Identifying USPs regulating immune signals in Drosophila: USP2 deubiquitinates Imd and promotes its degradation by interacting with the proteasome.

International audienceBACKGROUND: Rapid activation of innate immune defences upon microbial infection depends on the evolutionary conserved NF-κB dependent signals which deregulation is frequently associated with chronic inflammation and oncogenesis. These signals are tightly regulated by the linkage of different kinds of ubiquitin moieties on proteins that modify either their activity or their stability. To investigate how ubiquitin specific proteases (USPs) orchestrate immune signal regulation, we created and screened a focused RNA interference library on Drosophila NF-κB-like pathways Toll and Imd in cultured S2 cells, and further analysed the function of selected genes in vivo. RESULTS: We report here that USP2 and USP34/Puf, in addition to the previously described USP36/Scny, prevent inappropriate activation of Imd-dependent immune signal in unchallenged conditions. Moreover, USP34 is also necessary to prevent constitutive activation of the Toll pathway. However, while USP2 also prevents excessive Imd-dependent signalling in vivo, USP34 shows differential requirement depending on NF-κB target genes, in response to fly infection by either Gram-positive or Gram-negative bacteria. We further show that USP2 prevents the constitutive activation of signalling by promoting Imd proteasomal degradation. Indeed, the homeostasis of the Imd scaffolding molecule is tightly regulated by the linkage of lysine 48-linked ubiquitin chains (K48) acting as a tag for its proteasomal degradation. This process is necessary to prevent constitutive activation of Imd pathway in vivo and is inhibited in response to infection. The control of Imd homeostasis by USP2 is associated with the hydrolysis of Imd linked K48-ubiquitin chains and the synergistic binding of USP2 and Imd to the proteasome, as evidenced by both mass-spectrometry analysis of USP2 partners and by co-immunoprecipitation experiments. CONCLUSION: Our work identified one known (USP36) and two new (USP2, USP34) ubiquitin specific proteases regulating Imd or Toll dependent immune signalling in Drosophila. It further highlights the ubiquitin dependent control of Imd homeostasis and shows a new activity for USP2 at the proteasome allowing for Imd degradation. This study provides original information for the better understanding of the strong implication of USP2 in pathological processes in humans, including cancerogenesis

Fifteen years of research on oral–facial–digital syndromes: from 1 to 16 causal genes

Oral–facial–digital syndromes (OFDS) gather rare genetic disorders characterised by facial, oral and digital abnormalities associated with a wide range of additional features (polycystic kidney disease, cerebral malformations and several others) to delineate a growing list of OFDS subtypes. The most frequent, OFD type I, is caused by a heterozygous mutation in the OFD1 gene encoding a centrosomal protein. The wide clinical heterogeneity of OFDS suggests the involvement of other ciliary genes. For 15 years, we have aimed to identify the molecular bases of OFDS. This effort has been greatly helped by the recent development of whole-exome sequencing (WES). Here, we present all our published and unpublished results for WES in 24 cases with OFDS. We identified causal variants in five new genes (C2CD3, TMEM107, INTU, KIAA0753 and IFT57) and related the clinical spectrum of four genes in other ciliopathies (C5orf42, TMEM138, TMEM231 and WDPCP) to OFDS. Mutations were also detected in two genes previously implicated in OFDS. Functional studies revealed the involvement of centriole elongation, transition zone and intraflagellar transport defects in OFDS, thus characterising three ciliary protein modules: the complex KIAA0753-FOPNL-OFD1, a regulator of centriole elongation; the Meckel-Gruber syndrome module, a major component of the transition zone; and the CPLANE complex necessary for IFT-A assembly. OFDS now appear to be a distinct subgroup of ciliopathies with wide heterogeneity, which makes the initial classification obsolete. A clinical classification restricted to the three frequent/well-delineated subtypes could be proposed, and for patients who do not fit one of these three main subtypes, a further classification could be based on the genotype

A Solve-RD ClinVar-based reanalysis of 1522 index cases from ERN-ITHACA reveals common pitfalls and misinterpretations in exome sequencing

Purpose Within the Solve-RD project (https://solve-rd.eu/), the European Reference Network for Intellectual disability, TeleHealth, Autism and Congenital Anomalies aimed to investigate whether a reanalysis of exomes from unsolved cases based on ClinVar annotations could establish additional diagnoses. We present the results of the “ClinVar low-hanging fruit” reanalysis, reasons for the failure of previous analyses, and lessons learned. Methods Data from the first 3576 exomes (1522 probands and 2054 relatives) collected from European Reference Network for Intellectual disability, TeleHealth, Autism and Congenital Anomalies was reanalyzed by the Solve-RD consortium by evaluating for the presence of single-nucleotide variant, and small insertions and deletions already reported as (likely) pathogenic in ClinVar. Variants were filtered according to frequency, genotype, and mode of inheritance and reinterpreted. Results We identified causal variants in 59 cases (3.9%), 50 of them also raised by other approaches and 9 leading to new diagnoses, highlighting interpretation challenges: variants in genes not known to be involved in human disease at the time of the first analysis, misleading genotypes, or variants undetected by local pipelines (variants in off-target regions, low quality filters, low allelic balance, or high frequency). Conclusion The “ClinVar low-hanging fruit” analysis represents an effective, fast, and easy approach to recover causal variants from exome sequencing data, herewith contributing to the reduction of the diagnostic deadlock

Plantas Vasculares: Estudio de la sistemática, evolución y morfo-ecología de las traqueofitas

Este libro es la guía teórica y práctica de la asignatura Plantas Vasculares que forma parte del plan de estudio de la Licenciatura de Ciencias Biológicas de la Facultad de Ciencias Exactas y Naturales, UNMDP. Esta cursada ofrece un panorama de las plantas vasculares agrupadas en categorías sistemáticas. Abarca tres grandes entidades vegetales conocidas como pteridofitas, gimnospermas y angiospermas. Estos tres grupos incluyen a la mayor parte de la flora del mundo. Se presta especial atención a los grupos con representantes en el país, ubicándolos en el contexto fitogeográfico argentino. También son incluidas las especies cultivadas, destacándose las de mayor valor económico.Fil: Mancini, Maria Virginia. No especifíca;Fil: Mourelle Civano, Dominique. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Sottile, Gonzalo David. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Thevenon, Mario Alberto. No especifíca

The Nonaspanins TM9SF2 and TM9SF4 regulate the plasma membrane localization and signalling activity of the Peptidoglycan Recognition Protein PGRP-LC in Drosophila

Transmembrane 9 (TM9) proteins, or nonaspanins, are a family of proteins conserved throughout evolution and characterized by 9 transmembrane domains. In Drosophila, TM9 superfamily protein member 4 (TM9SF4) and its closest paralogue, TM9SF2, contribute to phagocytosis of various types of particles, while TM9SF4 displays non-redundant requirement in Gram-negative bacteria engulfment. In addition, the two TM9 proteins control the actin cytoskeleton in larval haemocytes and in Drosophila S2 cells. Here, we show that TM9SF4 and TM9SF2 co-immunoprecipitate with the peptidoglycan recognition protein (PGRP)-LC, which triggers the Drosophila immune response to bacterial infection. Furthermore, both TM9 proteins co-localize with this receptor in intracellular vesicles and at the plasma membrane in Drosophila S2 cells in culture and in the fly fat body. Silencing TM9SF4 prevents plasma membrane localization of PGRP-LC, whereas silencing TM9SF2 does not, which may account for the non-redundant role of TM9SF4 in phagocytosis of Gram-negative bacteria. Finally, we provide a set of data suggesting that TM9 proteins can prevent inappropriate signalling from the unstimulated receptor

A Nucleolar Isoform of the Drosophila Ubiquitin Specific Protease dUSP36 Regulates MYC-Dependent Cell Growth

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Development of new wood treatments combining boron impregnation and thermo modification: effect of additives on boron leachability

International audienc

The deubiquitinating enzyme USP36 controls selective autophagy activation by ubiquitinated proteins

Initially described as a nonspecific degradation process induced upon starvation, autophagy is now known also to be involved in the degradation of specific ubiquitinated substrates such as mitochondria, bacteria and aggregated proteins, ensuring crucial functions in cell physiology and immunity. We report here that the deubiquitinating enzyme USP36 controls selective autophagy activation in Drosophila and in human cells. We show that dUsp36 loss of function autonomously inhibits cell growth while activating autophagy. Despite the phenotypic similarity, dUSP36 is not part of the TOR signaling pathway. Autophagy induced by dUsp36 loss of function depends on p62/SQSTM1, an adaptor for delivering cargo marked by polyubiquitin to autophagosomes. Consistent with p62 requirement, dUsp36 mutant cells display nuclear aggregates of ubiquitinated proteins, including Histone H2B, and cytoplasmic ubiquitinated proteins; the latter are eliminated by autophagy. Importantly, USP36 function in p62-dependent selective autophagy is conserved in human cells. Our work identifies a novel, crucial role for a deubiquitinating enzyme in selective autophagy

A high-resolution historical sediment record of nutrients, trace elements and organochlorines (DDT and PCB) deposition in a drinking water reservoir (Lake Brêt, Switzerland) points at local and regional pollutant sources

The 137Cs and 210Pb dating of a 61-cm long sediment core retrieved from a drinking water reservoir (Lake Brêt) located in Switzerland revealed a linear and relatively high sedimentation rate (~1 cm year-1) over the last decades. The continuous centimeter scale measurement of physical (porewater and granulometry), organic (Corg, P, N, HI and OI indexes) and mineral (Cmin and lithogenic trace elements) parameters therefore enables reconstructing the environmental history of the lake and anthropogenic pollutant input (trace metals, DDT and PCBs) at high resolution. A major change in the physical properties of the lowermost sediments occurred following the artificial rise of the dam in 1922. After ca. 1940, there was a longterm up-core increase in organic matter deposition attributed to enhance primary production and anoxic bottom water conditions due to excessive nutrient input from a watershed predominantly used for agriculture that also received domestic effluents of two wastewater-treatment plants