The protein mini-chromosome maintenance 10 (Mcm10) was originally identified as an essential yeast protein in the maintenance of mini-chromosome plasmids. Subsequently, Mcm10 has been shown to be required for both initiation and elongation during chromosomal DNA replication. However, it is not fully understood how the multiple functions of Mcm10 are coordinated or how Mcm10 interacts with other factors at replication forks.
View Article and Find Full Text PDFIn eukaryotes, DNA replication is fired once in a single cell cycle before cell division starts to maintain stability of the genome. This event is tightly controlled by a series of proteins. Cdt1 is one of the licensing factors and is involved in recruiting replicative DNA helicase Mcm2-7 proteins into the pre-replicative complex together with Cdc6.
View Article and Find Full Text PDFDNA polymerase alpha is essential for the onset of eukaryotic DNA replication. Its correct folding and assembly within the nuclear replication pre-initiation complex is crucial for normal cell cycle progression and genome maintenance. Due to a single point mutation in the largest DNA polymerase alpha subunit, p180, the temperature-sensitive mouse cell line tsFT20 exhibits heat-labile DNA polymerase alpha activity and S phase arrest at restrictive temperature.
View Article and Find Full Text PDFSister chromatid cohesion is important for the correct alignment and segregation of chromosomes during cell division. Although the cohesin complex has been shown to play a physical role in holding sister chromatids together, its loading onto chromatin is not sufficient for the establishment of sister chromatid cohesion. The activity of the cohesin complex must be turned on by Ctf7/Eco1 acetyltransferase at the replication forks as the result of a specific mechanism.
View Article and Find Full Text PDFA human replication initiation protein Cdt1 is a very central player in the cell cycle regulation of DNA replication, and geminin down-regulates Cdt1 function by directly binding to it. It has been demonstrated that Cdt1 hyperfunction resulting from Cdt1-geminin imbalance, for example by geminin silencing with siRNA, induces DNA re-replication and eventual cell death in some cancer-derived cell lines. In the present study, we first established a high throughput screening system based on modified ELISA (enzyme linked immunosorbent assay) to identify compounds that interfere with human Cdt1-geminin binding.
View Article and Find Full Text PDFCdt1 is an essential component for the assembly of a pre-replicative complex. Cdt1 activity is inhibited by geminin, which also participates in neural development and embryonic differentiation in many eukaryotes. Although Cdt1 homologues have been identified in organisms ranging from yeast to human, geminin homologues had not been described for Caenorhabditis elegans and fungi.
View Article and Find Full Text PDFDNA replication is controlled by the stepwise assembly of the pre-replicative complex and the replication apparatus. Loading of the origin recognition complex (ORC) onto the chromatin is a prerequisite for the assembly of the pre-replicative complex. To define the physiological functions of the mammalian ORC, we cloned ORC subunit cDNAs from mouse NIH3T3 cells and found novel variant forms of Orc1, Orc2, and Orc3 each derived from alternative RNA splicing.
View Article and Find Full Text PDFDNA replication is controlled by the stepwise assembly of a pre-replicative complex and the replication apparatus. Cdt1 is a novel component of the pre-replicative complex and plays a role in loading the minichromosome maintenance (MCM) 2-7 complex onto chromatin. Cdt1 activity is inhibited by geminin, which is essential for the G(2)/M transition in metazoan cells.
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