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CANCELLED
| When |
Mar 13, 2020
from 11:00 to 12:00 |
|---|---|
| Contact Name | Salle des Thèses, Equipe Delattre |
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Understanding the organizing principles driving the assembly of cellular organelles is a fundamental pursuit in biology. The centriole is a microtubule-based organelle essential for the formation of flagella, cilia and centrosomes. As such, the centriole is critical notably for cell motility, sensing of the environment and cell architecture. The centriole has a signature nine-fold symmetrical arrangement of microtubules and is organized around a likewise symmetrical cartwheel. The cartwheel comprises a stack of ring-containing elements that each accommodates nine homodimers of SAS-6 proteins. Although important advances have been made in recent years, understanding of centriole assembly remains incomplete, partly due to the lack of cell-free assays to probe the dynamics of the process at nanometric scale. To fill this gap, we have developed a high-speed atomic force microscopy (AFM) to reconstitute and monitor the assembly dynamics of SAS-6 proteins with high spatial and temporal resolution. This novel assay enabled us to better understand the mechanisms imparting the signature nine-fold radial symmetry of the organelle. Moreover, in order to develop tools to dissect and modulate centriole assembly, we have identified monobodies that recognize SAS-6 proteins with high affinity. One of these monobodies prevent the assembly of ring-containing elements in vitro and of the centriole organelle in the cellular context. Together, these approaches provide novel insights into the mechanisms governing centriole biogenesis.
Contact : Marie Delattre