THE INTERFERON-INDUCIBLE GROWTH-INHIBITORY P202 PROTEIN - DNA-BINDINGPROPERTIES AND IDENTIFICATION OF A DNA-BINDING DOMAIN

p202 is an interferon-inducible protein whose expression in transfecte d cells inhibits proliferation. p202 binds to the retinoblastoma tumor suppressor protein in vitro and in vivo and the transcription factors AP-1 c-Fos and c-Jun, NF-kappa B p50 and p65, and inhibits the transc riptional activity of theses factors in vivo. Here we report that p202 nonspecifically binds to double-stranded DNA and to single-stranded D NA in vitro. Analysis with recombinant p202 revealed that DNA binding activity is intrinsic to p202. A C-terminal deletion mutant of p202 ex hibited DNA-binding properties, indicating that the C-terminus is disp ensable for DNA binding. We also found that underphosphorylated p202 e fficiently binds to DNA. Our data suggest that DNA binding activity of p202 may contribute to its functions. (C) 1996 Academic Press, Inc.