Septins regulate bacterial entry into host cells.
BACKGROUND
Septins are conserved GTPases that form filaments and are required in many organisms for several processes including cytokinesis. We previously identified SEPT9 associated with phagosomes containing latex beads coated with the Listeria surface protein InlB.


RESULTS
Here, we investigated septin function during entry of invasive bacteria in non-phagocytic mammalian cells. We found that SEPT9, and its interacting partners SEPT2 and SEPT11, are recruited as collars next to actin at the site of entry of Listeria and Shigella. SEPT2-depletion by siRNA decreased bacterial invasion, suggesting that septins have roles during particle entry. Incubating cells with InlB-coated beads confirmed an essential role for SEPT2. Moreover, SEPT2-depletion impaired InlB-mediated stimulation of Met-dependent signaling as shown by FRET.


CONCLUSIONS
Together these findings highlight novel roles for SEPT2, and distinguish the roles of septin and actin in bacterial entry.
Mostowy
Serge
S
Institut Pasteur, Unité des Interactions Bactéries-Cellules, Paris, France.
Nam Tham
To
T
Danckaert
Anne
A
Guadagnini
Stéphanie
S
Boisson-Dupuis
Stéphanie
S
Pizarro-Cerdá
Javier
J
Cossart
Pascale
P
D000199:Actins; D001419:Bacteria / Q000472:pathogenicity*; D018797:Cell Cycle Proteins / Q000502:physiology; D045744:Cell Line, Tumor; D004705:Endocytosis; D020558:GTP Phosphohydrolases / Q000502:physiology; D006801:Humans; D008087:Listeria / Q000472:pathogenicity; D010744:Phosphoric Monoester Hydrolases / Q000502:physiology*; D058112:Septins; D012760:Shigella / Q000472:pathogenicity
D000199:Actins; D018797:Cell Cycle Proteins; D010744:Phosphoric Monoester Hydrolases; D020558:GTP Phosphohydrolases; C496549:SEPTIN11 protein, human; C474315:SEPTIN9 protein, human; D058112:Septins