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Sanmartí-Vila L, Tognetti S, Beduini F, Carrasco S. CARLA, the career launch hub to promote careers in photonics. J Phys Photonics 2020. [DOI: 10.1088/2515-7647/ab95f1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Abstract
Europe faces a situation in which the photonics industry is growing and needs more well-prepared
professionals to support its growth and innovation potential. Addressing this
pressing need requires engaging all photonics stakeholders to increase the visibility of the
outstanding professional opportunities of photonics and provide the future workforce with
tools to increase their employability.
CARLA, a new European funded project, aims to create a novel, rigorous and tested
instrument to address this need at the source. It will develop a model for European photonics
career camp −a reproducible 2-day intense, multi-format event− that 1) obtains coordinated
input from all stakeholders, 2) encourages STEM university students, PhD students and
young postdocs to pursue a career in photonics and 3) can be replicated by other
organisations. CARLA will create a robust, competitive and sustainable career camp that will
be tested on 11 occasions during the 2020–21 period, solidifying a ready-to-replicate camp
model. It will incorporate the dimensions of industry, academia, innovation, entrepreneurship,
and employability, putting special attention on empowering diversity, both within the camps
and in the future photonics workforce.
Sustainability of the model will be ensured through the creation of a virtual careers in
photonics hub that will support the photonics community at large during and beyond
CARLA, and develop a comprehensive handbook to facilitate camp replication. With the
promotion of diversity serving as one of the cornerstones in the design and implementation of
CARLA, the project will furthermore translate lessons learned in the camps into an
“Empowering Diversity in Photonics” guide applicable to future camps and the photonics
community in general.
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Chang YL, Tseng SF, Huang YC, Shen ZJ, Hsu PH, Hsieh MH, Yang CW, Tognetti S, Canal B, Subirana L, Wang CW, Chen HT, Lin CY, Posas F, Teng SC. Yeast Cip1 is activated by environmental stress to inhibit Cdk1-G1 cyclins via Mcm1 and Msn2/4. Nat Commun 2017; 8:56. [PMID: 28676626 PMCID: PMC5496861 DOI: 10.1038/s41467-017-00080-y] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Accepted: 06/01/2017] [Indexed: 12/20/2022] Open
Abstract
Upon environmental changes, proliferating cells delay cell cycle to prevent further damage accumulation. Yeast Cip1 is a Cdk1 and Cln2-associated protein. However, the function and regulation of Cip1 are still poorly understood. Here we report that Cip1 expression is co-regulated by the cell-cycle-mediated factor Mcm1 and the stress-mediated factors Msn2/4. Overexpression of Cip1 arrests cell cycle through inhibition of Cdk1–G1 cyclin complexes at G1 stage and the stress-activated protein kinase-dependent Cip1 T65, T69, and T73 phosphorylation may strengthen the Cip1and Cdk1–G1 cyclin interaction. Cip1 accumulation mainly targets Cdk1–Cln3 complex to prevent Whi5 phosphorylation and inhibit early G1 progression. Under osmotic stress, Cip1 expression triggers transient G1 delay which plays a functionally redundant role with another hyperosmolar activated CKI, Sic1. These findings indicate that Cip1 functions similarly to mammalian p21 as a stress-induced CDK inhibitor to decelerate cell cycle through G1 cyclins to cope with environmental stresses. A G1 cell cycle regulatory kinase Cip1 has been identified in budding yeast but how this is regulated is unclear. Here the authors identify cell cycle (Mcm1) and stress-mediated (Msn 2/4) transcription factors as regulating Cip1, causing stress induced CDK inhibition and delay in cell cycle progression.
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Affiliation(s)
- Ya-Lan Chang
- Department of Microbiology, College of Medicine, National Taiwan University, Taipei, 10051, Taiwan
| | - Shun-Fu Tseng
- Department of Microbiology, College of Medicine, National Taiwan University, Taipei, 10051, Taiwan.,Department and Graduate Institute of Microbiology and Immunology, National Defense Medical Center, Taipei, 11490, Taiwan
| | - Yu-Ching Huang
- Department of Microbiology, College of Medicine, National Taiwan University, Taipei, 10051, Taiwan
| | - Zih-Jie Shen
- Department of Microbiology, College of Medicine, National Taiwan University, Taipei, 10051, Taiwan
| | - Pang-Hung Hsu
- Department of Bioscience and Biotechnology, National Taiwan Ocean University, Keelung, 20224, Taiwan
| | - Meng-Hsun Hsieh
- Department of Microbiology, College of Medicine, National Taiwan University, Taipei, 10051, Taiwan
| | - Chia-Wei Yang
- Department of Microbiology, College of Medicine, National Taiwan University, Taipei, 10051, Taiwan
| | - Silvia Tognetti
- Cell Signaling Research Group, Departament de Ciències Experimentals i de la Salut, Universitat Pompeu Fabra, Barcelona, 08003, Spain
| | - Berta Canal
- Cell Signaling Research Group, Departament de Ciències Experimentals i de la Salut, Universitat Pompeu Fabra, Barcelona, 08003, Spain
| | - Laia Subirana
- Cell Signaling Research Group, Departament de Ciències Experimentals i de la Salut, Universitat Pompeu Fabra, Barcelona, 08003, Spain
| | - Chien-Wei Wang
- Department of Microbiology, College of Medicine, National Taiwan University, Taipei, 10051, Taiwan
| | - Hsiao-Tan Chen
- Department of Microbiology, College of Medicine, National Taiwan University, Taipei, 10051, Taiwan
| | - Chi-Ying Lin
- Department of Microbiology, College of Medicine, National Taiwan University, Taipei, 10051, Taiwan
| | - Francesc Posas
- Cell Signaling Research Group, Departament de Ciències Experimentals i de la Salut, Universitat Pompeu Fabra, Barcelona, 08003, Spain
| | - Shu-Chun Teng
- Department of Microbiology, College of Medicine, National Taiwan University, Taipei, 10051, Taiwan.
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Tognetti S, Speck C. Replicating repetitive DNA. Nat Cell Biol 2016; 18:593-4. [PMID: 27230530 DOI: 10.1038/ncb3367] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The function and regulation of repetitive DNA, the 'dark matter' of the genome, is still only rudimentarily understood. Now a study investigating DNA replication of repetitive centromeric chromosome segments has started to expose a fascinating replication program that involves suppression of ATR signalling, in particular during replication stress.
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Affiliation(s)
- Silvia Tognetti
- DNA Replication Group, Institute of Clinical Sciences, Imperial College London, London, W12 0NN, UK.,MRC Clinical Sciences Centre, Du Cane Road, London, W12 0NN, UK.,Cell Signalling Unit, Departament de Ciències Experimentals i de la Salut, Universitat Pompeu Fabra, Parc de Recerca Biomèdica de Barcelona, Barcelona, Spain
| | - Christian Speck
- DNA Replication Group, Institute of Clinical Sciences, Imperial College London, London, W12 0NN, UK.,MRC Clinical Sciences Centre, Du Cane Road, London, W12 0NN, UK
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Herrera MC, Tognetti S, Riera A, Zech J, Clarke P, Fernández-Cid A, Speck C. A reconstituted system reveals how activating and inhibitory interactions control DDK dependent assembly of the eukaryotic replicative helicase. Nucleic Acids Res 2015; 43:10238-50. [PMID: 26338774 PMCID: PMC4666391 DOI: 10.1093/nar/gkv881] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Accepted: 08/22/2015] [Indexed: 11/17/2022] Open
Abstract
During G1-phase of the cell-cycle the replicative MCM2–7 helicase becomes loaded onto DNA into pre-replicative complexes (pre-RCs), resulting in MCM2–7 double-hexamers on DNA. In S-phase, Dbf4-dependent kinase (DDK) and cyclin-dependent-kinase (CDK) direct with the help of a large number of helicase-activation factors the assembly of a Cdc45–MCM2–7–GINS (CMG) complex. However, in the absence of S-phase kinases complex assembly is inhibited, which is unexpected, as the MCM2–7 double-hexamer represents a very large interaction surface. Currently it is unclear what mechanisms restricts complex assembly and how DDK can overcome this inhibition to promote CMG-assembly. We developed an advanced reconstituted-system to study helicase activation in-solution and discovered that individual factors like Sld3 and Sld2 can bind directly to the pre-RC, while Cdc45 cannot. When Sld3 and Sld2 were incubated together with the pre-RC, we observed that competitive interactions restrict complex assembly. DDK stabilizes the Sld3/Sld2–pre-RC complex, but the complex is only short-lived, indicating an anti-cooperative mechanism. Yet, a Sld3/Cdc45–pre-RC can form in the presence of DDK and the addition of Sld2 enhances complex stability. Our results indicate that helicase activation is regulated by competitive and cooperative interactions, which restrict illegitimate complex formation and direct limiting helicase-activation factors into pre-initiation complexes.
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Affiliation(s)
- M Carmen Herrera
- DNA Replication Group, Institute of Clinical Sciences, Imperial College London, London W12 0NN, UK
| | - Silvia Tognetti
- DNA Replication Group, Institute of Clinical Sciences, Imperial College London, London W12 0NN, UK
| | - Alberto Riera
- DNA Replication Group, Institute of Clinical Sciences, Imperial College London, London W12 0NN, UK
| | - Juergen Zech
- DNA Replication Group, Institute of Clinical Sciences, Imperial College London, London W12 0NN, UK
| | - Pippa Clarke
- DNA Replication Group, Institute of Clinical Sciences, Imperial College London, London W12 0NN, UK
| | - Alejandra Fernández-Cid
- DNA Replication Group, Institute of Clinical Sciences, Imperial College London, London W12 0NN, UK
| | - Christian Speck
- DNA Replication Group, Institute of Clinical Sciences, Imperial College London, London W12 0NN, UK
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Sun J, Fernandez-Cid A, Riera A, Tognetti S, Yuan Z, Stillman B, Speck C, Li H. Structural and mechanistic insights into Mcm2-7 double-hexamer assembly and function. Genes Dev 2014; 28:2291-303. [PMID: 25319829 PMCID: PMC4201289 DOI: 10.1101/gad.242313.114] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Eukaryotic cells license each DNA replication origin during G1 phase by assembling a prereplication complex (pre-RC) that contains a Mcm2–7 double hexamer. In this study, Sun et al. examined the helicase loading reaction in the presence of ATP, revealing the basic architecture of a number of pre-RC assembly reaction intermediates, including a newly identified ORC–Cdc6–Mcm2–7–Mcm2–7 complex. The detailed architecture of the Mcm2–7 double hexamer was also established. Eukaryotic cells license each DNA replication origin during G1 phase by assembling a prereplication complex that contains a Mcm2–7 (minichromosome maintenance proteins 2–7) double hexamer. During S phase, each Mcm2–7 hexamer forms the core of a replicative DNA helicase. However, the mechanisms of origin licensing and helicase activation are poorly understood. The helicase loaders ORC–Cdc6 function to recruit a single Cdt1–Mcm2–7 heptamer to replication origins prior to Cdt1 release and ORC–Cdc6–Mcm2–7 complex formation, but how the second Mcm2–7 hexamer is recruited to promote double-hexamer formation is not well understood. Here, structural evidence for intermediates consisting of an ORC–Cdc6–Mcm2–7 complex and an ORC–Cdc6–Mcm2–7–Mcm2–7 complex are reported, which together provide new insights into DNA licensing. Detailed structural analysis of the loaded Mcm2–7 double-hexamer complex demonstrates that the two hexamers are interlocked and misaligned along the DNA axis and lack ATP hydrolysis activity that is essential for DNA helicase activity. Moreover, we show that the head-to-head juxtaposition of the Mcm2–7 double hexamer generates a new protein interaction surface that creates a multisubunit-binding site for an S-phase protein kinase that is known to activate DNA replication. The data suggest how the double hexamer is assembled and how helicase activity is regulated during DNA licensing, with implications for cell cycle control of DNA replication and genome stability.
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Affiliation(s)
- Jingchuan Sun
- Biosciences Department, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - Alejandra Fernandez-Cid
- DNA Replication Group, MRC Clinical Sciences Centre, Imperial College Faculty of Medicine, London W12 0NN, United Kingdom
| | - Alberto Riera
- DNA Replication Group, MRC Clinical Sciences Centre, Imperial College Faculty of Medicine, London W12 0NN, United Kingdom
| | - Silvia Tognetti
- DNA Replication Group, MRC Clinical Sciences Centre, Imperial College Faculty of Medicine, London W12 0NN, United Kingdom
| | - Zuanning Yuan
- Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, New York 11794, USA
| | - Bruce Stillman
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York 11724, USA
| | - Christian Speck
- DNA Replication Group, MRC Clinical Sciences Centre, Imperial College Faculty of Medicine, London W12 0NN, United Kingdom;
| | - Huilin Li
- Biosciences Department, Brookhaven National Laboratory, Upton, New York 11973, USA; Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, New York 11794, USA
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Tognetti S, Riera A, Speck C. Switch on the engine: how the eukaryotic replicative helicase MCM2-7 becomes activated. Chromosoma 2014; 124:13-26. [PMID: 25308420 DOI: 10.1007/s00412-014-0489-2] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2014] [Revised: 09/24/2014] [Accepted: 09/25/2014] [Indexed: 12/17/2022]
Abstract
A crucial step during eukaryotic initiation of DNA replication is the correct loading and activation of the replicative DNA helicase, which ensures that each replication origin fires only once. Unregulated DNA helicase loading and activation, as it occurs in cancer, can cause severe DNA damage and genomic instability. The essential mini-chromosome maintenance proteins 2-7 (MCM2-7) represent the core of the eukaryotic replicative helicase that is loaded at DNA replication origins during G1-phase of the cell cycle. The MCM2-7 helicase activity, however, is only triggered during S-phase once the holo-helicase Cdc45-MCM2-7-GINS (CMG) has been formed. A large number of factors and several kinases interact and contribute to CMG formation and helicase activation, though the exact mechanisms remain unclear. Crucially, upon DNA damage, this reaction is temporarily halted to ensure genome integrity. Here, we review the current understanding of helicase activation; we focus on protein interactions during CMG formation, discuss structural changes during helicase activation, and outline similarities and differences of the prokaryotic and eukaryotic helicase activation process.
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Affiliation(s)
- Silvia Tognetti
- DNA Replication Group, Institute of Clinical Science, Imperial College, London, W12 0NN, UK
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Samel SA, Fernández-Cid A, Sun J, Riera A, Tognetti S, Herrera MC, Li H, Speck C. A unique DNA entry gate serves for regulated loading of the eukaryotic replicative helicase MCM2-7 onto DNA. Genes Dev 2014; 28:1653-66. [PMID: 25085418 PMCID: PMC4117941 DOI: 10.1101/gad.242404.114] [Citation(s) in RCA: 90] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2014] [Accepted: 06/25/2014] [Indexed: 01/24/2023]
Abstract
The regulated loading of the replicative helicase minichromosome maintenance proteins 2-7 (MCM2-7) onto replication origins is a prerequisite for replication fork establishment and genomic stability. Origin recognition complex (ORC), Cdc6, and Cdt1 assemble two MCM2-7 hexamers into one double hexamer around dsDNA. Although the MCM2-7 hexamer can adopt a ring shape with a gap between Mcm2 and Mcm5, it is unknown which Mcm interface functions as the DNA entry gate during regulated helicase loading. Here, we establish that the Saccharomyces cerevisiae MCM2-7 hexamer assumes a closed ring structure, suggesting that helicase loading requires active ring opening. Using a chemical biology approach, we show that ORC-Cdc6-Cdt1-dependent helicase loading occurs through a unique DNA entry gate comprised of the Mcm2 and Mcm5 subunits. Controlled inhibition of DNA insertion triggers ATPase-driven complex disassembly in vitro, while in vivo analysis establishes that Mcm2/Mcm5 gate opening is essential for both helicase loading onto chromatin and cell cycle progression. Importantly, we demonstrate that the MCM2-7 helicase becomes loaded onto DNA as a single hexamer during ORC/Cdc6/Cdt1/MCM2-7 complex formation prior to MCM2-7 double hexamer formation. Our study establishes the existence of a unique DNA entry gate for regulated helicase loading, revealing key mechanisms in helicase loading, which has important implications for helicase activation.
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Affiliation(s)
- Stefan A Samel
- DNA Replication Group, Institute of Clinical Science, Imperial College, London W12 0NN, United Kingdom
| | - Alejandra Fernández-Cid
- DNA Replication Group, Institute of Clinical Science, Imperial College, London W12 0NN, United Kingdom
| | - Jingchuan Sun
- Biosciences Department, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - Alberto Riera
- DNA Replication Group, Institute of Clinical Science, Imperial College, London W12 0NN, United Kingdom
| | - Silvia Tognetti
- DNA Replication Group, Institute of Clinical Science, Imperial College, London W12 0NN, United Kingdom
| | - M Carmen Herrera
- DNA Replication Group, Institute of Clinical Science, Imperial College, London W12 0NN, United Kingdom
| | - Huilin Li
- Biosciences Department, Brookhaven National Laboratory, Upton, New York 11973, USA; Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, New York 11794, USA
| | - Christian Speck
- DNA Replication Group, Institute of Clinical Science, Imperial College, London W12 0NN, United Kingdom;
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Abstract
A central step in eukaryotic initiation of DNA replication is the loading of the helicase at replication origins, misregulation of this reaction leads to DNA damage and genome instability. Here we discuss how the helicase becomes recruited to origins and loaded into a double-hexamer around double-stranded DNA. We specifically describe the individual steps in complex assembly and explain how this process is regulated to maintain genome stability. Structural analysis of the helicase loader and the helicase has provided key insights into the process of double-hexamer formation. A structural comparison of the bacterial and eukaryotic system suggests a mechanism of helicase loading.
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Affiliation(s)
- Alberto Riera
- DNA Replication Group, Faculty of Medicine, Institute of Clinical Sciences, Imperial College, Hammersmith Hospital Campus, Du Cane Road, London W12 0NN, UK
| | - Silvia Tognetti
- DNA Replication Group, Faculty of Medicine, Institute of Clinical Sciences, Imperial College, Hammersmith Hospital Campus, Du Cane Road, London W12 0NN, UK
| | - Christian Speck
- DNA Replication Group, Faculty of Medicine, Institute of Clinical Sciences, Imperial College, Hammersmith Hospital Campus, Du Cane Road, London W12 0NN, UK.
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Evrin C, Fernández-Cid A, Riera A, Zech J, Clarke P, Herrera MC, Tognetti S, Lurz R, Speck C. The ORC/Cdc6/MCM2-7 complex facilitates MCM2-7 dimerization during prereplicative complex formation. Nucleic Acids Res 2013; 42:2257-69. [PMID: 24234446 PMCID: PMC3936773 DOI: 10.1093/nar/gkt1148] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
The replicative mini-chromosome-maintenance 2–7 (MCM2-7) helicase is loaded in Saccharomyces cerevisiae and other eukaryotes as a head-to-head double-hexamer around origin DNA. At first, ORC/Cdc6 recruits with the help of Cdt1 a single MCM2-7 hexamer to form an ‘initial’ ORC/Cdc6/Cdt1/MCM2-7 complex. Then, on ATP hydrolysis and Cdt1 release, the ‘initial’ complex is transformed into an ORC/Cdc6/MCM2-7 (OCM) complex. However, it remains unclear how the OCM is subsequently converted into a MCM2-7 double-hexamer. Through analysis of MCM2-7 hexamer-interface mutants we discovered a complex competent for MCM2-7 dimerization. We demonstrate that these MCM2-7 mutants arrest during prereplicative complex (pre-RC) assembly after OCM formation, but before MCM2-7 double-hexamer assembly. Remarkably, only the OCM complex, but not the ‘initial’ ORC/Cdc6/Cdt1/MCM2-7 complex, is competent for MCM2-7 dimerization. The MCM2-7 dimer, in contrast to the MCM2-7 double-hexamer, interacts with ORC/Cdc6 and is salt-sensitive, classifying the arrested complex as a helicase-loading intermediate. Accordingly, we found that overexpression of the mutants cause cell-cycle arrest and dominant lethality. Our work identifies the OCM complex as competent for MCM2-7 dimerization, reveals MCM2-7 dimerization as a limiting step during pre-RC formation and defines critical mechanisms that explain how origins are licensed.
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Affiliation(s)
- Cecile Evrin
- DNA Replication Group, MRC Clinical Sciences Centre, Imperial College, Du Cane Road, London W12 0NN, UK and Microscopy Unit, Max Planck Institute for Molecular Genetics, Berlin 14195, Germany
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Fernández-Cid A, Riera A, Tognetti S, Herrera MC, Samel S, Evrin C, Winkler C, Gardenal E, Uhle S, Speck C. An ORC/Cdc6/MCM2-7 complex is formed in a multistep reaction to serve as a platform for MCM double-hexamer assembly. Mol Cell 2013; 50:577-88. [PMID: 23603117 DOI: 10.1016/j.molcel.2013.03.026] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2012] [Revised: 03/22/2013] [Accepted: 03/28/2013] [Indexed: 01/08/2023]
Abstract
In Saccharomyces cerevisiae and higher eukaryotes, the loading of the replicative helicase MCM2-7 onto DNA requires the combined activities of ORC, Cdc6, and Cdt1. These proteins load MCM2-7 in an unknown way into a double hexamer around DNA. Here we show that MCM2-7 recruitment by ORC/Cdc6 is blocked by an autoinhibitory domain in the C terminus of Mcm6. Interestingly, Cdt1 can overcome this inhibitory activity, and consequently the Cdt1-MCM2-7 complex activates ORC/Cdc6 ATP-hydrolysis to promote helicase loading. While Cdc6 ATPase activity is known to facilitate Cdt1 release and MCM2-7 loading, we discovered that Orc1 ATP-hydrolysis is equally important in this process. Moreover, we found that Orc1/Cdc6 ATP-hydrolysis promotes the formation of the ORC/Cdc6/MCM2-7 (OCM) complex, which functions in MCM2-7 double-hexamer assembly. Importantly, CDK-dependent phosphorylation of ORC inhibits OCM establishment to ensure once per cell cycle replication. In summary, this work reveals multiple critical mechanisms that redefine our understanding of DNA licensing.
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Fatoba ST, Tognetti S, Berto M, Leo E, Mulvey CM, Godovac-Zimmermann J, Pommier Y, Okorokov AL. Human SIRT1 regulates DNA binding and stability of the Mcm10 DNA replication factor via deacetylation. Nucleic Acids Res 2013; 41:4065-79. [PMID: 23449222 PMCID: PMC3627603 DOI: 10.1093/nar/gkt131] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The eukaryotic DNA replication initiation factor Mcm10 is essential for both replisome assembly and function. Human Mcm10 has two DNA-binding domains, the conserved internal domain (ID) and the C-terminal domain (CTD), which is specific to metazoans. SIRT1 is a nicotinamide adenine dinucleotide (NAD)-dependent deacetylase that belongs to the sirtuin family. It is conserved from yeast to human and participates in cellular controls of metabolism, longevity, gene expression and genomic stability. Here we report that human Mcm10 is an acetylated protein regulated by SIRT1, which binds and deacetylates Mcm10 both in vivo and in vitro, and modulates Mcm10 stability and ability to bind DNA. Mcm10 and SIRT1 appear to act synergistically for DNA replication fork initiation. Furthermore, we show that the two DNA-binding domains of Mcm10 are modulated in distinct fashion by acetylation/deacetylation, suggesting an integrated regulation mechanism. Overall, our study highlights the importance of protein acetylation for DNA replication initiation and progression, and suggests that SIRT1 may mediate a crosstalk between cellular circuits controlling metabolism and DNA synthesis.
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Affiliation(s)
- Samuel T Fatoba
- Wolfson Institute for Biomedical Research, University College London, Gower Street, London WC1E 6BT, UK
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Ghirri P, Ciulli C, Vuerich M, Cuttano A, Faraoni M, Guerrini L, Spinelli C, Tognetti S, Boldrini A. Incidence at birth and natural history of cryptorchidism: a study of 10,730 consecutive male infants. J Endocrinol Invest 2002; 25:709-15. [PMID: 12240903 DOI: 10.1007/bf03345105] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Of the 10,730 neonates born in the period 1978-1997 and examined for cryptorchidism (C) at birth, 1387 were pre-term (gestational age <37 wk), and 9343 were full-term. At birth, a total of 737 neonates (6.9%) were cryptorchid, 487 had bilateral C and 250 unilateral C. The C rate of pre-terms was 10 times higher than that of the full-terms (30.1 and 3.4%, respectively). Comparing the two studied decades, a significant decrease of C rate was found in the second decade in full-term neonates. The rates of C at birth were significantly elevated for low birth weight, babies born from mothers with an age <20 or >35 yr, newborns from mothers with A Rh positive and B Rh positive blood group. Of the 737 cryptorchid newborns at birth, 613 (83%) were re-examined after 12 months from the expected date of delivery, and those born in the period 1988-1997 were also re-evaluated at 6 months of life. Late spontaneous descent occurred in 464 cases (75.7%), while 149 (24.3%) were still cryptorchid. The incidence of C at 12 months from the expected date of delivery, after survival curve calculation, in term and pre-term infants, was 1.53 and 7.31%, respectively, in the period 1978-1987, and 1.22 and 3.13% respectively, in the 2nd decade (1988-1997). In the groups also examined at 6 months of life, spontaneous descent occurred almost completely within the first 6 months of life in term infants, but not in pre-terms. No evidence of seasonal cyclicity was found. Medical and/or surgical treatment was generally started within 2-4 yr of age earlier in the second decade of the study. In conclusion, the main risk factor for C at birth and at 12 months of life seems to be pre-term birth and low birth weight. If this is associated itself to a higher risk of infertility too, it remains to be defined.
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Affiliation(s)
- P Ghirri
- Division of Neonatology, University of Pisa, S. Chiara Hospital, Italy.
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Tognetti S. [Problems of citizen provisioning and political measures of food provisioning in Florence during the 15th century (1430-1500)]. Arch Stor Ital 1999; 157:419-452. [PMID: 19378502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
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