This family consists of several eukaryotic gene associated with retinoic-interferon-induced mortality 19 (GRIM-19) proteins. GRIM-19, was reported to encode a small protein primarily distributed in the nucleus and was able to promote cell death induced by IFN-beta and RA. A bovine homologue of GRIM-19 was co-purified with mitochondrial NADH:ubiquinone oxidoreductase (complex I) in bovine heart. Therefore, its exact cellular localisation and function are unclear. It has now been discovered that GRIM-19 is a specific interacting protein which negatively regulates Stat3 activity [1].

1: GRIM-19, a death-regulatory gene product, suppresses Stat3 activity via functional interaction. Lufei C, Ma J, Huang G, Zhang T, Novotny-Diermayr V, Ong CT, Cao X; EMBO J 2003;22:1325-1335. PMID:12628925