Project acronym DTSSCP
Project Determinants of mammalian transcription start site selection and core promoter usage
Researcher (PI) Albin Sandelin
Host Institution (HI) KOBENHAVNS UNIVERSITET
Call Details Starting Grant (StG), LS2, ERC-2007-StG
Summary Understanding the mechanisms underlying the initiation and regulation of transcription remains one of the most fundamental questions in biology. Much of what we know about the transcription process was inferred from experiments on a handful of genes. As these experiments are not realistically scalable, corresponding computational methods building on these findings have emerged; however, these are not accurate enough for annotation of genomes. The limitations reflect that we have no accurate universal model describing transcription initiation; to a large extent, our understanding is based on case stories. Recently, high-throughput methods have been developed to chart the TSS landscape with nucleotide resolution. Using these data, I have dissected promoters at nucleotide level and found patterns that explain the transcription initiation rate for individual nucleotides. The objective for this work is to extend this to the first universal model for how cells select core promoters and associated TSSs. This will have two counterparts: i)prediction of TSSs from DNA sequence given a region of accessible DNA, and ii)prediction of DNA accessibility based on DNA sequences and dynamic epigenetic factors. Such a model will be a corner stone of future experimental and computational transcriptome and gene regulation studies.
Summary
Understanding the mechanisms underlying the initiation and regulation of transcription remains one of the most fundamental questions in biology. Much of what we know about the transcription process was inferred from experiments on a handful of genes. As these experiments are not realistically scalable, corresponding computational methods building on these findings have emerged; however, these are not accurate enough for annotation of genomes. The limitations reflect that we have no accurate universal model describing transcription initiation; to a large extent, our understanding is based on case stories. Recently, high-throughput methods have been developed to chart the TSS landscape with nucleotide resolution. Using these data, I have dissected promoters at nucleotide level and found patterns that explain the transcription initiation rate for individual nucleotides. The objective for this work is to extend this to the first universal model for how cells select core promoters and associated TSSs. This will have two counterparts: i)prediction of TSSs from DNA sequence given a region of accessible DNA, and ii)prediction of DNA accessibility based on DNA sequences and dynamic epigenetic factors. Such a model will be a corner stone of future experimental and computational transcriptome and gene regulation studies.
Max ERC Funding
812 399 €
Duration
Start date: 2008-09-01, End date: 2013-08-31
Project acronym DualRP
Project Exploring cell interactions in the tumor microenvironment with dual ribosome profiling
Researcher (PI) Fabricio LOAYZA-PUCH
Host Institution (HI) DEUTSCHES KREBSFORSCHUNGSZENTRUM HEIDELBERG
Call Details Starting Grant (StG), LS2, ERC-2017-STG
Summary Cancers develop in very heterogeneous tissue environments. They depend on the tumor microenvironment (TME) for sustained growth, metastasis, and therapy resistance. Stromal cells are genetically stable and they have less likelihood to develop resistance than cancer cells. Therefore, targeting the TME represents an attractive approach for treating cancer. In order to develop new therapeutic strategies to reprogram the TME and inhibit tumor growth and resistance, it is essential to understand in detail the molecular mechanisms of the interactions between cancer and stromal cell populations. However, current methods to study these interactions require complete dissociation of the tumor, exposing the cells to severe stress and affecting dramatically gene expression patterns. Here, I propose to use Dual Ribosome Profiling (DualRP), a system that I recently developed, to study cell interactions in the TME. DualRP is an approach that allows not only simultaneous analysis of gene expression in two interacting cell populations in vivo, but also is able to uncover metabolic limitations in tumors. I aim to apply DualRP to mouse xenograft models where cancer cells interact with non-transformed fibroblasts and I’ll explore the combined response of both populations to cancer therapy. Moreover, I’ll utilize mouse genetic models tailored for DualRP to study cancer cell and macrophages/endothelial cells interactions. I will employ a combination of mouse genetic models, biochemical tools, deep sequencing, and bioinformatics. These studies will provide insight into how gene expression and metabolic programs define the interaction between cancer and stromal cells to promote tumor growth and metastasis, identify potential targets for therapeutic intervention, and provide maps of cell interactions in vivo. Therefore, this research has the potential to significantly advance our understanding of the molecular and metabolic mechanisms underlying the complex cell interactions in the TME.
Summary
Cancers develop in very heterogeneous tissue environments. They depend on the tumor microenvironment (TME) for sustained growth, metastasis, and therapy resistance. Stromal cells are genetically stable and they have less likelihood to develop resistance than cancer cells. Therefore, targeting the TME represents an attractive approach for treating cancer. In order to develop new therapeutic strategies to reprogram the TME and inhibit tumor growth and resistance, it is essential to understand in detail the molecular mechanisms of the interactions between cancer and stromal cell populations. However, current methods to study these interactions require complete dissociation of the tumor, exposing the cells to severe stress and affecting dramatically gene expression patterns. Here, I propose to use Dual Ribosome Profiling (DualRP), a system that I recently developed, to study cell interactions in the TME. DualRP is an approach that allows not only simultaneous analysis of gene expression in two interacting cell populations in vivo, but also is able to uncover metabolic limitations in tumors. I aim to apply DualRP to mouse xenograft models where cancer cells interact with non-transformed fibroblasts and I’ll explore the combined response of both populations to cancer therapy. Moreover, I’ll utilize mouse genetic models tailored for DualRP to study cancer cell and macrophages/endothelial cells interactions. I will employ a combination of mouse genetic models, biochemical tools, deep sequencing, and bioinformatics. These studies will provide insight into how gene expression and metabolic programs define the interaction between cancer and stromal cells to promote tumor growth and metastasis, identify potential targets for therapeutic intervention, and provide maps of cell interactions in vivo. Therefore, this research has the potential to significantly advance our understanding of the molecular and metabolic mechanisms underlying the complex cell interactions in the TME.
Max ERC Funding
1 499 375 €
Duration
Start date: 2018-06-01, End date: 2023-05-31
Project acronym DUB-DECODE
Project Systematic Decoding of Deubiquitylase-Regulated Signaling Networks
Researcher (PI) Chuna Ram Choudhary
Host Institution (HI) KOBENHAVNS UNIVERSITET
Call Details Consolidator Grant (CoG), LS2, ERC-2014-CoG
Summary Cellular processes are largely governed by sophisticated protein posttranslational modification (PTM)-dependent signaling networks, and a systematic understanding of regulatory PTM-based networks is a key goal in modern biology. Ubiquitin is a small, evolutionarily conserved signaling protein that acts as a PTM after being covalently conjugated to other proteins. Reversible ubiquitylation forms the most versatile and largest eukaryote-exclusive signaling system, and regulates the stability and function of almost all proteins in cells. Deubiquitylases (DUBs) are ubiquitin-specific proteases that remove substrate-conjugated ubiquitin, and thereby regulate virtually all ubiquitylation-dependent signaling. Because of their central role in ubiquitin signaling, DUBs have essential functions in mammalian physiology and development, and the dysregulated expression and mutation of DUBs is frequently associated with human diseases. Despite their vital functions, very little is known about the proteins and ubiquitylation sites that are regulated by DUBs and this knowledge gap is hampering our understanding of the molecular mechanisms by which DUBs control diverse biological processes. Recently, we developed a mass spectrometry-based proteomics approach that allowed unbiased and site-specific quantification of ubiquitylation on a systems-wide scale. Here we propose to comprehensively investigate DUB-regulated ubiquitin signaling in human cells. We will integrate interdisciplinary approaches to develop next-generation cell models and innovative proteomic technologies to systematically decode DUB function in human cells. This will enable a novel and detailed understanding of DUB-regulated signaling networks, and open up new avenues for further research into the mechanisms and biological functions of ubiquitylation and of ubiquitin-like modifiers.
Summary
Cellular processes are largely governed by sophisticated protein posttranslational modification (PTM)-dependent signaling networks, and a systematic understanding of regulatory PTM-based networks is a key goal in modern biology. Ubiquitin is a small, evolutionarily conserved signaling protein that acts as a PTM after being covalently conjugated to other proteins. Reversible ubiquitylation forms the most versatile and largest eukaryote-exclusive signaling system, and regulates the stability and function of almost all proteins in cells. Deubiquitylases (DUBs) are ubiquitin-specific proteases that remove substrate-conjugated ubiquitin, and thereby regulate virtually all ubiquitylation-dependent signaling. Because of their central role in ubiquitin signaling, DUBs have essential functions in mammalian physiology and development, and the dysregulated expression and mutation of DUBs is frequently associated with human diseases. Despite their vital functions, very little is known about the proteins and ubiquitylation sites that are regulated by DUBs and this knowledge gap is hampering our understanding of the molecular mechanisms by which DUBs control diverse biological processes. Recently, we developed a mass spectrometry-based proteomics approach that allowed unbiased and site-specific quantification of ubiquitylation on a systems-wide scale. Here we propose to comprehensively investigate DUB-regulated ubiquitin signaling in human cells. We will integrate interdisciplinary approaches to develop next-generation cell models and innovative proteomic technologies to systematically decode DUB function in human cells. This will enable a novel and detailed understanding of DUB-regulated signaling networks, and open up new avenues for further research into the mechanisms and biological functions of ubiquitylation and of ubiquitin-like modifiers.
Max ERC Funding
1 972 570 €
Duration
Start date: 2015-10-01, End date: 2021-03-31
Project acronym DYNACLOCK
Project Dynamic protein-DNA interactomes and circadian transcription regulatory networks in mammals
Researcher (PI) Felix Naef
Host Institution (HI) ECOLE POLYTECHNIQUE FEDERALE DE LAUSANNE
Call Details Starting Grant (StG), LS2, ERC-2010-StG_20091118
Summary The aim of this project is to understand the dynamics of protein-DNA interactomes underlying circadian oscillators in mammals, and how these shape circadian transcriptional output programs. Specifically our goal is to solve a fundamental issue in circadian biology: the phase specificity problem underlying circadian gene expression. We have taken a challenging and original multi-disciplinary approach in which molecular biology experiments will be tightly interlinked with computational analyses and biophysical modeling. The approach will generate time resolved protein-DNA interactomes in mouse liver for several key circadian repressors at unprecedented resolution. These experiments will be complemented with chromosome conformation capture (3C) experiments to monitor how looping interactions and 3D genome structure rearrange during the circadian cycle, which will inform on how circadian transcription networks use long-range gene regulatory mechanisms. Novel computational algorithms based on biophysical principles will be developed and implemented to optimally analyze interactome and 3C datasets. For the latter, statistical models from polymer physics will be used to reconstruct the chromatin networks and interaction maps from the 3C data. At the detailed level of individual cells, we will investigate transcription bursts, and how those are involved in the control of circadian gene expression. In particular we will exploit high temporal resolution bioluminescence reporters using a biophysical model of transcription coupled with a Hidden Markov Model (HMM). Through our innovative approach, we expect that the data generated and state-of-the-art analyses performed will lead novel insight into the role and mechanics of circadian transcription in controlling circadian outputs in mammals.
Summary
The aim of this project is to understand the dynamics of protein-DNA interactomes underlying circadian oscillators in mammals, and how these shape circadian transcriptional output programs. Specifically our goal is to solve a fundamental issue in circadian biology: the phase specificity problem underlying circadian gene expression. We have taken a challenging and original multi-disciplinary approach in which molecular biology experiments will be tightly interlinked with computational analyses and biophysical modeling. The approach will generate time resolved protein-DNA interactomes in mouse liver for several key circadian repressors at unprecedented resolution. These experiments will be complemented with chromosome conformation capture (3C) experiments to monitor how looping interactions and 3D genome structure rearrange during the circadian cycle, which will inform on how circadian transcription networks use long-range gene regulatory mechanisms. Novel computational algorithms based on biophysical principles will be developed and implemented to optimally analyze interactome and 3C datasets. For the latter, statistical models from polymer physics will be used to reconstruct the chromatin networks and interaction maps from the 3C data. At the detailed level of individual cells, we will investigate transcription bursts, and how those are involved in the control of circadian gene expression. In particular we will exploit high temporal resolution bioluminescence reporters using a biophysical model of transcription coupled with a Hidden Markov Model (HMM). Through our innovative approach, we expect that the data generated and state-of-the-art analyses performed will lead novel insight into the role and mechanics of circadian transcription in controlling circadian outputs in mammals.
Max ERC Funding
1 500 000 €
Duration
Start date: 2011-03-01, End date: 2016-02-29
Project acronym DynaMech
Project Linking Transcription Factor Binding Dynamics to Promoter Output
Researcher (PI) Frank Charles Patrick Holstege
Host Institution (HI) PRINSES MAXIMA CENTRUM VOOR KINDERONCOLOGIE BV
Call Details Advanced Grant (AdG), LS2, ERC-2014-ADG
Summary "Transcription is a stepwise process that is inherently dynamic. Different types of transcription factors are continuously interacting off and onto DNA, ""searching"" for appropriate interactions - each bringing different functions into play. The rates with which these factors interact with chromatin, their association and dissociation rates, dictate the outcome of ""steady-state"", developmental and rapidly responsive regulatory programs. Given the central role of transcription factors in biology and disease, it is remarkable that we know next to nothing about the dynamics of transcription factor-chromatin interactions.
The objective of DynaMech is to implement technologies that will allow us to measure transcription factor binding dynamics (on- and off-rates) genome-wide, at binding site resolution. This will be applied to gain a systematic understanding of how these dynamics effect the function of transcription factors. Analyses will encompass components of the RNA polymerase II pre-initiation complex in yeast, as well as a comprehensive set of gene-specific transcription factors. For each of these factors we will determine the on- and off-rates genome-wide as well as the degree to which the mRNA synthesis rates from all promoters are dependent on the factor. This data will all be analysed in the context of nucleosome binding dynamics to understand the general principles of how chromatin-transcripton factor binding dynamics shape regulatory mechanisms. Through modelling promoter output and by additional perturbations, these principles will be explored to understand which properties of regulatory DNA determine differential transcription factor dynamics thereby causing differential promoter behaviour.
We are as yet far from predicting regulatory outcome from regulatory sequence. The long-term aim of this work is to bring this closer, by bringing into play the almost completely unexplored aspect of transcription factor-chromatin interaction dynamics.
"
Summary
"Transcription is a stepwise process that is inherently dynamic. Different types of transcription factors are continuously interacting off and onto DNA, ""searching"" for appropriate interactions - each bringing different functions into play. The rates with which these factors interact with chromatin, their association and dissociation rates, dictate the outcome of ""steady-state"", developmental and rapidly responsive regulatory programs. Given the central role of transcription factors in biology and disease, it is remarkable that we know next to nothing about the dynamics of transcription factor-chromatin interactions.
The objective of DynaMech is to implement technologies that will allow us to measure transcription factor binding dynamics (on- and off-rates) genome-wide, at binding site resolution. This will be applied to gain a systematic understanding of how these dynamics effect the function of transcription factors. Analyses will encompass components of the RNA polymerase II pre-initiation complex in yeast, as well as a comprehensive set of gene-specific transcription factors. For each of these factors we will determine the on- and off-rates genome-wide as well as the degree to which the mRNA synthesis rates from all promoters are dependent on the factor. This data will all be analysed in the context of nucleosome binding dynamics to understand the general principles of how chromatin-transcripton factor binding dynamics shape regulatory mechanisms. Through modelling promoter output and by additional perturbations, these principles will be explored to understand which properties of regulatory DNA determine differential transcription factor dynamics thereby causing differential promoter behaviour.
We are as yet far from predicting regulatory outcome from regulatory sequence. The long-term aim of this work is to bring this closer, by bringing into play the almost completely unexplored aspect of transcription factor-chromatin interaction dynamics.
"
Max ERC Funding
2 132 500 €
Duration
Start date: 2016-02-01, End date: 2021-01-31
Project acronym DyNAmecs
Project Early embryonic events, life-long consequences: DNA methylation dynamics in mammalian development
Researcher (PI) Maxim Greenberg
Host Institution (HI) CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE CNRS
Call Details Starting Grant (StG), LS2, ERC-2019-STG
Summary Immediately after fertilization, mammalian genomes undergo a dramatic reshaping of the epigenome as the embryo transitions from the zygote into the pluripotent cells primed for lineage commitment. This is best exemplified by DNA methylation reprogramming, as the gametic patterns are largely erased, and the embryonic genome undergoes a wave of de novo DNA methylation. Moreover, once DNA methylation patterns are established, mechanisms faithfully maintain the mark across cell division. Thus, there is latent potential for DNA methylation deposited in the early embryo to exhibit a lifelong effect.
DNA methylation is a modification that is typically associated with gene repression at repetitive elements and at a minority of protein coding genes. I previously described the regulation of the Zdbf2 gene in mice, which is programmed during the de novo DNA methylation program. Challenging the paradigm, in this case DNA methylation is required for activation of a gene via antagonism of the polycomb-group of silencing proteins. If the DNA methylation fails to occur, the gene stays silent throughout life, resulting in a reduced growth phenotype.
For my proposed research I will utilize both a cell-based system that recapitulates these early embryonic events as well as an in vivo mouse model to investigate the extent and mechanisms of non-canonical DNA methylation functions. I plan to use a combinatorial approach of genomics, genetics, and proteomics in order to ascertain novel insights into DNA methylation-based regulation. Furthermore, I plan to employ precision epigenome editing tools to address the locus-specific impact of DNA methylation. Ultimately, I strive to gain a clear understanding of the profound epigenetic consequences of DNA methylation on this window of development, which occurs in the first week of mouse embryogenesis, and the second of human, but the repercussions of which can ripple throughout life.
Summary
Immediately after fertilization, mammalian genomes undergo a dramatic reshaping of the epigenome as the embryo transitions from the zygote into the pluripotent cells primed for lineage commitment. This is best exemplified by DNA methylation reprogramming, as the gametic patterns are largely erased, and the embryonic genome undergoes a wave of de novo DNA methylation. Moreover, once DNA methylation patterns are established, mechanisms faithfully maintain the mark across cell division. Thus, there is latent potential for DNA methylation deposited in the early embryo to exhibit a lifelong effect.
DNA methylation is a modification that is typically associated with gene repression at repetitive elements and at a minority of protein coding genes. I previously described the regulation of the Zdbf2 gene in mice, which is programmed during the de novo DNA methylation program. Challenging the paradigm, in this case DNA methylation is required for activation of a gene via antagonism of the polycomb-group of silencing proteins. If the DNA methylation fails to occur, the gene stays silent throughout life, resulting in a reduced growth phenotype.
For my proposed research I will utilize both a cell-based system that recapitulates these early embryonic events as well as an in vivo mouse model to investigate the extent and mechanisms of non-canonical DNA methylation functions. I plan to use a combinatorial approach of genomics, genetics, and proteomics in order to ascertain novel insights into DNA methylation-based regulation. Furthermore, I plan to employ precision epigenome editing tools to address the locus-specific impact of DNA methylation. Ultimately, I strive to gain a clear understanding of the profound epigenetic consequences of DNA methylation on this window of development, which occurs in the first week of mouse embryogenesis, and the second of human, but the repercussions of which can ripple throughout life.
Max ERC Funding
1 495 480 €
Duration
Start date: 2020-01-01, End date: 2024-12-31
Project acronym dynamicmodifications
Project Complexity and dynamics of nucleic acids modifications in vivo
Researcher (PI) Petra Hajkova
Host Institution (HI) IMPERIAL COLLEGE OF SCIENCE TECHNOLOGY AND MEDICINE
Call Details Consolidator Grant (CoG), LS2, ERC-2014-CoG
Summary Development of any organism starts with a totipotent cell (zygote). Through series of cell divisions and differentiation processes this cell will eventually give rise to the whole organism containing hundreds of specialised cell. While the cells at the onset of development have the capacity to generate all cell types (ie are toti-or pluripotent), this developmental capacity is progressively lost as the cells undertake cell fate decisions. At the molecular level, the memory of these events is laid down in a complex layer of epigenetic modifications at both the DNA and the chromatin level. Unidirectional character of the developmental progress dictates that the key acquired epigenetic modifications are stable and inherited through subsequent cell divisions. This paradigm is, however, challenged during cellular reprogramming that requires de-differentiation (nuclear transfer, induced pluripotent stem cells, wound healing and regeneration in lower organisms) or a change in cell fate (transdifferentiation). Despite intense efforts of numerous research teams, the molecular mechanisms of these processes remain enigmatic.
In order to understand cellular reprogramming at the molecular level, this proposal takes advantage of epigenetic reprogramming processes that occur naturally during mouse development. By using mouse fertilised zygote and mouse developing primordial germ cells we will investigate novel molecular components implicated in the genome-wide erasure of DNA methylation. Additionally, by using a unique combination of the developmental models with the state of the art ultra-sensitive LC/MS and genomics approaches we propose to investigate the dynamics and the interplay between DNA and RNA modifications during these key periods of embryonic development characterised by genome-wide epigenetic changes . Our work will thus provide new fundamental insights into a complex dynamics and interactions between epigenetic modifications that underlie epigenetic reprogramming
Summary
Development of any organism starts with a totipotent cell (zygote). Through series of cell divisions and differentiation processes this cell will eventually give rise to the whole organism containing hundreds of specialised cell. While the cells at the onset of development have the capacity to generate all cell types (ie are toti-or pluripotent), this developmental capacity is progressively lost as the cells undertake cell fate decisions. At the molecular level, the memory of these events is laid down in a complex layer of epigenetic modifications at both the DNA and the chromatin level. Unidirectional character of the developmental progress dictates that the key acquired epigenetic modifications are stable and inherited through subsequent cell divisions. This paradigm is, however, challenged during cellular reprogramming that requires de-differentiation (nuclear transfer, induced pluripotent stem cells, wound healing and regeneration in lower organisms) or a change in cell fate (transdifferentiation). Despite intense efforts of numerous research teams, the molecular mechanisms of these processes remain enigmatic.
In order to understand cellular reprogramming at the molecular level, this proposal takes advantage of epigenetic reprogramming processes that occur naturally during mouse development. By using mouse fertilised zygote and mouse developing primordial germ cells we will investigate novel molecular components implicated in the genome-wide erasure of DNA methylation. Additionally, by using a unique combination of the developmental models with the state of the art ultra-sensitive LC/MS and genomics approaches we propose to investigate the dynamics and the interplay between DNA and RNA modifications during these key periods of embryonic development characterised by genome-wide epigenetic changes . Our work will thus provide new fundamental insights into a complex dynamics and interactions between epigenetic modifications that underlie epigenetic reprogramming
Max ERC Funding
2 000 000 €
Duration
Start date: 2015-08-01, End date: 2020-07-31
Project acronym EASTFE3
Project Efficient and accurate simulation techniques for free energies, enthalpies and entropies
Researcher (PI) Bernard Christiaan Oostenbrink
Host Institution (HI) UNIVERSITAET FUER BODENKULTUR WIEN
Call Details Starting Grant (StG), LS2, ERC-2010-StG_20091118
Summary Computational, structure-based, drug design offers insight at an atomic resolution, which is commonly not attainable by experimental means. Detailed calculations on protein-ligand interactions help to rationalize and predict experimental findings. Accurate and efficient calculations of binding free energies is essential in this respect. In addition, knowledge concerning the enthalpic and entropic contributions are highly relevant to determine novel drug design strategies and to understand the underlying principles of ligand binding.
Currently available methods to address ligand affinity either do not include all relevant contributions to the binding free energy, or are too computationally demanding to be applied straightforwardly. In addition, calculations on enthalpy and entropy for drug design purposes are very rare, due to the difficulty in calculating these accurately. This proposal describes the research that leads the way to new, standard applications to be used in drug design processes in academia and industry. Furthermore, we propose to investigate the enthalpic and entropic contributions to ligand binding. We define a ligand-surroundings enthalpy and entropy, which conveys more information than the experimentally accessible enthalpy and entropy of ligand binding.
In support of this research, we will develop new enhanced sampling techniques which not only render the above calculations practically feasible, but which will also find their application in related research questions such as the protein folding problem or the elucidation of protein-protein interactions.
The methods described are highly relevant for the pharmaceutical industry, where currently available computational approaches are insufficient to answer the questions of todays drug discovery programmes.
Summary
Computational, structure-based, drug design offers insight at an atomic resolution, which is commonly not attainable by experimental means. Detailed calculations on protein-ligand interactions help to rationalize and predict experimental findings. Accurate and efficient calculations of binding free energies is essential in this respect. In addition, knowledge concerning the enthalpic and entropic contributions are highly relevant to determine novel drug design strategies and to understand the underlying principles of ligand binding.
Currently available methods to address ligand affinity either do not include all relevant contributions to the binding free energy, or are too computationally demanding to be applied straightforwardly. In addition, calculations on enthalpy and entropy for drug design purposes are very rare, due to the difficulty in calculating these accurately. This proposal describes the research that leads the way to new, standard applications to be used in drug design processes in academia and industry. Furthermore, we propose to investigate the enthalpic and entropic contributions to ligand binding. We define a ligand-surroundings enthalpy and entropy, which conveys more information than the experimentally accessible enthalpy and entropy of ligand binding.
In support of this research, we will develop new enhanced sampling techniques which not only render the above calculations practically feasible, but which will also find their application in related research questions such as the protein folding problem or the elucidation of protein-protein interactions.
The methods described are highly relevant for the pharmaceutical industry, where currently available computational approaches are insufficient to answer the questions of todays drug discovery programmes.
Max ERC Funding
1 485 615 €
Duration
Start date: 2011-01-01, End date: 2015-12-31
Project acronym EcCRISPR
Project Novel roles, components, and mechanisms of the Escherichia coli CRISPR/Cas system
Researcher (PI) Ehud Itzhak Qimron
Host Institution (HI) TEL AVIV UNIVERSITY
Call Details Starting Grant (StG), LS2, ERC-2013-StG
Summary A novel type of defense system was recently identified in bacteria: the CRISPR array and its associated gene products (Cas). The system inserts short DNA sequences, called spacers, derived from foreign nucleic acid molecules in between direct repeats, thus forming the CRISPR array. The transcribed spacers eventually serve as molecular guides for Cas proteins that monitor and destroy nucleic acids having sequences similar to those spacers. Thorough mapping of the functional components and regulators of the system in a single model organism will be extremely valuable for understanding its mechanism of action. Studying the interactions between bacteria and phages should highlight the evolutionary role of the system and its consequences for shaping ecological systems. These insights will lead to novel ways of exploiting the system to improve molecular biology tools, to protect fermenting bacteria from phage spoilage, to equip phages with anti-CRISPR warfare to fight bacteria, and to prevent horizontal gene transfer between pathogens. Here, I intend to systematically seek out new roles of the system and to identify fundamental mechanisms and components that allow the system to function efficiently. I will address fundamental questions such as how the system avoids sampling self DNA into the CRISPR array. In addition, I will pursue two revolutionary possibilities. One, that the CRISPR/Cas system is not merely an adaptive defense system against phages, but that one of its roles is to serve as molecular machinery for silencing specific harmful genes by generating small silencing RNAs without the need for Cas proteins. The other is to test the system’s ability to prevent horizontal gene transfer of antibiotic resistance genes in an effort to study the system’s ecological value, potentially for applicative uses. My proposed studies will allow deeper understanding of the system, and enable breakthroughs from both basic and applicative aspects of the CRISPR field studies.
Summary
A novel type of defense system was recently identified in bacteria: the CRISPR array and its associated gene products (Cas). The system inserts short DNA sequences, called spacers, derived from foreign nucleic acid molecules in between direct repeats, thus forming the CRISPR array. The transcribed spacers eventually serve as molecular guides for Cas proteins that monitor and destroy nucleic acids having sequences similar to those spacers. Thorough mapping of the functional components and regulators of the system in a single model organism will be extremely valuable for understanding its mechanism of action. Studying the interactions between bacteria and phages should highlight the evolutionary role of the system and its consequences for shaping ecological systems. These insights will lead to novel ways of exploiting the system to improve molecular biology tools, to protect fermenting bacteria from phage spoilage, to equip phages with anti-CRISPR warfare to fight bacteria, and to prevent horizontal gene transfer between pathogens. Here, I intend to systematically seek out new roles of the system and to identify fundamental mechanisms and components that allow the system to function efficiently. I will address fundamental questions such as how the system avoids sampling self DNA into the CRISPR array. In addition, I will pursue two revolutionary possibilities. One, that the CRISPR/Cas system is not merely an adaptive defense system against phages, but that one of its roles is to serve as molecular machinery for silencing specific harmful genes by generating small silencing RNAs without the need for Cas proteins. The other is to test the system’s ability to prevent horizontal gene transfer of antibiotic resistance genes in an effort to study the system’s ecological value, potentially for applicative uses. My proposed studies will allow deeper understanding of the system, and enable breakthroughs from both basic and applicative aspects of the CRISPR field studies.
Max ERC Funding
1 499 000 €
Duration
Start date: 2013-12-01, End date: 2018-11-30
Project acronym ECMETABOLISM
Project Targeting endothelial metabolism: a novel anti-angiogenic therapy
Researcher (PI) Peter Frans Martha Carmeliet
Host Institution (HI) VIB VZW
Call Details Advanced Grant (AdG), LS2, ERC-2010-AdG_20100317
Summary Current anti-angiogenesis based anti-tumor therapy relies on starving tumors by blocking their vascular supply via inhibition of growth factors. However, limitations such as resistance and toxicity, mandate conceptually distinct approaches. We will explore an entirely novel and long-overlooked strategy to discover additional anti-angiogenic candidates, based on the following innovative concept: ¿rather than STARVING TUMORS BY BLOCKING THEIR VASCULAR SUPPLY, we intend TO STARVE BLOOD VESSELS BY BLOCKING THEIR METABOLIC ENERGY SUPPLY¿, so that new vessels cannot form and nourish the growing tumor. This project is a completely new research avenue in our group, but we expect that it will offer refreshing long-term research and translational opportunities for the field.
Because so little is known on endothelial cell (EC) metabolism, we will (i) via a multi-disciplinary systems-biology approach of transcriptomics, proteomics, computational network modeling, metabolomics and flux-omics, draw an endothelio-metabolic map in angiogenesis. This will allow us to identify metabolic regulators of angiogenesis, which will be further validated and characterized in (ii) loss and gain-of-function studies in various angiogenesis models in vitro and (iii) in vivo in zebrafish (knockdown; zinc finger nuclease mediated knockout), providing prescreen data to select the most promising candidates. (iv) EC-specific down-regulation (miR RNAi) or knockout studies of selected candidates in mice will confirm their relevance for angiogenic phenotypes in a preclinical model; and ultimately (v) a translational study evaluating EC metabolism-targeted anti-angiogenic strategies (pharmacological inhibitors, antibodies, small molecular compounds) will be performed in tumor models in the mouse.
Summary
Current anti-angiogenesis based anti-tumor therapy relies on starving tumors by blocking their vascular supply via inhibition of growth factors. However, limitations such as resistance and toxicity, mandate conceptually distinct approaches. We will explore an entirely novel and long-overlooked strategy to discover additional anti-angiogenic candidates, based on the following innovative concept: ¿rather than STARVING TUMORS BY BLOCKING THEIR VASCULAR SUPPLY, we intend TO STARVE BLOOD VESSELS BY BLOCKING THEIR METABOLIC ENERGY SUPPLY¿, so that new vessels cannot form and nourish the growing tumor. This project is a completely new research avenue in our group, but we expect that it will offer refreshing long-term research and translational opportunities for the field.
Because so little is known on endothelial cell (EC) metabolism, we will (i) via a multi-disciplinary systems-biology approach of transcriptomics, proteomics, computational network modeling, metabolomics and flux-omics, draw an endothelio-metabolic map in angiogenesis. This will allow us to identify metabolic regulators of angiogenesis, which will be further validated and characterized in (ii) loss and gain-of-function studies in various angiogenesis models in vitro and (iii) in vivo in zebrafish (knockdown; zinc finger nuclease mediated knockout), providing prescreen data to select the most promising candidates. (iv) EC-specific down-regulation (miR RNAi) or knockout studies of selected candidates in mice will confirm their relevance for angiogenic phenotypes in a preclinical model; and ultimately (v) a translational study evaluating EC metabolism-targeted anti-angiogenic strategies (pharmacological inhibitors, antibodies, small molecular compounds) will be performed in tumor models in the mouse.
Max ERC Funding
2 365 224 €
Duration
Start date: 2011-05-01, End date: 2016-04-30
