Boosting endoplasmic reticulum folding capacity reduces unfolded protein response activation and intracellular accumulation of human kidney anion exchanger 1 in Saccharomyces cerevisiae

Human kidney anion exchanger 1 (kAE1) facilitates simultaneous efflux of bicarbonate and absorption of chloride at the basolateral membrane of α-intercalated cells. In these cells, kAE1 contributes to systemic acid–base balance along with the proton pump v-H+-ATPase and the cytosolic carbonic anhydrase II. Recent electron microscopy analyses in yeast demonstrate that heterologous expression of several kAE1 variants causes a massive accumulation of the anion transporter in intracellular membrane structures. Here, we examined the origin of these kAE1 aggregations in more detail. Using various biochemical techniques and advanced light and electron microscopy, we showed that accumulation of kAE1 mainly occurs in endoplasmic reticulum (ER) membranes which eventually leads to strong unfolded protein response (UPR) activation and severe growth defect in kAE1 expressing yeast cells. Furthermore, our data indicate that UPR activation is dose dependent and uncoupled from the bicarbonate transport activity. By using truncated kAE1 variants, we identified the C-terminal region of kAE1 as crucial factor for the increased ER stress level. Finally, a redistribution of ER-localized kAE1 to the cell periphery was achieved by boosting the ER folding capacity. Our findings not only demonstrate a promising strategy for preventing intracellular kAE1 accumulation and improving kAE1 plasma membrane targeting but also highlight the versatility of yeast as model to investigate kAE1-related research questions including the analysis of structural features, protein degradation and trafficking. Furthermore, our approach might be a promising strategy for future analyses to further optimize the cell surface targeting of other disease-related PM proteins, not only in yeast but also in mammalian cells. Take Away We analysed the intracellular transport of human kAE1 to the yeast plasma membrane. We studied the effect of human kAE1 expression on yeast growth and UPR activation. We investigated the impact of different kAE1 truncation variants on UPR induction We implemented intervention strategies to improve PM targeting of kAE1

(Re)conceptualising physical activity participation as career

Physical activity is increasingly positioned as playing an important role in preventing and mitigating many of the decrements associated with biological ageing. As a result, public health messages encourage older people to remain active in later life. Despite this, physical activity participation rates among older adults are low. This may be in part related to the conventional approach to understanding physical activity participation as a product of motivation. We contend that this approach does not allow for a deeper exploration of the wider structural, historical and discursive contexts in which physical activity participation occurs. Therefore, we propose that physical activity can be reconceptualised as a career. Through a synthesis of findings from four studies exploring physical activity experiences in later life, we demonstrate that beginning and maintaining a physical activity career requires a disposition towards physical activity, the legitimation of physically active practices and dealing with contingencies. In addition, we demonstrate that maintaining a physical activity career requires investment and deliberation to adapt physical activity practices continually within an individual's own personal biography. As such, we conclude that current strategies to promote physical activity to older adults are unlikely to result in increased levels of participation. To promote physical activity to older adults an understanding of how structural, cultural and historical contexts influence participation is needed

Functional Integrative Levels in the Human Interactome Recapitulate Organ Organization

Interactome networks represent sets of possible physical interactions between proteins. They lack spatio-temporal information by construction. However, the specialized functions of the differentiated cell types which are assembled into tissues or organs depend on the combinatorial arrangements of proteins and their physical interactions. Is tissue-specificity, therefore, encoded within the interactome? In order to address this question, we combined protein-protein interactions, expression data, functional annotations and interactome topology. We first identified a subnetwork formed exclusively of proteins whose interactions were observed in all tested tissues. These are mainly involved in housekeeping functions and are located at the topological center of the interactome. This ‘Largest Common Interactome Network’ represents a ‘functional interactome core’. Interestingly, two types of tissue-specific interactions are distinguished when considering function and network topology: tissue-specific interactions involved in regulatory and developmental functions are central whereas tissue-specific interactions involved in organ physiological functions are peripheral. Overall, the functional organization of the human interactome reflects several integrative levels of functions with housekeeping and regulatory tissue-specific functions at the center and physiological tissue-specific functions at the periphery. This gradient of functions recapitulates the organization of organs, from cells to organs. Given that several gradients have already been identified across interactomes, we propose that gradients may represent a general principle of protein-protein interaction network organization

A method to identify target molecules and extract the corresponding graph of interactions in BioPAX

International audienc

The ReproGenomics Viewer: an integrative cross-species toolbox for the reproductive science community.

International audienceWe report the development of the ReproGenomics Viewer (RGV), a multi-and cross-species working environment for the visualization, mining and comparison of published omics data sets for the reproductive science community. The system currently embeds 15 published data sets related to gametogenesis from nine model organisms. Data sets have been curated and conveniently organized into broad categories including biological topics, technologies, species and publications. RGV's modular design for both organisms and genomic tools enables users to upload and compare their data with that from the data sets embedded in the system in a cross-species manner. The RGV is freely available at http://rgv.genouest.org

Merkel Cell Polyomavirus Strains in Patients with Merkel Cell Carcinoma

We investigated whether Merkel cell carcinoma (MCC) patients in France carry Merkel cell polyomavirus (MCPyV) and then identified strain variations. All frozen MCC specimens and 45% of formalin-fixed and paraffin-embedded specimens, but none of the non-MCC neuroendocrine carcinomas specimens, had MCPyV. Strains from France and the United States were similar

Anais do 2º Encontro de Iniciação Científica da Unila "Resultados em debate"

Anais do II Encontro de Iniciação Científica da Unila. Unila-PTI, Foz do Iguaçu, Estado do Paraná, 03 e 04 de julho de 2013O Programa de Bolsas de Iniciação Científica da Unila (Probic) e o Programa Institucional de Bolsas de Iniciação Científica (Pibic), da Fundação Araucária de Apoio ao Desenvolvimento Científico e Tecnológico do Paraná (FA), incentivam e promovem a capacitação de estudantes de graduação para produzir conhecimento científico sob responsabilidade de um professor orientador. Na atividade, o orientador tem papel central em direcionar o desenvolvimento das atitudes críticas e habilidades do estudante à missão da Universidade. Neste processo, a iniciação científica tem a missão de aperfeiçoar a formação acadêmica e profissional de estudantes, que são introduzidos nos diferentes campos do saber pelas disciplinas e projetos de pesquisa docente para serem capacitados a refletir, formular e testar hipóteses, resolver problemas e situações colocadas, tanto pela simples curiosidade humana de conhecer quanto pela necessidade social de transformar. Constitui-se na formulação de questionamentos, na aprendizagem da elaboração do objeto de pesquisa, escolha dos referenciais epistemológicos e metodológicos, busca de informações, sistematização da argumentação e produção de conhecimento. Dada a importância dos projetos de pesquisa, propôs-se a realização do II Encontro de Iniciação Científica da UNILA como um espaço institucional de avaliação e exposição pública dos projetos de iniciativa docente, promovendo uma discussão sobre as necessidades de pesquisa e as dificuldades de desenvolvê-las concomitante à construção da universidade, de modo a registrar sugestões de docentes e estudantes.Universidade Federal da Integração Latino-Americana (UNILA) e Parque Tecnológico de Itaipu (PTI

Multifunctional proteins revealed by overlapping clustering in protein interaction network

Motivation: Multifunctional proteins perform several functions. They are expected to interact specifically with distinct sets of partners, simultaneously or not, depending on the function performed. Current graph clustering methods usually allow a protein to belong to only one cluster, therefore impeding a realistic assignment of multifunctional proteins to clusters

Anais do 1º Encontro de Iniciação Científica e de Extensão da Unila: "Conhecer e Transformar"

Anais do I Encontro de Iniciação Científica e de Extensão da Unila. Unila-Centro, Foz do Iguaçu, Estado do Paraná, 04 e 05 de junho de 2012A indissocialibidade entre as ações de ensino, pesquisa e extensão, cuja unidade caracteriza o processo pedagógico no ensino superior tem, neste evento, a manifestação da sua aplicabilidade. Os planos de trabalho e projetos de estudantes e orientadores de iniciação científica e extensão demarcam os processos formadores da capacidade de pensamento crítico dos futuros profissionais egressos de uma universidade inovadora. Neste processo, a iniciação científica tem a missão de aperfeiçoar a formação acadêmica e profissional de estudantes de graduação, que são introduzidos nos diferentes campos do Saber pelas disciplinas e projetos de pesquisa docente para serem capacitados a refletir sobre limitações das sociedades, formular e testar hipóteses, resolver problemas e situações colocadas tanto pela simples curiosidade humana de conhecer quanto pela necessidade social de transformar. Constitui-se na formulação de questionamentos, na aprendizagem da elaboração do objeto de pesquisa, escolha dos referenciais epistemológicos e metodológicos, busca de informações, sistematização da argumentação e produção de conhecimento. A extensão é, por natureza, de vocação transformadora da realidade social, cultural e ambiental. Demanda uma ação de pesquisa, que pode ser chamada de pesquisa-ação ou de observação. Envolve a todos, comunidade universitária e comunidade onde está inserida a Universidade, num processo de troca de saberes. Os saberes e conhecimentos adquiridos, bem como as tecnologias produzidas, fomentam resultados coletivos sempre e quando são transferidos sob os princípios da responsabilidade, cooperação, solidariedade, racionalidade e da inclusão. Espera-se que cada estudante desenvolva atitudes críticas e habilidades de pesquisador, tais como dedicação, criatividade, honestidade, ética e compromisso com a transformação da realidade. O I Encontro de Iniciação Científica e de Extensão da Unila colabora para a avaliação e a exposição pública dos resultados dos projetos. Será realizada uma conferência de abertura composta pelo Magnífico Reitor Pro tempore da Unila, Hélgio Trindade, pelo Pró-Reitor de Pesquisa e Pós-graduação, Andrea Ciacchi, pela Pró-Reitora de Extensão, Luisa Maria de Moura e Silva e pelo pesquisador Flávio Bortolozzi, para expor ao público o tema “Pesquisa no Meio Acadêmico e suas Oportunidades”. O evento contará ainda com a palestra da pesquisadora Laura Tavares Ribeiro Soares com o título “A Pesquisa na Extensão”.Universidade Federal da Integração Latino-Americana (UNILA

Autoantibodies in Systemic Lupus Erythematosus Target Mitochondrial RNA

The mitochondrion supplies energy to the cell and regulates apoptosis. Unlike other mammalian organelles, mitochondria are formed by binary fission and cannot be directly produced by the cell. They contain numerous copies of a compact circular genome that encodes RNA molecules and proteins involved in mitochondrial oxidative phosphorylation. Whereas, mitochondrial DNA (mtDNA) activates the innate immune system if present in the cytosol or the extracellular milieu, it is also the target of circulating autoantibodies in systemic lupus erythematosus (SLE). However, it is not known whether mitochondrial RNA is also recognized by autoantibodies in SLE. In the present study, we evaluated the presence of autoantibodies targeting mitochondrial RNA (AmtRNA) in SLE. We quantified AmtRNA in an inducible model of murine SLE. The AmtRNA were also determined in SLE patients and healthy volunteers. AmtRNA titers were measured in both our induced model of murine SLE and in human SLE, and biostatistical analyses were performed to determine whether the presence and/or levels of AmtRNA were associated with clinical features expressed by SLE patients. Both IgG and IgM classes of AmtRNA were increased in SLE patients (n = 86) compared to healthy controls (n = 30) (p < 0.0001 and p = 0.0493, respectively). AmtRNA IgG levels correlated with anti-mtDNA-IgG titers (rs = 0.54, p < 0.0001) as well as with both IgG and IgM against β-2-glycoprotein I (anti-β2GPI; rs = 0.22, p = 0.05), and AmtRNA-IgG antibodies were present at higher levels when patients were positive for autoantibodies to double-stranded-genomic DNA (p < 0.0001). AmtRNA-IgG were able to specifically discriminate SLE patients from healthy controls, and were negatively associated with plaque formation (p = 0.04) and lupus nephritis (p = 0.03). Conversely, AmtRNA-IgM titers correlated with those of anti-β2GPI-IgM (rs = 0.48, p < 0.0001). AmtRNA-IgM were higher when patients were positive for anticardiolipin antibodies (aCL-IgG: p = 0.01; aCL-IgM: p = 0.002), but AmtRNA-IgM were not associated with any of the clinical manifestations assessed. These findings identify mtRNA as a novel mitochondrial antigen target in SLE, and support the concept that mitochondria may provide an important source of circulating autoantigens in SLE