Poly(ADP-ribose) polymerase 1 interacts with OAZ and regulates BMP-target genes

OAZ is a multi zinc finger protein which interacts with several distinct nuclear proteins including Olf-1/EBF, Smad1, and Smad4 and regulates transcription of various genes. Here we show that poly(ADP-ribose) polymerase 1 (Parp1) forms a complex with OAZ and positively regulates BMP-target genes, Xenopus Vent-2 and mouse Smad6 genes. Both wild type and the mutant forms of Parp1, which is deficient in poly(ADP-ribose) polymerase activity, constitutively interact with OAZ; however, the mutant Parp1 did not activate transcription. These results suggest that poly(ADP-ribose) polymerase activity is essential for the transcriptional activation of Vent-2 and Smad6. These results suggest that Parp1 serves as a transcriptional coactivator of OAZ in BMP-dependent gene regulation.