Project acronym CRIPTON
Project Role of ncRNAs in Chromatin and Transcription
Researcher (PI) Tony Kouzarides
Host Institution (HI) THE CHANCELLOR MASTERS AND SCHOLARSOF THE UNIVERSITY OF CAMBRIDGE
Call Details Advanced Grant (AdG), LS1, ERC-2010-AdG_20100317
Summary The human genome is highly transcribed, with over 90% of sequences contributing to the production of RNA. The function of the vast majority of these RNAs is unknown. Evidence over many years has revealed that transcription factors and chromatin regulators are associated with a variety of non-coding (nc)RNAs, but their function remains largely unknown. There are a few cases where a role has been ascribed for ncRNAs in transcription, but no clear mechanistic insight has been defined yet. We predict that many of the newly identified ncRNAs emanating from the genome will play a role in transcriptional processes. We intend to identify and characterise such ncRNAs. This will take place in two phases. In the first phase we will use biochemical approaches to identify ncRNAs involved in the regulation of chromatin and transcription. Our investigations will focus on proteins leading to the induction of pluripotency and oncogenesis. ncRNAs associated with such proteins will be identified using targeted screens. In the second phase, the importance of these RNAs in determining pluripotency and oncogenesis will be analysed. In addition, a variety of molecular approaches will be used to investigate the mechanism by which these ncRNAs regulate the function of the proteins or complexes they associate with. One particular hypothesis we will explore is that such ncRNAs play a role in guiding proteins to DNA sequences, via the formation of RNA/DNA triplexes. This concerted and focused analysis will provide mechanistic insights into the functions of ncRNAs in transcriptional regulation and validate their role in key biological processes. The identification of such new ncRNA-regulated pathways may open up new avenues for therapeutic intervention.
Summary
The human genome is highly transcribed, with over 90% of sequences contributing to the production of RNA. The function of the vast majority of these RNAs is unknown. Evidence over many years has revealed that transcription factors and chromatin regulators are associated with a variety of non-coding (nc)RNAs, but their function remains largely unknown. There are a few cases where a role has been ascribed for ncRNAs in transcription, but no clear mechanistic insight has been defined yet. We predict that many of the newly identified ncRNAs emanating from the genome will play a role in transcriptional processes. We intend to identify and characterise such ncRNAs. This will take place in two phases. In the first phase we will use biochemical approaches to identify ncRNAs involved in the regulation of chromatin and transcription. Our investigations will focus on proteins leading to the induction of pluripotency and oncogenesis. ncRNAs associated with such proteins will be identified using targeted screens. In the second phase, the importance of these RNAs in determining pluripotency and oncogenesis will be analysed. In addition, a variety of molecular approaches will be used to investigate the mechanism by which these ncRNAs regulate the function of the proteins or complexes they associate with. One particular hypothesis we will explore is that such ncRNAs play a role in guiding proteins to DNA sequences, via the formation of RNA/DNA triplexes. This concerted and focused analysis will provide mechanistic insights into the functions of ncRNAs in transcriptional regulation and validate their role in key biological processes. The identification of such new ncRNA-regulated pathways may open up new avenues for therapeutic intervention.
Max ERC Funding
2 141 470 €
Duration
Start date: 2011-05-01, End date: 2017-04-30
Project acronym CRISPAIR
Project Study of the interplay between CRISPR interference and DNA repair pathways towards the development of novel CRISPR tools
Researcher (PI) David Bikard
Host Institution (HI) INSTITUT PASTEUR
Call Details Starting Grant (StG), LS1, ERC-2015-STG
Summary CRISPR-Cas loci are the adaptive immune system of archaea and bacteria. They can capture pieces of invading DNA and use this information to degrade target DNA through the action of RNA-guided nucleases. The consequences of DNA cleavage by Cas nucleases, i.e. how breaks are processed and whether they can be repaired, remains to be investigated. A better understanding of the interplay between DNA repair and CRISPR-Cas is critical both to shed light on the evolution and biology of these fascinating systems and for the development of biotechnological tools based on Cas nucleases. CRISPR systems have indeed become a popular tool to edit Eukaryotic genomes. The strategies employed take advantage of different DNA repair pathways to introduce mutations upon DNA cleavage. In bacteria however, the introduction of breaks by Cas nucleases in the chromosome has been described to kill the cell. Preliminary data indicates that this might not always be the case and that some DNA repair pathways could compete with CRISPR immunity allowing cells to survive. Using a combination of bioinformatics and genetics approaches we will investigate the interplay between CRISPR and DNA repair in bacteria with a particular focus on the widely used CRISPR-Cas9 system. The knowledge gained from this study will then help us develop novel tools for bacterial genome engineering. In particular we will introduce a NHEJ pathway in E.coli making it possible to perform CRISPR knockout screens. Finally using CRISPR libraries and multiplexed targeting, we will generate for the first time all combinations of pair-wise gene knockouts in an organism, a task that for now remains elusive, even for large consortiums and with the use of automation. This will enable to decipher genome-scale genetic interaction networks, an important step for our understanding of bacteria as a system.
Summary
CRISPR-Cas loci are the adaptive immune system of archaea and bacteria. They can capture pieces of invading DNA and use this information to degrade target DNA through the action of RNA-guided nucleases. The consequences of DNA cleavage by Cas nucleases, i.e. how breaks are processed and whether they can be repaired, remains to be investigated. A better understanding of the interplay between DNA repair and CRISPR-Cas is critical both to shed light on the evolution and biology of these fascinating systems and for the development of biotechnological tools based on Cas nucleases. CRISPR systems have indeed become a popular tool to edit Eukaryotic genomes. The strategies employed take advantage of different DNA repair pathways to introduce mutations upon DNA cleavage. In bacteria however, the introduction of breaks by Cas nucleases in the chromosome has been described to kill the cell. Preliminary data indicates that this might not always be the case and that some DNA repair pathways could compete with CRISPR immunity allowing cells to survive. Using a combination of bioinformatics and genetics approaches we will investigate the interplay between CRISPR and DNA repair in bacteria with a particular focus on the widely used CRISPR-Cas9 system. The knowledge gained from this study will then help us develop novel tools for bacterial genome engineering. In particular we will introduce a NHEJ pathway in E.coli making it possible to perform CRISPR knockout screens. Finally using CRISPR libraries and multiplexed targeting, we will generate for the first time all combinations of pair-wise gene knockouts in an organism, a task that for now remains elusive, even for large consortiums and with the use of automation. This will enable to decipher genome-scale genetic interaction networks, an important step for our understanding of bacteria as a system.
Max ERC Funding
1 499 763 €
Duration
Start date: 2016-03-01, End date: 2021-11-30
Project acronym CRISPR2.0
Project Microbial genome defence pathways: from molecular mechanisms to next-generation molecular tools
Researcher (PI) Martin JINEK
Host Institution (HI) UNIVERSITAT ZURICH
Call Details Consolidator Grant (CoG), LS1, ERC-2018-COG
Summary The constant arms race between prokaryotic microbes and their molecular parasites such as viruses, plasmids and transposons has driven the evolution of complex genome defence mechanisms. The CRISPR-Cas defence systems provide adaptive RNA-guided immunity against invasive nucleic acid elements. CRISPR-associated effector nucleases such as Cas9, Cas12a and Cas13 have emerged as powerful tools for precision genome editing, gene expression control and nucleic acid detection. However, these technologies suffer from drawbacks that limit their efficacy and versatility, necessitating the search for additional exploitable molecular activities. Building on our recent structural and biochemical studies, the goal of this project is to investigate the molecular architectures and mechanisms of CRISPR-associated systems and other genome defence mechanisms, aiming not only to shed light on their biological roles but also inform their technological development. Specifically, the proposed studies will examine (i) the molecular basis of cyclic oligoadenylate signalling in type III CRISPR-Cas systems, (ii) the mechanism of transposon-associated type I CRISPR-Cas systems and their putative function in RNA-guided DNA transposition, and (iii) molecular activities associated with recently described non-CRISPR defence systems. Collectively, the proposed studies will advance our understanding of the molecular functions of genome defence mechanisms in shaping the evolution of prokaryotic genomes and make critical contributions to their development as novel genetic engineering tools.
Summary
The constant arms race between prokaryotic microbes and their molecular parasites such as viruses, plasmids and transposons has driven the evolution of complex genome defence mechanisms. The CRISPR-Cas defence systems provide adaptive RNA-guided immunity against invasive nucleic acid elements. CRISPR-associated effector nucleases such as Cas9, Cas12a and Cas13 have emerged as powerful tools for precision genome editing, gene expression control and nucleic acid detection. However, these technologies suffer from drawbacks that limit their efficacy and versatility, necessitating the search for additional exploitable molecular activities. Building on our recent structural and biochemical studies, the goal of this project is to investigate the molecular architectures and mechanisms of CRISPR-associated systems and other genome defence mechanisms, aiming not only to shed light on their biological roles but also inform their technological development. Specifically, the proposed studies will examine (i) the molecular basis of cyclic oligoadenylate signalling in type III CRISPR-Cas systems, (ii) the mechanism of transposon-associated type I CRISPR-Cas systems and their putative function in RNA-guided DNA transposition, and (iii) molecular activities associated with recently described non-CRISPR defence systems. Collectively, the proposed studies will advance our understanding of the molecular functions of genome defence mechanisms in shaping the evolution of prokaryotic genomes and make critical contributions to their development as novel genetic engineering tools.
Max ERC Funding
1 996 525 €
Duration
Start date: 2019-05-01, End date: 2024-04-30
Project acronym CRYOREP
Project Chromosome Replication Visualised by Cryo-EM
Researcher (PI) Alessandro COSTA
Host Institution (HI) THE FRANCIS CRICK INSTITUTE LIMITED
Call Details Consolidator Grant (CoG), LS1, ERC-2018-COG
Summary In eukaryotic cells, DNA replication is tightly regulated to ensure that the genome is duplicated only once per cell cycle. Errors in the control mechanisms that regulate chromosome ploidy cause genomic instability, which is linked to the development of cellular abnormalities, genetic disease and the onset of cancer. Recent reconstitution experiments performed with purified proteins revealed that initiation of eukaryotic genome duplication requires three distinct steps. First, DNA replication start sites are identified and targeted for the loading of an inactive MCM helicase motor, which encircles the double helix. Second, MCM activators are recruited, causing duplex-DNA untwisting. Third, upon interaction with a firing factor, the MCM ring opens to eject one DNA strand, leading to unwinding of the replication fork and duplication by dedicated replicative polymerases. These three events are not understood at a molecular level. Structural investigations so far aimed at imaging artificially isolated replication steps and used simplified templates, such as linear duplex DNA to study helicase loading or pre-formed forks to understand unwinding. However, the natural substrate of the eukaryotic replication machinery is not DNA but rather chromatin, formed of nucleosome arrays that compact the genome. Chromatin plays important regulatory roles in all steps of DNA replication, by dictating origin start-site selection and stimulating replication fork progression. Only by studying chromatin replication, we argue, will we understand the molecular basis of genome propagation. To this end, we have developed new protocols to perform visual biochemistry experiments under the cryo-electron microscope, to image chromatin duplication at high resolution, frozen as it is being catalysed. Using these strategies we want to generate a molecular movie of the entire replication reaction. Our achievements will change the way we think about genome stability in eukaryotic cells.
Summary
In eukaryotic cells, DNA replication is tightly regulated to ensure that the genome is duplicated only once per cell cycle. Errors in the control mechanisms that regulate chromosome ploidy cause genomic instability, which is linked to the development of cellular abnormalities, genetic disease and the onset of cancer. Recent reconstitution experiments performed with purified proteins revealed that initiation of eukaryotic genome duplication requires three distinct steps. First, DNA replication start sites are identified and targeted for the loading of an inactive MCM helicase motor, which encircles the double helix. Second, MCM activators are recruited, causing duplex-DNA untwisting. Third, upon interaction with a firing factor, the MCM ring opens to eject one DNA strand, leading to unwinding of the replication fork and duplication by dedicated replicative polymerases. These three events are not understood at a molecular level. Structural investigations so far aimed at imaging artificially isolated replication steps and used simplified templates, such as linear duplex DNA to study helicase loading or pre-formed forks to understand unwinding. However, the natural substrate of the eukaryotic replication machinery is not DNA but rather chromatin, formed of nucleosome arrays that compact the genome. Chromatin plays important regulatory roles in all steps of DNA replication, by dictating origin start-site selection and stimulating replication fork progression. Only by studying chromatin replication, we argue, will we understand the molecular basis of genome propagation. To this end, we have developed new protocols to perform visual biochemistry experiments under the cryo-electron microscope, to image chromatin duplication at high resolution, frozen as it is being catalysed. Using these strategies we want to generate a molecular movie of the entire replication reaction. Our achievements will change the way we think about genome stability in eukaryotic cells.
Max ERC Funding
2 000 000 €
Duration
Start date: 2019-03-01, End date: 2024-02-29
Project acronym CRYOTRANSLATION
Project High Resolution cryo-EM Analysis of Ribosome-associated Functions
Researcher (PI) Roland Beckmann
Host Institution (HI) LUDWIG-MAXIMILIANS-UNIVERSITAET MUENCHEN
Call Details Advanced Grant (AdG), LS1, ERC-2011-ADG_20110310
Summary "Translation of the genetically encoded information into polypeptides, protein biosynthesis, is a central function executed by ribosomes in all cells. In the case of membrane protein synthesis, integration into the membrane usually occurs co-translationally and requires a ribosome-associated translocon (SecYEG/Sec61). This highly coordinated process is poorly understood, since high-resolution structural information is lacking. Although single particle cryo-electron microscopy (cryo-EM) has given invaluable structural insights for such dynamic ribosomal complexes, the resolution is so far limited to 5-10 Å for asymmetrical particles. Thus, the mechanistic depth and reliability of interpretation has accordingly been limited.
Here, I propose to use single particle cryo-EM at improved, molecular resolution of 3-4 Å to study two fundamental ribosome-associated processes:
(i) co-translational integration of polytopic membrane proteins and
(ii) recycling of the eukaryotic ribosome.
First, we will visualize nascent polytopic membrane proteins inserting into the lipid bilayer via the bacterial ribosome-bound SecYEG translocon. Notably, the translocon will be embedded in a lipid environment provided by so-called nanodiscs. Second, we will visualize in a similar approach membrane protein insertion via the YidC insertase, the main alternative translocon. Third, as a novel research direction, we will determine the structure and function of eukaryotic ribosome recycling complexes involving the ABC-ATPase RLI.
The results will allow, together with functional biochemical data, an in-depth molecular structure-function analysis of these fundamental ribosome-associated processes. Moreover, reaching molecular resolution for asymmetrical particles by single particle cryo-EM will lift this technology to a level of analytical power approaching X-ray and NMR methods. ERC funding would allow for this highly challenging research to be conducted in an internationally competitive way in Europe."
Summary
"Translation of the genetically encoded information into polypeptides, protein biosynthesis, is a central function executed by ribosomes in all cells. In the case of membrane protein synthesis, integration into the membrane usually occurs co-translationally and requires a ribosome-associated translocon (SecYEG/Sec61). This highly coordinated process is poorly understood, since high-resolution structural information is lacking. Although single particle cryo-electron microscopy (cryo-EM) has given invaluable structural insights for such dynamic ribosomal complexes, the resolution is so far limited to 5-10 Å for asymmetrical particles. Thus, the mechanistic depth and reliability of interpretation has accordingly been limited.
Here, I propose to use single particle cryo-EM at improved, molecular resolution of 3-4 Å to study two fundamental ribosome-associated processes:
(i) co-translational integration of polytopic membrane proteins and
(ii) recycling of the eukaryotic ribosome.
First, we will visualize nascent polytopic membrane proteins inserting into the lipid bilayer via the bacterial ribosome-bound SecYEG translocon. Notably, the translocon will be embedded in a lipid environment provided by so-called nanodiscs. Second, we will visualize in a similar approach membrane protein insertion via the YidC insertase, the main alternative translocon. Third, as a novel research direction, we will determine the structure and function of eukaryotic ribosome recycling complexes involving the ABC-ATPase RLI.
The results will allow, together with functional biochemical data, an in-depth molecular structure-function analysis of these fundamental ribosome-associated processes. Moreover, reaching molecular resolution for asymmetrical particles by single particle cryo-EM will lift this technology to a level of analytical power approaching X-ray and NMR methods. ERC funding would allow for this highly challenging research to be conducted in an internationally competitive way in Europe."
Max ERC Funding
2 995 640 €
Duration
Start date: 2012-05-01, End date: 2017-04-30
Project acronym CRYTOCOP
Project Coat assembly and membrane remodelling: understanding regulation of protein secretion
Researcher (PI) Giulia Zanetti
Host Institution (HI) BIRKBECK COLLEGE - UNIVERSITY OF LONDON
Call Details Starting Grant (StG), LS1, ERC-2019-STG
Summary Eukaryotic cells are organised in membrane-bound compartments, which have defined chemical identities and carry out specific essential functions. Exchange of material between these compartments is necessary to maintain cell functionality, and is achieved in a highly specific and regulated manner by vesicular transport. To mediate protein trafficking, coat complexes assemble on membranes and couple bilayer deformation with cargo capture into transport carriers. How coat assembly can deliver the flexibility necessary to accommodate a wide variety of cargo proteins, and how the process can be regulated, are outstanding questions in the field. This is exemplified by the COPII coat, which mediates export from the ER of about a third of newly synthesized proteins. COPII assembles into two concentric layers and can form transport carriers of a variety of shapes and sizes, including tubules and spherical vesicles. This is important for export of large cargoes and is a process targeted by cargo-specific regulatory factors. The aim of this project proposal is to shed light on the molecular interactions between coat components, and understand their role in determination of coat architecture and membrane shape. We will use a combination of structural and functional approaches to characterise COPII coat assembly, and its relationship with membranes in systems of increasing complexity, ranging from in vitro reconstitutions to cells. In particular, we will use cryo-electron tomography and subtomogram averaging to understand the architecture of the coat layers in these systems. These are fast-developing techniques that uniquely target complex structures while achieving high resolutions. With my lab at the forefront of current advances, we are perfectly placed to obtain a complete view of the COPII coat assembled on membranes. Our research will answer outstanding questions in the membrane trafficking field and open new perspectives to tackle ill-characterised regulation systems.
Summary
Eukaryotic cells are organised in membrane-bound compartments, which have defined chemical identities and carry out specific essential functions. Exchange of material between these compartments is necessary to maintain cell functionality, and is achieved in a highly specific and regulated manner by vesicular transport. To mediate protein trafficking, coat complexes assemble on membranes and couple bilayer deformation with cargo capture into transport carriers. How coat assembly can deliver the flexibility necessary to accommodate a wide variety of cargo proteins, and how the process can be regulated, are outstanding questions in the field. This is exemplified by the COPII coat, which mediates export from the ER of about a third of newly synthesized proteins. COPII assembles into two concentric layers and can form transport carriers of a variety of shapes and sizes, including tubules and spherical vesicles. This is important for export of large cargoes and is a process targeted by cargo-specific regulatory factors. The aim of this project proposal is to shed light on the molecular interactions between coat components, and understand their role in determination of coat architecture and membrane shape. We will use a combination of structural and functional approaches to characterise COPII coat assembly, and its relationship with membranes in systems of increasing complexity, ranging from in vitro reconstitutions to cells. In particular, we will use cryo-electron tomography and subtomogram averaging to understand the architecture of the coat layers in these systems. These are fast-developing techniques that uniquely target complex structures while achieving high resolutions. With my lab at the forefront of current advances, we are perfectly placed to obtain a complete view of the COPII coat assembled on membranes. Our research will answer outstanding questions in the membrane trafficking field and open new perspectives to tackle ill-characterised regulation systems.
Max ERC Funding
1 499 175 €
Duration
Start date: 2019-11-01, End date: 2024-10-31
Project acronym CsnCRL
Project The molecular basis of CULLIN E3 ligase regulation by the COP9 signalosome
Researcher (PI) Nicolas Thoma
Host Institution (HI) FRIEDRICH MIESCHER INSTITUTE FOR BIOMEDICAL RESEARCH FONDATION
Call Details Advanced Grant (AdG), LS1, ERC-2014-ADG
Summary Specificity in the ubiquitin-proteasome system is largely conferred by ubiquitin E3 ligases (E3s). Cullin-RING ligases (CRLs), constituting ~30% of all E3s in humans, mediate the ubiquitination of ~20% of the proteins degraded by the proteasome. CRLs are divided into seven families based on their cullin constituent. Each cullin binds a RING domain protein, and a vast repertoire of adaptor/substrate receptor modules, collectively creating more than 200 distinct CRLs. All CRLs are regulated by the COP9 signalosome (CSN), an eight-protein isopeptidase that removes the covalently attached activator, NEDD8, from the cullin. Independent of NEDD8 cleavage, CSN forms protective complexes with CRLs, which prevents destructive auto-ubiquitination.
The integrity of the CSN-CRL system is crucially important for the normal cell physiology. Based on our previous work on CRL structures (Fischer, et al., Nature 2014; Fischer, et al., Cell 2011) and that of isolated CSN (Lingaraju et al., Nature 2014), We now intend to provide the underlying molecular mechanism of CRL regulation by CSN. Structural insights at atomic resolution, combined with in vitro and in vivo functional studies are designed to reveal (i) how the signalosome deneddylates and maintains the bound ligases in an inactive state, (ii) how the multiple CSN subunits bind to structurally diverse CRLs, and (iii) how CSN is itself subject to regulation by post-translational modifications or additional further factors.
The ERC funding would allow my lab to pursue an ambitious interdisciplinary approach combining X-ray crystallography, cryo-electron microscopy, biochemistry and cell biology. This is expected to provide a unique molecular understanding of CSN action. Beyond ubiquitination, insight into this >13- subunit CSN-CRL assembly will allow examining general principles of multi-subunit complex action and reveal how the numerous, often essential, subunits contribute to complex function.
Summary
Specificity in the ubiquitin-proteasome system is largely conferred by ubiquitin E3 ligases (E3s). Cullin-RING ligases (CRLs), constituting ~30% of all E3s in humans, mediate the ubiquitination of ~20% of the proteins degraded by the proteasome. CRLs are divided into seven families based on their cullin constituent. Each cullin binds a RING domain protein, and a vast repertoire of adaptor/substrate receptor modules, collectively creating more than 200 distinct CRLs. All CRLs are regulated by the COP9 signalosome (CSN), an eight-protein isopeptidase that removes the covalently attached activator, NEDD8, from the cullin. Independent of NEDD8 cleavage, CSN forms protective complexes with CRLs, which prevents destructive auto-ubiquitination.
The integrity of the CSN-CRL system is crucially important for the normal cell physiology. Based on our previous work on CRL structures (Fischer, et al., Nature 2014; Fischer, et al., Cell 2011) and that of isolated CSN (Lingaraju et al., Nature 2014), We now intend to provide the underlying molecular mechanism of CRL regulation by CSN. Structural insights at atomic resolution, combined with in vitro and in vivo functional studies are designed to reveal (i) how the signalosome deneddylates and maintains the bound ligases in an inactive state, (ii) how the multiple CSN subunits bind to structurally diverse CRLs, and (iii) how CSN is itself subject to regulation by post-translational modifications or additional further factors.
The ERC funding would allow my lab to pursue an ambitious interdisciplinary approach combining X-ray crystallography, cryo-electron microscopy, biochemistry and cell biology. This is expected to provide a unique molecular understanding of CSN action. Beyond ubiquitination, insight into this >13- subunit CSN-CRL assembly will allow examining general principles of multi-subunit complex action and reveal how the numerous, often essential, subunits contribute to complex function.
Max ERC Funding
2 200 677 €
Duration
Start date: 2016-01-01, End date: 2020-12-31
Project acronym CSUMECH
Project Cholesterol and Sugar Uptake Mechanisms
Researcher (PI) Bjørn Pedersen
Host Institution (HI) AARHUS UNIVERSITET
Call Details Starting Grant (StG), LS1, ERC-2014-STG
Summary Cardiovascular disease, diabetes and cancer have a dramatic impact on modern society, and in great part are related to uptake of cholesterol and sugar. We still know surprisingly little about the molecular details of the processes that goes on in this essential part of human basic metabolism. This application addresses cholesterol and sugar transport and aim to elucidate the molecular mechanism of cholesterol and sugar uptake in humans. It moves the frontiers of the field by shifting the focus to in vitro work allowing hitherto untried structural and biochemical experiments to be performed.
Cholesterol uptake from the intestine is mediated by the membrane protein NPC1L1. Despite extensive research, the molecular mechanism of NPC1L1-dependent cholesterol uptake still remains largely unknown.
Facilitated sugar transport in humans is made possible by sugar transporters called GLUTs and SWEETs, and every cell possesses these sugar transport systems. For all these uptake systems structural information is sorely lacking to address important mechanistic questions to help elucidate their molecular mechanism.
I will address this using a complementary set of methods founded in macromolecular crystallography and electron microscopy to determine the 3-dimensional structures of key players in these uptake systems. My unpublished preliminary results have established the feasibility of this approach. This will be followed up by biochemical characterization of the molecular mechanism in vitro and in silico.
This high risk/high reward membrane protein proposal could lead to a breakthrough in how we approach human biochemical pathways that are linked to trans-membrane transport. An improved understanding of cholesterol and sugar homeostasis has tremendous potential for improving general public health, and furthermore this proposal will help to uncover general principles of endocytotic uptake and facilitated diffusion systems at the molecular level.
Summary
Cardiovascular disease, diabetes and cancer have a dramatic impact on modern society, and in great part are related to uptake of cholesterol and sugar. We still know surprisingly little about the molecular details of the processes that goes on in this essential part of human basic metabolism. This application addresses cholesterol and sugar transport and aim to elucidate the molecular mechanism of cholesterol and sugar uptake in humans. It moves the frontiers of the field by shifting the focus to in vitro work allowing hitherto untried structural and biochemical experiments to be performed.
Cholesterol uptake from the intestine is mediated by the membrane protein NPC1L1. Despite extensive research, the molecular mechanism of NPC1L1-dependent cholesterol uptake still remains largely unknown.
Facilitated sugar transport in humans is made possible by sugar transporters called GLUTs and SWEETs, and every cell possesses these sugar transport systems. For all these uptake systems structural information is sorely lacking to address important mechanistic questions to help elucidate their molecular mechanism.
I will address this using a complementary set of methods founded in macromolecular crystallography and electron microscopy to determine the 3-dimensional structures of key players in these uptake systems. My unpublished preliminary results have established the feasibility of this approach. This will be followed up by biochemical characterization of the molecular mechanism in vitro and in silico.
This high risk/high reward membrane protein proposal could lead to a breakthrough in how we approach human biochemical pathways that are linked to trans-membrane transport. An improved understanding of cholesterol and sugar homeostasis has tremendous potential for improving general public health, and furthermore this proposal will help to uncover general principles of endocytotic uptake and facilitated diffusion systems at the molecular level.
Max ERC Funding
1 499 848 €
Duration
Start date: 2015-07-01, End date: 2020-06-30
Project acronym CYRE
Project Cytokine Receptor Signaling Revisited: Implementing novel concepts for cytokine-based therapies
Researcher (PI) Jan Tavernier
Host Institution (HI) VIB VZW
Call Details Advanced Grant (AdG), LS1, ERC-2013-ADG
Summary "Cytokine receptor signaling is an essential part of the intercellular communication networks that govern key physiological processes in the body. Cytokine dysfunction is associated with numerous pathologies including autoimmune disorders and cancer, and both cytokines and cytokine antagonists have found their way into the clinic. Yet, there are still many unfulfilled promises and opportunities. In this project we will reinvestigate key aspects of cytokine receptor activation and signaling using novel insights and techniques recently developed in our laboratory. This will include the AcTakine concept for cell-specific targeting of cytokine activity, and applications of our MAPPIT, KISS and Virotrap toolboxes to systematically map protein interactions involved in cytokine signaling. We expect to obtain important new insights, both in fundamental and in applied medical sciences."
Summary
"Cytokine receptor signaling is an essential part of the intercellular communication networks that govern key physiological processes in the body. Cytokine dysfunction is associated with numerous pathologies including autoimmune disorders and cancer, and both cytokines and cytokine antagonists have found their way into the clinic. Yet, there are still many unfulfilled promises and opportunities. In this project we will reinvestigate key aspects of cytokine receptor activation and signaling using novel insights and techniques recently developed in our laboratory. This will include the AcTakine concept for cell-specific targeting of cytokine activity, and applications of our MAPPIT, KISS and Virotrap toolboxes to systematically map protein interactions involved in cytokine signaling. We expect to obtain important new insights, both in fundamental and in applied medical sciences."
Max ERC Funding
2 487 728 €
Duration
Start date: 2014-02-01, End date: 2019-01-31
Project acronym D-END
Project Telomeres: from the DNA end replication problem to the control of cell proliferation
Researcher (PI) Maria Teresa Teixeira Fernandes Bernardo
Host Institution (HI) CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE CNRS
Call Details Starting Grant (StG), LS1, ERC-2010-StG_20091118
Summary Linear chromosomes of eukaryotes end with telomeres that ensure their stability. Because of the inability of semi-conservative DNA replication machinery to fully replicate DNA ends, telomeres require dedicated mechanisms to be duplicated and their length is eroded at each cell division. For this reason, telomeres constitute molecular clocks that determine cell proliferation potential in eukaryotes. Strikingly, we have shown recently that it is the shortest telomere in the cell that determines the onset of replicative senescence. This project aims a complete and detailed dissection of the in vivo DNA-end replication problem and the deep understanding of its impact for cell division capability. Specifically my goals are (1) the determination of the exact structures that result from the replication of DNA extremities, (2) the examination of the activities operating at the shortest telomere that triggers replicative senescence and (3) the investigation of the correspondence between telomere molecular structure and cell proliferation state at individual cell scale. To achieve this, I will undertake in Saccharomyces cerevisiae original and innovative single-molecule and single-cell approaches, that, in combination with genome-wide screens and sophisticated cellular settings, will allow to track and challenge a specified telomere of defined length. I anticipate that this work will lead to an in-depth understanding of how telomeres are replicated and how they enable the control of cell proliferation in eukaryotic cells, a matter at the intersection of the fundamentals of molecular genetics, cell biology of aging and oncology.
Summary
Linear chromosomes of eukaryotes end with telomeres that ensure their stability. Because of the inability of semi-conservative DNA replication machinery to fully replicate DNA ends, telomeres require dedicated mechanisms to be duplicated and their length is eroded at each cell division. For this reason, telomeres constitute molecular clocks that determine cell proliferation potential in eukaryotes. Strikingly, we have shown recently that it is the shortest telomere in the cell that determines the onset of replicative senescence. This project aims a complete and detailed dissection of the in vivo DNA-end replication problem and the deep understanding of its impact for cell division capability. Specifically my goals are (1) the determination of the exact structures that result from the replication of DNA extremities, (2) the examination of the activities operating at the shortest telomere that triggers replicative senescence and (3) the investigation of the correspondence between telomere molecular structure and cell proliferation state at individual cell scale. To achieve this, I will undertake in Saccharomyces cerevisiae original and innovative single-molecule and single-cell approaches, that, in combination with genome-wide screens and sophisticated cellular settings, will allow to track and challenge a specified telomere of defined length. I anticipate that this work will lead to an in-depth understanding of how telomeres are replicated and how they enable the control of cell proliferation in eukaryotic cells, a matter at the intersection of the fundamentals of molecular genetics, cell biology of aging and oncology.
Max ERC Funding
1 498 504 €
Duration
Start date: 2010-11-01, End date: 2015-10-31
