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

Intensification et requalification des centralités pour lutter contre l'étalement urbain et la dépendance à la voiture : rapport final de la subvention 2021

Intensification et requalification des centralités pour lutter contre l’étalement urbain et la dépendance à la voiture12. Responsible consumption and production13. Climate actio

Le musée français: guerras napoleônicas, coleções artísticas e o longínquo destino de um livro

This paper is about Le Musée Français [The French Museum], a book found in the collection of the library of the Imperial Academy of Fine Arts in Rio de Janeiro. As a catalog of the Napoleon Museum, it bears witness to the reorganization of the arts in Europe as a result of the Napoleonic wars and the project of making Paris a true successor to Athens and Rome, as the center of a new republic of the arts. This process was the object of a dispute where Quatremère de Quincy and Joachim Lebreton played an important role. It was also one of the causes leading to the exile of a group of artists who then helped to lay the foundations for an academic environment in Rio de Janeiro.O artigo trata de Le musée français, livro que fez parte da coleção da biblioteca da Academia Imperial das Belas Artes, no RiodeJaneiro. Como catálogo do Museu Napoleão, é testemunho do processo de reordenamento, resultante das guerras napoleônicas, do universo das artes na Europa e do projeto de fazer de Paris a legítima herdeira de Atenas e Roma, como centro de uma nova idéia de república das artes. Processo esse que foi objeto de disputa, em que se destacaram Quatremère de Quincy eJoachim Lebreton, e foi uma das causas do exílio do grupo de artistas que esteve na origem da formação do ambiente acadêmico no Rio de Janeiro

Conception d'un biocapteur électrochimique pour la détection des interactions oligosaccharides/protéines

Les oligosaccharides situés à la surface des cellules, en interagissant de manière spécifique avec certaines protéines (lectines), jouent un rôle majeur dans la vie sociale de ces cellules et sont directement impliqués dans différents processus biologique. Dans ce contexte, la mise en place d'outils de diagnostique et de détection d'agents pathogènes, tel qu'un biocapteur a été envisagée. Les oligosaccharides (lactose et sialyllactose) ont été immobilisés à la surface d'une électrode via un film polypyrrole, afin de pouvoir par la suite détecter directement la reconnaissance oligosaccharides/lectines par électrochimie. Les lectines étudiées sont la lectine PNA pour le lactose et la lectine de Maackia Amurensis pour le sialyllactose. Les interactions oligosaccharides/lectines ont pu être mises en évidence par voltampérométrie cyclique, perméabilité et spectroscopie d'impédance. Deux études quantitatives ont été menées, l'une en résonance plasmonique de surface permettant l'obtention d'un seuil de détection des deux couples étudiés, ainsi que l'estimation des constantes de dissociation, et l'autre en spectroscopie d'impédance permettant l'obtention d'un biocapteur, avec une limite de détection de 1,5 nmo1. L-1GRENOBLE1-BU Sciences (384212103) / SudocSudocFranceF

Fluorescence enhancement near metallic nanoparticles under two photon excitation

International audienceFluorescence is widely used as a spectroscopic tool or for biomedical imaging. To extend these measurements to small concentrations or to fluorophores with very low quantum yield we have developed nanostructured substrates made of silver nanoparticles covered with a spacerlayer of alumina. Factors of about 200 are obtained for fluorescence enhancement with two photon excitation. Lifetime measurements reveal additional information on the decay channels induced by the nanoparticle presence

Electrogenerated poly(pyrrole-lactosyl) and poly(pyrrole-3'-sialyllactosyl) interfaces: toward the impedimetric detection of lectins

International audienc

Immunological comparative studies of octopine dehydrogenase and other “pyruvate reductases” from different species

1. Antisera against the two purified A and B forms of ODH from Pecten maximus were prepared and used to compare immunological relationship between ODHs from different species. 2. A-ODH and B-ODH from Pecten maximus do not exhibit any detectable antigenic differences as shown by means of cross-reaction and cross-inhibition tests. 3. ODHs from sea anemones, bivalvia and cephalopoda molluscs were compared by “blotting” technique and revealed by immunoenzymatic assays. 4. Antigenic similarities could only be detected between P. maximus ODH and both the native and the denatured ODH from the closely related species Chlamys opercularis. 5. Conformational antigenic homology was found between mantle ODH isoenzyme from two cephalopods and is discussed in terms of active site similarities. 6. No immunological relationship was observed between ODH from P. maximus and the other ODHs as well as pyruvate-reductases from different marine species examined. 7. No cross-reaction occurred between ODHs from P. maximus and from crown-gall

Mirror slides for high-sensitivity cell and tissue fluorescence imaging

International audienceFluorescence microscopy has become the method of choice in the majority of life-science applications. We describe development and use of mirror slides to significantly enhance the fluorescence signal using standard air microscope objectives. This technique offers sufficient gain to achieve high-sensitivity imaging, together with wide field of observation and large depth of focus, two major breakthroughs for routine analysis and high-throughput screening applications on cells and tissue samples