Invasion plasmid antigen D (IpaD)

Invasion plasmid antigen D (IpaD) is a critical virulence factor found in Shigella species, serving as the tip protein of the Type III secretion system (T3SS) needle apparatus (UniProt: P13223). It functions as a molecular switch and gatekeeper that senses the host environment and regulates the secretion of effector proteins necessary for bacterial invasion (PubMed: 22493101). Upon interaction with host cell membranes or environmental triggers like bile salts, IpaD facilitates the recruitment of other translocator proteins, IpaB and IpaC, to form a pore in the host cell membrane (PubMed: 17233936). Because IpaD is essential for the delivery of virulence factors into host intestinal epithelial cells, it is a major target for the development of subunit vaccines and anti-infective agents designed to block the initial stages of shigellosis (PubMed: 28416501). Current therapeutic strategies include the development of fusion proteins and monoclonal antibodies that neutralize the needle tip to prevent infection (PubMed: 25605354).

Other names

IpaD proteinShigella invasion plasmid antigen DT3SS tip protein IpaDInvasion plasmid antigen D (IpaD)

Inhibition of the Type III secretion system (T3SS) needle tip function, preventing the assembly of the translocon pore and subsequent injection of effector proteins into host cells (PubMed: 28416501).