David Stroebel

Ecole Normale Supérieure de Paris | ENS · Département de Biologie

The comparative study of the four non‐bilaterian phyla (Cnidaria, Placozoa, Ctenophora, and Porifera) provides insights into the origin of bilaterian traits. To complete our knowledge of the cell biology and development of these animals, additional non‐bilaterian models are needed. Given the developmental, histological, ecological, and genomic diff...

Fast synaptic neurotransmission in the vertebrate central nervous system relies primarily on ionotropic glutamate receptors (iGluRs), that drive neuronal excitation, and type A γ-aminobutyric acid receptors (GABA A Rs), responsible for neuronal inhibition. However, the GluD1 receptor, an iGluR family member, is present at both excitatory and inhibi...

Amino acids evolve at different speeds within protein sequences, because their functional and structural roles are different. Notably, amino-acids located at the surface of proteins are known to evolve more rapidly than those in the core. In particular, amino-acids at the N- and C-termini of protein sequences are likely to be more exposed than thos...

Amino acids evolve at different speeds within protein sequences, because their functional and structural roles are different. However, the position of an amino-acid within the sequence is not known to influence this evolutionary speed. Here we discovered that amino-acid evolve almost twice faster at protein termini than in their centre, hinting at...

Allostery represents a fundamental mechanism of biological regulation that involves long-range communication between distant protein sites. It also provides a powerful framework for novel therapeutics. NMDA receptors (NMDARs), glutamate-gated ionotropic receptors that play central roles in synapse maturation and plasticity, are prototypical alloste...

N-methyl-D-aspartate (NMDA) receptors are glutamate-gated calcium-permeable ion channels that are widely implicated in synaptic transmission and plasticity. Here, we report a gallery of cryo-electron microscopy (cryo-EM) structures of the human GluN1-GluN2A NMDA receptor at an overall resolution of 4 Å in complex with distinct ligands or modulators...

Ionotropic glutamate receptors (iGluRs) are ligand-gated ion channels that mediate the majority of excitatory neurotransmission in the vertebrate CNS. Classified as AMPA, kainate, delta and NMDA receptors, iGluRs are central drivers of synaptic plasticity widely considered as a major cellular substrate of learning and memory. Surprisingly however,...

Ionotropic glutamate receptors (iGluRs) are a major class of ligand‐gated ion channels that are widespread in the living kingdom. Their critical role in excitatory neurotransmission and brain function of arthropods and vertebrates has made them a compelling subject of interest for neurophysiologists and pharmacologists. This is particularly true fo...

Significance The Hv1 proton channel is an unusual voltage-gated ion channel with atypical architecture and stoichiometry. While functional as a monomer, Hv1 is usually expressed as a dimer of two voltage-sensing domains (VSDs). How the two VSDs arrange relative to each other is a matter of debate and the functional impact of VSD–VSD interactions is...

The voltage-gated proton channel Hv1 is a member of the voltage-gated ion channel superfamily, which stands out in design: It is a dimer of two voltage-sensing domains (VSDs), each containing a pore pathway, a voltage sensor (S4), and a gate (S1) and forming its own ion channel. Opening of the two channels in the dimer is cooperative. Part of the c...

Background The functional determinants of H3K4me3, their potential dependency on histone H2B monoubiquitination, and their contribution to defining transcriptional regimes are poorly defined in plant systems. Unlike in Saccharomyces cerevisiae, where a single SET1 protein catalyzes H3K4me3 as part of COMPlex of proteins ASsociated with Set1 (COMPAS...

The functional determinants of histone H3 Lys-4 trimethylation (H3K4me3), their potential dependency on histone H2B monoubiquitination (H2Bub) and their contribution to defining transcriptional regimes are poorly defined in plant systems. Unlike in S. cerevisiae, where a single SET1 protein catalyzes H3 Lys-4 trimethylation as part of COMPASS (COMP...

NMDA receptors (NMDARs) are glutamate-gated ion channels that are key mediators of excitatory neurotransmission and synaptic plasticity throughout the central nervous system. They form massive heterotetrameric complexes endowed with unique allosteric capacity provided by eight extracellular clamshell-like domains arranged as two superimposed layers...

DE-ETIOLATED 1 (DET1) is an evolutionarily conserved component of the ubiquitination machinery that mediates the destabilization of key regulators of cell differentiation and proliferation in multicellular organisms. In this study, we provide evidence from Arabidopsis that DET1 is essential for the regulation of histone H2B monoubiquitination (H2Bu...

Gene lists summarizing ChIP-Rx analysis of H2Bub levels in WT and det1-1 seedlings grown under dark or light conditions.

RNA-seq identification of genes differentially expressed in WT, det1-1, ubp22-1 and det1-1ubp22-1 mutant lines grown under dark or light conditions using DESeq2.

RNA-seq differential analyses.

original blot of data in (B).

Detailed identification of differentially modified histone peptides in wild-type and det1-1 samples.

ChIP differential analyses.

Detailed TAP protein identification.

pdb of the modeled At-UBP-ENY2-SGF11 complex structure.

DE-ETIOLATED 1 (DET1) is an evolutionarily conserved component of the ubiquitination machinery that mediates the destabilization of key regulators of cell differentiation and proliferation in multicellular organisms. In this study, we provide evidence from Arabidopsis that DET1 is essential for the regulation of histone H2B monoubiquitination (H2Bu...

N-methyl-D-aspartate receptors (NMDARs) are glutamate-gated ion channels that play crucial roles in brain development and synaptic plasticity. They are also therapeutic targets of interest since their dysfunction is associated with multiple neurological and psychiatric disorders. In vivo, NMDARs exist as multiple subtypes that differ in their subun...

Cadherin linkages between adjacent stereocilia and microvilli are essential for mechanotransduction and maintaining their organization. They are anchored to actin through interaction of their cytoplasmic domains with related tripartite complexes consisting of a class VII myosin and adaptor proteins: Myo7a/SANS/Harmonin in stereocilia and Myo7b/ANKS...

Position of the 25 missense mutations found in Myo7a MF2. Representation of the missense mutations found in the MF2 of Myo7a (spheres). The spheres are colored following the color code used in Fig. 4C. The MF lobes are colored in red (MyTH4), blue (F1), orange (F2) and green (F3). The PDZ3c of Harmonin is in purple.

Supplementary figures, supplementary tables and supplementary references.

Myo7b MF2 FERM central cavity is very different from those of Myo7b and Myo7a MF1. Structural superimposition between Myo7b MF2 FERM (multi-colored), Myo7b MF1 (yellow) and Myo7a MF1 (violet) using the F1 lobe as a reference. The central cavity between the three FERM lobes (F1, F2 and F3) is drastically different between MF1 and MF2, explaining the

Cytokinetic abscission, the terminal step of cell division, crucially depends on the local constriction of ESCRT-III helices after cytoskeleton disassembly. While the microtubules of the intercellular bridge are cut by the ESCRT-associated enzyme Spastin, the mechanism that clears F-actin at the abscission site is unknown. Here we show that oxidati...

Supplementary Figures, Supplementary Tables and Supplementary References.

The proper function of neural circuits requires spatially and temporally balanced development of excitatory and inhibitory synapses. However, the molecular mechanisms coordinating excitatory and inhibitory synaptogenesis remain unknown. Here we demonstrate that SRGAP2A and its human-specific paralog SRGAP2C co-regulate the development of excitatory...

NMDA receptors (NMDARs) are glutamate-gated ion channels that play key roles in brain physiology and pathology. Because numerous pathological conditions involve NMDAR overactivation, subunit-selective antagonists hold strong therapeutic potential, although clinical successes remain limited. Among the most promising NMDAR-targeting drugs are alloste...

Ligand-gated ion channels (LGICs) mediate fast synaptic transmission in the CNS. Typically, these membrane proteins are multimeric complexes associating several homologous subunits around a central pore. Because of the large repertoire of subunits within each family, LGICs exist in vivo as multiple subtypes that differ in subunit composition and fu...

NMDA receptors are crucial in the workings of the brain and in its disorders. Two structures of almost complete receptors reveal the intricate complexity of these large, multi-domain molecular machines. See Article p.191

N-methyl-D-aspartate receptors (NMDARs), neuronal glutamate-gated ion channels, are obligatory heterotetramers composed of GluN1 and GluN2 subunits. Each subunit contains two extracellular clamshell-like domains with an agonist-binding domain and a distal N-terminal domain (NTD). The GluN2 NTDs form mobile regulatory domains. In contrast, the dynam...

NMDA receptors are widely expressed in the central nervous system and play a major role in excitatory synaptic transmission and plasticity. Here, we used atomic force microscopy (AFM) imaging to visualize activation-induced structural changes in the GluN1/GluN2A NMDA receptor reconstituted into a lipid bilayer. In the absence of agonist, AFM imagin...

NMDA receptors (NMDARs) form glutamate-gated ion channels that play a critical role in CNS physiology and pathology. Together with AMPA and kainate receptors, NMDARs are known to operate as tetrameric complexes with four membrane-embedded subunits associating to form a single central ion-conducting pore. While AMPA and some kainate receptors can fu...

Ionotropic glutamate receptors (iGluRs) possess in their extracellular region a large N-terminal domain (NTD) that precedes the agonist-binding domain and displays a clamshell-like architecture similar to the bacterial leucine/isoleucine/valine-binding protein (LIVBP). In addition to their role in receptor assembly, in NMDA receptors (NMDARs), the...

For Abstract see ChemInform Abstract in Full Text.

DC-SIGN is a C-type lectin receptor of dendritic cells and is involved in the early stages of numerous infectious diseases. DC-SIGN is organized into a tetramer enabling multivalent interaction with pathogens. Once formed, the DC-SIGN-pathogen complex can be internalized into compartments of increasing acidity. We have studied the pH dependence of...

Characterization of 'unknown' proteins is one of the challenges of the post-genomic era. Here, we report a study of Bacillus subtilis YdiB, which belongs to an uncharted class of bacterial P-loop ATPases. Precise deletion of the ydiB gene yielded a mutant with much reduced growth rate compared to the wild-type strain. In vitro, purified YdiB was in...

Ionotropic glutamate receptor (iGluR) subunits contain a large N-terminal domain (NTD) that precedes the agonist-binding domain (ABD) and participates in subunit oligomerization. In NMDA receptors (NMDARs), the NTDs of NR2A and NR2B subunits also form binding sites for the endogenous inhibitor Zn(2+) ion. Although these allosteric sites have been c...

Figure S1. Mutations aimed at stabilizing the ABD dimer interface through hydrogen bonds decrease zinc and pH sensitivities. Comparison of the zinc (Left) and proton (Right) sensitivities of NR1-E522Q/NR2A-G784E (circles, solid line) with wt NR1/NR2A receptors (open squares, dashed line). For zinc inhibition, Inhib max , IC 50 and n H values are: 7...

We have used analytical ultracentrifugation to explore the oligomeric states of AcrB and CusA in micellar solution of detergent. These two proteins belong to the resistance, nodulation and cell division (RND) family of efflux proteins that are involved in multiple drug and heavy metal resistance. Only the structure of AcrB has been determined so fa...

Photosystems I and II (PSI and II) are reaction centres that capture light energy in order to drive oxygenic photosynthesis; however, they can only do so by interacting with the multisubunit cytochrome b(6)f complex. This complex receives electrons from PSII and passes them to PSI, pumping protons across the membrane and powering the Q-cycle. Unlik...

Human plasma paraoxonase (HuPON1) is a high density lipoprotein (HDL)-bound enzyme exhibiting antiatherogenic properties. The molecular basis for the binding specificity of HuPON1 to HDL has not been established. Isolation of HuPON1 from HDL requires the use of detergents. We have determined the activity, dispersity, and oligomeric states of HuPON1...

The synthesis and usefulness in membrane biochemistry of a new class of surfactants have been investigated. 1-Ethyl-2-dimethylamine oxide polar heads were grafted onto a hydrocarbon, a fluorocarbon or an ethyl-capped fluorocarbon hydrophobic tail. The ability of the resulting surfactants to extract and/or to stabilize in aqueous solution a test mem...