Abstract
Regulation of DNA replication initiation is essential for the faithful inheritance of genetic information. Replication initiation is a multi-step process involving many factors including ORC, Cdt1p, Mcm2-7p and other proteins that bind to replication origins to form a pre-replicative complex (pre-RC). As a prerequisite for pre-RC assembly, Cdt1p and the Mcm2-7p heterohexameric complex accumulate in the nucleus in G1 phase in an interdependent manner in budding yeast. However, the nature of this interdependence is not clear, nor is it known whether Cdt1p is required for the assembly of the MCM complex. In this study, we provide the first evidence that Cdt1p, through its interaction with Mcm6p with the C-terminal regions of the two proteins, is crucial for the formation of the MCM complex in both the cytoplasm and nucleoplasm. We demonstrate that disruption of the interaction between Cdt1p and Mcm6p prevents the formation of the MCM complex, excludes Mcm2-7p from the nucleus, and inhibits pre-RC assembly and DNA replication. Our findings suggest a function for Cdt1p in promoting the assembly of the MCM complex and maintaining its integrity by interacting with Mcm6p.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Cell Cycle Proteins / chemistry
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Cell Cycle Proteins / deficiency
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Cell Cycle Proteins / metabolism*
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Cell Division
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Cell Enlargement
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Cell Nucleus / metabolism*
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Chromatin / metabolism*
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Chromosomal Proteins, Non-Histone / chemistry
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Chromosomal Proteins, Non-Histone / metabolism*
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DNA Replication
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DNA-Binding Proteins / chemistry
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DNA-Binding Proteins / deficiency
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DNA-Binding Proteins / metabolism*
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G1 Phase
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Minichromosome Maintenance Complex Component 6
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Minichromosome Maintenance Complex Component 7
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Multiprotein Complexes / chemistry
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Multiprotein Complexes / metabolism*
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Nuclear Proteins / metabolism
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Protein Binding
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Protein Structure, Tertiary
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Saccharomyces cerevisiae / cytology*
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Saccharomyces cerevisiae / genetics
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Saccharomyces cerevisiae / metabolism*
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Saccharomyces cerevisiae Proteins / chemistry
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Saccharomyces cerevisiae Proteins / metabolism*
Substances
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Cell Cycle Proteins
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Chromatin
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Chromosomal Proteins, Non-Histone
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DNA-Binding Proteins
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Multiprotein Complexes
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Nuclear Proteins
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Saccharomyces cerevisiae Proteins
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TAH11 protein, S cerevisiae
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MCM2 protein, S cerevisiae
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MCM6 protein, S cerevisiae
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MCM7 protein, S cerevisiae
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Minichromosome Maintenance Complex Component 6
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Minichromosome Maintenance Complex Component 7