Methylation of DNA polymerase ß by protein arginine methyltransferase 1 regulates its binding to proliferating cell nuclear antigen

DNA polymerase β (pol β) is a key player in DNA base excision repair (BER). Here, we describe the complex formation of pol β with the protein arginine methyltransferase 1 (PRMT1). PRMT1 specifically methylated pol β in vitro and in vivo . Arginine 137 was identified in pol β as an important target for methylation by PRMT1. Neither the polymerase nor the dRP‐lyase activities of pol β were affected by PRMT1 methylation. However, this modification abolished the interaction of pol β with proliferating cell nuclear antigen (PCNA). Together, our results provide evidence that PRMT1 methylation of pol β might play a regulatory role in BER by preventing the involvement of pol β in PCNA‐dependent DNA metabolic events. El‐Andaloussi, N., Valovka, T., Toueille, M., Hassa, P. O., Gehrig, P., Covic, M., Hübscher, U., Hottiger, M. O. Methylation of DNA polymerase f by protein arginine methyltransferase 1 regulates its binding to proliferating cell nuclear antigen. FASEB J. 21, 26–34 (2007)