ERC FUNDED PROJECTS

Programmable biomolecular circuits have received increasing attention in recent years as the scope of chemistry expands from the synthesis of individual molecules to the construction of chemical networks that can perform sophisticated functions such as logic operations and feedback control. Rationally engineered biomolecular circuits that robustly execute higher-order spatiotemporal behaviours typically associated with intracellular regulatory functions present a unique and uncharted platform to systematically explore the molecular logic and physical design principles of the cell. The experience gained by in-vitro construction of artificial cells displaying advanced system-level functions deepens our understanding of regulatory networks in living cells and allows theoretical assumptions and models to be refined in a controlled setting. This proposal combines elements from systems chemistry, in-vitro synthetic biology and micro-engineering and explores generic strategies to investigate the molecular logic of biology’s regulatory circuits by applying a physical chemistry-driven bottom-up approach. Progress in this field requires 1) proof-of-principle systems where in-vitro biomolecular circuits are designed to emulate characteristic system-level functions of regulatory circuits in living cells and 2) novel experimental tools to operate biochemical networks under out-of-equilibrium conditions. Here, a comprehensive research program is proposed that addresses these challenges by engineering three biochemical model systems that display elementary signal transduction and information processing capabilities. In addition, an open microfluidic droplet reactor is developed that will allow, for the first time, high-throughput analysis of biomolecular circuits encapsulated in water-in-oil droplets. An integral part of the research program is to combine the computational design of in-vitro circuits with novel biochemistry and innovative micro-engineering tools.

1 887 180 €

Start date: 2016-08-01, End date: 2021-07-31

Celiac disease affects at least 1% of the world population. Its onset is triggered by gluten, a common dietary protein, however, its etiology is poorly understood. More than 80% of patients are not properly diagnosed and they therefore do not follow a gluten-free diet, thereby increasing their risk for disease-associated complications and early death. A better understanding of the disease biology would improve the diagnosis, prevention, and treatment of celiac disease. This project investigates the disease mechanisms in celiac disease by using predisposing genes and genetic variants as disease initiating factors. Specifically, it will investigate if long, intergenic non-coding RNAs (lincRNAs) are causally involved in celiac disease pathogenesis by regulating protein-coding genes and pathways associated with the disease. This project is based on two important observations by my group: (1) Our genetic studies, which led to identifying 39 celiac disease risk loci, suggest that the mechanism underlying the disease is largely governed by dysregulation of gene expression. (2) We uncovered a previously unrecognized role for lincRNAs that provides clues as to exactly how genetic variation causes disease, as this class of biologically important RNA molecules regulate gene expression. The research will be performed in CD4+ T cells, a severely affected cell type in disease pathology. I will first use celiac disease-associated protein-coding genes to delineate their regulatory pathways and then study the transcriptional programs of lincRNAs present in celiac disease loci. Next I will combine the information and investigate if the expressed lincRNAs modulate the pathways and affect T cell function, thereby discovering if lincRNAs are a missing link between non-coding genetic variation and protein-coding genes. Our findings may well lead to potential therapeutic targets and provide a solid scientific basis for new diagnostic markers, particularly biomarkers, based on genetics.

2 319 914 €

Start date: 2013-02-01, End date: 2018-11-30

Chromatin is the ensemble of genomic DNA and hundreds of structural and regulatory proteins. Together these proteins govern the gene expression program of a cell. While biochemical and genetic approaches have tought us much about interactions between individual chromatin proteins, we still lack a “big picture” of chromatin: how is the entire interaction network of chromatin proteins organized? My lab discovered that chromatin in Drosophila consists of a limited number of principal types that partition the genome into domains with distinct regulatory properties. Among these is BLACK chromatin, a novel repressive type of chromatin that covers nearly half of the fly genome. It is still largely unclear how these different chromatin types are formed, how they are targeted to specific genomic regions, and how they interact with each other. Here, I propose a combination of systematic approaches aimed to gain insight into the basic mechanisms that drive the partioning of the genome into distinct chromatin types. New genomics techniques, developed in my laboratory, will be used to construct an integrated view of the interplay of more than one hundred representative chromatin proteins with each other and with sequence elements in the genome. Specifically, we will: (1) Study the genome-wide dynamic repositioning of chromatin domains during development in relation to gene regulation; (2) Use a novel and versatile parallel genome-wide reporter assay to dissect the interplay among DNA sequences and chromatin types; (3) Combine computational modeling with a high-throughput genome-wide assay to uncover the network of interactions responsible for the formation of the principal chromatin types; (4) Dissect the molecular architecture of BLACK chromatin and its role in gene repression. The results will provide understanding of the basic principles that govern the structure and composition of chromatin, and reveal how the principal chromatin types together direct gene expression.

2 495 080 €

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

The 3D organization of chromosomes within the nucleus is of great importance to control gene expression. The cohesin complex plays a key role in such higher-order chromosome organization by looping together regulatory elements in cis. How these often megabase-sized looped structures are formed is one of the main open questions in chromosome biology. Cohesin is a ring-shaped complex that can entrap DNA inside its lumen. However, cohesin’s default behaviour is that it only transiently entraps and then releases DNA. Our recent findings indicate that chromosomes are structured through the processive enlargement of chromatin loops, and that the duration with which cohesin embraces DNA determines the degree to which loops are enlarged. The goal of this proposal is two-fold. First, we plan to investigate the mechanism by which chromatin loops are formed, and secondly we wish to dissect how looped structures are maintained. We will use a multi-disciplinary approach that includes refined genetic screens in haploid human cells, chromosome conformation capture techniques, the tracing in vivo of cohesin on individual DNA molecules, and visualization of chromosome organization by super-resolution imaging. With unbiased genetic screens, we have identified chromatin regulators involved in the formation of chromosomal loops. We will investigate how they drive loop formation, and also whether cohesin’s own enzymatic activity plays a role in the enlargement of loops. We will study whether and how these factors control the movement of cohesin along individual DNA molecules, and whether chromatin loops pass through cohesin rings during their formation. Ultimately, we plan to couple cohesin’s linear trajectory along chromatin to the 3D consequences for chromosomal architecture. Together our experiments will provide vital insight into how cohesin structures chromosomes.

1 998 375 €

Start date: 2018-04-01, End date: 2023-03-31