PIP5KI gamma 90-generated phosphatidylinositol-4,5-bisphosphate promotes the uptake of Staphylococcus aureus by host cells

Staphylococcus aureus, a Gram-positive pathogen, invades cells mainly in an integrin-dependent manner. As the activity or conformation of several integrin-associated proteins can be regulated by phosphatidylinositol-4,5-bisphosphate (PI-4,5-P-2), we investigated the roles of PI-4,5-P-2 and PI-4,5-P-2-producing enzymes in cellular invasion by S. aureus. PI-4,5-P-2 accumulated upon contact of S. aureus with the host cell, and targeting of an active PI-4,5-P-2 phosphatase to the plasma membrane reduced bacterial invasion. Knockdown of individual phosphatidylinositol-4-phosphate 5-kinases revealed that phosphatidylinositol-4-phosphate 5-kinase gamma (PIP5KI gamma) plays an important role in bacterial internalization. Specific ablation of the talin and FAK-binding motif in PIP5KI gamma 90 reduced bacterial invasion, which could be rescued by reexpression of an active, but not inactive PIP5KI gamma 90. Furthermore, PIP5KI gamma 90-deficient cells showed normal basal PI-4,5-P-2 levels in the plasma membrane but reduced the accumulation of PI-4,5-P-2 and talin at sites of S. aureus attachment and overall lower levels of FAK phosphorylation. These results highlight the importance of local synthesis of PI-4,5-P-2 by a focal adhesion-associated lipid kinase for integrin-mediated internalization of S. aureus.

Automated summary

Staphylococcus aureus invades host cells mainly through an integrin-dependent manner, with phosphatidylinositol-4,5-bisphosphate (PI-4,5-P-2) playing a significant role in regulating integrin-associated proteins. Local synthesis of PI-4,5-P-2 by a focal adhesion-associated lipid kinase is crucial for integrin-mediated internalization of S. aureus. Targeting active PI-4,5-P-2 phosphatase to the plasma membrane and specific ablation of talin and FAK-binding motif in PIP5KI gamma 90 can reduce bacterial invasion.