellular thiol reducing capacity, both the ISC system and iron homeostasis were normal, yet cytosolic and nu...
Source: Biochimica et Biophysica Acta (BBA) Molecular Cell Research - Category: Molecular Biology Source Type: research