ADP-ribosylation signaling by PARP1 is a key early event of the DNA damage response. While recent works have elucidated the role of PARP1 auto-ADP-ribosylation, less is known about the impact of the ADP-ribosylation of histones, which are the second main target of this signaling pathway after PARP1 itself. In this project, we aim to uncover the functions of histone ADP-ribosylation in three key steps of the DNA repair process known to be regulated by this signaling pathway: i) modulation of the chromatin architecture, ii) recruitment of repair factors and iii) control of the timely release of PARP1 from the sites of damage. To study these different components of the repair mechanism, we set up an interdisciplinary consortium of 5 research teams with complementary expertise in the fields of ADP-ribosylation signaling, chromatin architecture and repair protein dynamics. The chromatin architecture will be characterized both in vitro and in living cells using cutting edge microscopy methods that will give us access to the chromatin structure and dynamics at the single nucleosome level. These tools will be applied in cells lacking specific components of the ADP-ribosylation signaling pathway to be able to delineate the impact of histone ADP-ribosylation on the chromatin architecture. We will also investigate two alternative mechanisms by which histone ADP-ribosylation could promote the recruitment of repair factors at sites of damage. First, by combining advanced proteomics assays with live cell microscopy, we intend to identify factors displaying binding specificity to ADP-ribosylated histones. Second, we will study whether histone ADP-ribosylation could promote the accumulation of repair proteins to DNA lesions via liquid-liquid phase separation mechanisms, focusing on the two key actors 53BP1 and BRCA2. Using complementary assays to characterize the dynamics of these two proteins at the population and single-molecule levels in living cells, we will be able to distinguish between accumulation mechanisms driven by specific binding to the damaged chromatin, and confinement within liquid droplets surrounding the lesions. Then, we will analyze the dynamics of 53BP1 and BRCA2 at DNA lesions in cells lacking histone ADP-ribosylation compared to control cells to establish the specific impact of this histone mark on the recruitment mechanism. Finally, we will monitor PARP1 recruitment kinetics and turnover at sites of damage to define how histone ADP-ribosylation could contribute to the rapid dissipation of PARP1 from the DNA lesions. Altogether, building-up on the interdisciplinary expertise of the consortium established for this project and the use of high-end quantitative methods, this project will provide a precise description of the roles of histone ADP-ribosylation in the context of the DNA damage response. We anticipate that these findings will deepen our understanding of the complex histone-based epigenetic landscape by dissecting the functions of one of its least characterized components.

Clean water is ubiquitous from drinking to agriculture and from energy supply to industrial manufacturing. Since the conventional water sources are becoming increasingly rare, the development of new technologies for water supply is crucial to address the world’s clean water needs. Desalination is in many regards the most promising approach to long-term water supply since it potentially delivers an unlimited source of fresh water. Seawater desalination using reverse osmosis (RO) membranes has become over the past decade a standard approach to produce fresh water. While this technology has proven to be efficient, it remains however relatively costly in terms of energy input due to the use of high-pressure pumps resulting of the low water permeation through polymeric polyamide (PA) RO membranes. Recently, water channels incorporated in lipidic membranes were demonstrated to provide a selective water translocation that enables to break permeability-selectivity trade-off. biomimetic Artificial Water channels (AWCs) are becoming highly attractive systems to achieve a selective transport of water. Recently pioneer work in this field with the fabrication of the first AWC@PA composite membrane with outstanding desalination performance was carried out. However, the microscopic desalination mechanism in play is still unknown and its understanding represents the shortest way for a long-term conception and design of AWC@PA composite membranes with better performance. BIOWATER aims to gain an unprecedented fundamental understanding of the nanostructuration of the AWC@PA membranes and of the microscopic mechanism at the origin of their water transport and ion rejection performance. This ground-breaking project will rely on interwoven activities in fabrication of AWC@PA membranes, cutting-edge experimental characterization of their desalination performance and advanced multiscale modelling.

Lead Zirconate Titanate (PZT) is today, thanks to its high piezoelectric coefficients, the best performing material for piezoelectric micro-actuator applications. However, the presence of lead (Pb) in this material represents a threat for its long-term use in industry. Despite active research worldwide on lead-free piezoelectrics in the last decade, today no material seems to be able to replace PZT in PiezoMEMS industry. Increasing collaboration between scientists developing new materials and researchers in application-relevant properties, as gathered in TILPAC, is key for defining both a piezoelectric lead free material and a deposition process suitable for a considered application. This project aims at replacing lead based piezoelectric thin films considering the properties of both the material and the material integrated in capacitor structure, and the deposition process as a whole. Particular attention will be given to electrical properties: piezoelectric effect and leakage currents. TILPAC will address potassium sodium niobate (KNN) and bismuth sodium titanate (BNT) based ceramics thin films, carefully tuned for micro-actuator applications.

Fish exhibit an extraordinary phenotypic plasticity facing environmental variations. In addition, they are able to transmit information on their life history to their offspring, susceptible to compromise their performances or, in contrary, allow a better acclimation to changing environments. This non-genetic information is transmitted via gametes. DNA methylation is an excellent candidate for being a molecular vector of inter- and even transgenerational inheritance. It is indeed sensitive to the environment and in male fish gamete, it plays a demonstrated role in the kinetics of zygotic genes activation (studies performed in zebrafish). However, the question of methylome alterations induced by the environment and transmitted throughout generations via the gametes remains to be addressed. Partner 1 has demonstrated in a previous work that sperm DNA methylome is altered upon a 4°C increase in temperature during spermatogenesis in rainbow trout. We now seek to test the inter- and transgenerational transmission of a temperature-induced altered methylome and its potential effects on offspring reproductive performances, using an appropriate model exhibiting a short generation time. We therefore propose to perform, using medaka fish, an exhaustive phenotyping of spermatozoa from males exposed to an increased rearing temperature during spermatogenesis at the cellular (functionality) and molecular (transcriptomics) levels and study the effect of temperature on the sperm methylome at whole genome scale and CpG resolution. Inter- and transgenerational transmission of phenotypic and/or epigenetic alterations will then be tested, as well as the capacity of males to acclimate to the similar thermal treatment from generation to generation.

Pathogenic bacteria represent a worldwide public health concern, not only because of the frequency of infections but also because of the phenomena of drug resistance. Today, it is estimated that more than 50% of infections in intensive care units are caused by bacterial pathogens. Here we will focus on Enterococcus faecium and Staphylococcus aureus, which represents a global health problem because it causes severe infections (complicated urinary tract and intraabdominal infections, pneumonia, bloodstream infections or endocarditis). Thus, there is desperate need of new classes of antibacterial drugs, ideally directed to novel targets, to develop the next generation of antibiotics. Benzoxaboroles are novel boron-derived compounds that have gained a big interest, notably with the discovery of the clinically used antifungal kerydin, an inhibitor of leucyl-tRNA synthetase (LeuRS). Here, we will investigate the use of these compounds to treat infections by Gram-positive pathogens listed as WHO top priority. Indeed, data generated by the consortium indicates that benzoxaboroles have activity against these multi-drug resistant bacteria via the inhibition of LeuRS. Here, we propose to target LeuRS of Gram-positive bacteria of the ESKAPE group (S. aureus and E. faecium) to develop novel benzoxaborole-derived antibiotics. Second, given the similarity between the drug binding pocket of LeuRS and IleRS, we will design novel inhibitors of IleRS, or even a dual LeuRS/IleRS inhibitor to hamper the emergence of resistance. We will use a multidisciplinary approach by combining structural biology and biophysical approaches focused on drug discovery with molecular microbiology to provide insights ranging from the atomic scale to the in cellulo level. We believe that the synergy of this interdisciplinary research, involving highly complementary teams, provides the optimal environment to succeed on this project and contribute to accelerate the discovery of next generation antibiotics.