Project acronym CENDUP
Project Decoding the mechanisms of centrosome duplication
Researcher (PI) Pierre Gönczy
Host Institution (HI) ECOLE POLYTECHNIQUE FEDERALE DE LAUSANNE
Call Details Advanced Grant (AdG), LS3, ERC-2008-AdG
Summary Centrosome duplication entails the formation of a single procentriole next to each centriole once per cell cycle. The mechanisms governing procentriole formation are poorly understood and constitute a fundamental open question in cell biology. We will launch an innovative multidisciplinary research program to gain significant insight into these mechanisms using C. elegans and human cells. This research program is also expected to have a significant impact by contributing important novel assays to the field. Six specific aims will be pursued: 1) SAS-6 as a ZYG-1 substrate: mechanisms of procentriole formation in C. elegans. We will test in vivo the consequence of SAS-6 phosphorylation by ZYG-1. 2) Biochemical and structural analysis of SAS-6-containing macromolecular complexes (SAMACs). We will isolate and characterize SAMACs from C. elegans embryos and human cells, and analyze their structure using single-particle electron microscopy. 3) Novel cell-free assay for procentriole formation in human cells. We will develop such an assay and use it to test whether SAMACs can direct procentriole formation and whether candidate proteins are needed at centrioles or in the cytoplasm. 4) Mapping interactions between centriolar proteins in live human cells. We will use chemical methods developed by our collaborators to probe interactions between HsSAS-6 and centriolar proteins in a time- and space-resolved manner. 5) Functional genomic and chemical genetic screens in human cells. We will conduct high-throughput fluorescence-based screens in human cells to identify novel genes required for procentriole formation and small molecule inhibitors of this process. 6) Mechanisms underlying differential centriolar maintenance in the germline. In C. elegans, we will characterize how the sas-1 locus is required for centriole maintenance during spermatogenesis, as well as analyze centriole elimination during oogenesis and identify components needed for this process
Summary
Centrosome duplication entails the formation of a single procentriole next to each centriole once per cell cycle. The mechanisms governing procentriole formation are poorly understood and constitute a fundamental open question in cell biology. We will launch an innovative multidisciplinary research program to gain significant insight into these mechanisms using C. elegans and human cells. This research program is also expected to have a significant impact by contributing important novel assays to the field. Six specific aims will be pursued: 1) SAS-6 as a ZYG-1 substrate: mechanisms of procentriole formation in C. elegans. We will test in vivo the consequence of SAS-6 phosphorylation by ZYG-1. 2) Biochemical and structural analysis of SAS-6-containing macromolecular complexes (SAMACs). We will isolate and characterize SAMACs from C. elegans embryos and human cells, and analyze their structure using single-particle electron microscopy. 3) Novel cell-free assay for procentriole formation in human cells. We will develop such an assay and use it to test whether SAMACs can direct procentriole formation and whether candidate proteins are needed at centrioles or in the cytoplasm. 4) Mapping interactions between centriolar proteins in live human cells. We will use chemical methods developed by our collaborators to probe interactions between HsSAS-6 and centriolar proteins in a time- and space-resolved manner. 5) Functional genomic and chemical genetic screens in human cells. We will conduct high-throughput fluorescence-based screens in human cells to identify novel genes required for procentriole formation and small molecule inhibitors of this process. 6) Mechanisms underlying differential centriolar maintenance in the germline. In C. elegans, we will characterize how the sas-1 locus is required for centriole maintenance during spermatogenesis, as well as analyze centriole elimination during oogenesis and identify components needed for this process
Max ERC Funding
2 004 155 €
Duration
Start date: 2009-04-01, End date: 2014-03-31
Project acronym CENFOR
Project Dissecting the mechanisms governing centriole formation
Researcher (PI) Pierre Gönczy
Host Institution (HI) ECOLE POLYTECHNIQUE FEDERALE DE LAUSANNE
Call Details Advanced Grant (AdG), LS3, ERC-2013-ADG
Summary "Centrioles are critical for the formation of cilia, flagella and centrosomes, as well as for human health. The mechanisms governing centriole formation constitute a long-standing question in cell biology. We will pursue an innovative multidisciplinary research program to gain further insight into these mechanisms, using human cells, C. elegans and Trichonympha as model systems. This program is expected to also have a major impact by contributing a novel cell free assay to the field, thus paving the way towards making synthetic centrioles. Six specific aims will be pursued:
1) Deciphering HsSAS-6/STIL distribution and dynamics. We will use super-resolution microscopy, molecular counting, photoconversion and FCS to further characterize these two key components required for centriole formation in human cells.
2) The SAS-6 ring model as a tool to redirect centriole organization. Utilizing predictions from the SAS-6 ring model, we will assay the consequences for centrioles and cilia of altering the diameter and symmetry of the structure.
3) Determining the architecture of C. elegans centrioles. We will conduct molecular counting and cryo-ET of purified C. elegans centrioles to determine if they contain a spiral or a cartwheel, as well as identify SAS-6-interacting components.
4) Comprehensive 3D map and proteomics of Trichonympha centriole. We will obtain a ~35 Å 3D map of the complete T. agilis centriole, perform proteomic analysis to identify its constituents and test their function using RNAi.
5) Regulation of cartwheel height and centriole length. We will explore whether cartwheel height is set by SAS-6 proteins and perform screens in human cells to identify novel components regulating cartwheel height and centriole length.
6) Novel cell free assay for cartwheel assembly and centriole formation. Using SAS-6 proteins on a lipid monolayer as starting point, we will develop and utilize a cell-free assay to reconstitute cartwheel assembly and centriole format"
Summary
"Centrioles are critical for the formation of cilia, flagella and centrosomes, as well as for human health. The mechanisms governing centriole formation constitute a long-standing question in cell biology. We will pursue an innovative multidisciplinary research program to gain further insight into these mechanisms, using human cells, C. elegans and Trichonympha as model systems. This program is expected to also have a major impact by contributing a novel cell free assay to the field, thus paving the way towards making synthetic centrioles. Six specific aims will be pursued:
1) Deciphering HsSAS-6/STIL distribution and dynamics. We will use super-resolution microscopy, molecular counting, photoconversion and FCS to further characterize these two key components required for centriole formation in human cells.
2) The SAS-6 ring model as a tool to redirect centriole organization. Utilizing predictions from the SAS-6 ring model, we will assay the consequences for centrioles and cilia of altering the diameter and symmetry of the structure.
3) Determining the architecture of C. elegans centrioles. We will conduct molecular counting and cryo-ET of purified C. elegans centrioles to determine if they contain a spiral or a cartwheel, as well as identify SAS-6-interacting components.
4) Comprehensive 3D map and proteomics of Trichonympha centriole. We will obtain a ~35 Å 3D map of the complete T. agilis centriole, perform proteomic analysis to identify its constituents and test their function using RNAi.
5) Regulation of cartwheel height and centriole length. We will explore whether cartwheel height is set by SAS-6 proteins and perform screens in human cells to identify novel components regulating cartwheel height and centriole length.
6) Novel cell free assay for cartwheel assembly and centriole formation. Using SAS-6 proteins on a lipid monolayer as starting point, we will develop and utilize a cell-free assay to reconstitute cartwheel assembly and centriole format"
Max ERC Funding
2 499 270 €
Duration
Start date: 2014-04-01, End date: 2019-03-31
Project acronym CENGIN
Project Deciphering and engineering centriole assembly
Researcher (PI) Pierre Jörg GÖNCZY
Host Institution (HI) ECOLE POLYTECHNIQUE FEDERALE DE LAUSANNE
Call Details Advanced Grant (AdG), LS3, ERC-2018-ADG
Summary Deciphering and engineering the assembly of cellular organelles is a key pursuit in biology. The centriole is an evolutionarily conserved organelle well suited for this goal, and which is crucial for cell signaling, motility and division. The centriole exhibits a striking 9-fold radial symmetry of microtubules around a likewise symmetrical cartwheel containing stacked ring-bearing structures. Components essential for generating this remarkable architecture from alga to man have been identified. A next critical step is to engineer assays to probe the dynamics of centriole assembly with molecular precision to fully understand how these components together build a functional organelle. Our ambitious research proposal aims at taking groundbreaking steps in this direction through four specific aims:
1) Reconstituting cartwheel ring assembly dynamics. We will use high-speed AFM (HS-AFM) to dissect the biophysics of SAS-6 ring polymer dynamics at the root of cartwheel assembly. We will also use HS-AFM to analyze monobodies against SAS-6, as well as engineer surfaces and DNA origamis to further dissect ring assembly.
2) Deciphering ring stacking mechanisms. We will use cryo-ET to identify SAS-6 features that direct stacking of ring structures and set cartwheel height. Moreover, we will develop an HS-AFM stacking assay and a reconstituted stacking assay from human cells.
3) Understanding peripheral element contributions to centriole biogenesis. We will dissect the function of the peripheral centriole pinhead protein Cep135/Bld10p, as well as identify and likewise dissect peripheral A-C linker proteins. Furthermore, we will further engineer the HS-AFM assay to include such peripheral components.
4) Dissecting de novo centriole assembly mechanisms. We will dissect de novo centriole formation in human cells and water fern. We will also explore whether de novo formation involves a phase separation mechanism and repurpose the HS-AFM assay to probe de novo organelle biogenes
Summary
Deciphering and engineering the assembly of cellular organelles is a key pursuit in biology. The centriole is an evolutionarily conserved organelle well suited for this goal, and which is crucial for cell signaling, motility and division. The centriole exhibits a striking 9-fold radial symmetry of microtubules around a likewise symmetrical cartwheel containing stacked ring-bearing structures. Components essential for generating this remarkable architecture from alga to man have been identified. A next critical step is to engineer assays to probe the dynamics of centriole assembly with molecular precision to fully understand how these components together build a functional organelle. Our ambitious research proposal aims at taking groundbreaking steps in this direction through four specific aims:
1) Reconstituting cartwheel ring assembly dynamics. We will use high-speed AFM (HS-AFM) to dissect the biophysics of SAS-6 ring polymer dynamics at the root of cartwheel assembly. We will also use HS-AFM to analyze monobodies against SAS-6, as well as engineer surfaces and DNA origamis to further dissect ring assembly.
2) Deciphering ring stacking mechanisms. We will use cryo-ET to identify SAS-6 features that direct stacking of ring structures and set cartwheel height. Moreover, we will develop an HS-AFM stacking assay and a reconstituted stacking assay from human cells.
3) Understanding peripheral element contributions to centriole biogenesis. We will dissect the function of the peripheral centriole pinhead protein Cep135/Bld10p, as well as identify and likewise dissect peripheral A-C linker proteins. Furthermore, we will further engineer the HS-AFM assay to include such peripheral components.
4) Dissecting de novo centriole assembly mechanisms. We will dissect de novo centriole formation in human cells and water fern. We will also explore whether de novo formation involves a phase separation mechanism and repurpose the HS-AFM assay to probe de novo organelle biogenes
Max ERC Funding
2 500 000 €
Duration
Start date: 2019-09-01, End date: 2024-08-31
Project acronym CentrioleBirthDeath
Project Mechanism of centriole inheritance and maintenance
Researcher (PI) Monica BETTENCOURT CARVALHO DIAS
Host Institution (HI) FUNDACAO CALOUSTE GULBENKIAN
Call Details Consolidator Grant (CoG), LS3, ERC-2015-CoG
Summary Centrioles assemble centrosomes and cilia/flagella, critical structures for cell division, polarity, motility and signalling, which are often deregulated in human disease. Centriole inheritance, in particular the preservation of their copy number and position in the cell is critical in many eukaryotes. I propose to investigate, in an integrative and quantitative way, how centrioles are formed in the right numbers at the right time and place, and how they are maintained to ensure their function and inheritance. We first ask how centrioles guide their own assembly position and centriole copy number. Our recent work highlighted several properties of the system, including positive and negative feedbacks and spatial cues. We explore critical hypotheses through a combination of biochemistry, quantitative live cell microscopy and computational modelling. We then ask how the centrosome and the cell cycle are both coordinated. We recently identified the triggering event in centriole biogenesis and how its regulation is akin to cell cycle control of DNA replication and centromere assembly. We will explore new hypotheses to understand how assembly time is coupled to the cell cycle. Lastly, we ask how centriole maintenance is regulated. By studying centriole disappearance in the female germline we uncovered that centrioles need to be actively maintained by their surrounding matrix. We propose to investigate how that matrix provides stability to the centrioles, whether this is differently regulated in different cell types and the possible consequences of its misregulation for the organism (infertility and ciliopathy-like symptoms). We will take advantage of several experimental systems (in silico, ex-vivo, flies and human cells), tailoring the assay to the question and allowing for comparisons across experimental systems to provide a deeper understanding of the process and its regulation.
Summary
Centrioles assemble centrosomes and cilia/flagella, critical structures for cell division, polarity, motility and signalling, which are often deregulated in human disease. Centriole inheritance, in particular the preservation of their copy number and position in the cell is critical in many eukaryotes. I propose to investigate, in an integrative and quantitative way, how centrioles are formed in the right numbers at the right time and place, and how they are maintained to ensure their function and inheritance. We first ask how centrioles guide their own assembly position and centriole copy number. Our recent work highlighted several properties of the system, including positive and negative feedbacks and spatial cues. We explore critical hypotheses through a combination of biochemistry, quantitative live cell microscopy and computational modelling. We then ask how the centrosome and the cell cycle are both coordinated. We recently identified the triggering event in centriole biogenesis and how its regulation is akin to cell cycle control of DNA replication and centromere assembly. We will explore new hypotheses to understand how assembly time is coupled to the cell cycle. Lastly, we ask how centriole maintenance is regulated. By studying centriole disappearance in the female germline we uncovered that centrioles need to be actively maintained by their surrounding matrix. We propose to investigate how that matrix provides stability to the centrioles, whether this is differently regulated in different cell types and the possible consequences of its misregulation for the organism (infertility and ciliopathy-like symptoms). We will take advantage of several experimental systems (in silico, ex-vivo, flies and human cells), tailoring the assay to the question and allowing for comparisons across experimental systems to provide a deeper understanding of the process and its regulation.
Max ERC Funding
2 000 000 €
Duration
Start date: 2017-01-01, End date: 2021-12-31
Project acronym CENTRIOLSTRUCTNUMBER
Project Control of Centriole Structure And Number
Researcher (PI) Monica Bettencourt Carvalho Dias
Host Institution (HI) FUNDACAO CALOUSTE GULBENKIAN
Call Details Starting Grant (StG), LS3, ERC-2010-StG_20091118
Summary Centrioles are essential for the formation of several microtubule organizing structures including cilia, flagella and centrosomes. These structures are involved in a variety of functions, from cell motility to division. Centrosome defects are seen in many cancers, while abnormalities in cilia and flagella can lead to a variety of human diseases, such as polycystic kidney disease. The molecular mechanisms regulating centriole biogenesis have only recently started to be unravelled, opening new ways to answer a wide range of questions that have fascinated biologists for more than a century. In this grant we are asking two fundamental questions that are central to human disease: how is centriole structure and number established and regulated in the eukaryotic cell? To address these questions we propose to identify new molecular players, and to test the role of these and known players in the context of specific mechanistic hypothesis, using in vitro and in vivo models. We propose to develop novel assays for centriole structure and regulation in order to address mechanistic problems not accessible with today s assays. In our search for novel components we will use a multidisciplinary approach combining bioinformatics with high throughput screening. The use of in vitro systems will permit the quantitative dissection of molecular mechanisms, while the study of those mechanisms in Drosophila will allow us to understand them at the whole organism level. Furthermore, this analysis, together with studies in human tissue culture cells, will allow us to understand the consequences of misregulation of these fundamental centriole properties for human disease, such as ciliopathies and cancer. My group is already collaborating with medical doctors in the study of centriole aberrations in human disease (cancer and ciliopathies), which will be invaluable to bringing the results of this study to the translational level.
Summary
Centrioles are essential for the formation of several microtubule organizing structures including cilia, flagella and centrosomes. These structures are involved in a variety of functions, from cell motility to division. Centrosome defects are seen in many cancers, while abnormalities in cilia and flagella can lead to a variety of human diseases, such as polycystic kidney disease. The molecular mechanisms regulating centriole biogenesis have only recently started to be unravelled, opening new ways to answer a wide range of questions that have fascinated biologists for more than a century. In this grant we are asking two fundamental questions that are central to human disease: how is centriole structure and number established and regulated in the eukaryotic cell? To address these questions we propose to identify new molecular players, and to test the role of these and known players in the context of specific mechanistic hypothesis, using in vitro and in vivo models. We propose to develop novel assays for centriole structure and regulation in order to address mechanistic problems not accessible with today s assays. In our search for novel components we will use a multidisciplinary approach combining bioinformatics with high throughput screening. The use of in vitro systems will permit the quantitative dissection of molecular mechanisms, while the study of those mechanisms in Drosophila will allow us to understand them at the whole organism level. Furthermore, this analysis, together with studies in human tissue culture cells, will allow us to understand the consequences of misregulation of these fundamental centriole properties for human disease, such as ciliopathies and cancer. My group is already collaborating with medical doctors in the study of centriole aberrations in human disease (cancer and ciliopathies), which will be invaluable to bringing the results of this study to the translational level.
Max ERC Funding
1 500 000 €
Duration
Start date: 2011-01-01, End date: 2016-12-31
Project acronym CENTROSTEMCANCER
Project Investigating the link between centrosomes, stem cells and cancer
Researcher (PI) Renata Homem De Gouveia Xavier De Basto
Host Institution (HI) INSTITUT CURIE
Call Details Starting Grant (StG), LS3, ERC-2009-StG
Summary Centrosomes are cytoplasmic organelles found in most animal cells with important roles in polarity establishment and maintenance. Theodor Boveri s pioneering work first suggested that extra-centrosomes could contribute to genetic instability and consequently to tumourigenesis. Although many human tumours do exhibit centrosome amplification (extra centrosomes) or centrosome abnormalities, the exact contribution of centrosomes to tumour initiation in vertebrate organisms remains to be determined. I have recently showed that Drosophila flies carrying extra-centrosomes, following the over-expression of the centriole replication kinase Sak, did not exhibit chromosome segregation errors and were able to maintain a stable diploid genome over many generations. Surprisingly, however, neural stem cells fail frequently to align the mitotic spindle with their polarity axis during asymmetric division. Moreover, I have found that centrosome amplification is permissive to tumour formation in flies. So far, however, we do not know the molecular mechanisms that allow transformation when extra centrosomes are present and elucidating these mechanisms is the aim of the work presented in this proposal. Here, I describe a series of complementary approaches that will help us to decipher the link between centrosomes, stem cells and tumour biology. In addition, I wish to pursue the original observations made in Drosophila and investigate the consequences of centrosome amplification in mammals.
Summary
Centrosomes are cytoplasmic organelles found in most animal cells with important roles in polarity establishment and maintenance. Theodor Boveri s pioneering work first suggested that extra-centrosomes could contribute to genetic instability and consequently to tumourigenesis. Although many human tumours do exhibit centrosome amplification (extra centrosomes) or centrosome abnormalities, the exact contribution of centrosomes to tumour initiation in vertebrate organisms remains to be determined. I have recently showed that Drosophila flies carrying extra-centrosomes, following the over-expression of the centriole replication kinase Sak, did not exhibit chromosome segregation errors and were able to maintain a stable diploid genome over many generations. Surprisingly, however, neural stem cells fail frequently to align the mitotic spindle with their polarity axis during asymmetric division. Moreover, I have found that centrosome amplification is permissive to tumour formation in flies. So far, however, we do not know the molecular mechanisms that allow transformation when extra centrosomes are present and elucidating these mechanisms is the aim of the work presented in this proposal. Here, I describe a series of complementary approaches that will help us to decipher the link between centrosomes, stem cells and tumour biology. In addition, I wish to pursue the original observations made in Drosophila and investigate the consequences of centrosome amplification in mammals.
Max ERC Funding
1 550 000 €
Duration
Start date: 2010-01-01, End date: 2015-06-30
Project acronym CentSatRegFunc
Project Dissecting the function and regulation of centriolar satellites: key regulators of the centrosome/cilium complex
Researcher (PI) Elif Nur Firat Karalar
Host Institution (HI) KOC UNIVERSITY
Call Details Starting Grant (StG), LS3, ERC-2015-STG
Summary Centrosomes are the main microtubule-organizing centers of animal cells. They influence the morphology of the microtubule cytoskeleton and function as the base of primary cilium, a nexus for important signaling pathways. Structural and functional defects in centrosome/cilium complex cause a variety of human diseases including cancer, ciliopathies and microcephaly. To understand the relationship between human diseases and centrosome/cilium abnormalities, it is essential to elucidate the biogenesis of centrosome/cilium complex and the control mechanisms that regulate their structure and function. To tackle these fundamental problems, we will dissect the function and regulation of centriolar satellites, the array of granules that localize around the centrosome/cilium complex in mammalian cells. Only recently interest in the satellites has grown because mutations affecting satellite components were shown to cause ciliopathies, microcephaly and schizophrenia.
Remarkably, many centrosome/cilium proteins localize to these structures and we lack understanding of when, why and how these proteins localize to satellites. The central hypothesis of this grant is that satellites ensure proper centrosome/cilium complex structure and function by acting as transit paths for modification, assembly, storage, stability and trafficking of centrosome/cilium proteins. In Aim 1, we will identify the nature of regulatory and molecular relationship between satellites and the centrosome/cilium complex. In Aim 2, we will elucidate the role of satellites in proteostasis of centrosome/cilium proteins. In Aim 3, we will investigate the functional significance of satellite-localization of centrosome/cilium proteins during processes that go awry in human disease. Using a multidisciplinary approach, the proposed research will expand our knowledge of the spatiotemporal regulation of the centrosome/cilium complex and provide new insights into pathogenesis of ciliopathies and primary microcephaly.
Summary
Centrosomes are the main microtubule-organizing centers of animal cells. They influence the morphology of the microtubule cytoskeleton and function as the base of primary cilium, a nexus for important signaling pathways. Structural and functional defects in centrosome/cilium complex cause a variety of human diseases including cancer, ciliopathies and microcephaly. To understand the relationship between human diseases and centrosome/cilium abnormalities, it is essential to elucidate the biogenesis of centrosome/cilium complex and the control mechanisms that regulate their structure and function. To tackle these fundamental problems, we will dissect the function and regulation of centriolar satellites, the array of granules that localize around the centrosome/cilium complex in mammalian cells. Only recently interest in the satellites has grown because mutations affecting satellite components were shown to cause ciliopathies, microcephaly and schizophrenia.
Remarkably, many centrosome/cilium proteins localize to these structures and we lack understanding of when, why and how these proteins localize to satellites. The central hypothesis of this grant is that satellites ensure proper centrosome/cilium complex structure and function by acting as transit paths for modification, assembly, storage, stability and trafficking of centrosome/cilium proteins. In Aim 1, we will identify the nature of regulatory and molecular relationship between satellites and the centrosome/cilium complex. In Aim 2, we will elucidate the role of satellites in proteostasis of centrosome/cilium proteins. In Aim 3, we will investigate the functional significance of satellite-localization of centrosome/cilium proteins during processes that go awry in human disease. Using a multidisciplinary approach, the proposed research will expand our knowledge of the spatiotemporal regulation of the centrosome/cilium complex and provide new insights into pathogenesis of ciliopathies and primary microcephaly.
Max ERC Funding
1 499 819 €
Duration
Start date: 2016-06-01, End date: 2021-05-31
Project acronym ChaperoneRegulome
Project ChaperoneRegulome: Understanding cell-type-specificity of chaperone regulation
Researcher (PI) Ritwick SAWARKAR
Host Institution (HI) MAX-PLANCK-GESELLSCHAFT ZUR FORDERUNG DER WISSENSCHAFTEN EV
Call Details Consolidator Grant (CoG), LS3, ERC-2018-COG
Summary Protein misfolding causes devastating health conditions such as neurodegeneration. Although the disease-causing protein is widely expressed, its misfolding occurs only in certain cell-types such as neurons. What governs the susceptibility of some tissues to misfolding is a fundamental question with biomedical relevance.
Molecular chaperones help cellular proteins fold into their native conformation. Despite the generality of their function, chaperones are differentially expressed across various tissues. Moreover exposure to misfolding stress changes chaperone expression in a cell-type-dependent manner. Thus cell-type-specific regulation of chaperones is a major determinant of susceptibility to misfolding. The molecular mechanisms governing chaperone levels in different cell-types are not understood, forming the basis of this proposal. We will take a multidisciplinary approach to address two key questions: (1) How are chaperone levels co-ordinated with tissue-specific demands on protein folding? (2) How do different cell-types regulate chaperone genes when exposed to the same misfolding stress?
Cellular chaperone levels and their response to misfolding stress are both driven by transcriptional changes and influenced by chromatin. The proposed work will bring the conceptual, technological and computational advances of chromatin/ transcription field to understand chaperone biology and misfolding diseases. Using in vivo mouse model and in vitro differentiation model, we will investigate molecular mechanisms that control chaperone levels in relevant tissues. Our work will provide insights into functional specialization of chaperones driven by tissue-specific folding demands. We will develop a novel and ambitious approach to assess protein-folding capacity in single cells moving the chaperone field beyond state-of-the-art. Thus by implementing genetic, computational and biochemical approaches, we aim to understand cell-type-specificity of chaperone regulation.
Summary
Protein misfolding causes devastating health conditions such as neurodegeneration. Although the disease-causing protein is widely expressed, its misfolding occurs only in certain cell-types such as neurons. What governs the susceptibility of some tissues to misfolding is a fundamental question with biomedical relevance.
Molecular chaperones help cellular proteins fold into their native conformation. Despite the generality of their function, chaperones are differentially expressed across various tissues. Moreover exposure to misfolding stress changes chaperone expression in a cell-type-dependent manner. Thus cell-type-specific regulation of chaperones is a major determinant of susceptibility to misfolding. The molecular mechanisms governing chaperone levels in different cell-types are not understood, forming the basis of this proposal. We will take a multidisciplinary approach to address two key questions: (1) How are chaperone levels co-ordinated with tissue-specific demands on protein folding? (2) How do different cell-types regulate chaperone genes when exposed to the same misfolding stress?
Cellular chaperone levels and their response to misfolding stress are both driven by transcriptional changes and influenced by chromatin. The proposed work will bring the conceptual, technological and computational advances of chromatin/ transcription field to understand chaperone biology and misfolding diseases. Using in vivo mouse model and in vitro differentiation model, we will investigate molecular mechanisms that control chaperone levels in relevant tissues. Our work will provide insights into functional specialization of chaperones driven by tissue-specific folding demands. We will develop a novel and ambitious approach to assess protein-folding capacity in single cells moving the chaperone field beyond state-of-the-art. Thus by implementing genetic, computational and biochemical approaches, we aim to understand cell-type-specificity of chaperone regulation.
Max ERC Funding
1 992 500 €
Duration
Start date: 2019-07-01, End date: 2024-06-30
Project acronym CHROMABOLISM
Project Chromatin-localized central metabolism regulating gene expression and cell identity
Researcher (PI) Stefan KUBICEK
Host Institution (HI) CEMM - FORSCHUNGSZENTRUM FUER MOLEKULARE MEDIZIN GMBH
Call Details Consolidator Grant (CoG), LS3, ERC-2017-COG
Summary Epigenetics research has revealed that in the cell’s nucleus all kinds of biomolecules–DNA, RNAs, proteins, protein posttranslational modifications–are highly compartmentalized to occupy distinct chromatin territories and genomic loci, thereby contributing to gene regulation and cell identity. In contrast, small molecules and cellular metabolites are generally considered to passively enter the nucleus from the cytoplasm and to lack distinct subnuclear localization. The CHROMABOLISM proposal challenges this assumption based on preliminary data generated in my laboratory. I hypothesize that chromatin-bound enzymes of central metabolism and subnuclear metabolite gradients contribute to gene regulation and cellular identity.
To address this hypothesis, we will first systematically profile chromatin-bound metabolic enzymes, chart nuclear metabolomes across representative leukemia cell lines, and develop tools to measure local metabolite concentrations at distinct genomic loci. In a second step, we will then develop and apply technology to perturb these nuclear metabolite patterns by forcing the export of metabolic enzymes for the nucleus, aberrantly recruiting these enzymes to selected genomic loci, and perturbing metabolite patterns by addition and depletion of metabolites. In all these conditions we will measure the impact of nuclear metabolism on chromatin structure and gene expression. Based on the data obtained, we will model for the effects of cellular metabolites on cancer cell identity and proliferation. In line with the recent discovery of oncometabolites and the clinical use of antimetabolites, we expect to predict chromatin-bound metabolic enzymes that can be exploited as druggable targets in oncology. In a final aim we will validate these targets in leukemia and develop chemical probes against them.
Successful completion of this project has the potential to transform our understanding of nuclear metabolism in control of gene expression and cellular identity.
Summary
Epigenetics research has revealed that in the cell’s nucleus all kinds of biomolecules–DNA, RNAs, proteins, protein posttranslational modifications–are highly compartmentalized to occupy distinct chromatin territories and genomic loci, thereby contributing to gene regulation and cell identity. In contrast, small molecules and cellular metabolites are generally considered to passively enter the nucleus from the cytoplasm and to lack distinct subnuclear localization. The CHROMABOLISM proposal challenges this assumption based on preliminary data generated in my laboratory. I hypothesize that chromatin-bound enzymes of central metabolism and subnuclear metabolite gradients contribute to gene regulation and cellular identity.
To address this hypothesis, we will first systematically profile chromatin-bound metabolic enzymes, chart nuclear metabolomes across representative leukemia cell lines, and develop tools to measure local metabolite concentrations at distinct genomic loci. In a second step, we will then develop and apply technology to perturb these nuclear metabolite patterns by forcing the export of metabolic enzymes for the nucleus, aberrantly recruiting these enzymes to selected genomic loci, and perturbing metabolite patterns by addition and depletion of metabolites. In all these conditions we will measure the impact of nuclear metabolism on chromatin structure and gene expression. Based on the data obtained, we will model for the effects of cellular metabolites on cancer cell identity and proliferation. In line with the recent discovery of oncometabolites and the clinical use of antimetabolites, we expect to predict chromatin-bound metabolic enzymes that can be exploited as druggable targets in oncology. In a final aim we will validate these targets in leukemia and develop chemical probes against them.
Successful completion of this project has the potential to transform our understanding of nuclear metabolism in control of gene expression and cellular identity.
Max ERC Funding
1 980 916 €
Duration
Start date: 2018-05-01, End date: 2023-04-30
Project acronym ChromHeritance
Project Chromosome inheritance from mammalian oocytes to embryos
Researcher (PI) Kikue Tachibana-Konwalski
Host Institution (HI) INSTITUT FUER MOLEKULARE BIOTECHNOLOGIE GMBH
Call Details Starting Grant (StG), LS3, ERC-2013-StG
Summary One of the most dramatic transitions in biology is the oocyte-to-zygote transition. This refers to the maturation of the female germ cell or oocyte, which undergoes two rounds of meiotic chromosome segregation and, following fertilization, is converted to a mitotically dividing embryo. We aim to establish an innovative research program that addresses fundamental questions about the molecular processes controlling the mammalian oocyte-to-zygote transition to ensure faithful inheritance of genomes from one generation to the next. We are taking an interdisciplinary approach combining germ cell and chromosome biology with cell cycle and epigenetic studies to understand how maternal factors regulate chromosome segregation in oocytes and chromatin organization in the zygote. A molecular understanding of key players regulating these processes is a requisite step for investigating how their deterioration contributes to maternal age-related aneuploidy and infertility. Aneuploidy is the leading cause of mental retardation and spontaneous miscarriage. The current trend towards advanced maternal age has increased the frequency of trisomic fetuses by 71% in the past ten years. A better understanding of mammalian meiosis is therefore relevant to human reproductive health.
A special feature of the female germ line is that meiotic DNA replication occurs in the embryo but oocytes remain arrested until the first meiotic division is triggered months (mouse) or decades (human) later. The longevity of oocytes poses a challenge for the cohesin complex that must hold together sister chromatids from DNA synthesis until chromosome segregation. We specifically aim to: 1) elucidate how sister chromatid cohesion is maintained in mammalian oocytes, 2) identify mechanisms regulating cohesion in young and aged oocytes, and 3) investigate how the inheritance of genetic and resetting of epigenetic information is coordinated with cell cycle progression at the oocyte-to-zygote transition.
Summary
One of the most dramatic transitions in biology is the oocyte-to-zygote transition. This refers to the maturation of the female germ cell or oocyte, which undergoes two rounds of meiotic chromosome segregation and, following fertilization, is converted to a mitotically dividing embryo. We aim to establish an innovative research program that addresses fundamental questions about the molecular processes controlling the mammalian oocyte-to-zygote transition to ensure faithful inheritance of genomes from one generation to the next. We are taking an interdisciplinary approach combining germ cell and chromosome biology with cell cycle and epigenetic studies to understand how maternal factors regulate chromosome segregation in oocytes and chromatin organization in the zygote. A molecular understanding of key players regulating these processes is a requisite step for investigating how their deterioration contributes to maternal age-related aneuploidy and infertility. Aneuploidy is the leading cause of mental retardation and spontaneous miscarriage. The current trend towards advanced maternal age has increased the frequency of trisomic fetuses by 71% in the past ten years. A better understanding of mammalian meiosis is therefore relevant to human reproductive health.
A special feature of the female germ line is that meiotic DNA replication occurs in the embryo but oocytes remain arrested until the first meiotic division is triggered months (mouse) or decades (human) later. The longevity of oocytes poses a challenge for the cohesin complex that must hold together sister chromatids from DNA synthesis until chromosome segregation. We specifically aim to: 1) elucidate how sister chromatid cohesion is maintained in mammalian oocytes, 2) identify mechanisms regulating cohesion in young and aged oocytes, and 3) investigate how the inheritance of genetic and resetting of epigenetic information is coordinated with cell cycle progression at the oocyte-to-zygote transition.
Max ERC Funding
1 499 738 €
Duration
Start date: 2014-02-01, End date: 2019-01-31
