Rab complexes and membrane biogenesis in the endocytic pathway

Rab complexes and membrane biogenesis in the endocytic pathway: structural imaging of
a cell dynamic architecture.
Jean Salamero, CNRS UMR 144, Institut Curie
The structural and functional properties of the organelles involved in membrane trafficking
are defined by molecular and dynamic architectures that permit membranes to fuse with or
exit from a given compartment. These architectures must therefore not be distributed
randomly, which requires conflicting needs for communication and segregation. Maintenance
of segregation between Rab-defined compartments and partition of Rab complexes into
membrane subdomains, point to Rab proteins as key players in these processes. However,
proximal Rab domains must also “talk to each other” and this might be a generic role for
many Rab interacting proteins. Our previous studies revealed the function of Rab11A together
with a cohort of Rab11 Interacting Proteins, as membrane organizers in the endosomal
pathway, which may lead to biogenesis or maintenance of specialized cellular compartments.
The imaging techniques allow to consider the different Rab domains and their progressive
conversion as a function of temporally defined multimolecular interactions. We adapted or
developed diverse biophotonic approaches aimed to determine the dynamic and topological
characterization of multi Rab complexes (Rab11A/Rabin8/Rab8; Rab11A/ RCP/Rab4; Rab6A
or A’/Rab6IP1/Rab11A), in living cells.