A role for protein phosphatase PP1γ in SMN complex formation and subnuclear localization to Cajal bodies

The spinal muscular atrophy (SMA) gene product SMN forms with gem-associated protein 2-8 (Gemin2-8) and unrip (also known as STRAP) the ubiquitous survival motor neuron (SMN) complex, which is required for the assembly of spliceosomal small nuclear ribonucleoproteins (snRNPs), their nuclear import and their localization to subnuclear domain Cajal bodies (CBs). The concentration of the SMN complex and snRNPs in CBs is reduced upon SMN deficiency in SMA cells. Subcellular localization of the SMN complex is regulated in a phosphorylation-dependent manner and the precise mechanisms remain poorly understood. Using co-immunoprecipitation in HeLa cell extracts and in vitro protein binding assays, we show here that the SMN complex and its component Gemin8 interact directly with protein phosphatase PP1γ. Overexpression of Gemin8 in cells increases the number of CBs and results in targeting of PP1γ to CBs. Moreover, depletion of PP1γ by RNA interference enhances the localization of the SMN complex and snRNPs to CBs. Consequently, the interaction between SMN and Gemin8 increases in cytoplasmic and nuclear extracts of PP1γ-depleted cells. Two-dimensional protein gel electrophoresis revealed that SMN is hyperphosphorylated in nuclear extracts of PP1γ-depleted cells and expression of PP1γ restores these isoforms. Notably, SMN deficiency in SMA leads to the aberrant subcellular localization of Gemin8 and PP1γ in the atrophic skeletal muscles, suggesting that the function of PP1γ is likely to be affected in disease. Our findings reveal a role of PP1γ in the formation of the SMN complex and the maintenance of CB integrity. Finally, we propose Gemin8 interaction with PP1γ as a target for therapeutic intervention in SMA

Analysis of durum wheat proteome changes under marine and fungal biostimulant treatments using large-scale quantitative proteomics: A useful dataset of durum wheat proteins

Durum wheat requires high nitrogen inputs to obtain the high protein concentration necessary to satisfy pasta and semolina quality criteria. Optimizing plant nitrogen use efficiency is therefore of major importance for wheat grain quality. Here, we studied the impact on grain yield, protein concentration, and for the first time on protein composition of a marine (DPI4913) and a fungal (AF086) biostimulants applied to plant leaves. A large-scale quantitative proteomics analysis of wheat flour samples led to a dataset of 1471 identified proteins. Quantitative analysis of 1391 proteins revealed 26 and 38 proteins with a significantly varying abundance after DPI4913 and AF086 treatment, respectively, with 14 proteins in common. Major effects affected proteins involved in grain technological properties like grain hardness, in storage functions with the gluten protein gamma-gliadin, in regulation processes with transcription regulator proteins, and in stress responses with biotic and abiotic stress defense proteins. The involvement of biostimulants in the abiotic stress response was further suggested by an increase in water-use efficiency for both DPI4913 (15.4%) and AF086 (9.9%) treatments. Overall, our work performed in controlled conditions showed that DPI4913 and AF086 treatments promoted grain yield while maintaining protein concentration, and positively affected protein composition for grain quality. Data are available via ProteomeXchange with identifier PXD012469

Segregation of mtDNA Throughout Human Embryofetal Development: m.3243A > G as a Model System

Mitochondrial DNA (mtDNA) mutations cause a wide range of serious diseases with high transmission risk and maternal inheritance. Tissue heterogeneity of the heteroplasmy rate (“mutant load”) accounts for the wide phenotypic spectrum observed in carriers. Owing to the absence of therapy, couples at risk to transmit such disorders commonly ask for prenatal (PND) or preimplantation diagnosis (PGD). The lack of data regarding heteroplasmy distribution throughout intrauterine development, however, hampers the implementation of such procedures. We tracked the segregation of the m.3243A > G mutation (MT-TL1 gene) responsible for the MELAS syndrome in the developing embryo/fetus, using tissues and cells from eight carrier females, their 38 embryos and 12 fetuses. Mutant mtDNA segregation was found to be governed by random genetic drift, during oogenesis and somatic tissue development. The size of the bottleneck operating for m.3243A > G during oogenesis was shown to be individual-dependent. Comparison with data we achieved for the m.8993T > G mutation (MT-ATP6 gene), responsible for the NARP/Leigh syndrome, indicates that these mutations differentially influence mtDNA segregation during oogenesis, while their impact is similar in developing somatic tissues. These data have major consequences for PND and PGD procedures in mtDNA inherited disorders. Hum Mutat 32:116–125, 2011. © 2010 Wiley-Liss, Inc

PIP30/FAM192A is a novel regulator of the nuclear proteasome activator PA28γ

PA28γ is a nuclear activator of the 20S proteasome involved in the regulation of several essential cellular processes, such as cell proliferation, apoptosis, nuclear dynamics, and cellular stress response. Unlike the 19S regulator of the proteasome, which specifically recognizes ubiquitylated proteins, PA28γ promotes the degradation of several substrates by the proteasome in an ATP- and ubiquitin-independent manner. However, its exact mechanisms of action are unclear and likely involve additional partners that remain to be identified. Here we report the identification of a cofactor of PA28γ, PIP30/FAM192A. PIP30 binds directly and specifically via its C-terminal end and in an interaction stabilized by casein kinase 2 phosphorylation to both free and 20S proteasome-associated PA28γ. Its recruitment to proteasome-containing complexes depends on PA28γ and its expression increases the association of PA28γ with the 20S proteasome in cells. Further dissection of its possible roles shows that PIP30 alters PA28γ-dependent activation of peptide degradation by the 20S proteasome in vitro and negatively controls in cells the presence of PA28γ in Cajal bodies by inhibition of its association with the key Cajal body component coilin. Taken together, our data show that PIP30 deeply affects PA28γ interactions with cellular proteins, including the 20S proteasome, demonstrating that it is an important regulator of PA28γ in cells and thus a new player in the control of the multiple functions of the proteasome within the nucleus

Characterization of Sleep in Zebrafish and Insomnia in Hypocretin Receptor Mutants

Sleep is a fundamental biological process conserved across the animal kingdom. The study of how sleep regulatory networks are conserved is needed to better understand sleep across evolution. We present a detailed description of a sleep state in adult zebrafish characterized by reversible periods of immobility, increased arousal threshold, and place preference. Rest deprivation using gentle electrical stimulation is followed by a sleep rebound, indicating homeostatic regulation. In contrast to mammals and similarly to birds, light suppresses sleep in zebrafish, with no evidence for a sleep rebound. We also identify a null mutation in the sole receptor for the wake-promoting neuropeptide hypocretin (orexin) in zebrafish. Fish lacking this receptor demonstrate short and fragmented sleep in the dark, in striking contrast to the excessive sleepiness and cataplexy of narcolepsy in mammals. Consistent with this observation, we find that the hypocretin receptor does not colocalize with known major wake-promoting monoaminergic and cholinergic cell groups in the zebrafish. Instead, it colocalizes with large populations of GABAergic neurons, including a subpopulation of Adra2a-positive GABAergic cells in the anterior hypothalamic area, neurons that could assume a sleep modulatory role. Our study validates the use of zebrafish for the study of sleep and indicates molecular diversity in sleep regulatory networks across vertebrates

Contribution à l'étude systématique et écologique des Micromycètes parasites des plantes spontanées des Alpes françaises (6e note) Session de Pralognan (Savoie)

We collected 178 species of microfungi ; 22 species are uncommon (1 Ascomycete and 23 Imperfect fungi) of wich 16 are new for France ; and 14 has a new host.Nous avons récolté 178 espèces (dont 12 Péronosporales, 65 Urédi-nales, 8 Ustilaginales, 6 Erysiphales, 5 autres Ascomycètes, 85 Fungi Imperfecti (= Champignons imparfaits) dont 58 Hyphales (et 43 Ramularia) 3 Mélanconiales et 24 Sphaeropsidales (et 4 Septoria ). Parmi les raretés, citons 23 espèces rares à très rares (1 Ascomycète et 22 Fungi Imperfecti ) dont 13 espèces nouvelles pour la France (et dont c'est la première et seule récolte française) 14 hôtes nouveaux et 9 espèces encore très peu récoltées en France (2e à 5e récoltes).Chevassut Georges, Pellicier Philippe, Burlet Christiane. Contribution à l'étude systématique et écologique des Micromycètes parasites des plantes spontanées des Alpes françaises (6e note) Session de Pralognan (Savoie). In: Bulletin mensuel de la Société linnéenne de Lyon, 65ᵉ année, n°1, janvier 1996. pp. 20-24

Du Mont-Saint-Michel à La Rochelle. Quelle est la qualité des eaux littorales ?

7 panneaux (90 X 200 cm) qui présentent la façon dont est observé le littoral Loire-Bretagne pour le qualifier au titre de la Directive cadre sur l'eau (DCE). Ifremer et l'Agence de l'eau Loire Bretagne ont conçu cet outil de communication mis à disposition des acteurs locaux

Morphometrics of Second Iron Age ceramics - strengths, weaknesses, and comparison with traditional typology.

12 pagesInternational audienceAlthough the potential of geometric morphometrics for the study of archaeological artefacts is recognised, quantitative evaluations of the concordance between such methods and traditional typology are rare. The present work seeks to fill this gap, using as a case study a corpus of 154 complete ceramic vessels from the Bibracte oppidum (France), the capital of the Celtic tribe Aedui from the Second Iron Age. Two outline-based approaches were selected: the Elliptic Fourier Analysis and the Discrete Cosine Transform. They were combined with numerous methods of standardisation/normalisation. Although standardisations may use either perimeter or surface, the resulting morphospaces remain comparable, and, interestingly, are also comparable with the morphospace built from traditional typology. Geometric morphometrics also present the advantage of being easily implemented and automated for large sets of artefacts. The method is reproducible and provides quantitative estimates, such as mean shape, and shape diversity of ceramic assemblages, allowing objective inferences to be statistically tested. The approach can easily be generalised and adopted for other kinds of artefacts, to study the level of production standardisation and the evolution of shape over space and time, and to provide information about material and cultural exchanges

Multiple views in single‐path synthetic aperture sonar for mine counter‐measures classification and pre‐identification

Abstract The authors present exploitation of Multiple Views in Single‐Path (MVSP) Synthetic Aperture Sonar (SAS). The authors demonstrate the interest of MVSP SAS for underwater Mine Counter‐Measures (MCM) with unmanned vehicles, to comply with requirements for performances of detection and classification and time constraints. The authors here lay the emphasis on exploitation in reduction of false alarms of classification by alleviating the ambiguity between mines and natural bottom objects. Finally, the authors show that MVSP SAS is offering a pre‐identification tool with high impact on MCM process duration