Project acronym ACTMECH
Project Emergent Active Mechanical Behaviour of the Actomyosin Cell Cortex
Researcher (PI) Stephan Wolfgang Grill
Host Institution (HI) TECHNISCHE UNIVERSITAET DRESDEN
Country Germany
Call Details Starting Grant (StG), LS3, ERC-2011-StG_20101109
Summary The cell cortex is a highly dynamic layer of crosslinked actin filaments and myosin molecular motors beneath the cell membrane. It plays a central role in large scale rearrangements that occur inside cells. Many molecular mechanisms contribute to cortex structure and dynamics. However, cell scale physical properties of the cortex are difficult to grasp. This is problematic because for large scale rearrangements inside a cell, such as coherent flow of the cell cortex, it is the cell scale emergent properties that are important for the realization of such events. I will investigate how the actomyosin cytoskeleton behaves at a coarse grained and cellular scale, and will study how this emergent active behaviour is influenced by molecular mechanisms. We will study the cell cortex in the one cell stage C. elegans embryo, which undergoes large scale cortical flow during polarization and cytokinesis. We will combine theory and experiment. We will characterize cortex structure and dynamics with biophysical techniques such as cortical laser ablation and quantitative photobleaching experiments. We will develop and employ novel theoretical approaches to describe the cell scale mechanical behaviour in terms of an active complex fluid. We will utilize genetic approaches to understand how these emergent mechanical properties are influenced by molecular activities. A central goal is to arrive at a coarse grained description of the cortex that can predict future dynamic behaviour from the past structure, which is conceptually similar to how weather forecasting is accomplished. To date, systematic approaches to link molecular scale physical mechanisms to those on cellular scales are missing. This work will open new opportunities for cell biological and cell biophysical research, by providing a methodological approach for bridging scales, for studying emergent and large-scale active mechanical behaviours and linking them to molecular mechanisms.
Summary
The cell cortex is a highly dynamic layer of crosslinked actin filaments and myosin molecular motors beneath the cell membrane. It plays a central role in large scale rearrangements that occur inside cells. Many molecular mechanisms contribute to cortex structure and dynamics. However, cell scale physical properties of the cortex are difficult to grasp. This is problematic because for large scale rearrangements inside a cell, such as coherent flow of the cell cortex, it is the cell scale emergent properties that are important for the realization of such events. I will investigate how the actomyosin cytoskeleton behaves at a coarse grained and cellular scale, and will study how this emergent active behaviour is influenced by molecular mechanisms. We will study the cell cortex in the one cell stage C. elegans embryo, which undergoes large scale cortical flow during polarization and cytokinesis. We will combine theory and experiment. We will characterize cortex structure and dynamics with biophysical techniques such as cortical laser ablation and quantitative photobleaching experiments. We will develop and employ novel theoretical approaches to describe the cell scale mechanical behaviour in terms of an active complex fluid. We will utilize genetic approaches to understand how these emergent mechanical properties are influenced by molecular activities. A central goal is to arrive at a coarse grained description of the cortex that can predict future dynamic behaviour from the past structure, which is conceptually similar to how weather forecasting is accomplished. To date, systematic approaches to link molecular scale physical mechanisms to those on cellular scales are missing. This work will open new opportunities for cell biological and cell biophysical research, by providing a methodological approach for bridging scales, for studying emergent and large-scale active mechanical behaviours and linking them to molecular mechanisms.
Max ERC Funding
1 500 000 €
Duration
Start date: 2011-12-01, End date: 2017-08-31
Project acronym COMBIPATTERNING
Project Combinatorial Patterning of Particles for High Density Peptide Arrays
Researcher (PI) Alexander Nesterov-Mueller
Host Institution (HI) KARLSRUHER INSTITUT FUER TECHNOLOGIE
Country Germany
Call Details Starting Grant (StG), PE8, ERC-2011-StG_20101014
Summary We want to use selective laser melting to pattern a substrate with different solid micro particles at a density of 1 million spots per cm2. First, a homogeneous particle layer is deposited on a substrate and a pattern of micro spots of melted matrix is generated by laser radiation. Then, non-melted particles are blown away. Embedded within the particles are different chemically reactive amino acid derivatives that will start coupling to very small synthesis sites upon melting the particle pattern in an oven. This is done once all of the 20 different amino acid particles have been glued by laser patterning to the surface. Washing away uncoupled material, removing Fmoc protecting group, and repeating the patterning steps according to standard Merrifield synthesis, leads to the combinatorial synthesis of very high-density peptide arrays. The main objective of this proposal is to develop this method up to the level of a semi-automated synthesis machine. In addition, we will use the manufactured very high-density peptide arrays to readout the information that is deposited in the immune system, i.e. find a peptide binder for every one of the 200-500 antibody species that patrol the serum of an individual in elevated levels. These experiments might lead to novel tools to find out the causes of hitherto enigmatic diseases because then we might be able to correlate antibody patterns with disease status without knowing in advance the disease-specific antibodies. Beyond the life sciences, we want to embed 10.000 peptides per cm2 within an insulating layer of alkane thiols, each on a different gold pad of a specially designed screening chip. Then, we could readout I/V characteristics of individual peptide species, and eventually find peptide-based diodes. These could be modified in their sequence and screened again for better performance. This evolution-inspired screening approach might lead to novel materials that could be used in fuel cells.
Summary
We want to use selective laser melting to pattern a substrate with different solid micro particles at a density of 1 million spots per cm2. First, a homogeneous particle layer is deposited on a substrate and a pattern of micro spots of melted matrix is generated by laser radiation. Then, non-melted particles are blown away. Embedded within the particles are different chemically reactive amino acid derivatives that will start coupling to very small synthesis sites upon melting the particle pattern in an oven. This is done once all of the 20 different amino acid particles have been glued by laser patterning to the surface. Washing away uncoupled material, removing Fmoc protecting group, and repeating the patterning steps according to standard Merrifield synthesis, leads to the combinatorial synthesis of very high-density peptide arrays. The main objective of this proposal is to develop this method up to the level of a semi-automated synthesis machine. In addition, we will use the manufactured very high-density peptide arrays to readout the information that is deposited in the immune system, i.e. find a peptide binder for every one of the 200-500 antibody species that patrol the serum of an individual in elevated levels. These experiments might lead to novel tools to find out the causes of hitherto enigmatic diseases because then we might be able to correlate antibody patterns with disease status without knowing in advance the disease-specific antibodies. Beyond the life sciences, we want to embed 10.000 peptides per cm2 within an insulating layer of alkane thiols, each on a different gold pad of a specially designed screening chip. Then, we could readout I/V characteristics of individual peptide species, and eventually find peptide-based diodes. These could be modified in their sequence and screened again for better performance. This evolution-inspired screening approach might lead to novel materials that could be used in fuel cells.
Max ERC Funding
1 494 600 €
Duration
Start date: 2011-11-01, End date: 2016-10-31
Project acronym COMPLEXNMD
Project NMD Complexes: Eukaryotic mRNA Quality Control
Researcher (PI) Christiane Helene Berger-Schaffitzel
Host Institution (HI) EUROPEAN MOLECULAR BIOLOGY LABORATORY
Country Germany
Call Details Starting Grant (StG), LS1, ERC-2011-StG_20101109
Summary Nonsense-mediated mRNA decay (NMD) is an essential mechanism controlling translation in the eukaryotic cell. NMD ascertains accurate expression of the genetic information by quality controlling messenger RNA (mRNA). During translation, NMD factors recognize and target to degradation aberrant mRNAs that have a premature stop codon (PTC) and that would otherwise lead to the production of truncated proteins which could be harmful for the cell. A wide range of genetic diseases have their origin in the mechanisms of NMD. Discrimination of a PTC from a correct termination codon depends on splicing and translation, and it is the first and foremost step in human NMD. The molecular mechanism of this process remains elusive to date.
In the research proposed, I will undertake to elucidate the molecular basis of translation termination and induction of NMD. I will study complexes involved in human translation termination at a normal stop codon and involved in NMD. I will employ an array of innovative techniques including recombinant production of human protein complexes by the MultiBac system, mammalian in vitro translation, mass spectrometry for detecting relevant protein modifications, biophysical techniques, mutational analyses and RNA-interference experiments. Stable ribosomal complexes with termination factors and complexes of NMD factors will be used for structure determination by cryo-electron microscopy. State-of-the-art image processing will be applied to address the inherent heterogeneity of the complexes. Hybrid approaches will allow the combination of cryo-EM structures with existing high-resolution structures of factors involved for generation of quasi-atomic models thereby visualizing molecular mechanisms of NMD action. This interdisciplinary work will foster our understanding at a molecular level of a paramount step in mRNA quality control, which is a vital prerequisite for the development of new treatment strategies in NMD-related diseases.
Summary
Nonsense-mediated mRNA decay (NMD) is an essential mechanism controlling translation in the eukaryotic cell. NMD ascertains accurate expression of the genetic information by quality controlling messenger RNA (mRNA). During translation, NMD factors recognize and target to degradation aberrant mRNAs that have a premature stop codon (PTC) and that would otherwise lead to the production of truncated proteins which could be harmful for the cell. A wide range of genetic diseases have their origin in the mechanisms of NMD. Discrimination of a PTC from a correct termination codon depends on splicing and translation, and it is the first and foremost step in human NMD. The molecular mechanism of this process remains elusive to date.
In the research proposed, I will undertake to elucidate the molecular basis of translation termination and induction of NMD. I will study complexes involved in human translation termination at a normal stop codon and involved in NMD. I will employ an array of innovative techniques including recombinant production of human protein complexes by the MultiBac system, mammalian in vitro translation, mass spectrometry for detecting relevant protein modifications, biophysical techniques, mutational analyses and RNA-interference experiments. Stable ribosomal complexes with termination factors and complexes of NMD factors will be used for structure determination by cryo-electron microscopy. State-of-the-art image processing will be applied to address the inherent heterogeneity of the complexes. Hybrid approaches will allow the combination of cryo-EM structures with existing high-resolution structures of factors involved for generation of quasi-atomic models thereby visualizing molecular mechanisms of NMD action. This interdisciplinary work will foster our understanding at a molecular level of a paramount step in mRNA quality control, which is a vital prerequisite for the development of new treatment strategies in NMD-related diseases.
Max ERC Funding
1 176 825 €
Duration
Start date: 2012-02-01, End date: 2016-11-30
Project acronym COMPNET
Project Dynamics and Self-organisation in Complex Cytoskeletal Networks
Researcher (PI) Andreas Bausch
Host Institution (HI) TECHNISCHE UNIVERSITAET MUENCHEN
Country Germany
Call Details Starting Grant (StG), PE3, ERC-2011-StG_20101014
Summary The requirements on the eukaryotic cytoskeleton are not only of high complexity, but include demands that are actually contradictory in the first place: While the dynamic character of cytoskeletal structures is essential for the motility of cells, their ability for morphological reorganisations and cell division, the structural integrity of cells relies on the stability of cytoskeletal structures. From a biophysical point of view, this dynamic structure formation and stabilization stems from a self-organisation process that is tightly controlled by the simultaneous and competing function of a plethora of actin binding proteins (ABPs). To understand the self-organisation phenomena observed in the cytoskeleton it is therefore indispensable to first shed light on the functional role of ABPs and their underlying molecular mechanisms. Hereby development of reliable reconstituted model systems as has been proven by the great progress achieved in our understanding of individual crosslinking proteins that turn the cytoskeleton into a viscoelastic physical gel. The advantage of such reconstituted systems is that the biological complexity is decreased to an accessible level that the physical principles can be explored and identified.
It is the aim of the present proposal to successively increase the complexity in a well defined manner to further progress in understanding the functional units of a cell. On the way to a sound physical understanding of cellular self organizing principles, the planned major step comprises the incorporation of active processes like the active (de-)polymerisation of filaments and motor mediated active reorganisation and contraction. We plan to develop new tools and approaches to address how the different kinds of ABPs are interacting with each other and how the structure, dynamics and function of the cytoskeleton is locally governed by the competition and interplay between them.
Summary
The requirements on the eukaryotic cytoskeleton are not only of high complexity, but include demands that are actually contradictory in the first place: While the dynamic character of cytoskeletal structures is essential for the motility of cells, their ability for morphological reorganisations and cell division, the structural integrity of cells relies on the stability of cytoskeletal structures. From a biophysical point of view, this dynamic structure formation and stabilization stems from a self-organisation process that is tightly controlled by the simultaneous and competing function of a plethora of actin binding proteins (ABPs). To understand the self-organisation phenomena observed in the cytoskeleton it is therefore indispensable to first shed light on the functional role of ABPs and their underlying molecular mechanisms. Hereby development of reliable reconstituted model systems as has been proven by the great progress achieved in our understanding of individual crosslinking proteins that turn the cytoskeleton into a viscoelastic physical gel. The advantage of such reconstituted systems is that the biological complexity is decreased to an accessible level that the physical principles can be explored and identified.
It is the aim of the present proposal to successively increase the complexity in a well defined manner to further progress in understanding the functional units of a cell. On the way to a sound physical understanding of cellular self organizing principles, the planned major step comprises the incorporation of active processes like the active (de-)polymerisation of filaments and motor mediated active reorganisation and contraction. We plan to develop new tools and approaches to address how the different kinds of ABPs are interacting with each other and how the structure, dynamics and function of the cytoskeleton is locally governed by the competition and interplay between them.
Max ERC Funding
1 495 196 €
Duration
Start date: 2011-10-01, End date: 2012-03-31
Project acronym DYNACOM
Project From Genome Integrity to Genome Plasticity:
Dynamic Complexes Controlling Once per Cell Cycle Replication
Researcher (PI) Zoi Lygerou
Host Institution (HI) PANEPISTIMIO PATRON
Country Greece
Call Details Starting Grant (StG), LS3, ERC-2011-StG_20101109
Summary Accurate genome duplication is controlled by multi-subunit protein complexes which associate with chromatin and dictate when and where replication should take place. Dynamic changes in these complexes lie at the heart of their ability to ensure the maintenance of genomic integrity. Defects in origin bound complexes lead to re-replication of the genome across evolution, have been linked to DNA-replication stress and may predispose for gene amplification events. Such genomic aberrations are central to malignant transformation.
We wish to understand how once per cell cycle replication is normally controlled within the context of the living cell and how defects in this control may result in loss of genome integrity and provide genome plasticity. To this end, live cell imaging in human cells in culture will be combined with genetic studies in fission yeast and modelling and in silico analysis.
The proposed research aims to:
1. Decipher the regulatory mechanisms which act in time and space to ensure once per cell cycle replication within living cells and how they may be affected by system aberrations, using functional live cell imaging.
2. Test whether aberrations in the licensing system may provide a selective advantage, through amplification of multiple genomic loci. To this end, a natural selection experiment will be set up in fission yeast .
3. Investigate how rereplication takes place along the genome in single cells. Is there heterogeneity amongst a population, leading to a plethora of different genotypes? In silico analysis of full genome DNA rereplication will be combined to single cell analysis in fission yeast.
4. Assess the relevance of our findings for gene amplification events in cancer. Does ectopic expression of human Cdt1/Cdc6 in cancer cells enhance drug resistance through gene amplification?
Our findings are expected to offer novel insight into mechanisms underlying cancer development and progression.
Summary
Accurate genome duplication is controlled by multi-subunit protein complexes which associate with chromatin and dictate when and where replication should take place. Dynamic changes in these complexes lie at the heart of their ability to ensure the maintenance of genomic integrity. Defects in origin bound complexes lead to re-replication of the genome across evolution, have been linked to DNA-replication stress and may predispose for gene amplification events. Such genomic aberrations are central to malignant transformation.
We wish to understand how once per cell cycle replication is normally controlled within the context of the living cell and how defects in this control may result in loss of genome integrity and provide genome plasticity. To this end, live cell imaging in human cells in culture will be combined with genetic studies in fission yeast and modelling and in silico analysis.
The proposed research aims to:
1. Decipher the regulatory mechanisms which act in time and space to ensure once per cell cycle replication within living cells and how they may be affected by system aberrations, using functional live cell imaging.
2. Test whether aberrations in the licensing system may provide a selective advantage, through amplification of multiple genomic loci. To this end, a natural selection experiment will be set up in fission yeast .
3. Investigate how rereplication takes place along the genome in single cells. Is there heterogeneity amongst a population, leading to a plethora of different genotypes? In silico analysis of full genome DNA rereplication will be combined to single cell analysis in fission yeast.
4. Assess the relevance of our findings for gene amplification events in cancer. Does ectopic expression of human Cdt1/Cdc6 in cancer cells enhance drug resistance through gene amplification?
Our findings are expected to offer novel insight into mechanisms underlying cancer development and progression.
Max ERC Funding
1 531 000 €
Duration
Start date: 2012-02-01, End date: 2017-01-31
Project acronym DYNAMOM
Project New magnetic resonance techniques to determine the dynamic structure of mitochondrial outer membrane proteins and their complexes
Researcher (PI) Markus Heinz-Georg Sebastian Zweckstetter
Host Institution (HI) DEUTSCHES ZENTRUM FUR NEURODEGENERATIVE ERKRANKUNGEN EV
Country Germany
Call Details Starting Grant (StG), LS1, ERC-2011-StG_20101109
Summary Membrane proteins are coded by about 30% of the genes in the human genome and are primary targets for the action of drugs. I propose an interdisciplinary approach that will provide insight into the dynamic structure of membrane proteins of the outer mitochondrial membrane at unprecedented detail with respect to spatial resolution and time scale separation. Analysis of the dynamics and structure of membrane proteins is one of the biggest challenges in structural biology. I propose several new techniques mainly for solution NMR spectroscopy but also for solid-state NMR and electron paramagnetic resonance that go far beyond the state of art and enrich the sparse information from each of the individual techniques. The integration of complementary experimental information together with molecular dynamics simulations will push the description of the dynamic structure of membrane proteins to a new level. This new level is characterized by the possibility to determine structural ensembles of higher structural complexity and by access to dynamic time scales ranging from picoseconds to milliseconds. The characterization of motion is expected to establish the essential link between structure and function. The chosen outer mitochondrial membrane proteins are linked to several human pathologies that cannot be treated because structural and dynamic information at atomic resolution is missing. I expect that the novel insight into the dynamic structure of mitochondrial proteins will be critical to lay the basis for the development of novel, selective and improved therapies for cancer and age-related neurodegeneration.
Summary
Membrane proteins are coded by about 30% of the genes in the human genome and are primary targets for the action of drugs. I propose an interdisciplinary approach that will provide insight into the dynamic structure of membrane proteins of the outer mitochondrial membrane at unprecedented detail with respect to spatial resolution and time scale separation. Analysis of the dynamics and structure of membrane proteins is one of the biggest challenges in structural biology. I propose several new techniques mainly for solution NMR spectroscopy but also for solid-state NMR and electron paramagnetic resonance that go far beyond the state of art and enrich the sparse information from each of the individual techniques. The integration of complementary experimental information together with molecular dynamics simulations will push the description of the dynamic structure of membrane proteins to a new level. This new level is characterized by the possibility to determine structural ensembles of higher structural complexity and by access to dynamic time scales ranging from picoseconds to milliseconds. The characterization of motion is expected to establish the essential link between structure and function. The chosen outer mitochondrial membrane proteins are linked to several human pathologies that cannot be treated because structural and dynamic information at atomic resolution is missing. I expect that the novel insight into the dynamic structure of mitochondrial proteins will be critical to lay the basis for the development of novel, selective and improved therapies for cancer and age-related neurodegeneration.
Max ERC Funding
1 496 200 €
Duration
Start date: 2011-11-01, End date: 2017-10-31
Project acronym E3
Project E3 - Extreme Event Ecology
Researcher (PI) Annette Menzel
Host Institution (HI) TECHNISCHE UNIVERSITAET MUENCHEN
Country Germany
Call Details Starting Grant (StG), LS9, ERC-2011-StG_20101109
Summary With anthropogenic warming, extreme events have already increased in magnitude and frequency and are likely to continue to do so in the near future. These extreme events play decisive roles in climate change impacts. Natural and managed systems, such as agriculture and forestry, are more strongly affected by extremes than by a change in average conditions. Classical parameters considered have included temperature, precipitation and wind speed, but here we will concentrate on multi-factorial complex situations, such as drought, and subsequent ecological events, such as pests. Novel methods from finance mathematics and statistics will be transferred for application to natural systems in order to assess risks of extremes in past, present and future conditions. Special emphasis will be given to deriving critical thresholds and prediction for when they will be crossed. Here, analyses of long-term ecoclimatological data from dendrology, phenology, seed quality, as well as both manipulated experiments and simulations are needed to provide information on the effects stemming from multiple stressors and extremes. In contrast, real data, no matter how long-term, cannot model the risk of new threatening combinations of climatological and ecological parameters. Adaptation should therefore focus not only on retrospective but also on new extremes, in other words, should look forward to the future. In particular, low probabilities and high risk scenarios have to be taken into account. Adaptation measures can range from breeding, and selection of suitable species and varieties to management options, such as sanitation and forest protection. Insurance also needs to adapt to changes in climate and ecology and accurate forecasting becomes more critical in the face of unforeseen extremes and calamities. Thus, future risk management must be based on both adaptation and insurance, with new products, such as index insurance, facilitating the handling of customer claims.
Summary
With anthropogenic warming, extreme events have already increased in magnitude and frequency and are likely to continue to do so in the near future. These extreme events play decisive roles in climate change impacts. Natural and managed systems, such as agriculture and forestry, are more strongly affected by extremes than by a change in average conditions. Classical parameters considered have included temperature, precipitation and wind speed, but here we will concentrate on multi-factorial complex situations, such as drought, and subsequent ecological events, such as pests. Novel methods from finance mathematics and statistics will be transferred for application to natural systems in order to assess risks of extremes in past, present and future conditions. Special emphasis will be given to deriving critical thresholds and prediction for when they will be crossed. Here, analyses of long-term ecoclimatological data from dendrology, phenology, seed quality, as well as both manipulated experiments and simulations are needed to provide information on the effects stemming from multiple stressors and extremes. In contrast, real data, no matter how long-term, cannot model the risk of new threatening combinations of climatological and ecological parameters. Adaptation should therefore focus not only on retrospective but also on new extremes, in other words, should look forward to the future. In particular, low probabilities and high risk scenarios have to be taken into account. Adaptation measures can range from breeding, and selection of suitable species and varieties to management options, such as sanitation and forest protection. Insurance also needs to adapt to changes in climate and ecology and accurate forecasting becomes more critical in the face of unforeseen extremes and calamities. Thus, future risk management must be based on both adaptation and insurance, with new products, such as index insurance, facilitating the handling of customer claims.
Max ERC Funding
1 487 000 €
Duration
Start date: 2012-01-01, End date: 2016-12-31
Project acronym ECOMAGICS
Project Electric Control of Magnetization Dynamics
Researcher (PI) Georg Woltersdorf
Host Institution (HI) MARTIN-LUTHER-UNIVERSITAET HALLE-WITTENBERG
Country Germany
Call Details Starting Grant (StG), PE3, ERC-2011-StG_20101014
Summary In this proposal a new electric field based approach for the control of magnetization dynamics is discussed. The advantage of using electric fields compared to magnetic fields is twofold: (i) electric fields are easy to confine in nano-structures (screening), and (ii) no current flow is required which may allow for the development of new spintronic devices with ultra low power consumption.
Physically the application of an electric field to an ultrathin ferromagnetic material gives rise to modification of the wave-function overlap at the interface between a ferromagnetic metal and a dielectric. This electronic tuning causes a modified occupation of the d-orbitals at the interface and leads to electrically induced anisotropies. Hence external electric fields generate internal magnetic fields. Due to the modified orbital moment also a large voltage induced effect on the Gilbert damping is expected in magnetization dynamic experiments. In principle these fields can be applied even on ultrafast time scales. This will be explored when rf-electric fields are used to drive internal magnetic fields in the GHz frequency range to generate spin-waves. Furthermore this technique will be used to excite monochromatic spin-waves with wave-vectors well in the exchange dominated regime in order to study their propagation properties.
I propose to use the spin-wave Doppler effect in order to break the intrinsic mirror symmetry required in for four-magnon scattering processes. In this way the resonance saturation may be tuned electrically to much larger values. Moreover electrically driven surface acoustic waves will be used to generate spin-waves which will be manipulated by an electric current using the spin-wave Doppler effect.
The research described in the proposal is likely to have a large impact as a shift to electric field controlled spintronic devices is favorable on small length scales. In addition the power consumption of these devices may be reduced significantly.
Summary
In this proposal a new electric field based approach for the control of magnetization dynamics is discussed. The advantage of using electric fields compared to magnetic fields is twofold: (i) electric fields are easy to confine in nano-structures (screening), and (ii) no current flow is required which may allow for the development of new spintronic devices with ultra low power consumption.
Physically the application of an electric field to an ultrathin ferromagnetic material gives rise to modification of the wave-function overlap at the interface between a ferromagnetic metal and a dielectric. This electronic tuning causes a modified occupation of the d-orbitals at the interface and leads to electrically induced anisotropies. Hence external electric fields generate internal magnetic fields. Due to the modified orbital moment also a large voltage induced effect on the Gilbert damping is expected in magnetization dynamic experiments. In principle these fields can be applied even on ultrafast time scales. This will be explored when rf-electric fields are used to drive internal magnetic fields in the GHz frequency range to generate spin-waves. Furthermore this technique will be used to excite monochromatic spin-waves with wave-vectors well in the exchange dominated regime in order to study their propagation properties.
I propose to use the spin-wave Doppler effect in order to break the intrinsic mirror symmetry required in for four-magnon scattering processes. In this way the resonance saturation may be tuned electrically to much larger values. Moreover electrically driven surface acoustic waves will be used to generate spin-waves which will be manipulated by an electric current using the spin-wave Doppler effect.
The research described in the proposal is likely to have a large impact as a shift to electric field controlled spintronic devices is favorable on small length scales. In addition the power consumption of these devices may be reduced significantly.
Max ERC Funding
1 495 860 €
Duration
Start date: 2012-01-01, End date: 2017-10-31
Project acronym EVOLATERAL
Project The mechanisms for lateral gene transfer in nature as reflected in prokaryote genomes
Researcher (PI) Tal Dagan
Host Institution (HI) CHRISTIAN-ALBRECHTS-UNIVERSITAET ZU KIEL
Country Germany
Call Details Starting Grant (StG), LS8, ERC-2011-StG_20101109
Summary Lateral gene transfer (LGT) is the process by which prokaryotes acquire DNA across wide taxonomic boundaries and incorporate it into their genome. Accumulating evidence shows that LGT plays a major role in prokaryote evolution. The biological and evolutionary significance of lateral gene transfer has broad implications for our understanding of microbial biology, not only in terms of evolution, but also in terms of human health.
Mechanisms of lateral gene transfer include: transformation, transduction, conjugation, and gene transfer agents. Each of these transfer mechanisms leaves distinct and recognizable molecular footprints in genome sequences. The molecular details of these footprints betray the workings of the corresponding mechanisms in nature, but their relative contributions to the evolution of sequenced genomes have so far not been investigated. By identifying these footprints one can specify and quantify the relative contribution of the different LGT mechanisms during prokaryote genome evolution and thereby uncover more of the biology underlying prokaryote evolution in nature. The goal of this proposal is to quantify those contributions and to bring forth a general computer-based model of prokaryote genome evolution that approximates the underlying evolutionary process far more realistically than phylogenetic trees alone possibly can.
Here I propose to apply directed networks to the study of prokaryotic genome evolution in an evolutionary model that allows both for vertical inheritance and for lateral gene transfer events. With methods to identify gene donors, all recent LGTs can be described in a single directed network. This is a fundamentally new, biologically more realistic and evolutionarily more accurate, general computational model of prokaryote genome evolution. Such a model will substantially enrich our ability to understand the process of prokaryote evolution as it is recorded in genomic and metagenomic data.
Summary
Lateral gene transfer (LGT) is the process by which prokaryotes acquire DNA across wide taxonomic boundaries and incorporate it into their genome. Accumulating evidence shows that LGT plays a major role in prokaryote evolution. The biological and evolutionary significance of lateral gene transfer has broad implications for our understanding of microbial biology, not only in terms of evolution, but also in terms of human health.
Mechanisms of lateral gene transfer include: transformation, transduction, conjugation, and gene transfer agents. Each of these transfer mechanisms leaves distinct and recognizable molecular footprints in genome sequences. The molecular details of these footprints betray the workings of the corresponding mechanisms in nature, but their relative contributions to the evolution of sequenced genomes have so far not been investigated. By identifying these footprints one can specify and quantify the relative contribution of the different LGT mechanisms during prokaryote genome evolution and thereby uncover more of the biology underlying prokaryote evolution in nature. The goal of this proposal is to quantify those contributions and to bring forth a general computer-based model of prokaryote genome evolution that approximates the underlying evolutionary process far more realistically than phylogenetic trees alone possibly can.
Here I propose to apply directed networks to the study of prokaryotic genome evolution in an evolutionary model that allows both for vertical inheritance and for lateral gene transfer events. With methods to identify gene donors, all recent LGTs can be described in a single directed network. This is a fundamentally new, biologically more realistic and evolutionarily more accurate, general computational model of prokaryote genome evolution. Such a model will substantially enrich our ability to understand the process of prokaryote evolution as it is recorded in genomic and metagenomic data.
Max ERC Funding
1 500 000 €
Duration
Start date: 2012-07-01, End date: 2018-06-30
Project acronym EXPLOGEN
Project Exploitation of actinomycetes genomics using synthetic and system biology approaches
Researcher (PI) Andriy Luzhetskyy
Host Institution (HI) HELMHOLTZ-ZENTRUM FUR INFEKTIONSFORSCHUNG GMBH
Country Germany
Call Details Starting Grant (StG), LS9, ERC-2011-StG_20101109
Summary "Actinomycetes produce a wealth of important natural products, which play a pivotal role in modern drug-based therapy of various diseases. Recent whole-genome sequencing projects have revealed that the number of biosynthetic gene clusters significantly outnumbers the natural products produced by actinomycetes under laboratory conditions. Only a minority of biosynthetic gene clusters are expressed under known laboratory conditions. The major challenge in the field now is to exploit this untapped reservoir of potentially active and useful compounds. Using synthetic and system biology approaches we will access these so far unavailable natural products.
The overall strategy of the EXPLOGEN project will be implemented through the activities of four different work packages.
WP1. Synthetic biobricks. Construction of different synthetic biobricks, which can be mixed and matched to build the synthetic devices and systems in actinomycetes. Generation of streptomyces strains with minimized genomes.
WP2. Systems biology. The metabolic reconstruction of Streptomyces albus and S. lividans and its simulation in order to deliver gene targets for knockouts and overexpression experiments. Predicted mutants should accumulate main precursors of natural products, particularly polyketides.
WP3. Regulatory network identification. Using systematic in vivo transposon mutagenesis combined with GFP-based flow cytometry assay and gusA based screening, we will identify gene networks responsible for the regulation and “silencing” of natural product biosynthesis.
WP4. Metabolic engineering of the hosts. Generation of S. albus and S. lividans hosts accumulating main precursors for the heterologous production of natural products. Heterologous expression of the aranciamycin, phenalinolactone, and two ""cryptic"" biosynthetic gene clusters in the developed hosts.
The outcome of this project will be a new platform for the production of novel natural products including valuable pharmaceuticals."
Summary
"Actinomycetes produce a wealth of important natural products, which play a pivotal role in modern drug-based therapy of various diseases. Recent whole-genome sequencing projects have revealed that the number of biosynthetic gene clusters significantly outnumbers the natural products produced by actinomycetes under laboratory conditions. Only a minority of biosynthetic gene clusters are expressed under known laboratory conditions. The major challenge in the field now is to exploit this untapped reservoir of potentially active and useful compounds. Using synthetic and system biology approaches we will access these so far unavailable natural products.
The overall strategy of the EXPLOGEN project will be implemented through the activities of four different work packages.
WP1. Synthetic biobricks. Construction of different synthetic biobricks, which can be mixed and matched to build the synthetic devices and systems in actinomycetes. Generation of streptomyces strains with minimized genomes.
WP2. Systems biology. The metabolic reconstruction of Streptomyces albus and S. lividans and its simulation in order to deliver gene targets for knockouts and overexpression experiments. Predicted mutants should accumulate main precursors of natural products, particularly polyketides.
WP3. Regulatory network identification. Using systematic in vivo transposon mutagenesis combined with GFP-based flow cytometry assay and gusA based screening, we will identify gene networks responsible for the regulation and “silencing” of natural product biosynthesis.
WP4. Metabolic engineering of the hosts. Generation of S. albus and S. lividans hosts accumulating main precursors for the heterologous production of natural products. Heterologous expression of the aranciamycin, phenalinolactone, and two ""cryptic"" biosynthetic gene clusters in the developed hosts.
The outcome of this project will be a new platform for the production of novel natural products including valuable pharmaceuticals."
Max ERC Funding
1 484 016 €
Duration
Start date: 2012-01-01, End date: 2016-12-31
