tailieunhanh - Báo cáo khoa học: Characterization of a second proliferating cell nuclear antigen (PCNA2) from Drosophila melanogaster

The eukaryotic DNA polymerase processivity factor, proliferating cell nuc-lear antigen, is an essential component in the DNA replication and repair machinery. InDrosophila melanogaster, we cloned a second PCNA cDNA that differs from that encoded by the gene mus209(for convenience called DmPCNA1in this article). | ễFEBS Journal Characterization of a second proliferating cell nuclear antigen PCNA2 from Drosophila melanogaster Tatsushi Ruike1 Ryo Takeuchi1 Kei-ichi Takata1 2 Masahiko Oshige1 3 Nobuyuki Kasai1 Kaori Shimanouchi1 Yoshihiro Kanai1 Ryoichi Nakamura1 Fumio Sugawara1 and Kengo Sakaguchi1 1 Department of Applied BiologicalScience Faculty of Science and Technology Tokyo University of Science Japan 2 University of Pittsburgh Cancer Institute Hillman Cancer Center PA USA 3 Department of Biochemistry and Molecular Biology Indiana University Schoolof Medicine IN USA Keywords DNA repair Drosophila melanogaster proliferating cell nuclear antigen sliding clamp Correspondence K. Sakaguchi Department of Applied Biological Science Faculty of Science and Technology Tokyo University of Science 2641 Yamazaki Noda-shi Chiba-ken 278 Japan Fax 81 471 23 9767 Tel 81 471 24 1501 E-mail kengo@ Received 09 August 2006 revised 14 September 2006 accepted 18 September 2006 doi The eukaryotic DNA polymerase processivity factor proliferating cell nuclear antigen is an essential component in the DNA replication and repair machinery. In Drosophila melanogaster we cloned a second PCNA cDNA that differs from that encoded by the gene mus209 for convenience called DmPCNAl in this article . The second PCNA cDNA DmPCNA2 encoded a 255 amino acid protein with identity to DmPCNA1 and was ubiquitously expressed during Drosophila development. DmPCNA2 was localized in nuclei as a homotrimeric complex and associated with Drosophila DNA polymerase Ỗ and e in vivo. Treatment of cells with methyl methanesulfonate or hydrogen peroxide increased the amount of both DmPCNA2 and DmPCNA1 associating with chromatin whereas exposure to UV light increased the level of association of only DmPCNA1. Our observations suggest that DmPCNA2 may function as an independent sliding clamp of DmPCNA1 when DNA repair occurs. In eukaryotes proliferating cell nuclear antigen PCNA