P202 SELF-ASSOCIATES THROUGH A SEQUENCE CONSERVED AMONG THE MEMBERS OF THE 200-FAMILY PROTEINS

Murine p202 is an interferon-inducible primarily nuclear phosphoprotei n (52 kDa) whose expression in transfected cells inhibits colony forma tion. p202-binding proteins include the pocket proteins (pRb, p107 and p130), a p53-binding protein (sm53BP1), and transcription factors (e, g, NF-kappa B (p50 and p65), AP-1 (c-Fos and c-Jun), E2F-1, E2F-4, Myo D, and myogenin), p202 modulates the transcriptional activity of these factors in transfected cells. Here we demonstrate that p202 self-asso ciates directly and a sequence in p202, which is conserved among the m embers of the 200-family proteins, was sufficient for self-association in vitro. Our observations reported herein raise the possibility that self-association of p202 may provide a mechanism for the regulation o f its activity, (C) 1998 Federation of European Biochemical Societies.