Repression of origin assembly in metaphase depends on inhibition of RLF-B/Cdt1 by geminin

Shusuke Tada, Anatoliy Li, Domenico Maiorano, Marcel Méchali, J. Julian Blow

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393 Citations (Scopus)


Eukaryotic replication origins are ‘licensed’ for replication early in the cell cycle by loading Mcm(2–7) proteins. As chromatin replicates, Mcm(2–7) are removed, thus preventing the origin from firing again. Here we report the purification of the RLF-B component of the licensing system and show that it corresponds to Cdt1. RLF-B/Cdt1 was inhibited by geminin, a protein that is degraded during late mitosis. Immunodepletion of geminin from metaphase extracts allowed them to assemble licensed replication origins. Inhibition of CDKs in metaphase stimulated origin assembly only after the depletion of geminin. These experiments suggest that geminin-mediated inhibition of RLFB/ Cdt1 is essential for repressing origin assembly late in the cell cycle of higher eukaryotes.
Original languageEnglish
Pages (from-to)107-113
Number of pages7
JournalNature Cell Biology
Issue number2
Publication statusPublished - 27 Dec 2001

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