Proteinaceous infectious particles or prions are self-perpetuating alternate conformations of proteins that are the causative agents of pathologies in mammals (including Humans) and of heritable non-mendelian traits in filamentous fungi and yeast. We have showed that the cytotoxic fibrillar aggregates which are believed to be at the origin of several neurodegenerative diseases (Alzheimer, Parkinson, Huntington) behave as prions that propagate their abnormal conformation from neuron-to-neuron. The yeast Saccharomyces cerevisiae hosts many prion or prion-like proteins, unrelated in sequence and function, which proved to be excellent models for understanding the mechanisms of epigenetic structural inheritance.
Specifically, we are interested in the mechanisms of propagation, elimination and degradation of the yeast prions Sup35p and Ure2p. We have highlighted a role for the proteasome, a major cellular proteolytic nanomachine, in the degradation of both the native and aggregated forms of these prions. More recently, we reported that these prions are secreted within extracellular vesicles in their aggregated and infectious conformation. Among the possible implications of our work is the possibility of previously unsuspected extracellular vesicle-mediated horizontal cell-to-cell transfer of fungal prions. We now aim at pursuing this work by documenting the role of the vesicular traffic and autophagy in the secretion, degradation and the vertical or horizontal transfer of yeast prions.
The thesis project will specifically aim at answering the numerous questions raised by our findings: are yeast prions targeted for degradation by autophagy and under which conditions? How and when are the aggregated forms of these prion proteins packaged within extracellular vesicles? What are the structural determinants, the cellular factors and the signals that regulate these processes? Are extracellular vesicles more than just cellular trash bins or do they play more elaborate roles as vectors of the horizontal transfer of genetic information in general and of yeast prions in particular?
This is a highly multidisciplinary project that will combine in vitro approaches using purified components (prions, extracellular vesicles) with cell biological, cellular biochemistry and molecular genetics approaches.
The next “Biology of the Cell Scientific Meeting” will take place on Monday 15 May 2017 • 1:30 – 4:30 pm – Amphi Turing, Bâtiment SOPHIE GERMAIN, Université Paris-Diderot, Place Aurélie Nemours, Paris, France.
- Mechanisms Underlying Neuroblast Migration and Division in C. elegans – Guangshuo OU, Tsinghua University, Beijing, China
- Crosstalk of cadherin complexes and RNAi in epithelial homeostasis and cancer – Panagiotis Z. ANASTASIADIS, Mayo Clinic, Jacksonville, Florida, USA
- Membrane Traffic and Cell Division: the final cut – Arnaud ECHARD, Institut Pasteur, Paris
- Mechanotransduction at adherens junctions and collective cell behavior – René Marc MEGE, Institut Jacques Monod, Paris
The laboratory “Genetics and Biology of Pediatric Tumors“ directed by Olivier Delattre at Institut Curie develop several research programs to understand the biology and oncogenic transformation mechanisms of various pediatric tumors and identify new therapeutic strategies that could improve patients outcome. Institut Curie provides an excellent scientific environment for high quality research with state-of-the-art equipments as well as a constellation of seminars covering many resarch areas. The successful postdoctoral applicant will join the neuroblastoma team on a translational research project funded by INCa/DGOS and led by Isabelle Janoueix-Lerosey in collaboration with a group at Gustave Roussy and one at CEA.
Research project Neuroblastoma is an embryonal cancer of the sympathetic nervous system that accounts for 8-10% of pediatric cancers. It represents an uttermost biological challenge for scientists and remains a disease with highly unmet medical needs for clinicians. The identification of ALK activating mutations has placed neuroblastoma among other ALKoma entities that may benefit from tumor-targeted therapies with tyrosine kinase inhibitors (TKIs) or monoclonal antibodies. The efficacy of new immunomodulatory antibodies, also called “immune checkpoint antibodies”, has been demonstrated in several aggressive adult cancers. Interestingly, it has been shown that various TKIs have not only cell-autonomous effects but also impacts on the immune microenvironment, providing a rationale for the use of TKIs in combination with immunomodulatory antibodies.
The whole project aims at exploring the link between ALK induced oncogenic stress and immune suppression within the neuroblastoma microenvironment, and then at evaluating the synergistic combination between therapies blocking these two hallmarks of cancer. The successful candidate will define the impact of ALK-driven oncogenic stress on the tumor immune microenvironment in our neuroblastoma mouse models. The candidate will also evaluate the therapeutic potential of a monoclonal ALK antagonist antibody alone or in combination with ALK TKIs in vitro and in vivo using various models. We expect to discover new insights into the biology of ALK-driven neuroblastoma, and provide the rationale for both tumor-targeted and immune-targeted therapies that may benefit to neuroblastoma patients.
A 3-year postdoctoral position is available in the group of Dr Emmanuel Derivery at the MRC Laboratory of Molecular Biology in Cambridge, UK. Our lab investigates the asymmetric segregation of cell fate determinants during asymmetric division in the context of stem cells. Our approach is highly multidisciplinary, combining in vitro reconstitution of cytoskeleton systems with high-resolution quantitative imaging of cytoskeleton and endosome dynamics during Drosophila development, and also of physical modelling to bridge these different scales.
This project aims to understand the molecular mechanisms of symmetry breaking of the central spindle during asymmetric cell division. The successful applicant will use the broad range of techniques available in the lab, in particular a novel assay based on nanobodies and optogenetics to remodel the cytoskeleton in space and time in vivo.
The MRC Laboratory of Molecular Biology is one of the birthplaces of molecular biology and excels at deciphering the molecular mechanisms of life. It provides an unsurpassed environment for both new and established researchers. Scientists are drawn to the LMB from all over the world, creating a lively and international community for the exchange of ideas and technical innovation. In addition, the LMB has outstanding core facilities, including world-class Electron and Light microscopy facilities harboring in particular two Titan Krios electron microscopes and various super-resolution and light sheet instruments.
A 24 months postdoctoral position is available from September 2017 in our group, based at the CRBM, Montpellier, France (http://www.crbm.cnrs.fr/index.php/fr/).
Current work in the lab analyzes the role of flotillins, new metastatic markers, in the deregulation of intravesicular trafficking favoring cellular invasive behavior. In collaboration with biophysicists, combining cutting edge cell biology and microscopy techniques (optogenetic, super resolution, correlative electron microscopy), we investigate how flotillins influence membrane organization and remodelling.
PhD in cell biology or biochemistry is required, with a strong background in cell biology of vesicular tracking, membrane remodelling and protein/membrane interactions.
Skills on developing imaging techniques to study membrane remodelling processes in cellulo and in reconstructed systems in vitro will be highly valued. Interest in interaction with scientists expert in modelisation of protein/protein and protein/lipid interactions would be highly appreciated.
We are looking for highly motivated and creative Ph.D. The candidate must be able to work independently, as well as demonstrate a strong commitment to team based work with strong organization skills.
La SBCF était à nouveau aux côtés de l’ITMO BCDE pour représenter la Biologie Cellulaire en France au meeting ASCB de San Francisco. Une centaine de personnes ont assisté à la présentation « Cell Biology Research in France » de Thierry Galli et Arnaud Echard, et plus de 150 ont visité notre stand. Le stand a été animé cette année par Christine Lemaître (ITMO BCDE), Mireille Guyader (Ambassade de France) ainsi que par les membres du Conseil de la SBCF et les étudiants/post-docs ayant reçu une bourse de voyage SBCF.
Félicitations aux deux lauréates des Prix SBCF/ASCB :
Léa Ripoll (doctorante à l’Institut Curie, Paris) et Ingrid Chamma (post-doctorante à l’Institut Interdisciplinaire de Neurosciences, Bordeaux).
PRIX JEUNE CHERCHEUR 2017
Mettre en valeur la recherche ainsi que ses acteurs est une des missions de la SBCF.
Chaque année, la SBCF attribue un « Prix Jeune Chercheur » d’un montant de 5000€.
Date limite de candidature :
1er Février 2017
Following the great success of the 8th edition in Bordeaux (2015), the French Society for Cell Biology is pleased to announce the forthcoming 2017 9th edition of the “Imaging the Cell” congress in Rennes, June 28-30 2017. This meeting will cover the most recent conceptual and technological advances in cell imaging at both cellular and ultrastructural levels.
Continuer à lire “Imaging the Cell 2017 – Strasbourg”
The meeting of the American Society of Cell Biology (ASCB) this year will be held from December 3-7, in San Franscisco, California, USA.
ASCB2016 will focus on the latest discoveries in the field, including CRISPR, and on building links from fundamental research to clinical issues.
This meeting is a wonderful chance for you to present your science and to meet in person many of the prominent names you know from the literature. It will also be a great occasion to promote cell biology as a world science.
To learn more about the ASCB2016 meeting, please go to http://www.ascb.org/2016meeting/