A p53-Dependent Checkpoint Pathway Prevents Rereplication

Vaziri, Cyrus; Saxena, Sandeep; Jeon, Yongho; Lee, Charles; Murata, Kazutaka; Machida, Yuichi; Wagle, Nikhil; Hwang, Deog Su; Dutta, Anindya

doi:10.1016/s1097-2765(03)00099-6

Cited by 365 publications

(327 citation statements)

References 56 publications

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“…Interestingly, in 73% of cases in which p53 was also mutated, aneuploidy was observed. Our laboratory has reported similar observations; in tumor cell lines lacking p53 and overexpressing Cdt1 and Cdc6, re-replication is observed (18). Furthermore, high levels of Cdt1 appear to have a causative role in cancer.…”

supporting

confidence: 71%

“…Our laboratory has shown previously that by either overexpressing hsCdt1 (18) or relieving its inhibition via knockdown of geminin (20,30), re-replication can be induced in human cells. As expected, transient overexpression of wild type full-length hsCdt1 induced Ͼ4N DNA content as determined by FACS (Fig.…”

Section: Resultsmentioning

confidence: 99%

“…FACS-Cells were prepared as described previously (18). Cells were cotransfected with farnesylated EGFP and gated for GFP-positive cells to ensure analysis was limited to the Cdt1-transfected cells.…”

Section: Methodsmentioning

confidence: 99%

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Human Cdt1 Lacking the Evolutionarily Conserved Region That Interacts with MCM2–7 Is Capable of Inducing Re-replication

Teer

Dutta

2008

Journal of Biological Chemistry

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Replication initiation must be a carefully regulated process to avoid genomic instability caused by aberrant replication. In eukaryotic cells, distinct steps of protein loading (origin licensing) and replication activation are choreographed such that a cell can replicate only once per cell cycle. The first proteins recruited to the origins form the pre-replication complex. Of these proteins, Cdt1 is of interest, as it is the focus of several pathways to control replication initiation. It is degraded by two different pathways, mediated by the interaction of Cdt1 with proliferating cell nuclear antigen (PCNA) or with cyclin-Cdk2 and inhibited by geminin once cells are in S-phase, presumably to prevent reloading of pre-replication complexes once S-phase has begun. Although the requirement of Cdt1 in loading MCM2-7 is known, the mechanism by which overexpressed Cdt1 stimulates re-replication is unclear. In this study we have designed various mutations in Cdt1 to determine which portion of Cdt1 is important for re-replication, providing insight into possible mechanisms. Surprisingly, we found that mutants of Cdt1 that do not interact with MCM2-7 are able to induce rereplication when overexpressed. The re-replication is not due to titration of geminin from endogenous Cdt1 and is not accompanied by stabilization of endogenous Cdt1. Additionally, the N-terminal one-third of Cdt1 is sufficient to induce re-replication. The N terminus contains the PCNA-and cyclin-interacting motifs, and deletion of both motifs simultaneously in the overexpressed Cdt1 prevents re-replication. These findings suggest that exogenous Cdt1 induces re-replication by de-repressing endogenous Cdt1 through the titration of PCNA and cyclin.

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supporting

confidence: 71%

Section: Resultsmentioning

confidence: 99%

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Human Cdt1 Lacking the Evolutionarily Conserved Region That Interacts with MCM2–7 Is Capable of Inducing Re-replication

Teer

Dutta

2008

Journal of Biological Chemistry

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“…35 Overexpression of Cdt1 not only promotes re-replication but also stimulates ATM/ATR/Chk2 DNA damage-induced checkpoint pathway. This pathway activates p53 as an additional tool of mammalian cells to prevent re-replication, through the induction of cdk2 inhibitor p21.…”

Section: Geminin-cdt1: An Important Balancementioning

confidence: 99%

“…This pathway activates p53 as an additional tool of mammalian cells to prevent re-replication, through the induction of cdk2 inhibitor p21. 35 Interestingly, geminin depletion causes partial DNA over-replication in HCT116, U2OS cancer cells and diploid fibroblasts TIG3 human cells, accompanied by an activation of a different ATR/ATM checkpoint pathway. 36 Significantly, this over-replication did not occur when Cdt1 was also repressed.…”

Section: Geminin-cdt1: An Important Balancementioning

confidence: 99%

Role of geminin: from normal control of DNA replication to cancer formation and progression?

Montanari

Macaluso

Cittadini³

et al. 2006

Cell Death Differ

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The normal cell proliferation involves the passage through a series of finely regulated phases that are known as cell cycle checkpoints. In order to carry out a correct replication, the eukaryotic cell undergoes to a series of events ensuring that each copy of duplicated chromosome exactly segregates in each of daughter cells. 1,2 A main critical control of the cell cycle is to ensure that the DNA replication takes place and that it is followed by mitosis, once for each cell cycle. Alterations in the expression of genes that regulate the cell cycle can lead to malignant transformation and tumor progression by perturbing cell proliferation and/ or genomic stability. 3,4 The normal progression through the cell cycle is a critical step for the survival of eukaryotic cells, in which the initiation of DNA replication is under the tight control of several factors that ensure the exact duplication of chromosomes in S phase and their subsequent segregation in phase M. The strict regulation of the cell cycle combined with the presence of a licensing phase, in which the chromatin becomes licensed to be replicated, leads to the existence of a single DNA replication start site for each round of replication. 5 In this complicated network of signals regulating the cell cycle and maintaining genome integrity, the geminin protein is considered one of the main players. However, if the geminin acts as oncosuppressor gene or as a proto-oncogene is still an open question.In this article, we will report the mechanism by which geminin controls that the huge quantity of eukaryotes DNA, distributed over multiples chromosomes, is replicated once and once only for each cell cycle. Moreover, we will open and discuss an important question: what role does geminin play in cancer formation and progression? Does geminin act as an oncosuppressor, as a proto-oncogene or exhibit both roles? Geminin in the LicensingThe replication of eukaryotic genome is a complex process strictly regulated by an intricate intracellular and extracellular signaling network, which controls different phenomena such as cell proliferation, differentiation and apoptosis. 6,7 All these processes have a common function: the regulation of the initial phase of DNA replication. During this event, specific proteins sequentially assemble onto the replication origin by forming specific replicative complexes (pre-RC), which allow for the chromatin to be competent (licensed) for the next DNA replication step of the cell cycle. 8 Geminin is a 25 kDa nuclear protein that functions by inhibiting DNA replication. 9 During specific phases of the cell cycle, geminin is able to bind to Cdt1 protein and inhibits pre-RC formation. 10 In eukaryotes, the origins of replication are bound by a complex of six proteins, evolutionally well conserved among different species. 11,12 These proteins constitute the origin recognition complex (ORC) (1-6), a complex of proteins essential for the initiation of DNA replication, which was first identified in Saccharomyces cerevisiae as protein that bound t...

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Preparation for DNA replication: the key to a successful S phase

Limas

Cook

2019

FEBS Letters

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Successful genome duplication is required for cell proliferation and demands extraordinary precision and accuracy. The mechanisms by which cells enter, progress through, and exit S phase are intense areas of focus in the cell cycle and genome stability fields. Key molecular events in the G1 phase of the cell division cycle, especially origin licensing, are essential for pre‐establishing conditions for efficient DNA replication during the subsequent S phase. If G1 events are poorly regulated or disordered, then DNA replication can be compromised leading to genome instability, a hallmark of tumorigenesis. Upon entry into S phase, coordinated origin firing and replication progression ensure complete, timely, and precise chromosome replication. Both G1 and S phase progressions are controlled by master cell cycle protein kinases and ubiquitin ligases that govern the activity and abundance of DNA replication factors. In this short review, we describe current understanding and recent developments related to G1 progression and S phase entrance and exit with a particular focus on origin licensing regulation in vertebrates.

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A p53-Dependent Checkpoint Pathway Prevents Rereplication

Cited by 365 publications

References 56 publications

Human Cdt1 Lacking the Evolutionarily Conserved Region That Interacts with MCM2–7 Is Capable of Inducing Re-replication

Human Cdt1 Lacking the Evolutionarily Conserved Region That Interacts with MCM2–7 Is Capable of Inducing Re-replication

Role of geminin: from normal control of DNA replication to cancer formation and progression?

Preparation for DNA replication: the key to a successful S phase

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