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Assembly and polarization of the Golgi apparatus
Par Frédéric Pincet, Laboratoire de Physique de l'ENS, Paris
Le 5 Mai 2026 à 11h00 - Laboratoire Jean Perrin - Campus Jussieu - T 22-32- 4e et. - P407
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Résumé
The architecture of the Golgi apparatus is remarkably complex. In mammalian cells, it is composed of stacks of disk-shaped membrane compartments that are laterally connected to form a ribbon-like structure. These stacks are polarized along the cis-to-trans axis and are embedded within a dense protein matrix, whose primary components belong to the Golgin protein family. This refined organization is transiently lost during mitosis, when the Golgi apparatus disperses into small vesicular and tubular remnants. However, during telophase, these remnants rapidly reassemble within minutes, restoring the original architecture and cisternal composition. Even during interphase, the integrity of the Golgi architecture is continuously challenged by dynamic processes, including intensive vesicular trafficking both within the Golgi and with neighboring compartments, as well as by cisternal maturation. As a result, the Golgi apparatus presents a seemingly paradoxical combination of dynamic plasticity and structural robustness. In this seminar, I will propose that Golgins, long rod-like proteins surrounding the Golgi act as key regulators balancing this duality. Golgins can function both as vesicle tethers, facilitating trafficking, and as structural scaffolds, promoting the spontaneous organization of the Golgi matrix. We tested this hypothesis using a combination of in vitro biophysical and biochemical assays, super-resolution imaging of Golgin localization, and live monitoring of golgins in cells. Our results show that Golgins can self-assemble into two-dimensional condensates exhibiting a hierarchical set of interactions correlated with Golgi organization. Simultaneously, Golgins and their condensates are capable of specifically tethering vesicles, thus maintaining efficient vesicular trafficking within the matrix.







