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Accueil > Séminaires

Vendredi 09 mars - 9h30

Séminaire de Maxime Tourte, Equipe AME, MAP.
Insights into the Thermococcales membrane architecture : clarifications on their core lipid compositions

Salle de réunion bat. Lwoff, sous-sol.

Insights into the Thermococcales membrane architecture : clarifications on their core lipid compositions
Maxime Tourte (équipe AME)

Since the origin of life, the plasma membrane functions as the first and ultimate barrier between the cell cytoplasm and its surrounding environment. The production of diethers, tetraethers and apolar lipids by Thermococcus barophilus MP, a piezophilic and hyperthermophilic archaeon isolated from a deep-sea hydrothermal vent, suggested a novel membrane architecture similar to eukaryotic lipid rafts. To this date, archaeal membrane organization is only accessible through its lipid composition, which remains highly dependent on the culture conditions and the extraction procedures. To estimate the ubiquity of this novel membrane ultrastructure, we (re)assessed under similar experimental conditions the core and apolar lipid compositions of 50 and 10 Thermococcales strains, respectively. We shed light on a common core lipidome, containing both di- and tetraethers, and a potentially huge pan-lipidome in this archaeal order. Despite strain-specific lipid proportions, the plasma membrane of most of the Thermococcales strains contains a majority of monopolar lipids with high proportions of bipolar lipids, similarly to T. barophilus MP. At the time, the ability to produce membrane apolar lipids is sparse among Thermococcales and seems to be a peculiarity of species closely related to T. barophilus MP. If the new membrane model is validated, the common core structures may pinpoint toward a widespread distribution of such cell membrane organization, not only in Thermococcales, but in all archaeal lineages. This may thus lead to major breakthroughs regarding life origins and archaeal cell biology and adaptation.