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Home > Departments > Cell Biology > Béatrice SATIAT-JEUNEMAITRE : Dynamics of Cell Compartmentation in plant cells

Béatrice SATIAT-JEUNEMAITRE : Group Presentation

Our group aims at understanding the functional organization of the endomembrane system in eukaryotic cells. Combining developments in multiscale / time-resolved 3D imaging and the use of Arabidopsis genetic resources, we look for common and specific rules sustaining the morphodynamics of cell compartments.

Hosted by the Institut des Sciences du Végétal from 1998 to 2015, the team “Dynamics of Cell Compartmentation in Plant cells” is a founding member of the Cell Biology department of I2BC. The team is also partner of The Laboratory of Excellence Saclay Plant Sciences gathering Plant Science labs from the Paris area, and of the French distributed Infrastructure “France-BioImaging”, both funded by ANR grants “Investissements d’avenir”.

We are located in the new Building 21 of the Campus of Gif-sur-Yvette, backing theImaging and Cell Biology Core Facilities.

Research topic

The group has a long-standing experience in cell imaging of secretory trafficking pathways and in plant endomembrane biology. Our research topic is the morphodynamics of cell compartmentation. We focus in particular on the morphogenesis of endomembrane compartments and on the processes involved in the exchange at the interface between two distinct membrane compartments.

Indeed, eukaryotic cells have developed membrane and cargo exchanges between these compartments, based on vectorial routes of transport within the cell. How is membrane identity acquired for each compartment? How is membrane composition maintained despite the vectorial membrane fluxes within the cell? How are these processes regulated and even adapted throughout developmental programs? What are the molecular machineries regulating the delivery of membrane from one compartment to the other along the secretory pathway? What are the relationships between shapes and functions?

We address these questions by combining the use of plant models, cell biology approaches and the development of new original protocols in close relationship with the Imaging and Cell Biology Core Facilities.

Research in our group is currently organised around three main axes:

- Formation of autophagosomes, dynamics of the autophagic pathways and relationship with the endomembrane system.

Autophagy is a vesicular degradative process of cytoplasmic material, conserved in eukaryotic cells, based on specialized double-membrane compartments, the autophagosomes. Mechanisms of autophagosome biogenesis, and their regulation within different autophagic processes are currently studied in the lab. We have recently outlined the interest of the plant cell as a model to decode early events of autophagosome formation (Le bars et al., 2014a; Le Bars et al., 2014b).

- Functional relationships between cytoskeleton and membrane remodeling: the roles of microtubules and + TIPs (+End Tracking Proteins).

AtEB1-GFP
TuA6-GFP/STED

In plant cells, it is widely admitted that actin microfilaments maintain the 3D architecture of membranous organelles. However, interactions between microtubules and endomembranes could play a crucial role in membrane remodeling. We are currently investigating the role of the +TIP AtEB1 in the regulation of microtubule architecture and dynamics and its related function at microtubule / endomembranes interface in A. thaliana.

- Development of multiscale/4D Imaging approaches in plant cells.
The laboratory is involved in the development of plant light microscopy protocols to master super resolution (PALM /STORM) imaging techniques. We also research the use of biosensors or photoconvertible proteins, to explore cell functions or to perform pulse-chase experiments in cellulo (Brown et al., 2012; Bourge et al., 2014). Protocols based on transmission electron microscopy are also developed (ultrastructural tomography, cryo-EM and STEM, correlative light and electron microscopy) to further explore the plant endomembrane system.
These developments are related to the activity of the Imaging and Cell Biology Core Facilities, which is backed up by our team.

 

 

 

 

 

Key words

Autophagosome, Morphogenesis, Dynamics, Cell compartments, Endomembrane system, Endoplasmic reticulum, Golgi apparatus, Vacuole; Cytoskeleton, Multiscale / time-resolved 3D imaging, Plant biology, Arabidopsis thaliana.

Contact


SATIAT-JEUNEMAITRE Béatrice [Senior Researcher - CNRS]
Imagery and Cellular Biology Pole (IMAGERIE-GIF) [Leader]
01 69 82 46 60 Gif - Bât 21

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