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Intrinsic nuclear import activity of geminin is essential to prevent re‐initiation of DNA replication in Xenopus eggs
Author(s) -
Yoshida Kazumasa,
Takisawa Haruhiko,
Kubota Yumiko
Publication year - 2005
Publication title -
genes to cells
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.912
H-Index - 115
eISSN - 1365-2443
pISSN - 1356-9597
DOI - 10.1111/j.1365-2443.2005.00815.x
Subject(s) - dna replication factor cdt1 , biology , xenopus , licensing factor , dna re replication , microbiology and biotechnology , control of chromosome duplication , dna replication , pre replication complex , origin recognition complex , eukaryotic dna replication , cell cycle , minichromosome maintenance , mitosis , genetics , dna , cell , gene
Prior to S phase, eukaryotic chromosomes are licensed for initiation of DNA replication, and re‐licensing is prohibited after S phase has started until late mitosis, thus ensuring that genomic DNA is duplicated precisely once in each cell cycle. Here, we report that over‐expression of Cdt1, an essential licensing protein, induced re‐replication in Xenopus egg extracts. Geminin, a metazoan‐specific inhibitor of Cdt1, was critical for preventing re‐replication induced by Cdt1. Re‐replication induced by the addition of recombinant Cdt1 and/or by the depletion of geminin from extracts was enhanced by a proteasome inhibitor, which suppressed the degradation of Cdt1 in the extracts. Furthermore, a nuclear localization sequence identified in Xenopus geminin had a significant role in the suppression of re‐replication induced by Cdt1. These results suggest that nuclear accumulation of geminin plays a dominant role in the licensing system of Xenopus eggs.