Project acronym AGELESS
Project Comparative genomics / ‘wildlife’ transcriptomics uncovers the mechanisms of halted ageing in mammals
Researcher (PI) Emma Teeling
Host Institution (HI) UNIVERSITY COLLEGE DUBLIN, NATIONAL UNIVERSITY OF IRELAND, DUBLIN
Call Details Starting Grant (StG), LS2, ERC-2012-StG_20111109
Summary "Ageing is the gradual and irreversible breakdown of living systems associated with the advancement of time, which leads to an increase in vulnerability and eventual mortality. Despite recent advances in ageing research, the intrinsic complexity of the ageing process has prevented a full understanding of this process, therefore, ageing remains a grand challenge in contemporary biology. In AGELESS, we will tackle this challenge by uncovering the molecular mechanisms of halted ageing in a unique model system, the bats. Bats are the longest-lived mammals relative to their body size, and defy the ‘rate-of-living’ theories as they use twice as much the energy as other species of considerable size, but live far longer. This suggests that bats have some underlying mechanisms that may explain their exceptional longevity. In AGELESS, we will identify the molecular mechanisms that enable mammals to achieve extraordinary longevity, using state-of-the-art comparative genomic methodologies focused on bats. We will identify, using population transcriptomics and telomere/mtDNA genomics, the molecular changes that occur in an ageing wild population of bats to uncover how bats ‘age’ so slowly compared with other mammals. In silico whole genome analyses, field based ageing transcriptomic data, mtDNA and telomeric studies will be integrated and analysed using a networks approach, to ascertain how these systems interact to halt ageing. For the first time, we will be able to utilize the diversity seen within nature to identify key molecular targets and regions that regulate and control ageing in mammals. AGELESS will provide a deeper understanding of the causal mechanisms of ageing, potentially uncovering the crucial molecular pathways that can be modified to halt, alleviate and perhaps even reverse this process in man."
Summary
"Ageing is the gradual and irreversible breakdown of living systems associated with the advancement of time, which leads to an increase in vulnerability and eventual mortality. Despite recent advances in ageing research, the intrinsic complexity of the ageing process has prevented a full understanding of this process, therefore, ageing remains a grand challenge in contemporary biology. In AGELESS, we will tackle this challenge by uncovering the molecular mechanisms of halted ageing in a unique model system, the bats. Bats are the longest-lived mammals relative to their body size, and defy the ‘rate-of-living’ theories as they use twice as much the energy as other species of considerable size, but live far longer. This suggests that bats have some underlying mechanisms that may explain their exceptional longevity. In AGELESS, we will identify the molecular mechanisms that enable mammals to achieve extraordinary longevity, using state-of-the-art comparative genomic methodologies focused on bats. We will identify, using population transcriptomics and telomere/mtDNA genomics, the molecular changes that occur in an ageing wild population of bats to uncover how bats ‘age’ so slowly compared with other mammals. In silico whole genome analyses, field based ageing transcriptomic data, mtDNA and telomeric studies will be integrated and analysed using a networks approach, to ascertain how these systems interact to halt ageing. For the first time, we will be able to utilize the diversity seen within nature to identify key molecular targets and regions that regulate and control ageing in mammals. AGELESS will provide a deeper understanding of the causal mechanisms of ageing, potentially uncovering the crucial molecular pathways that can be modified to halt, alleviate and perhaps even reverse this process in man."
Max ERC Funding
1 499 768 €
Duration
Start date: 2013-01-01, End date: 2017-12-31
Project acronym ANOREP
Project Targeting the reproductive biology of the malaria mosquito Anopheles gambiae: from laboratory studies to field applications
Researcher (PI) Flaminia Catteruccia
Host Institution (HI) UNIVERSITA DEGLI STUDI DI PERUGIA
Call Details Starting Grant (StG), LS2, ERC-2010-StG_20091118
Summary Anopheles gambiae mosquitoes are the major vectors of malaria, a disease with devastating consequences for
human health. Novel methods for controlling the natural vector populations are urgently needed, given the
evolution of insecticide resistance in mosquitoes and the lack of novel insecticidals. Understanding the
processes at the bases of mosquito biology may help to roll back malaria. In this proposal, we will target
mosquito reproduction, a major determinant of the An. gambiae vectorial capacity. This will be achieved at
two levels: (i) fundamental research, to provide a deeper knowledge of the processes regulating reproduction
in this species, and (ii) applied research, to identify novel targets and to develop innovative approaches for
the control of natural populations. We will focus our analysis on three major players of mosquito
reproduction: male accessory glands (MAGs), sperm, and spermatheca, in both laboratory and field settings.
We will then translate this information into the identification of inhibitors of mosquito fertility. The
experimental activities will be divided across three objectives. In Objective 1, we will unravel the role of the
MAGs in shaping mosquito fertility and behaviour, by performing a combination of transcriptional and
functional studies that will reveal the multifaceted activities of these tissues. In Objective 2 we will instead
focus on the identification of the male and female factors responsible for sperm viability and function.
Results obtained in both objectives will be validated in field mosquitoes. In Objective 3, we will perform
screens aimed at the identification of inhibitors of mosquito reproductive success. This study will reveal as
yet unknown molecular mechanisms underlying reproductive success in mosquitoes, considerably increasing
our knowledge beyond the state-of-the-art and critically contributing with innovative tools and ideas to the
fight against malaria.
Summary
Anopheles gambiae mosquitoes are the major vectors of malaria, a disease with devastating consequences for
human health. Novel methods for controlling the natural vector populations are urgently needed, given the
evolution of insecticide resistance in mosquitoes and the lack of novel insecticidals. Understanding the
processes at the bases of mosquito biology may help to roll back malaria. In this proposal, we will target
mosquito reproduction, a major determinant of the An. gambiae vectorial capacity. This will be achieved at
two levels: (i) fundamental research, to provide a deeper knowledge of the processes regulating reproduction
in this species, and (ii) applied research, to identify novel targets and to develop innovative approaches for
the control of natural populations. We will focus our analysis on three major players of mosquito
reproduction: male accessory glands (MAGs), sperm, and spermatheca, in both laboratory and field settings.
We will then translate this information into the identification of inhibitors of mosquito fertility. The
experimental activities will be divided across three objectives. In Objective 1, we will unravel the role of the
MAGs in shaping mosquito fertility and behaviour, by performing a combination of transcriptional and
functional studies that will reveal the multifaceted activities of these tissues. In Objective 2 we will instead
focus on the identification of the male and female factors responsible for sperm viability and function.
Results obtained in both objectives will be validated in field mosquitoes. In Objective 3, we will perform
screens aimed at the identification of inhibitors of mosquito reproductive success. This study will reveal as
yet unknown molecular mechanisms underlying reproductive success in mosquitoes, considerably increasing
our knowledge beyond the state-of-the-art and critically contributing with innovative tools and ideas to the
fight against malaria.
Max ERC Funding
1 500 000 €
Duration
Start date: 2011-01-01, End date: 2015-12-31
Project acronym CellKarma
Project Dissecting the regulatory logic of cell fate reprogramming through integrative and single cell genomics
Researcher (PI) Davide CACCHIARELLI
Host Institution (HI) FONDAZIONE TELETHON
Call Details Starting Grant (StG), LS2, ERC-2017-STG
Summary The concept that any cell type, upon delivery of the right “cocktail” of transcription factors, can acquire an identity that otherwise it would never achieve, revolutionized the way we approach the study of developmental biology. In light of this, the discovery of induced pluripotent stem cells (IPSCs) and cell fate conversion approaches stimulated new research directions into human regenerative biology. However, the chance to successfully develop patient-tailored therapies is still very limited because reprogramming technologies are applied without a comprehensive understanding of the molecular processes involved.
Here, I propose a multifaceted approach that combines a wide range of cutting-edge integrative genomic strategies to significantly advance our understanding of the regulatory logic driving cell fate decisions during human reprogramming to pluripotency.
To this end, I will utilize single cell transcriptomics to isolate reprogramming intermediates, reconstruct their lineage relationships and define transcriptional regulators responsible for the observed transitions (AIM 1). Then, I will dissect the rules by which transcription factors modulate the activity of promoters and enhancer regions during reprogramming transitions, by applying synthetic biology and genome editing approaches (AIM 2). Then, I will adopt an alternative approach to identify reprogramming modulators by the analysis of reprogramming-induced mutagenesis events (AIM 3). Finally, I will explore my findings in multiple primary reprogramming approaches to pluripotency, with the ultimate goal of improving the quality of IPSC derivation (Aim 4).
In summary, this project will expose novel determinants and yet unidentified molecular barriers of reprogramming to pluripotency and will be essential to unlock the full potential of reprogramming technologies for shaping cellular identity in vitro and to address pressing challenges of regenerative medicine.
Summary
The concept that any cell type, upon delivery of the right “cocktail” of transcription factors, can acquire an identity that otherwise it would never achieve, revolutionized the way we approach the study of developmental biology. In light of this, the discovery of induced pluripotent stem cells (IPSCs) and cell fate conversion approaches stimulated new research directions into human regenerative biology. However, the chance to successfully develop patient-tailored therapies is still very limited because reprogramming technologies are applied without a comprehensive understanding of the molecular processes involved.
Here, I propose a multifaceted approach that combines a wide range of cutting-edge integrative genomic strategies to significantly advance our understanding of the regulatory logic driving cell fate decisions during human reprogramming to pluripotency.
To this end, I will utilize single cell transcriptomics to isolate reprogramming intermediates, reconstruct their lineage relationships and define transcriptional regulators responsible for the observed transitions (AIM 1). Then, I will dissect the rules by which transcription factors modulate the activity of promoters and enhancer regions during reprogramming transitions, by applying synthetic biology and genome editing approaches (AIM 2). Then, I will adopt an alternative approach to identify reprogramming modulators by the analysis of reprogramming-induced mutagenesis events (AIM 3). Finally, I will explore my findings in multiple primary reprogramming approaches to pluripotency, with the ultimate goal of improving the quality of IPSC derivation (Aim 4).
In summary, this project will expose novel determinants and yet unidentified molecular barriers of reprogramming to pluripotency and will be essential to unlock the full potential of reprogramming technologies for shaping cellular identity in vitro and to address pressing challenges of regenerative medicine.
Max ERC Funding
1 497 250 €
Duration
Start date: 2018-03-01, End date: 2023-02-28
Project acronym CHROMARRANGE
Project Programmed and unprogrammed genomic rearrangements during the evolution of yeast species
Researcher (PI) Kenneth Henry Wolfe
Host Institution (HI) UNIVERSITY COLLEGE DUBLIN, NATIONAL UNIVERSITY OF IRELAND, DUBLIN
Call Details Advanced Grant (AdG), LS2, ERC-2010-AdG_20100317
Summary By detailed evolutionary comparisons among multiple sequenced yeast genomes, we have identified several unusual regions where our preliminary evidence suggests that previously unknown molecular biology phenomena, involving rearrangement of genomic DNA, are occurring. I now propose to use a combination of dry-lab and wet-lab experimental approaches to characterize these regions and phenomena further. One region is a 24-kb section of chromosome XIV that appears to undergo recurrent 'flip/flop' inversion between two isomers at a fairly high rate in five species as diverse as Saccharomyces cerevisiae and Naumovia castellii, leading to a 1:1 ratio of the two isomers in each species. We hypothesize that this region is the site of a programmed DNA rearrangement analogous to mating-type switching. We have also identified two new genes related to the mating-type switching endonuclease HO, but different from it, that are potentially involved in rearrangement processes though not necessarily the inversion described above. We will determine the sites of action of these endonucleases. Separately, we have found evidence for a process of recurrent deletion of DNA from regions flanking the mating-type (MAT) locus in all yeast species that are descended from the whole-genome duplication (WGD) event, causing continual transpositions of genes from beside MAT to other locations in the genome. In related computational work, we propose to investigate an hypothesis that evolutionary loss of the MATa2 transcriptional activator may have been the cause of the WGD event.
Summary
By detailed evolutionary comparisons among multiple sequenced yeast genomes, we have identified several unusual regions where our preliminary evidence suggests that previously unknown molecular biology phenomena, involving rearrangement of genomic DNA, are occurring. I now propose to use a combination of dry-lab and wet-lab experimental approaches to characterize these regions and phenomena further. One region is a 24-kb section of chromosome XIV that appears to undergo recurrent 'flip/flop' inversion between two isomers at a fairly high rate in five species as diverse as Saccharomyces cerevisiae and Naumovia castellii, leading to a 1:1 ratio of the two isomers in each species. We hypothesize that this region is the site of a programmed DNA rearrangement analogous to mating-type switching. We have also identified two new genes related to the mating-type switching endonuclease HO, but different from it, that are potentially involved in rearrangement processes though not necessarily the inversion described above. We will determine the sites of action of these endonucleases. Separately, we have found evidence for a process of recurrent deletion of DNA from regions flanking the mating-type (MAT) locus in all yeast species that are descended from the whole-genome duplication (WGD) event, causing continual transpositions of genes from beside MAT to other locations in the genome. In related computational work, we propose to investigate an hypothesis that evolutionary loss of the MATa2 transcriptional activator may have been the cause of the WGD event.
Max ERC Funding
1 516 960 €
Duration
Start date: 2011-06-01, End date: 2016-05-31
Project acronym CLEAR
Project Modulating cellular clearance to cure human disease
Researcher (PI) Andrea Ballabio
Host Institution (HI) FONDAZIONE TELETHON
Call Details Advanced Grant (AdG), LS2, ERC-2009-AdG
Summary Cellular clearance is a fundamental process required by all cells in all species. Important physiological processes, such as aging, and pathological mechanisms, such as neurodegeneration, are strictly dependent on cellular clearance. In eukaryotes, most of the cellular clearing processes occur in a specialized organelle, the lysosome. This project is based on a recent discovery, made in our laboratory, of a gene network, which we have named CLEAR, that controls lysosomal biogenesis and function and regulates cellular clearance. The specific goals of the project are: 1) the comprehensive characterization of the mechanisms underlying the CLEAR network, 2) the thorough understanding of CLEAR physiological function at the cellular and organism levels, 3) the development of strategies and tools to modulate cellular clearance, and 4) the implementation of proof-of-principle therapeutic studies based on the activation of the CLEAR network in murine models of human lysosomal storage disorders and of neurodegenerative diseases, such as Alzheimers s and Huntington s diseases. A combination of genomics, bioinformatics, systems biology, chemical genomics, cell biology, and mouse genetics approaches will be used to achieve these goals. Our goal is to develop tools to modulate cellular clearance and to use such tools to develop therapies to cure human disease. The potential medical relevance of this project is very high, particularly in the field of neurodegenerative disease. Therapies that prevent, ameliorate or delay neurodegeneration in these diseases would have a huge impact on human health.
Summary
Cellular clearance is a fundamental process required by all cells in all species. Important physiological processes, such as aging, and pathological mechanisms, such as neurodegeneration, are strictly dependent on cellular clearance. In eukaryotes, most of the cellular clearing processes occur in a specialized organelle, the lysosome. This project is based on a recent discovery, made in our laboratory, of a gene network, which we have named CLEAR, that controls lysosomal biogenesis and function and regulates cellular clearance. The specific goals of the project are: 1) the comprehensive characterization of the mechanisms underlying the CLEAR network, 2) the thorough understanding of CLEAR physiological function at the cellular and organism levels, 3) the development of strategies and tools to modulate cellular clearance, and 4) the implementation of proof-of-principle therapeutic studies based on the activation of the CLEAR network in murine models of human lysosomal storage disorders and of neurodegenerative diseases, such as Alzheimers s and Huntington s diseases. A combination of genomics, bioinformatics, systems biology, chemical genomics, cell biology, and mouse genetics approaches will be used to achieve these goals. Our goal is to develop tools to modulate cellular clearance and to use such tools to develop therapies to cure human disease. The potential medical relevance of this project is very high, particularly in the field of neurodegenerative disease. Therapies that prevent, ameliorate or delay neurodegeneration in these diseases would have a huge impact on human health.
Max ERC Funding
2 100 000 €
Duration
Start date: 2010-03-01, End date: 2015-02-28
Project acronym DDRNA
Project A novel direct role of non coding RNA in DNA damage response activation
Researcher (PI) Fabrizio D'adda Di Fagagna
Host Institution (HI) IFOM FONDAZIONE ISTITUTO FIRC DI ONCOLOGIA MOLECOLARE
Call Details Advanced Grant (AdG), LS1, ERC-2012-ADG_20120314
Summary DNA, if damaged, cannot be replaced. If not replaceable, it must be repaired. The so-called “DNA damage response” (DDR) is a coordinate set of evolutionary conserved events that arrest the cell-cycle (DNA damage checkpoint function) in proliferating cells and attempts DNA repair. Until DNA damage has not been repaired in full, cell proliferation is not resumed in normal cells.
DNA damage is a physiological event. Ageing and cancer are both associated with DNA damage accumulation. In the past, we contribute to better understand the mechanisms and the consequences of DNA damage generation and DDR activation in both settings.
We have recently identified a completely hitherto undiscovered level of control of DDR activation, so far considered a proteinaceous only signaling cascade. We have discovered that short RNA species are detectable at DNA damage sites and are necessary for DDR activation at DNA lesions. These RNA species are generated by an evolutionary-conserved RNA processing machinery. However, they serve purposes never reported before.
We believe that our findings change radically our understanding of DDR modulation in mammals and disclose a fertile unspoilt ground for exciting investigations.
Summary
DNA, if damaged, cannot be replaced. If not replaceable, it must be repaired. The so-called “DNA damage response” (DDR) is a coordinate set of evolutionary conserved events that arrest the cell-cycle (DNA damage checkpoint function) in proliferating cells and attempts DNA repair. Until DNA damage has not been repaired in full, cell proliferation is not resumed in normal cells.
DNA damage is a physiological event. Ageing and cancer are both associated with DNA damage accumulation. In the past, we contribute to better understand the mechanisms and the consequences of DNA damage generation and DDR activation in both settings.
We have recently identified a completely hitherto undiscovered level of control of DDR activation, so far considered a proteinaceous only signaling cascade. We have discovered that short RNA species are detectable at DNA damage sites and are necessary for DDR activation at DNA lesions. These RNA species are generated by an evolutionary-conserved RNA processing machinery. However, they serve purposes never reported before.
We believe that our findings change radically our understanding of DDR modulation in mammals and disclose a fertile unspoilt ground for exciting investigations.
Max ERC Funding
2 329 200 €
Duration
Start date: 2013-06-01, End date: 2018-05-31
Project acronym DENDROWORLD
Project Mucosal dendritic cells in intestinal homeostasis and bacteria-related diseases
Researcher (PI) Maria Rescigno
Host Institution (HI) ISTITUTO EUROPEO DI ONCOLOGIA SRL
Call Details Starting Grant (StG), LS3, ERC-2007-StG
Summary The bacterial microflora has always been regarded as beneficial for the host but recent studies have shown that this symbiosis has risks as well as benefits. Although active mechanisms allow tolerating the commensal flora, the physiological stress that is associated with the symbionts’ metabolism can exhaust the intestinal barrier resulting in serious effects on the health of the host. Protracted immune deregulations can lead to severe disorders including diabetes, cancer and inflammatory bowel disease (IBD). Several mechanisms and players are involved in the maintenance of intestinal immune homeostasis, including T regulatory cells and Immunoglobulin (Ig)-A. In this proposal we focus our attention on dendritic cells (DCs) for their ability to induce both tolerance and immunity by regulating B and T cell responses. We have recently shown that DC function is controlled by intestinal epithelial cell (EC) derived factors and in particular by Thymic stromal lymphopoietin (TSLP). EC-conditioned DCs acquire a ‘mucosal’ phenotype as they are prone to activate T regulatory cells and IgA responses. Three major issues related to the maintenance and disruption of intestinal immune homeostasis will be explored in this project: 1) What are the mediators and mechanisms that regulate the interaction between intestinal epithelial cells and dendritic cells? What is the function of TSLP? 2) Which are the sites and players for the activation of an IgA response to pathogenic and commensal bacteria? Can we visualize them in vivo? 3) Can prolonged infections or bacterial products promote intestinal tumour development? Are there different bacterial constituents acting as inducers or protectors of carcinogenesis? What is the role of Toll-like receptors?
Summary
The bacterial microflora has always been regarded as beneficial for the host but recent studies have shown that this symbiosis has risks as well as benefits. Although active mechanisms allow tolerating the commensal flora, the physiological stress that is associated with the symbionts’ metabolism can exhaust the intestinal barrier resulting in serious effects on the health of the host. Protracted immune deregulations can lead to severe disorders including diabetes, cancer and inflammatory bowel disease (IBD). Several mechanisms and players are involved in the maintenance of intestinal immune homeostasis, including T regulatory cells and Immunoglobulin (Ig)-A. In this proposal we focus our attention on dendritic cells (DCs) for their ability to induce both tolerance and immunity by regulating B and T cell responses. We have recently shown that DC function is controlled by intestinal epithelial cell (EC) derived factors and in particular by Thymic stromal lymphopoietin (TSLP). EC-conditioned DCs acquire a ‘mucosal’ phenotype as they are prone to activate T regulatory cells and IgA responses. Three major issues related to the maintenance and disruption of intestinal immune homeostasis will be explored in this project: 1) What are the mediators and mechanisms that regulate the interaction between intestinal epithelial cells and dendritic cells? What is the function of TSLP? 2) Which are the sites and players for the activation of an IgA response to pathogenic and commensal bacteria? Can we visualize them in vivo? 3) Can prolonged infections or bacterial products promote intestinal tumour development? Are there different bacterial constituents acting as inducers or protectors of carcinogenesis? What is the role of Toll-like receptors?
Max ERC Funding
1 195 680 €
Duration
Start date: 2008-07-01, End date: 2013-06-30
Project acronym DEPTH
Project DEsigning new Paths in The differentiation Hyperspace
Researcher (PI) Giovanni Cesareni
Host Institution (HI) UNIVERSITA DEGLI STUDI DI ROMA TOR VERGATA
Call Details Advanced Grant (AdG), LS2, ERC-2012-ADG_20120314
Summary The adult human organism contains heterogeneous reservoirs of pluripotent stem cells characterized by a diversified differentiation potential. Understanding their biology at a system level would advance our ability to selectively activate and control their differentiation potential. Aside from the basic implications this would represent a substantial progress in regenerative medicine by providing a rational framework for using small molecules to control cell trans-determination and reprogramming.
Here we propose a combined experimental and modelling approach to assemble a predictive model of mesoderm stem cell differentiation. Different cell states are identified by a vector in the differentiation hyperspace, the coordinates of the vector being the activation levels of a large number of nodes of a logic model linking the cell signalling network to the transcription regulatory network.
The premise of this proposal is that differentiation is equivalent to rewiring the cell regulatory network as a consequence of induced perturbation of the gene expression program. This process can be rationally controlled by perturbing specific nodes of the signalling network that in turn control transcription factor activation. We will develop this novel strategy using the mesoangioblast ex vivo differentiation system. Mesoangioblasts are one of the many different types of mesoderm stem/progenitor cells that exhibit myogenic potential. Ex vivo, they readily differentiate into striated muscle. However, under appropriate conditions they can also differentiate, into smooth muscle and adipocytes, albeit less efficiently. We will start by assembling, training and optimizing different predictive models for the undifferentiated mesoangioblast. Next by a combination of experiments and modelling approaches we will learn how, by perturbing the signalling models with different inhibitors and activators we can rewire the cell networks to induce trans-determination or reprogramming.
Summary
The adult human organism contains heterogeneous reservoirs of pluripotent stem cells characterized by a diversified differentiation potential. Understanding their biology at a system level would advance our ability to selectively activate and control their differentiation potential. Aside from the basic implications this would represent a substantial progress in regenerative medicine by providing a rational framework for using small molecules to control cell trans-determination and reprogramming.
Here we propose a combined experimental and modelling approach to assemble a predictive model of mesoderm stem cell differentiation. Different cell states are identified by a vector in the differentiation hyperspace, the coordinates of the vector being the activation levels of a large number of nodes of a logic model linking the cell signalling network to the transcription regulatory network.
The premise of this proposal is that differentiation is equivalent to rewiring the cell regulatory network as a consequence of induced perturbation of the gene expression program. This process can be rationally controlled by perturbing specific nodes of the signalling network that in turn control transcription factor activation. We will develop this novel strategy using the mesoangioblast ex vivo differentiation system. Mesoangioblasts are one of the many different types of mesoderm stem/progenitor cells that exhibit myogenic potential. Ex vivo, they readily differentiate into striated muscle. However, under appropriate conditions they can also differentiate, into smooth muscle and adipocytes, albeit less efficiently. We will start by assembling, training and optimizing different predictive models for the undifferentiated mesoangioblast. Next by a combination of experiments and modelling approaches we will learn how, by perturbing the signalling models with different inhibitors and activators we can rewire the cell networks to induce trans-determination or reprogramming.
Max ERC Funding
2 639 804 €
Duration
Start date: 2013-04-01, End date: 2018-09-30
Project acronym DissectPcG
Project Dissecting the Function of Multiple Polycomb Group Complexes in Establishing Transcriptional Identity
Researcher (PI) Diego PASINI
Host Institution (HI) UNIVERSITA DEGLI STUDI DI MILANO
Call Details Consolidator Grant (CoG), LS3, ERC-2016-COG
Summary The activities of the Polycomb group (PcG) of repressive chromatin modifiers are required to maintain correct transcriptional identity during development and differentiation. These activities are altered in a variety of tumours by gain- or loss-of-function mutations, whose mechanistic aspects still remain unclear.
PcGs can be classified in two major repressive complexes (PRC1 and PRC2) with common pathways but distinct biochemical activities. PRC1 catalyses histone H2A ubiquitination of lysine 119, and PRC2 tri-methylation of histone H3 lysine 27. However, PRC1 has a more heterogeneous composition than PRC2, with six mutually exclusive PCGF subunits (PCGF1–6) essential for assembling distinct PRC1 complexes that differ in subunit composition but share the same catalytic core.
While up to six different PRC1 forms can co-exist in a given cell, the molecular mechanisms regulating their activities and their relative contributions to general PRC1 function in any tissue/cell type remain largely unknown. In line with this biochemical heterogeneity, PRC1 retains broader biological functions than PRC2. Critically, however, no molecular analysis has yet been published that dissects the contribution of each PRC1 complex in regulating transcriptional identity.
We will take advantage of newly developed reagents and unpublished genetic models to target each of the six Pcgf genes in either embryonic stem cells or mouse adult tissues. This will systematically dissect the contributions of the different PRC1 complexes to chromatin profiles, gene expression programs, and cellular phenotypes during stem cell self-renewal, differentiation and adult tissue homeostasis. Overall, this will elucidate some of the fundamental mechanisms underlying the establishment and maintenance of cellular identity and will allow us to further determine the molecular links between PcG deregulation and cancer development in a tissue- and/or cell type–specific manner.
Summary
The activities of the Polycomb group (PcG) of repressive chromatin modifiers are required to maintain correct transcriptional identity during development and differentiation. These activities are altered in a variety of tumours by gain- or loss-of-function mutations, whose mechanistic aspects still remain unclear.
PcGs can be classified in two major repressive complexes (PRC1 and PRC2) with common pathways but distinct biochemical activities. PRC1 catalyses histone H2A ubiquitination of lysine 119, and PRC2 tri-methylation of histone H3 lysine 27. However, PRC1 has a more heterogeneous composition than PRC2, with six mutually exclusive PCGF subunits (PCGF1–6) essential for assembling distinct PRC1 complexes that differ in subunit composition but share the same catalytic core.
While up to six different PRC1 forms can co-exist in a given cell, the molecular mechanisms regulating their activities and their relative contributions to general PRC1 function in any tissue/cell type remain largely unknown. In line with this biochemical heterogeneity, PRC1 retains broader biological functions than PRC2. Critically, however, no molecular analysis has yet been published that dissects the contribution of each PRC1 complex in regulating transcriptional identity.
We will take advantage of newly developed reagents and unpublished genetic models to target each of the six Pcgf genes in either embryonic stem cells or mouse adult tissues. This will systematically dissect the contributions of the different PRC1 complexes to chromatin profiles, gene expression programs, and cellular phenotypes during stem cell self-renewal, differentiation and adult tissue homeostasis. Overall, this will elucidate some of the fundamental mechanisms underlying the establishment and maintenance of cellular identity and will allow us to further determine the molecular links between PcG deregulation and cancer development in a tissue- and/or cell type–specific manner.
Max ERC Funding
2 000 000 €
Duration
Start date: 2017-11-01, End date: 2022-10-31
Project acronym DNAMEREP
Project The role of essential DNA metabolism genes in vertebrate chromosome replication
Researcher (PI) Vincenzo Costanzo
Host Institution (HI) IFOM FONDAZIONE ISTITUTO FIRC DI ONCOLOGIA MOLECOLARE
Call Details Consolidator Grant (CoG), LS1, ERC-2013-CoG
Summary "Faithful chromosomal DNA replication is essential to maintain genome stability. A number of DNA metabolism genes are involved at different levels in DNA replication. These factors are thought to facilitate the establishment of replication origins, assist the replication of chromatin regions with repetitive DNA, coordinate the repair of DNA molecules resulting from aberrant DNA replication events or protect replication forks in the presence of DNA lesions that impair their progression. Some DNA metabolism genes are present mainly in higher eukaryotes, suggesting the existence of more complex repair and replication mechanisms in organisms with complex genomes. The impact on cell survival of many DNA metabolism genes has so far precluded in depth molecular analysis. The use of cell free extracts able to recapitulate cell cycle events might help overcoming survival issues and facilitate these studies. The Xenopus laevis egg cell free extract represents an ideal system to study replication-associated functions of essential genes in vertebrate organisms. We will take advantage of this system together with innovative imaging and proteomic based experimental approaches that we are currently developing to characterize the molecular function of some essential DNA metabolism genes. In particular, we will characterize DNA metabolism genes involved in the assembly and distribution of replication origins in vertebrate cells, elucidate molecular mechanisms underlying the role of essential homologous recombination and fork protection proteins in chromosomal DNA replication, and finally identify and characterize factors required for faithful replication of specific vertebrate genomic regions.
The results of these studies will provide groundbreaking information on several aspects of vertebrate genome metabolism and will allow long-awaited understanding of the function of a number of vertebrate essential DNA metabolism genes involved in the duplication of large and complex genomes."
Summary
"Faithful chromosomal DNA replication is essential to maintain genome stability. A number of DNA metabolism genes are involved at different levels in DNA replication. These factors are thought to facilitate the establishment of replication origins, assist the replication of chromatin regions with repetitive DNA, coordinate the repair of DNA molecules resulting from aberrant DNA replication events or protect replication forks in the presence of DNA lesions that impair their progression. Some DNA metabolism genes are present mainly in higher eukaryotes, suggesting the existence of more complex repair and replication mechanisms in organisms with complex genomes. The impact on cell survival of many DNA metabolism genes has so far precluded in depth molecular analysis. The use of cell free extracts able to recapitulate cell cycle events might help overcoming survival issues and facilitate these studies. The Xenopus laevis egg cell free extract represents an ideal system to study replication-associated functions of essential genes in vertebrate organisms. We will take advantage of this system together with innovative imaging and proteomic based experimental approaches that we are currently developing to characterize the molecular function of some essential DNA metabolism genes. In particular, we will characterize DNA metabolism genes involved in the assembly and distribution of replication origins in vertebrate cells, elucidate molecular mechanisms underlying the role of essential homologous recombination and fork protection proteins in chromosomal DNA replication, and finally identify and characterize factors required for faithful replication of specific vertebrate genomic regions.
The results of these studies will provide groundbreaking information on several aspects of vertebrate genome metabolism and will allow long-awaited understanding of the function of a number of vertebrate essential DNA metabolism genes involved in the duplication of large and complex genomes."
Max ERC Funding
1 999 800 €
Duration
Start date: 2014-06-01, End date: 2019-05-31
