HIN-200 - A NOVEL FAMILY OF IFN-INDUCIBLE NUCLEAR PROTEINS EXPRESSED IN LEUKOCYTES

In recent years a novel family of interferon (IFN)-inducible nuclear p roteins has been identified in both mouse and humans and implicated in the control of myeloid differentiation. Recent evidence suggests that this role may be mediated by an effect on cell cycle regulation throu gh interaction with known transcriptional regulators. Our laboratory f irst identified a nuclear protein designated IFI 16, which is strongly inducible with IFN-alpha and -gamma in myeloid cells. IFI 16 shares h omology with at least six IFN-inducible mouse genes, designated the Ge ne 200 cluster, and also has close similarity with the human myeloid c ell nuclear differentiation antigen, whose expression has also been as sociated with later stages of normal myelopoiesis and some myeloid mal ignancies. The structural hallmark of each protein in this family of h emopoietic IFN-inducible nuclear proteins is a 200-amino acid motif (h ence HIN-200), present singly or as a tandem repeat. The restricted ex pression of these proteins, their ability to bind to nucleic acid, and their expression in response to a variety of stimuli eliciting myeloi d differentiation strongly suggest that they play a role in hemopoieti c maturation.