commentary. For the article “Oxygen toxicity and the health and survival of eukaryote cells: A new piece is added to the puzzle,“ by F. Archibald, which appeared in issue 18, September 2, 2003, of Proc. Natl. Acad. Sci. USA (100, 10141–10143; first published August 25, 2003; 10.1073/pnas.1934513100), the author notes that Fig. 1 and its legend were incomplete and omitted critical components of the localization and activation of MnSOD. The correct figure and its legend appear below.

Fig. 1.

Diagram of the postulated mechanisms of localization and activation of MnSOD (SOD2) in a cell of brewer's yeast (S. cerevisiae) based on the findings of Luk et al. (1). c.m., cell or plasma membrane; c.v., cytoplasmic vesicle (not Golgi); m.o.m., mitochondrial outer membrane; m.i.m., mitochondrial inner membrane; m.a., mitochondrial membrane-associated reaction; TCA, tricarboxylic acid cycle generating reducing equivalents for the electron transport (respiratory) chain (sinuous red line); ROS, reactive oxygen species, primarily and H₂O₂; GPX, glutathione peroxidase; GSH, reduced glutathione monomer; GSSG, oxidized glutathione dimer; Smf1p, high-affinity Mn-uptake protein; Smf2p, hydrophobic cytoplasmic vesicle-associated protein providing Mn to mitochondrial SOD; Mtm1p, SOD-2 activating protein first reported by Luk et al. (1).