Transcription factor Yin Yang 1 stimulates poly(ADP-ribosyl)ation and DNA repair

Poly(ADP-ribose) polymerase 1 (PARP-1) is a nuclear enzyme that catalyzes t he synthesis of ADP-ribose polymers from NAD(+). The function of PARP-1 is related to important nuclear processes including DNA repair and transcripti on. Previous studies demonstrated a specific physical interaction between P ARP-1 and the transcription factor Yin Yang 1 (YY1) in vitro. In this study , a functional relationship between both proteins in response to genotoxic treatment of cells is presented. The interaction of YY1 with PARP-1 greatly stimulates the enzymatic activity of PARP-1. Consistent with this, the ove rexpression of YY1 in HeLa cells resulted in an enhanced synthesis of poly( ADP-ribose) and an acceleration of DNA repair in response to a treatment wi th methyl-N ' -nitro-N ' -nitrosoguanidine. (C) 2001 Academic Press.