Differential transactivation by orphan nuclear receptor NOR1 and its fusion gene product EWS/NOR1: possible involvement of poly(ADP-ribose) polymerase I, PARP-1..     ///    and that EWS/NOR1 may acquire oncogenic activities by avoiding (or gaining) transcription factor-specific modulation by the associated proteins..     ///    "To clarify the mechanisms underlying the transcriptional divergence between NOR1 and EWS/NOR1, we searched for alternatively associated proteins, and identified poly(ADP-ribose) polymerase I (PARP-1) as an NOR1-specific binding protein. "    ///    "Consistent with its binding properties, PARP-1 acted as a transcriptional repressor of NOR1, but not EWS/NOR1, in a luciferase reporter assay employing PARP-1(-/-) fibroblasts. "    ///    "In addition, the proteins associated with NOR1 and EWS/NOR1 were mostly the same in these cells. "    ///    "Altogether, our findings suggest that NOR1 and EWS/NOR1 regulate overlapping target genes differently by utilizing associated proteins, including PARP-1. "    ///    "By comparing the gene expression profiles of NOR1- and EWS/NOR1-overexpressing cells, we found that they largely shared up-regulated genes, but no significant correlation was observed with respect to the transactivation levels of each gene. "    ///    The resulting fusion protein EWS/NOR1 has been believed to lead to malignant transformation by functioning as a transactivator for NOR1-target genes. 