Staphylococcus aureus induces a reorganization of endocytic membranes causing the formation of dynamic tubules.

LOPEZ DE ARMENTIA, M.M.; COLOMBO, M.I.

Mar del Plata

Congreso; SAIB (Sociedad Argentina de Investigación en Bioquímica y Biología Molecular); 2015

S. aureus is a pathogen that causes serious infectious diseases eventually leading to septic and toxic shock. One of the key features of S. aureus infection is the production of a series of virulence factors, including enzymes and toxins. After internalization by the host cell S. aureus resides in a phagosome labeled by the autophagic protein LC3.We have shown that the pore-forming toxin α-hemolysin is the S. aureus?secreted factor responsible for the activation of this autophagic response. Recent results from our laboratory indicate that S. aureus at early times post-infection generates tubular dynamic structures marked with LC3. We determined that these structures correspond also to the late endocytic pathway, as they recruited Rab7. However, they are neither acidic nor degradative. Furthermore, we demonstrate that the formation of these filaments depends on the integrity of microtubules. In the endo-lysosomal system, several small GTPases of the Rab family facilitate transport by recruitment of motor proteins from the dynein and kinesin families. We have demonstrated that the protein Kinesin1 (Kif5B) and the Rab7-interacting lysosomal protein (RILP) are necessary for S. aureus-induced filaments elongation. When the formation of these tubular structures was inhibited a marked decrease in S. aureus replication was observed, suggesting these structures are necessary for efficient bacterial replication.