AUTHOR=Picking Wendy L. , Picking William D. 

TITLE=The Many Faces of IpaB

JOURNAL=Frontiers in Cellular and Infection Microbiology

VOLUME=6

YEAR=2016

URL=https://www.frontiersin.org/journals/cellular-and-infection-microbiology/articles/10.3389/fcimb.2016.00012

DOI=10.3389/fcimb.2016.00012

ISSN=2235-2988

ABSTRACT=<p>The type III secretion system (T3SS) is <italic>Shigella</italic>'s most important virulence factor. The T3SS apparatus (T3SA) is comprised of an envelope-spanning basal body and an external needle topped by a tip complex protein called IpaD. This nanomachine is used to deliver effector proteins into host cells to promote pathogen entry. A key component of the matured T3SS needle tip complex is the translocator protein IpaB. IpaB can exist in multiple states when prepared as a recombinant protein, however, it has also been described as having additional roles in <italic>Shigella</italic> pathogenesis. This mini-review will briefly describe some of the features of IpaB as a T3SS needle tip protein, as a pore-forming translocator protein and as an effector protein. Reflection on the potential importance of the different <italic>in vitro</italic> states of IpaB on its function and importance in serotype-independent vaccines is also provided.</p>