PICOT (GLRX3) is a positive regulator of stress-induced DNA-damage response.

Protein kinase C (PKC)-interacting cousin of thioredoxin (PICOT; also termed glutaredoxin 3 (Glrx3)) is a ubiquitously expressed protein that possesses an N-terminal monothiol thioredoxin (Trx) domain and two C-terminal tandem copies of a monothiol Glrx domain. It has an overall highly conserved amino acid sequence and is encoded by a unique gene, both in humans and mice, without having other functional gene homologs in the entire genome. Despite being discovered almost two decades ago, the biological function of PICOT remains largely ill-defined and its ramifications are underestimated considering the fact that PICOT-deficiency in mice results in embryonic lethality.