2004 Fiscal Year Final Research Report Summary

Novel DNA replication checkpoint in the assembly of DNA replication complex

Research Project

Project/Area Number	15570155
Research Category	Grant-in-Aid for Scientific Research (C)
Allocation Type	Single-year Grants
Section	一般
Research Field	Cell biology
Research Institution	TOKYO INSTITUTE OF TECHNOLOGY
Principal Investigator	TACHIBANA Kazunori TOKYO INSTITUTE OF TECHNOLOGY, Graduate School of Bio science and Biotechnology, Assistant Professor, 生命理工学研究科, 助手 (60212031)
Project Period (FY)	2003 – 2004
Keywords	DNA REPLICATION / replication licensing / Mcm / Cdc45 / Checkpoint / Cell cycle / starfish / fertilization
Research Abstract	The regulation of the initiation of DNA replication in eukaryotic cells has been studied extensively the last enigmatic question is how cells form pre-initiation complex onto the DNA replication origins. The major factors involved in the assembly of the pre-initiation complex are Sld2-Dpb11,Sld3,GINS (Go, Ichi, Ni, and San), and S-phase kinases (Cdk;cyclin-dependent kinase, and Ddk,;Dbf4-dependent kinase). Recently, Wolter et al. reported that protein phosphatase 2A (PP2A) controls the pre-initiation complex in Xenopus cell-free system (J.Biol.Chem.2002). We have tested whether PP2A controlled the pre-initiation complex in starfish eggs. Neither the catalytic subunit of PP2A ligated with nuclear localization signal peptide sequence was ectopically expressed in starfish eggs nor okadaic acid, potent specific PP2A inhibitor was applied to starfish fertilized eggs, had significant effect to the initiation of the DNA replication.