This is a family of small, approximately 100 amino acid, proteins found from yeasts to humans. The majority of endogenous reactive oxygen species (ROS) in cells are produced by the mitochondrial respiratory chain. An increase or imbalance in ROS alters the intracellular redox homeostasis, triggers DNA damage, and may contribute to cancer development and progression [1]. Members of this family are mitochondrial reactive oxygen species modulator 1 (Romo1) proteins that are responsible for increasing the level of ROS in cells. Increased Romo1 expression can have a number of other effects including: inducing premature senescence of cultured human fibroblasts [2,3] and increased resistance to 5-fluorouracil [4].

1: A novel protein, Romo1, induces ROS production in the mitochondria. Chung YM, Kim JS, Yoo YD; Biochem Biophys Res Commun. 2006;347:649-655. PMID:16842742

2: A critical role for Romo1-derived ROS in cell proliferation. Na AR, Chung YM, Lee SB, Park SH, Lee MS, Yoo YD; Biochem Biophys Res Commun. 2008;369:672-678. PMID:18313394

3: Replicative senescence induced by Romo1-derived reactive oxygen species. Chung YM, Lee SB, Kim HJ, Park SH, Kim JJ, Chung JS, Yoo YD; J Biol Chem. 2008;283:33763-33771. PMID:18836179

4: Drug resistance to 5-FU linked to reactive oxygen species modulator 1. Hwang IT, Chung YM, Kim JJ, Chung JS, Kim BS, Kim HJ, Kim JS, Yoo YD; Biochem Biophys Res Commun. 2007;359:304-310. PMID:17537404