Conversion of PtdIns(4,5)P2 into PtdIns(5)P by the S.flexneri effector IpgD reorganizes host cell morphology

AUTOR(ES)

Niebuhr, Kirsten

FONTE

Oxford University Press

RESUMO

Phosphoinositides play a central role in the control of several cellular events including actin cytoskeleton organization. Here we show that, upon infection of epithelial cells with the Gram-negative pathogen Shigella flexneri, the virulence factor IpgD is translocated directly into eukaryotic cells and acts as a potent inositol 4-phosphatase that specifically dephosphorylates phosphatidylinositol 4,5-bisphosphate [PtdIns(4,5)P2] into phosphatidylinositol 5-monophosphate [PtdIns(5)P] that then accumulates. Transfection experiments indicate that the transformation of PtdIns(4,5)P2 into PtdIns(5)P by IpgD is responsible for dramatic morphological changes of the host cell, leading to a decrease in membrane tether force associated with membrane blebbing and actin filament remodelling. These data provide the molecular basis for a new mechanism employed by a pathogenic bacterium to promote membrane ruffling at the entry site.

Documentos Relacionados

• Interaction of Sla2p's ANTH Domain with PtdIns(4,5)P2 Is Important for Actin-dependent Endocytic InternalizationV⃞
• The Phox Domain of Sorting Nexin 5 Lacks Phosphatidylinositol 3-Phosphate (PtdIns(3)P) Specificity and Preferentially Binds to Phosphatidylinositol 4,5-Bisphosphate (PtdIns(4,5)P2)*♦
• A Phox among the Hounds♦: The Phox Domain of Sorting Nexin 5 Lacks Phosphatidylinositol 3-Phosphate (PtdIns(3)P) Specificity and Preferentially Binds to Phosphatidylinositol 4,5-Bisphosphate (PtdIns(4,5)P2)
• Aggregation-dependent, integrin-mediated increases in cytoskeletally associated PtdInsP2 (4,5) levels in human platelets are controlled by translocation of PtdIns 4-P 5-kinase C to the cytoskeleton.
• Vacuole Size Control: Regulation of PtdIns(3,5)P2 Levels by the Vacuole-associated Vac14-Fig4 Complex, a PtdIns(3,5)P2-specific Phosphatase