ERC FUNDED PROJECTS

Understanding how proteins respond to mutations is of paramount importance to biology and disease. While protein stability and misfolding have been instrumental in rationalizing the impact of mutations, we recently discovered that an alternative route is also frequent, where mutations at the surface of symmetric proteins trigger novel self-interactions that lead to infinite self-assembly. This mechanism can be involved in disease, as in sickle-cell anemia, but may also serve in adaptation. Importantly, it differs fundamentally from aggregation, because misfolding does not drive it. Thus, we term it “agglomeration”. The ease with which agglomeration can occur, even by single point mutations, shifts the paradigm of how quickly new protein assemblies can emerge, both in health and disease. This prompts us to determine the basic principles of protein agglomeration and explore its implications in cell physiology and human disease. We propose an interdisciplinary research program bridging atomic and cellular scales to explore agglomeration in three aims: (i) Map the landscape of protein agglomeration in response to mutation in endogenous yeast proteins; (ii) Characterize how yeast physiology impacts agglomeration by changes in gene expression or cell state, and, conversely, how protein agglomerates impact yeast fitness. (iii) Analyze agglomeration in relation to human disease via two approaches. First, by predicting single nucleotide polymorphisms that trigger agglomeration, prioritizing them using knowledge from Aims 1 & 2, and characterizing them experimentally. Second, by providing a proof-of-concept that agglomeration can be exploited in drug design, whereby drugs induce its formation, like mutations can do. Overall, through this research, we aim to establish agglomeration as a paradigm for protein assembly, with implications for our understanding of evolution, physiology, and disease.

2 574 819 €

Start date: 2019-04-01, End date: 2024-03-31

Humans diverged from our closest living relatives, chimpanzees and other great apes, 6-10 million years ago. Since this divergence, our ancestors acquired genetic changes that enhanced cognition, altered metabolism, and endowed our species with an adaptive capacity to colonize the entire planet and reshape the biosphere. Through genome comparisons between modern humans, Neandertals, chimpanzees and other apes we have identified genetic changes that likely contribute to innovations in human metabolic and cognitive physiology. However, it has been difficult to assess the functional effects of these genetic changes due to the lack of cell culture systems that recapitulate great ape organ complexity. Human and chimpanzee pluripotent stem cells (PSCs) can self-organize into three-dimensional (3D) tissues that recapitulate the morphology, function, and genetic programs controlling organ development. Our vision is to use organoids to study the changes that set modern humans apart from our closest evolutionary relatives as well as all other organisms on the planet. In ANTHROPOID we will generate a great ape developmental cell atlas using cortex, liver, and small intestine organoids. We will use single-cell transcriptomics and chromatin accessibility to identify cell type-specific features of transcriptome divergence at cellular resolution. We will dissect enhancer evolution using single-cell genomic screens and ancestralize human cells to resurrect pre-human cellular phenotypes. ANTHROPOID utilizes quantitative and state-of-the-art methods to explore exciting high-risk questions at multiple branches of the modern human lineage. This project is a ground breaking starting point to replay evolution and tackle the ancient question of what makes us uniquely human?

1 500 000 €

Start date: 2019-06-01, End date: 2024-05-31

AQSuS aims at experimentally implementing analogue quantum simulation of interacting spin models in two-dimensional geometries. The proposed experimental approach paves the way to investigate a broad range of currently inaccessible quantum phenomena, for which existing analytical and numerical methods reach their limitations. Developing precisely controlled interacting quantum systems in 2D is an important current goal well beyond the field of quantum simulation and has applications in e.g. solid state physics, computing and metrology. To access these models, I propose to develop a novel circuit quantum-electrodynamics (cQED) platform based on the 3D transmon qubit architecture. This platform utilizes the highly engineerable properties and long coherence times of these qubits. A central novel idea behind AQSuS is to exploit the spatial dependence of the naturally occurring dipolar interactions between the qubits to engineer the desired spin-spin interactions. This approach avoids the complicated wiring, typical for other cQED experiments and reduces the complexity of the experimental setup. The scheme is therefore directly scalable to larger systems. The experimental goals are: 1) Demonstrate analogue quantum simulation of an interacting spin system in 1D & 2D. 2) Establish methods to precisely initialize the state of the system, control the interactions and readout single qubit states and multi-qubit correlations. 3) Investigate unobserved quantum phenomena on 2D geometries e.g. kagome and triangular lattices. 4) Study open system dynamics with interacting spin systems. AQSuS builds on my backgrounds in both superconducting qubits and quantum simulation with trapped-ions. With theory collaborators my young research group and I have recently published an article in PRB [9] describing and analysing the proposed platform. The ERC starting grant would allow me to open a big new research direction and capitalize on the foundations established over the last two years.

1 498 515 €

Start date: 2017-04-01, End date: 2022-03-31

In mammals, transcriptional control of many genes relies on cis-regulatory elements such as enhancers, which are often located tens to hundreds of kilobases away from their cognate promoters. Functional interactions between distal regulatory elements and target promoters require mutual physical proximity, which is linked to the three-dimensional structure of the chromatin fiber. Chromosome conformation capture studies revealed that chromosomes are partitioned into Topologically Associating Domains (TADs), sub-megabase domains of preferential physical interactions of the chromatin fiber. Genetic evidence showed that TAD boundaries restrict the genomic range of enhancer-promoter communication, and that interactions between regulatory sequences within TADs are further fine-tuned by smaller-scale structures. However, the mechanistic details of how physical interactions translate into transcriptional outputs are totally unknown. Here we propose to explore the biophysical mechanisms that link chromosome conformation and long-range transcriptional regulation using molecular biology, genetic engineering, single-cell experiments and physical modeling. We will measure chromosomal interactions in single cells and in time using a novel method that relies on an enzymatic process in vivo. Genetic engineering will be used to establish a cell system that allows quantitative measurement of how enhancer-promoter interactions relate to transcription at the population and single-cell levels, and to test the effects of perturbations without confounding effects. Finally, we will develop physical models of promoter operation in the presence of distal enhancers, which will be used to interpret the experimental data and formulate new testable predictions. With this integrated approach we aim at providing an entirely new layer of description of the general principles underlying transcriptional control, which could establish new paradigms for research in epigenetics and gene regulation.

1 500 000 €

Start date: 2018-01-01, End date: 2022-12-31

The metabolism of cancer cells is altered to meet cellular requirements for growth, providing novel means to selectively target tumorigenesis. While extensively studied, our current view of cancer cellular metabolism is fundamentally limited by lack of information on variability in metabolic activity between distinct subcellular compartments and cells. We propose to develop a spatio-temporal fluxomics approach for quantifying metabolic fluxes in the cytoplasm vs. mitochondria as well as their cell-cycle dynamics, combining mass-spectrometry based isotope tracing with cell synchronization, rapid cellular fractionation, and computational metabolic network modelling. Spatio-temporal fluxomics will be used to revisit and challenge our current understanding of central metabolism and its induced adaptation to oncogenic events – an important endeavour considering that mitochondrial bioenergetics and biosynthesis are required for tumorigenesis and accumulating evidences for metabolic alterations throughout the cell-cycle. Our preliminary results show intriguing oscillations between oxidative and reductive TCA cycle flux throughout the cell-cycle. We will explore the extent to which cells adapt their metabolism to fulfil the changing energetic and anabolic demands throughout the cell-cycle, how metabolic oscillations are regulated, and their benefit to cells in terms of thermodynamic efficiency. Spatial flux analysis will be instrumental for investigating glutaminolysis - a ‘hallmark’ metabolic adaptation in cancer involving shuttling of metabolic intermediates and cofactors between mitochondria and cytoplasm. On a clinical front, our spatio-temporal fluxomics analysis will enable to disentangle oncogene-induced flux alterations, having an important tumorigenic role, from artefacts originating from population averaging. A comprehensive view of how cells adapt their metabolism due to oncogenic mutations will reveal novel targets for anti-cancer drugs.

1 481 250 €

Start date: 2017-02-01, End date: 2022-01-31

"The CCICO project will build a comprehensive understanding of how proximity to previously unexplored combinations of instabilities, as well as previously unidentified types of ordering, manifest in novel behaviors, and will develop design guidelines for practical realization of new materials with such behaviors. Taking transition-metal oxides as our model systems, we will develop and apply first-principles electronic structure theory methods to explore an extensive array of new combinations of orderings, with a focus on interactions between the electronic -- Jahn-Teller, orbital and charge -- and structural -- rotations, ferroelectric and other distortions -- degrees of freedom. Our goal is to spawn a new field of study based on a novel combination of orderings in the same way that the field of multiferroics was jump-started ten years ago by our work understanding the coexistence of ferroelectricity and magnetism. Conversely, we will apply the computational tools developed in our history of studying multiferroics, particularly descriptions of proximity to structural and magnetic phase transitions, to characterizing observed behaviors such as exotic superconductivity in existing materials. In the process we will search for and characterize elusive or poorly characterized forms of order in solids, with a focus on ferrotoroidicity and emergent local dipoles. A final application is to create designer materials for solid-state experiments relevant to high-energy physics and cosmology. Promising compounds that are amenable to bulk synthesis will be made in our new oxide single-crystal growth laboratory; materials that require thin-film routes will be pursued in collaboration with colleagues."

2 000 000 €

Start date: 2012-03-01, End date: 2017-02-28

The fitness landscape, the representation of how the genotype manifests at the phenotypic (fitness) levels, may be among the most useful concepts in biology with impact on diverse fields, including quantitative genetics, emergence of pathogen resistance, synthetic biology and protein engineering. While progress in characterizing fitness landscapes has been made, three directions of research in the field remain virtually unexplored: the nature of the genotype to phenotype of standing variation (variation found in a natural population), the shape of the fitness landscape encompassing many genotypes and the modelling of complex genetic interactions in protein sequences. The current proposal is designed to advance the study of fitness landscapes in these three directions using large-scale genomic experiments and experimental data from a model protein and theoretical work. The study of the fitness landscape of standing variation is aimed at the resolution of an outstanding question in quantitative genetics: the extent to which epistasis, non-additive genetic interactions, is shaping the phenotype. The second aim of characterizing the global fitness landscape will give us an understanding of how evolution proceeds along long evolutionary timescales, which can be directly applied to protein engineering and synthetic biology for the design of novel phenotypes. Finally, the third aim of modelling complex interactions will improve our ability to predict phenotypes from genotypes, such as the prediction of human disease mutations. In summary, the proposed study presents an opportunity to provide a unifying understanding of how phenotypes are shaped through genetic interactions. The consolidation of our empirical and theoretical work on different scales of the genotype to phenotype relationship will provide empirical data and novel context for several fields of biology.

1 998 280 €

Start date: 2019-01-01, End date: 2023-12-31

Epigenetic mechanisms play an important role in regulating and maintaining the functionality of cells and have been implicated in a wide range of human diseases. Histone proteins that form the protein core of nucleosomes are subject to a bewildering array of covalent and structural modifications, which can repress, permit, or promote transcription. These modifications can be added and removed by specialized complexes that are recruited by other covalent modifications, by transcription factors, or by the transcriptional machinery. Advances in genomics led to comprehensive mapping of the ``epigenome'' in a range of tissues and organisms. These maps established the tight connection between histone modifications and transcription programs. These static charts, however, are less successful at uncovering the underlying mechanisms, logic, and function of histone modifications in establishing and maintaining transcriptional programs. Our premise is that we can answer these basic questions by observing the effect of genetic perturbations on the dynamics of both chromatin state and transcriptional activity. We aim to dissect the chromatin-transcription system in a systematic manner by building on our extensive experience in modeling and analysis, and a unique high-throughput experimental system we established in my lab. We plan to use the budding yeast model organism, which allows for efficient genetic and experimental manipulations. We will combine two technologies: (1) high-throughput measurements of single-cell transcriptional output using fluorescence reporters; and (2) high-throughput immunoprecipitation sequencing assays to map chromatin state. Measuring with these the dynamics of response to stimuli under different genetic backgrounds and using advanced stochastic network models, we will chart detailed mechanisms that are opaque to current approaches and elucidate the general principles that govern the interplay between chromatin and transcription.

2 396 450 €

Start date: 2014-01-01, End date: 2018-12-31

The technology of the 20th century was dominated by a single material class: The semiconductors, whose properties can be tuned between those of metals and insulators all of which describable by single-electron effects. In contrast, quantum magnets and strongly correlated electron systems offer a full palette of quantum mechanical many-electron states. CONQUEST aim to discover, understand and demonstrate control over such quantum states. A new experimental approach, building on established powerful laboratory and neutron scattering techniques combined with dynamical control-perturbations, will be developed to study correlated quantum effects in magnetic materials. The immediate goal is to open a new field of non-equilibrium and time dependent studies in solid state physics. The long-term vision is that the approach might nurture the materials of the 21st century.

1 500 000 €

Start date: 2011-04-01, End date: 2016-03-31