Enteropathogenic Escherichia coli , Shigella flexneri , and Listeria monocytogenes Recruit a Junctional Protein, Zonula Occludens-1, to Actin Tails and Pedestals

Abstract

Enteropathogenic Escherichia coli, Shigella flexneri, and Listeria monocytogenes induce localized actin polymerization at the cytoplasmic face of the plasma membrane or within the host cytoplasm, creating unique actin-rich structures termed pedestals or actin tails. The process is known to be mediated by the actin-related protein 2 and 3 (Arp2/3) complex, which in these cases acts downstream of neural Wiskott-Aldrich syndrome protein (N-WASP) or of a listerial functional homolog of WASP family proteins. Here, we show that zonula occludens-1 (ZO-1), a protein in the tight junctions of polarized epithelial cells, is recruited to actin tails and pedestals. Immunocytochemical analysis revealed that ZO-1 was stained most in the distal part of the actin-rich structures, and the incorporation was mediated by the proline-rich region of the ZO-1 molecule. The direct clustering of membrane-targeted Nck, which is known to activate the N-WASP-Arp2/3 pathway, triggered the formation of the ZO-1-associated actin tails. The results suggest that the activation of the Arp2/3 complex downstream of N-WASP or a WASP-related molecule is a key to the formation of the particular actin-rich structures that bind with ZO-1. We propose that an analysis of the recruitment on a molecular basis will lead to an understanding of how ZO-1 recognizes a distinctive actin-rich structure under pathophysiological conditions.

EspF Interacts with Nucleation-Promoting Factors To Recruit Junctional Proteins into Pedestals for Pedestal Maturation and Disruption of Paracellular Permeability

“…5G and H; yellow pedestals). This was recently reported by Hanajima-Ozawa et al (15), who showed recruitment of ZO-1 into pedestals caused by a human EPEC strain. Moreover, cells infected with the wild type transformed with pespF showed pedestals bigger than those seen in cells infected with the untransformed wild type (Fig.…”

Listeria monocytogenes Uses Listeria Adhesion Protein (LAP) To Promote Bacterial Transepithelial Translocation and Induces Expression of LAP Receptor Hsp60

“…L. monocytogenes infection is known to reduce the TEER of epithelial monolayers (33), as also observed in this study (Table 2), which can contribute to paracellular bacterial translocation (15,27). Although the exact mechanism for a Listeriainduced reduction in TEER is unknown, it has been linked to virulence traits such as actin cytoskeleton disruption following invasion (26,52,60), as well as extracellular secretion of LLO (50). Although the presence or absence of LAP expression did not induce changes in TEER (Table 2), it is possible that a weakened epithelial barrier facilitates LAP-Hsp60-mediated bacterial translocation.…”

Campylobacter jejuni Mediated Disruption of Polarized Epithelial Monolayers is Cell-Type Specific, Time Dependent, and Correlates With Bacterial Invasion

“…In contrast, our findings indicate an opposite sequence of events, where bacteria enter into infected eukaryotic cells to induce changes in intercellular junctions by altering signal transduction pathways. A similar sequence of events has also been described for other invasive pathogens (38), but contrasts with Helicobacter pylori infection, which is reported to alter the physiology of apical junctional complexes without entering into the cytoplasm (39).…”