Membrane-deforming Proteins Play Distinct Roles in Actin Pedestal Biogenesis by Enterohemorrhagic Escherichia coli

Campellone, Kenneth; Siripala, Anosha D.; Leong, John M.; Welch, Matthew D.

doi:10.1074/jbc.m112.363473

Cited by 16 publications

(7 citation statements)

References 48 publications

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“…33 A recent study of CIP4 subfamily proteins in actin pepestal formation by enterohemorrhagic E.coli found distinct roles for CIP4, FBP17 and Toca-1. 45 Interestingly, CIP4 inhibited these F-actin-based structures, whereas Toca-1 promoted pedestal formation, 45 which is consistent with our findings for these proteins in invadopodia (Hu et al, 33 and this paper). Further studies using experimental models of breast cancer metastasis, such as the model reported here for Toca-1, should help resolve the contributions of CIP4 to this process.…”

Section: Discussionsupporting

confidence: 89%

Transducer of Cdc42-dependent actin assembly promotes breast cancer invasion and metastasis

et al. 2012

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Metastatic breast adenocarcinomas display activation signatures for signaling pathways that trigger cell motility and tissue invasion. Here, we report that the adaptor protein transducer of Cdc42-dependent actin assembly-1 (Toca-1) is expressed in highly invasive breast cancers and regulates their metastatic phenotypes. We show that Toca-1 localizes to the filamentous actin-rich core of invadopodial protrusions actively degrading the extracellular matrix (ECM). Toca-1 colocalizes with Cortactin, and we show that this interaction is mediated by the SH3 domain of Toca-1. Stable knockdown (KD) of Toca-1 expression in MDA-MB-231 cells led to a significant defect in epidermal growth factor (EGF)-induced cell migration and invasion. Toca-1 KD cells also showed significant defects in EGF- and Src-induced ECM digestion and formation of invadopodial membrane protrusions. To test the role of Toca-1 in metastasis, we achieved stable Toca-1 KD in both human and rat metastatic breast adenocarcinoma cell lines. Orthotopic tumor xenografting of control and Toca-1 KD cells in natural-killer /B-/T-cell-deficient mice revealed a significant defect in spontaneous lung metastases with Toca-1 silencing in vivo. In contrast, no defects in primary tumor growth or lung seeding following tail vein injection of Toca-1 KD cells was observed, suggesting that Toca-1 functions at an early step in the dissemination of metastatic breast tumor cells. Taken together, our results identify Toca-1 as a proinvasive protein in breast adenocarcinoma and a potential therapeutic target to limit tumor metastasis.

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Section: Discussionsupporting

confidence: 89%

Transducer of Cdc42-dependent actin assembly promotes breast cancer invasion and metastasis

et al. 2012

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“…Such pedestals have also been described in scanning electron microscopy studies on P. gingivalis infected coronary artery endothelial cells and human umbilical vein endothelial cells [23,34]. Pedestal formation is induced by pathogenhost interactions that are highly specific and not well understood for P. gingivalis, but commonly involve the rearrangement of the actin cytoskeleton and result in the pathogen entering the host cell [20,35]. Some bacteria appeared to be in the process of being endocytosed into the cell (Fig.…”

Section: P Gingivalis Interacts With the Neuron Membrane And Is Intementioning

confidence: 60%

Alzheimer’s Disease-Like Neurodegeneration in Porphyromonas gingivalis Infected Neurons with Persistent Expression of Active Gingipains

Haditsch¹,

Roth²,

Rodriguez³

et al. 2020

JAD

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Background: Porphyromonas gingivalis (P. gingivalis) and its gingipain virulence factors have been identified as pathogenic effectors in Alzheimer's disease (AD). In a recent study we demonstrated the presence of gingipains in over 90% of postmortem AD brains, with gingipains localizing to the cytoplasm of neurons. However, infection of neurons by P. gingivalis has not been previously reported. Objective: To demonstrate intraneuronal P. gingivalis and gingipain expression in vitro after infecting neurons derived from human inducible pluripotent stem cells (iPSC) with P. gingivalis for 24, 48, and 72 h. Methods: Infection was characterized by transmission electron microscopy, confocal microscopy, and bacterial colony forming unit assays. Gingipain expression was monitored by immunofluorescence and RT-qPCR, and protease activity monitored with activity-based probes. Neurodegenerative endpoints were assessed by immunofluorescence, western blot, and ELISA. Results: Neurons survived the initial infection and showed time dependent, infection induced cell death. P. gingivalis was found free in the cytoplasm or in lysosomes. Infected neurons displayed an accumulation of autophagic vacuoles and multivesicular bodies. Tau protein was strongly degraded, and phosphorylation increased at T231. Over time, the density of presynaptic boutons was decreased. Conclusion: P. gingivalis can invade and persist in mature neurons. Infected neurons display signs of AD-like neuropathology including the accumulation of autophagic vacuoles and multivesicular bodies, cytoskeleton disruption, an increase in phosphotau/tau ratio, and synapse loss. Infection of iPSC-derived mature neurons by P. gingivalis provides a novel model system to study the cellular mechanisms leading to AD and to investigate the potential of new therapeutic approaches.

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“…Canonical EspF U has six 47-residue repeats, each with the potential to recruit the N-WASP-WIP complex via a short α-helix that activates N-WASP through binding its autoinhibitory region [ 29 – 31 ]. Each repeat also possesses proline-rich motifs that bind the SH3 domains of IRTKS, IRSp53, and TOCA-1 to allow recruitment to Tir or enhanced N-WASP activation [ 25 , 26 , 63 ]. In vitro , each individual repeat can contribute to faster polymerization, although only two are required for efficient pedestal formation in cells [ 29 , 31 , 64 ].…”

Section: Discussionmentioning

confidence: 99%

Extracellular motility and cell-to-cell transmission of enterohemorrhagic E. coli is driven by EspFU-mediated actin assembly

Campellone

2017

PLoS Pathog

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Enteropathogenic and enterohemorrhagic Escherichia coli (EPEC and EHEC) are closely-related pathogens that attach tightly to intestinal epithelial cells, efface microvilli, and promote cytoskeletal rearrangements into protrusions called actin pedestals. To trigger pedestal formation, EPEC employs the tyrosine phosphorylated transmembrane receptor Tir, while EHEC relies on the multivalent scaffolding protein EspFU. The ability to generate these structures correlates with bacterial colonization in several animal models, but the precise function of pedestals in infection remains unclear. To address this uncertainty, we characterized the colonization properties of EPEC and EHEC during infection of polarized epithelial cells. We found that EPEC and EHEC both formed distinct bacterial communities, or “macrocolonies,” that encompassed multiple host cells. Tir and EspFU, as well as the host Arp2/3 complex, were all critical for the expansion of macrocolonies over time. Unexpectedly, EspFU accelerated the formation of larger macrocolonies compared to EPEC Tir, as EspFU-mediated actin assembly drove faster bacterial motility to cell junctions, where bacteria formed a secondary pedestal on a neighboring cell and divided, allowing one of the daughters to disengage and infect the second cell. Collectively, these data reveal that EspFU enhances epithelial colonization by increasing actin-based motility and promoting an efficient method of cell-to-cell transmission.

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Membrane-deforming Proteins Play Distinct Roles in Actin Pedestal Biogenesis by Enterohemorrhagic Escherichia coli

Cited by 16 publications

References 48 publications

Transducer of Cdc42-dependent actin assembly promotes breast cancer invasion and metastasis

Transducer of Cdc42-dependent actin assembly promotes breast cancer invasion and metastasis

Alzheimer’s Disease-Like Neurodegeneration in Porphyromonas gingivalis Infected Neurons with Persistent Expression of Active Gingipains

Extracellular motility and cell-to-cell transmission of enterohemorrhagic E. coli is driven by EspFU-mediated actin assembly

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