THE INTERFERON-ACTIVATABLE GENE-200-CLUSTER - FROM STRUCTURE TOWARD FUNCTION

The antimicrobial, cell growth-regulatory and immunomodulatory activit ies of the interferons (IFNs) are mediated by IFN-inducible proteins. One family of these (200 family) including the p202, p203, p204 and D3 proteins is encoded by a cluster of six or more structurally-related murine genes in the q21-q23 region of chromosome 1 (gene 200 cluster). Two homologous human genes (MNDA and IFI 16) were also identified. Th e 200 family proteins share one or two partially conserved 200 amino a cid segments. At least four of the proteins are nuclear One of these , p202, binds the hypophosphorylated form of the growth regulatory pRb protein and also the E2F-1 transcription factor that is involved in ce ll cycling. In transfected cells p202 inhibits E2F activity and slows down cell proliferation. Information about the genes and proteins of t he 200 cluster is surveyed.