Project acronym 20SComplexity
Project An integrative approach to uncover the multilevel regulation of 20S proteasome degradation
Researcher (PI) Michal Sharon
Host Institution (HI) WEIZMANN INSTITUTE OF SCIENCE
Call Details Starting Grant (StG), LS1, ERC-2014-STG
Summary For many years, the ubiquitin-26S proteasome degradation pathway was considered the primary route for proteasomal degradation. However, it is now becoming clear that proteins can also be targeted for degradation by a ubiquitin-independent mechanism mediated by the core 20S proteasome itself. Although initially believed to be limited to rare exceptions, degradation by the 20S proteasome is now understood to have a wide range of substrates, many of which are key regulatory proteins. Despite its importance, little is known about the mechanisms that control 20S proteasomal degradation, unlike the extensive knowledge acquired over the years concerning degradation by the 26S proteasome. Our overall aim is to reveal the multiple regulatory levels that coordinate the 20S proteasome degradation route.
To achieve this goal we will carry out a comprehensive research program characterizing three distinct levels of 20S proteasome regulation:
Intra-molecular regulation- Revealing the intrinsic molecular switch that activates the latent 20S proteasome.
Inter-molecular regulation- Identifying novel proteins that bind the 20S proteasome to regulate its activity and characterizing their mechanism of function.
Cellular regulatory networks- Unraveling the cellular cues and multiple pathways that influence 20S proteasome activity using a novel systematic and unbiased screening approach.
Our experimental strategy involves the combination of biochemical approaches with native mass spectrometry, cross-linking and fluorescence measurements, complemented by cell biology analyses and high-throughput screening. Such a multidisciplinary approach, integrating in vitro and in vivo findings, will likely provide the much needed knowledge on the 20S proteasome degradation route. When completed, we anticipate that this work will be part of a new paradigm – no longer perceiving the 20S proteasome mediated degradation as a simple and passive event but rather a tightly regulated and coordinated process.
Summary
For many years, the ubiquitin-26S proteasome degradation pathway was considered the primary route for proteasomal degradation. However, it is now becoming clear that proteins can also be targeted for degradation by a ubiquitin-independent mechanism mediated by the core 20S proteasome itself. Although initially believed to be limited to rare exceptions, degradation by the 20S proteasome is now understood to have a wide range of substrates, many of which are key regulatory proteins. Despite its importance, little is known about the mechanisms that control 20S proteasomal degradation, unlike the extensive knowledge acquired over the years concerning degradation by the 26S proteasome. Our overall aim is to reveal the multiple regulatory levels that coordinate the 20S proteasome degradation route.
To achieve this goal we will carry out a comprehensive research program characterizing three distinct levels of 20S proteasome regulation:
Intra-molecular regulation- Revealing the intrinsic molecular switch that activates the latent 20S proteasome.
Inter-molecular regulation- Identifying novel proteins that bind the 20S proteasome to regulate its activity and characterizing their mechanism of function.
Cellular regulatory networks- Unraveling the cellular cues and multiple pathways that influence 20S proteasome activity using a novel systematic and unbiased screening approach.
Our experimental strategy involves the combination of biochemical approaches with native mass spectrometry, cross-linking and fluorescence measurements, complemented by cell biology analyses and high-throughput screening. Such a multidisciplinary approach, integrating in vitro and in vivo findings, will likely provide the much needed knowledge on the 20S proteasome degradation route. When completed, we anticipate that this work will be part of a new paradigm – no longer perceiving the 20S proteasome mediated degradation as a simple and passive event but rather a tightly regulated and coordinated process.
Max ERC Funding
1 500 000 €
Duration
Start date: 2015-04-01, End date: 2020-03-31
Project acronym ABDESIGN
Project Computational design of novel protein function in antibodies
Researcher (PI) Sarel-Jacob Fleishman
Host Institution (HI) WEIZMANN INSTITUTE OF SCIENCE
Call Details Starting Grant (StG), LS1, ERC-2013-StG
Summary We propose to elucidate the structural design principles of naturally occurring antibody complementarity-determining regions (CDRs) and to computationally design novel antibody functions. Antibodies represent the most versatile known system for molecular recognition. Research has yielded many insights into antibody design principles and promising biotechnological and pharmaceutical applications. Still, our understanding of how CDRs encode specific loop conformations lags far behind our understanding of structure-function relationships in non-immunological scaffolds. Thus, design of antibodies from first principles has not been demonstrated. We propose a computational-experimental strategy to address this challenge. We will: (a) characterize the design principles and sequence elements that rigidify antibody CDRs. Natural antibody loops will be subjected to computational modeling, crystallography, and a combined in vitro evolution and deep-sequencing approach to isolate sequence features that rigidify loop backbones; (b) develop a novel computational-design strategy, which uses the >1000 solved structures of antibodies deposited in structure databases to realistically model CDRs and design them to recognize proteins that have not been co-crystallized with antibodies. For example, we will design novel antibodies targeting insulin, for which clinically useful diagnostics are needed. By accessing much larger sequence/structure spaces than are available to natural immune-system repertoires and experimental methods, computational antibody design could produce higher-specificity and higher-affinity binders, even to challenging targets; and (c) develop new strategies to program conformational change in CDRs, generating, e.g., the first allosteric antibodies. These will allow targeting, in principle, of any molecule, potentially revolutionizing how antibodies are generated for research and medicine, providing new insights on the design principles of protein functional sites.
Summary
We propose to elucidate the structural design principles of naturally occurring antibody complementarity-determining regions (CDRs) and to computationally design novel antibody functions. Antibodies represent the most versatile known system for molecular recognition. Research has yielded many insights into antibody design principles and promising biotechnological and pharmaceutical applications. Still, our understanding of how CDRs encode specific loop conformations lags far behind our understanding of structure-function relationships in non-immunological scaffolds. Thus, design of antibodies from first principles has not been demonstrated. We propose a computational-experimental strategy to address this challenge. We will: (a) characterize the design principles and sequence elements that rigidify antibody CDRs. Natural antibody loops will be subjected to computational modeling, crystallography, and a combined in vitro evolution and deep-sequencing approach to isolate sequence features that rigidify loop backbones; (b) develop a novel computational-design strategy, which uses the >1000 solved structures of antibodies deposited in structure databases to realistically model CDRs and design them to recognize proteins that have not been co-crystallized with antibodies. For example, we will design novel antibodies targeting insulin, for which clinically useful diagnostics are needed. By accessing much larger sequence/structure spaces than are available to natural immune-system repertoires and experimental methods, computational antibody design could produce higher-specificity and higher-affinity binders, even to challenging targets; and (c) develop new strategies to program conformational change in CDRs, generating, e.g., the first allosteric antibodies. These will allow targeting, in principle, of any molecule, potentially revolutionizing how antibodies are generated for research and medicine, providing new insights on the design principles of protein functional sites.
Max ERC Funding
1 499 930 €
Duration
Start date: 2013-09-01, End date: 2018-08-31
Project acronym BIZEB
Project Bio-Imaging of Zoonotic and Emerging Bunyaviruses
Researcher (PI) Juha Huiskonen
Host Institution (HI) HELSINGIN YLIOPISTO
Call Details Consolidator Grant (CoG), LS1, ERC-2014-CoG
Summary We aim to understand host cell entry of enveloped viruses at molecular level. A crucial step in this process is when the viral membrane fuses with the cell membrane. Similarly to cell–cell fusion, this step is mediated by fusion proteins (classes I–III). Several medically important viruses, notably dengue and many bunyaviruses, harbour a class II fusion protein. Class II fusion protein structures have been solved in pre- and post-fusion conformation and in some cases different factors promoting fusion have been determined. However, questions about the most important steps of this key process remain unanswered. I will focus on the entry mechanism of bunyaviruses by using cutting-edge, high spatial and temporal resolution bio-imaging techniques. These viruses have been chosen as a model system to maximise the significance of the project: they form an emerging viral threat to humans and animals, no approved vaccines or antivirals exist for human use and they are less studied than other class II fusion protein systems. Cryo-electron microscopy and tomography will be used to solve high-resolution structures (up to ~3 Å) of viruses, in addition to virus–receptor and virus–membrane complexes. Advanced fluorescence microscopy techniques will be used to probe the dynamics of virus entry and fusion in vivo and in vitro. Deciphering key steps in virus entry is expected to contribute to rational vaccine and drug design. During this project I aim to establish a world-class laboratory in structural and cellular biology of emerging viruses. The project greatly benefits from our unique biosafety level 3 laboratory offering advanced bio-imaging techniques. Furthermore it will also pave way for similar projects on other infectious viruses. Finally the novel computational image processing methods developed in this project will be broadly applicable for the analysis of flexible biological structures, which often pose the most challenging yet interesting questions in structural biology.
Summary
We aim to understand host cell entry of enveloped viruses at molecular level. A crucial step in this process is when the viral membrane fuses with the cell membrane. Similarly to cell–cell fusion, this step is mediated by fusion proteins (classes I–III). Several medically important viruses, notably dengue and many bunyaviruses, harbour a class II fusion protein. Class II fusion protein structures have been solved in pre- and post-fusion conformation and in some cases different factors promoting fusion have been determined. However, questions about the most important steps of this key process remain unanswered. I will focus on the entry mechanism of bunyaviruses by using cutting-edge, high spatial and temporal resolution bio-imaging techniques. These viruses have been chosen as a model system to maximise the significance of the project: they form an emerging viral threat to humans and animals, no approved vaccines or antivirals exist for human use and they are less studied than other class II fusion protein systems. Cryo-electron microscopy and tomography will be used to solve high-resolution structures (up to ~3 Å) of viruses, in addition to virus–receptor and virus–membrane complexes. Advanced fluorescence microscopy techniques will be used to probe the dynamics of virus entry and fusion in vivo and in vitro. Deciphering key steps in virus entry is expected to contribute to rational vaccine and drug design. During this project I aim to establish a world-class laboratory in structural and cellular biology of emerging viruses. The project greatly benefits from our unique biosafety level 3 laboratory offering advanced bio-imaging techniques. Furthermore it will also pave way for similar projects on other infectious viruses. Finally the novel computational image processing methods developed in this project will be broadly applicable for the analysis of flexible biological structures, which often pose the most challenging yet interesting questions in structural biology.
Max ERC Funding
1 998 375 €
Duration
Start date: 2015-04-01, End date: 2020-03-31
Project acronym CANCER SIGNALOSOMES
Project Spatially and temporally regulated membrane complexes in cancer cell invasion and cytokinesis
Researcher (PI) Johanna Ivaska
Host Institution (HI) TEKNOLOGIAN TUTKIMUSKESKUS VTT
Call Details Starting Grant (StG), LS1, ERC-2007-StG
Summary Cancer progression, characterized by uncontrolled proliferation and motility of cells, is a complex and deadly process. Integrins, a major cell surface adhesion receptor family, are transmembrane proteins known to regulate cell behaviour by transducing extracellular signals to cytoplasmic protein complexes. We and others have shown that recruitment of specific protein complexes by the cytoplasmic domains of integrins is important in tumorigenesis. Here our aim is to study three interrelated processes in cancer progression which involve integrin signalling, but which have not been elucidated earlier at all. 1) Integrins in cell division (cytokinesis). Since coordinated action of the cytoskeleton and membranes is needed both for cell division and motility, shared integrin functions can regulate both events. 2) Dynamic integrin signalosomes at the leading edge of invading cells. Spatially and temporally regulated, integrin-protein complexes at the front of infiltrating cells are likely to dictate the movement of cancer cells in tissues. 3) Transmembrane segments of integrins as scaffolds for integrin signalling. In addition to cytosolic proteins, integrins most likely interact with proteins within the membrane resulting into new signalling modalities. In this proposal we will use innovative, modern and even unconventional techniques (such as RNAi and live-cell arrays detecting integrin traffic, cell motility and multiplication, laser-microdissection, proteomics and bacterial-two-hybrid screens) to unravel these new integrin functions, for which we have preliminary evidence. Each project will give fundamentally novel mechanistic insight into the role of integrins in cancer. Moreover, these interdisciplinary new openings will increase our understanding in cancer progression in general and will open new possibilities for therapeutic intervention targeting both cancer proliferation and dissemination in the body.
Summary
Cancer progression, characterized by uncontrolled proliferation and motility of cells, is a complex and deadly process. Integrins, a major cell surface adhesion receptor family, are transmembrane proteins known to regulate cell behaviour by transducing extracellular signals to cytoplasmic protein complexes. We and others have shown that recruitment of specific protein complexes by the cytoplasmic domains of integrins is important in tumorigenesis. Here our aim is to study three interrelated processes in cancer progression which involve integrin signalling, but which have not been elucidated earlier at all. 1) Integrins in cell division (cytokinesis). Since coordinated action of the cytoskeleton and membranes is needed both for cell division and motility, shared integrin functions can regulate both events. 2) Dynamic integrin signalosomes at the leading edge of invading cells. Spatially and temporally regulated, integrin-protein complexes at the front of infiltrating cells are likely to dictate the movement of cancer cells in tissues. 3) Transmembrane segments of integrins as scaffolds for integrin signalling. In addition to cytosolic proteins, integrins most likely interact with proteins within the membrane resulting into new signalling modalities. In this proposal we will use innovative, modern and even unconventional techniques (such as RNAi and live-cell arrays detecting integrin traffic, cell motility and multiplication, laser-microdissection, proteomics and bacterial-two-hybrid screens) to unravel these new integrin functions, for which we have preliminary evidence. Each project will give fundamentally novel mechanistic insight into the role of integrins in cancer. Moreover, these interdisciplinary new openings will increase our understanding in cancer progression in general and will open new possibilities for therapeutic intervention targeting both cancer proliferation and dissemination in the body.
Max ERC Funding
1 529 369 €
Duration
Start date: 2008-08-01, End date: 2013-07-31
Project acronym CIRCOMMUNICATION
Project Deciphering molecular pathways of circadian clock communication
Researcher (PI) gad ASHER
Host Institution (HI) WEIZMANN INSTITUTE OF SCIENCE
Call Details Consolidator Grant (CoG), LS1, ERC-2017-COG
Summary The overarching objective of this interdisciplinary project is to elucidate mechanisms through which billions of individual clocks in the body communicate with each other and tick in harmony. The mammalian circadian timing system consists of a master clock in the brain and subsidiary oscillators in almost every cell of the body. Since these clocks anticipate environmental changes and function together to orchestrate daily physiology and behavior their temporal synchronization is critical.
Our recent finding that oxygen serves as a resetting cue for circadian clocks points towards the unprecedented involvement of blood gases as time signals. We will apply cutting edge continuous physiological measurements in freely moving animals, alongside biochemical/molecular biology approaches and advanced cell culture setup to determine the molecular role of oxygen, carbon dioxide and pH in circadian clock communication and function.
The intricate nature of the mammalian circadian system demands the presence of communication mechanisms between clocks throughout the body at multiple levels. While previous studies primarily addressed the role of the master clock in resetting peripheral clocks, our knowledge regarding the communication among clocks between and within peripheral organs is rudimentary. We will reconstruct the mammalian circadian system from the bottom up, sequentially restoring clocks in peripheral tissues of a non-rhythmic animal to (i) obtain a system-view of the peripheral circadian communication network; and (ii) study novel tissue-derived circadian communication mechanisms.
This integrative proposal addresses fundamental aspects of circadian biology. It is expected to unravel the circadian communication network and shed light on how billions of clocks in the body function in unison. Its impact extends beyond circadian rhythms and bears great potential for research on communication between cells/tissues in various fields of biology.
Summary
The overarching objective of this interdisciplinary project is to elucidate mechanisms through which billions of individual clocks in the body communicate with each other and tick in harmony. The mammalian circadian timing system consists of a master clock in the brain and subsidiary oscillators in almost every cell of the body. Since these clocks anticipate environmental changes and function together to orchestrate daily physiology and behavior their temporal synchronization is critical.
Our recent finding that oxygen serves as a resetting cue for circadian clocks points towards the unprecedented involvement of blood gases as time signals. We will apply cutting edge continuous physiological measurements in freely moving animals, alongside biochemical/molecular biology approaches and advanced cell culture setup to determine the molecular role of oxygen, carbon dioxide and pH in circadian clock communication and function.
The intricate nature of the mammalian circadian system demands the presence of communication mechanisms between clocks throughout the body at multiple levels. While previous studies primarily addressed the role of the master clock in resetting peripheral clocks, our knowledge regarding the communication among clocks between and within peripheral organs is rudimentary. We will reconstruct the mammalian circadian system from the bottom up, sequentially restoring clocks in peripheral tissues of a non-rhythmic animal to (i) obtain a system-view of the peripheral circadian communication network; and (ii) study novel tissue-derived circadian communication mechanisms.
This integrative proposal addresses fundamental aspects of circadian biology. It is expected to unravel the circadian communication network and shed light on how billions of clocks in the body function in unison. Its impact extends beyond circadian rhythms and bears great potential for research on communication between cells/tissues in various fields of biology.
Max ERC Funding
1 999 945 €
Duration
Start date: 2018-03-01, End date: 2023-02-28
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 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
Project acronym GENEXP
Project Gene Expression Explored in Space and Time Using Single Gene and Single Molecule Analysis
Researcher (PI) Yaron Shav-Tal
Host Institution (HI) BAR ILAN UNIVERSITY
Call Details Starting Grant (StG), LS1, ERC-2010-StG_20091118
Summary "Live-cell imaging combined with kinetic analyses has provided new biological insights on the gene expression pathway. However, such studies in mammalian cells typically require use of exogenous over-expressed gene constructs, which often form large tandem gene arrays and usually lack the complete endogenous regulatory sequences. It is therefore imperative to design methodology for analyzing gene expression kinetics of single alleles of endogenous genes. While certain steps have been taken in this direction, there are many experimental obstacles standing in the way of a robust genome-wide system for the in vivo examination of endogenous gene expression within the natural nuclear environment. GENEXP sets out to provide such a system.
It will start with methodology for robust tagging of a multitude of endogenous genes and their transcribed mRNAs in human cells using the ""CD tagging"" approach. Thereby, in vivo mRNA synthesis at the nuclear site of RNA birth will be explored in a unique manner. A high-resolution study of gene expression, in particular mRNA transcription and mRNA export, under endogenous cellular context and using a genome-wide live-cell approach will be performed. GENEXP will specifically focus on the:
i) Transcriptional kinetics of endogenous genes in single cells and cell populations;
ii) Kinetics of mRNA export on the single molecule level;
iii) Examination of the protein composition of endogenous mRNPs;
iv) High throughput scan for drugs that affect gene expression and mRNA export.
Altogether, GENEXP will provide breakthrough capability in kinetically quantifying the gene expression pathway of a large variety of endogenous genes, and the ability to examine the generated molecules on the single-molecule level. This will be done within their normal genomic and biological environment, at the single-allele level."
Summary
"Live-cell imaging combined with kinetic analyses has provided new biological insights on the gene expression pathway. However, such studies in mammalian cells typically require use of exogenous over-expressed gene constructs, which often form large tandem gene arrays and usually lack the complete endogenous regulatory sequences. It is therefore imperative to design methodology for analyzing gene expression kinetics of single alleles of endogenous genes. While certain steps have been taken in this direction, there are many experimental obstacles standing in the way of a robust genome-wide system for the in vivo examination of endogenous gene expression within the natural nuclear environment. GENEXP sets out to provide such a system.
It will start with methodology for robust tagging of a multitude of endogenous genes and their transcribed mRNAs in human cells using the ""CD tagging"" approach. Thereby, in vivo mRNA synthesis at the nuclear site of RNA birth will be explored in a unique manner. A high-resolution study of gene expression, in particular mRNA transcription and mRNA export, under endogenous cellular context and using a genome-wide live-cell approach will be performed. GENEXP will specifically focus on the:
i) Transcriptional kinetics of endogenous genes in single cells and cell populations;
ii) Kinetics of mRNA export on the single molecule level;
iii) Examination of the protein composition of endogenous mRNPs;
iv) High throughput scan for drugs that affect gene expression and mRNA export.
Altogether, GENEXP will provide breakthrough capability in kinetically quantifying the gene expression pathway of a large variety of endogenous genes, and the ability to examine the generated molecules on the single-molecule level. This will be done within their normal genomic and biological environment, at the single-allele level."
Max ERC Funding
1 498 510 €
Duration
Start date: 2010-12-01, End date: 2015-11-30
Project acronym METACYCLES
Project Uncovering metabolic cycles in mammals and dissecting their interplay with circadian clocks
Researcher (PI) Gad Asher
Host Institution (HI) WEIZMANN INSTITUTE OF SCIENCE
Call Details Starting Grant (StG), LS1, ERC-2012-StG_20111109
Summary The physiology and behavior of mammals are subject to daily oscillations that are driven by an endogenous circadian clock. The mammalian circadian timing system is composed of a central pacemaker in the brain that is entrained by daily light-dark cycles and in turn synchronizes subsidiary oscillators in virtually all cells of the body. The core clock molecular circuitry is based on interlocked negative transcription-translation feedback loops that generate daily oscillations of gene expression in cultured cells and living animals.
Circadian clocks play a major role in orchestrating daily metabolism and their disruption can lead to metabolic diseases such as diabetes and obesity. Concomitantly, circadian clocks are tightly coupled to cellular metabolism and respond to feeding cycles. The molecular mechanisms through which metabolism regulates clocks’ function are just starting to emerge. Recent work of ours and others revealed that NAD+/NADH are implicated in the function of circadian clocks, yet the molecular mechanisms involved are largely unknown. We propose to intensively study the role of NAD+/NADH in the function of circadian clocks and to reveal the underlying mechanisms.
The functional interplay between circadian clocks and metabolism raises the question whether there are daily cycles in cellular metabolism and intracellular metabolites. Hitherto, direct measurements of daily changes in cellular metabolism and intracellular metabolite levels are still in their infancy. Our overarching goal is to identify metabolic cycles in mammals and mechanistically address their interplay with circadian clocks. We will monitor metabolic outputs in intact cells and living animals and systemically measure daily changes in intracellular metabolites. Our findings are expected to push forward a paradigm shift in the circadian field from the current “transcriptional-translational clocks” to “metabolic clocks”.
Summary
The physiology and behavior of mammals are subject to daily oscillations that are driven by an endogenous circadian clock. The mammalian circadian timing system is composed of a central pacemaker in the brain that is entrained by daily light-dark cycles and in turn synchronizes subsidiary oscillators in virtually all cells of the body. The core clock molecular circuitry is based on interlocked negative transcription-translation feedback loops that generate daily oscillations of gene expression in cultured cells and living animals.
Circadian clocks play a major role in orchestrating daily metabolism and their disruption can lead to metabolic diseases such as diabetes and obesity. Concomitantly, circadian clocks are tightly coupled to cellular metabolism and respond to feeding cycles. The molecular mechanisms through which metabolism regulates clocks’ function are just starting to emerge. Recent work of ours and others revealed that NAD+/NADH are implicated in the function of circadian clocks, yet the molecular mechanisms involved are largely unknown. We propose to intensively study the role of NAD+/NADH in the function of circadian clocks and to reveal the underlying mechanisms.
The functional interplay between circadian clocks and metabolism raises the question whether there are daily cycles in cellular metabolism and intracellular metabolites. Hitherto, direct measurements of daily changes in cellular metabolism and intracellular metabolite levels are still in their infancy. Our overarching goal is to identify metabolic cycles in mammals and mechanistically address their interplay with circadian clocks. We will monitor metabolic outputs in intact cells and living animals and systemically measure daily changes in intracellular metabolites. Our findings are expected to push forward a paradigm shift in the circadian field from the current “transcriptional-translational clocks” to “metabolic clocks”.
Max ERC Funding
1 499 980 €
Duration
Start date: 2012-11-01, End date: 2017-10-31
Project acronym METSTEM
Project DNA methylation in stem cells
Researcher (PI) Howard Cedar
Host Institution (HI) THE HEBREW UNIVERSITY OF JERUSALEM
Call Details Advanced Grant (AdG), LS1, ERC-2010-AdG_20100317
Summary Embryonic and adult stem cells constitute an important component of biology by providing a pool of pluri- and multi-potent cells that supply a variety of different cell lineages. Little is known about the mechanisms involved in establishing and maintaining cell ¿stemness,¿ but it is most likely controlled by epigenetic signals such as DNA methylation. This proposal aims to understand these mechanisms and decipher the molecular logic used to program this plasticity.
We have developed a new strategy for studying the ¿DNA methylation potential¿ of any cell type throughout normal development. This utilizes a unique set of transgenic vectors programmed to detect both de novo methylation as well as the ability to protect CpG islands, and will, for the first time, allow one to evaluate the role of demethylation in normal stem cells and during reprogramming. This will be done using a new technique called ¿reverse epigenetics¿.
Preliminary studies indicate that embryonic stem cells differentiated in vitro undergo extensive aberrant methylation that does not reflect the normal pattern of methylation found in vivo. This artifact may be responsible for our inability to attain efficient differentiation in culture and may generate cells that are unhealthy and prone to cancer. We will characterize the causes of this phenomenon and decipher its underlying mechanism. This research should lead to the development of improved methods for tissue generation in vitro.
One of the most basic properties of adult stem cells is their ability to undergo asymmetric cell division that is often associated with unequal segregation of DNA. This mechanism is one of the most elemental, yet mysterious, aspects of stem cell biology. We have developed a completely new molecular model for this process that is based on the idea that non-symmetric DNA methylation serves as a strand-specific marker, and it is very likely that this will enable us to finally decipher this basic aspect of stem cells.
Summary
Embryonic and adult stem cells constitute an important component of biology by providing a pool of pluri- and multi-potent cells that supply a variety of different cell lineages. Little is known about the mechanisms involved in establishing and maintaining cell ¿stemness,¿ but it is most likely controlled by epigenetic signals such as DNA methylation. This proposal aims to understand these mechanisms and decipher the molecular logic used to program this plasticity.
We have developed a new strategy for studying the ¿DNA methylation potential¿ of any cell type throughout normal development. This utilizes a unique set of transgenic vectors programmed to detect both de novo methylation as well as the ability to protect CpG islands, and will, for the first time, allow one to evaluate the role of demethylation in normal stem cells and during reprogramming. This will be done using a new technique called ¿reverse epigenetics¿.
Preliminary studies indicate that embryonic stem cells differentiated in vitro undergo extensive aberrant methylation that does not reflect the normal pattern of methylation found in vivo. This artifact may be responsible for our inability to attain efficient differentiation in culture and may generate cells that are unhealthy and prone to cancer. We will characterize the causes of this phenomenon and decipher its underlying mechanism. This research should lead to the development of improved methods for tissue generation in vitro.
One of the most basic properties of adult stem cells is their ability to undergo asymmetric cell division that is often associated with unequal segregation of DNA. This mechanism is one of the most elemental, yet mysterious, aspects of stem cell biology. We have developed a completely new molecular model for this process that is based on the idea that non-symmetric DNA methylation serves as a strand-specific marker, and it is very likely that this will enable us to finally decipher this basic aspect of stem cells.
Max ERC Funding
1 941 930 €
Duration
Start date: 2011-04-01, End date: 2016-03-31
