Redox homeostasis

Abstract

Multiple factors, including small sulfur-containing molecules and oxidoreductases, are involved in the control of intracellular redox homeostasis. In this chapter, we first review properties and functions of the small sulfur-containing molecules glutathione, mycothiol, bacillithiol and trypanothione. These low molecular weight thiols, which cycle between a reduced and oxidized form, are present at high intracellular concentrations and function as redox buffers to protect cells against oxidative stress conditions. In the second part of this chapter, we focus on the two oxidoreductases, thioredoxin and glutaredoxin. These enzymes are key players in pathways aimed to reduce disulfide bonds in intracellular proteins and to maintain cellular redox homeostasis. We review the general properties of these enzymes and highlight their significant diversity. Finally, we discuss the recent discovery that monothiol glutaredoxins coordinate an iron sulfur cluster, which suggests a novel link between redox and iron homeostasis.