tailieunhanh - Báo cáo khoa học: Two types of replication protein A in seed plants Characterization of their functions in vitro and in vivo

Replication protein A (RPA), a heterotrimeric protein composed of 70, 32 and 14-kDa subunits, has been shown to be essential for DNA replication, repair, recombination, and transcription. Previously, we found that, in two seed plants, rice and Arabidopsis, there are two different types of RPA70-kDa subunit. Substantial biochemical and genetic characterization of these two subunits, termed OsRPA70aand OsRPA70bor AtRPA70a and AtRPA70b, respectively, is described in this report. | iFEBS Journal Two types of replication protein A in seed plants Characterization of their functions in vitro and in vivo r 1 11 1 1 1 A IZ 1 1 I X z .1xzi I III 1xzi AH 1 Toyotaka Ishibashi Asami Koga Taichi Yamamoto Yukinobu Uchiyama Yoko Mori Junji Hashimoto2 Seisuke Kimura1 and Kengo Sakaguchi1 1 Department of Applied BiologicalScience Faculty of Science and Technology Tokyo University of Science Japan 2 NationalInstitute of AgrobiologicalSciences Ibaraki Japan Keywords Arabidopsis DNA repair DNA replication replication protein A rice Correspondence K. Sakaguchi Department of Applied Biological Science Faculty of Science and Technology Tokyo University of Science 2641 Yamazaki Noda-shi Chiba-ken 2788510 Japan Fax 81 4 7123 9767 Tel 81 4 7124 1501 ext. 3409 E-mail kengo@ Received 20 January 2005 revised 18 March 2005 accepted 15 April 2005 doi Replication protein A RPA a heterotrimeric protein composed of 70 32 and 14-kDa subunits has been shown to be essential for DNA replication repair recombination and transcription. Previously we found that in two seed plants rice and Arabidopsis there are two different types of RPA70-kDa subunit. Substantial biochemical and genetic characterization of these two subunits termed OsRPA70a and OsRPA70b or AtRPA70a and AtRPA70b respectively is described in this report. Inactivation of AtRPA70a by transfer DNA insertion or RNA interference is lethal so the complex containing RPA70a may be essential for DNA replication. Transfer DNA insertion and RNAi lines for AtRPA70b are morphologically normal albeit hypersensitive to certain mutagens such as UV-B and methyl methanesulfonate suggesting that RPA70b functions mostly in DNA repair. In two-hybrid pull-down and coexpression analysis OsRPA70b was found to interact more selectively than OsRPA70a with OsRPA32. The data suggest that two different types of RPA heterotrimer are present in seed plants and that there may be additional 32 and