scholarly journals Cell Cycle-Dependent Switch of TopBP1 Functions by Cdk2 and Akt

2020 ◽  
Vol 40 (8) ◽  
Author(s):  
Kang Liu ◽  
Joshua D. Graves ◽  
Yu-Ju Lee ◽  
Fang-Tsyr Lin ◽  
Weei-Chin Lin
Keyword(s):  
Cell Cycle ◽  
Dna Replication ◽  
Cancer Cells ◽  
Cyclin A ◽  
Replication Initiation ◽  
Dna Replication Initiation ◽  
Cycle Dependent

ABSTRACT Cdk2-dependent TopBP1-treslin interaction is critical for DNA replication initiation. However, it remains unclear how this association is terminated after replication initiation is finished. Here, we demonstrate that phosphorylation of TopBP1 by Akt coincides with cyclin A activation during S and G2 phases and switches the TopBP1-interacting partner from treslin to E2F1, which results in the termination of replication initiation. Premature activation of Akt in G1 phase causes an early switch and inhibits DNA replication. TopBP1 is often overexpressed in cancer and can bypass control by Cdk2 to interact with treslin, leading to enhanced DNA replication. Consistent with this notion, reducing the levels of TopBP1 in cancer cells restores sensitivity to a Cdk2 inhibitor. Together, our study links Cdk2 and Akt pathways to the control of DNA replication through the regulation of TopBP1-treslin interaction. These data also suggest an important role for TopBP1 in driving abnormal DNA replication in cancer.

scholarly journals Polar Remodeling and Histidine Kinase Activation, Which Is Essential for Caulobacter Cell Cycle Progression, Are Dependent on DNA Replication Initiation

2010 ◽  
Vol 192 (15) ◽  
pp. 3893-3902 ◽  
Author(s):  
Antonio A. Iniesta ◽  
Nathan J. Hillson ◽  
Lucy Shapiro
Keyword(s):  
Cell Cycle ◽  
Dna Replication ◽  
Histidine Kinase ◽  
Cell Cycle Progression ◽  
Caulobacter Crescentus ◽  
Replication Initiation ◽  
Cycle Progression ◽  
Dna Replication Initiation ◽  
Flagellar Biosynthesis ◽  
Initiation Of Dna Replication

ABSTRACT Caulobacter crescentus initiates a single round of DNA replication during each cell cycle. Following the initiation of DNA replication, the essential CckA histidine kinase is activated by phosphorylation, which (via the ChpT phosphotransferase) enables the phosphorylation and activation of the CtrA global regulator. CtrA∼P then blocks the reinitiation of replication while regulating the transcription of a large number of cell cycle-controlled genes. It has been shown that DNA replication serves as a checkpoint for flagellar biosynthesis and cell division and that this checkpoint is mediated by the availability of active CtrA. Because CckA∼P promotes the activation of CtrA, we addressed the question of what controls the temporal activation of CckA. We found that the initiation of DNA replication is a prerequisite for remodeling the new cell pole, which includes the localization of the DivL protein kinase to that pole and, consequently, the localization, autophosphorylation, and activation of CckA at that pole. Thus, CckA activation is dependent on polar remodeling and a DNA replication initiation checkpoint that is tightly integrated with the polar phospho-signaling cascade governing cell cycle progression.

Association of cyclin A and cdk2 with SV40 DNA in replication initiation complexes is cell cycle dependent

Chromosoma ◽  
1997 ◽  
Vol 105 (6) ◽  
pp. 349-359 ◽  
Author(s):  
Dominique Cannella ◽  
James M. Roberts ◽  
Rati Fotedar
Keyword(s):  
Cell Cycle ◽  
Cyclin A ◽  
Replication Initiation ◽  
Cycle Dependent ◽  
Sv40 Dna

scholarly journals Control of DNA Replication Initiation by Ubiquitin

Cells ◽  
2018 ◽  
Vol 7 (10) ◽  
pp. 146 ◽  
Author(s):  
Esperanza Hernández-Carralero ◽  
Elisa Cabrera ◽  
Ignacio Alonso-de Vega ◽  
Santiago Hernández-Pérez ◽  
Veronique Smits ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Dna Replication ◽  
Replication Initiation ◽  
Post Translational Modifications ◽  
Precise Control ◽  
Dna Replication Initiation ◽  
Fundamental Part ◽  
Initiation Of Dna Replication ◽  
The Right ◽  
Hydrolysis Of

Eukaryotic cells divide by accomplishing a program of events in which the replication of the genome is a fundamental part. To ensure all cells have an accurate copy of the genome, DNA replication occurs only once per cell cycle and is controlled by numerous pathways. A key step in this process is the initiation of DNA replication in which certain regions of DNA are marked as competent to replicate. Moreover, initiation of DNA replication needs to be coordinated with other cell cycle processes. At the molecular level, initiation of DNA replication relies, among other mechanisms, upon post-translational modifications, including the conjugation and hydrolysis of ubiquitin. An example is the precise control of the levels of the DNA replication initiation protein Cdt1 and its inhibitor Geminin by ubiquitin-mediated proteasomal degradation. This control ensures that DNA replication occurs with the right timing during the cell cycle, thereby avoiding re-replication events. Here, we review the events that involve ubiquitin signalling during DNA replication initiation, and how they are linked to human disease.

Association of cyclin A and cdk2 with SV40 DNA in replication initiation complexes is cell cycle dependent

Chromosoma ◽  
1997 ◽  
Vol 105 (6) ◽  
pp. 349-359 ◽  
Author(s):  
Dominique Cannella ◽  
James M. Roberts ◽  
Rati Fotedar
Keyword(s):  
Cell Cycle ◽  
Cyclin A ◽  
Replication Initiation ◽  
Cycle Dependent ◽  
Sv40 Dna

scholarly journals Activation of a signaling pathway by the physical translocation of a chromosome

2021 ◽  
Author(s):  
Mathilde Guzzo ◽  
Allen G. Sanderlin ◽  
Lennice K. Castro ◽  
Michael T. Laub
Keyword(s):  
Cell Cycle ◽  
Cell Division ◽  
Dna Replication ◽  
Signaling Pathway ◽  
Chromosome Segregation ◽  
Caulobacter Crescentus ◽  
Replication Initiation ◽  
Dna Replication Initiation ◽  
Cellular Processes ◽  
Initiation Of Dna Replication

AbstractIn every organism, the cell cycle requires the execution of multiple cellular processes in a strictly defined order. However, the mechanisms used to ensure such order remain poorly understood, particularly in bacteria. Here, we show that the activation of the essential CtrA signaling pathway that triggers cell division in Caulobacter crescentus is intrinsically coupled to the successful initiation of DNA replication via the physical translocation of a newly-replicated chromosome, powered by the ParABS system. We demonstrate that ParA accumulation at the new cell pole during chromosome segregation recruits ChpT, an intermediate component of the CtrA signaling pathway. ChpT is normally restricted from accessing the selective PopZ polar microdomain until the new chromosome and ParA arrive. Consequently, any disruption to DNA replication initiation prevents the recruitment of ChpT and, in turn, cell division. Collectively, our findings reveal how major cell-cycle events are coordinated in Caulobacter and, importantly, how the physical translocation of a chromosome triggers an essential signaling pathway.

scholarly journals ATR Inhibitors VE-821 and VX-970 Sensitize Cancer Cells to Topoisomerase I Inhibitors by Disabling DNA Replication Initiation and Fork Elongation Responses

2014 ◽  
Vol 74 (23) ◽  
pp. 6968-6979 ◽  
Author(s):  
Rozenn Jossé ◽  
Scott E. Martin ◽  
Rajarshi Guha ◽  
Pinar Ormanoglu ◽  
Thomas D. Pfister ◽  
...  
Keyword(s):  
Dna Replication ◽  
Cancer Cells ◽  
Topoisomerase I ◽  
Replication Initiation ◽  
Dna Replication Initiation ◽  
Topoisomerase I Inhibitors
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