Listeria monocytogenes InlP interacts with afadin and facilitates basement membrane crossing

Cristina Faralla, Effie E. Bastounis, Fabian E. Ortega, Samuel H. Light, Gabrielle Rizzuto, Salvatorre Nocadello, Wayne F Anderson, Jennifer R. Robbins, Julie A. Theriot, Anna I. Bakardjiev*

*Corresponding author for this work

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

During pregnancy, the placenta protects the fetus against the maternal immune response, as well as bacterial and viral pathogens. Bacterial pathogens that have evolved specific mechanisms of breaching this barrier, such as Listeria monocytogenes, present a unique opportunity for learning how the placenta carries out its protective function. We previously identified the L. monocytogenes protein Internalin P (InlP) as a secreted virulence factor critical for placental infection. Here, we show that InlP, but not the highly similar L. monocytogenes internalin Lmo2027, binds to human afadin (encoded by AF-6), a protein associated with cell-cell junctions. A crystal structure of InlP reveals several unique features, including an extended leucine-rich repeat (LRR) domain with a distinctive Ca 2+ -binding site. Despite afadin’s involvement in the formation of cell-cell junctions, MDCK epithelial cells expressing InlP displayed a decrease in the magnitude of the traction stresses they could exert on deformable substrates, similar to the decrease in traction exhibited by AF-6 knock-out MDCK cells. L. monocytogenes ΔinlP mutants were deficient in their ability to form actin-rich protrusions from the basal face of polarized epithelial monolayers, a necessary step in the crossing of such monolayers (transcytosis). A similar phenotype was observed for bacteria expressing an internal in-frame deletion in inlP (inlP ΔLRR5) that specifically disrupts its interaction with afadin. However, afadin deletion in the host cells did not rescue the transcytosis defect. We conclude that secreted InlP targets cytosolic afadin to specifically promote L. monocytogenes transcytosis across the basal face of epithelial monolayers, which may contribute to the crossing of the basement membrane during placental infection.

Original languageEnglish (US)
Article numbere1007094
JournalPLoS pathogens
Volume14
Issue number5
DOIs
StatePublished - May 1 2018

Fingerprint

Listeria monocytogenes
Basement Membrane
Transcytosis
Madin Darby Canine Kidney Cells
Intercellular Junctions
Traction
Placenta
Aptitude
Virulence Factors
Infection
Leucine
Actins
Proteins
Fetus
Epithelial Cells
Binding Sites
Mothers
afadin
Learning
Bacteria

ASJC Scopus subject areas

  • Parasitology
  • Microbiology
  • Immunology
  • Molecular Biology
  • Genetics
  • Virology

Cite this

Faralla, C., Bastounis, E. E., Ortega, F. E., Light, S. H., Rizzuto, G., Nocadello, S., ... Bakardjiev, A. I. (2018). Listeria monocytogenes InlP interacts with afadin and facilitates basement membrane crossing. PLoS pathogens, 14(5), [e1007094]. https://doi.org/10.1371/journal.ppat.1007094
Faralla, Cristina ; Bastounis, Effie E. ; Ortega, Fabian E. ; Light, Samuel H. ; Rizzuto, Gabrielle ; Nocadello, Salvatorre ; Anderson, Wayne F ; Robbins, Jennifer R. ; Theriot, Julie A. ; Bakardjiev, Anna I. / Listeria monocytogenes InlP interacts with afadin and facilitates basement membrane crossing. In: PLoS pathogens. 2018 ; Vol. 14, No. 5.
@article{16ca3b20312b4814be575e66d88615d8,
title = "Listeria monocytogenes InlP interacts with afadin and facilitates basement membrane crossing",
abstract = "During pregnancy, the placenta protects the fetus against the maternal immune response, as well as bacterial and viral pathogens. Bacterial pathogens that have evolved specific mechanisms of breaching this barrier, such as Listeria monocytogenes, present a unique opportunity for learning how the placenta carries out its protective function. We previously identified the L. monocytogenes protein Internalin P (InlP) as a secreted virulence factor critical for placental infection. Here, we show that InlP, but not the highly similar L. monocytogenes internalin Lmo2027, binds to human afadin (encoded by AF-6), a protein associated with cell-cell junctions. A crystal structure of InlP reveals several unique features, including an extended leucine-rich repeat (LRR) domain with a distinctive Ca 2+ -binding site. Despite afadin’s involvement in the formation of cell-cell junctions, MDCK epithelial cells expressing InlP displayed a decrease in the magnitude of the traction stresses they could exert on deformable substrates, similar to the decrease in traction exhibited by AF-6 knock-out MDCK cells. L. monocytogenes ΔinlP mutants were deficient in their ability to form actin-rich protrusions from the basal face of polarized epithelial monolayers, a necessary step in the crossing of such monolayers (transcytosis). A similar phenotype was observed for bacteria expressing an internal in-frame deletion in inlP (inlP ΔLRR5) that specifically disrupts its interaction with afadin. However, afadin deletion in the host cells did not rescue the transcytosis defect. We conclude that secreted InlP targets cytosolic afadin to specifically promote L. monocytogenes transcytosis across the basal face of epithelial monolayers, which may contribute to the crossing of the basement membrane during placental infection.",
author = "Cristina Faralla and Bastounis, {Effie E.} and Ortega, {Fabian E.} and Light, {Samuel H.} and Gabrielle Rizzuto and Salvatorre Nocadello and Anderson, {Wayne F} and Robbins, {Jennifer R.} and Theriot, {Julie A.} and Bakardjiev, {Anna I.}",
year = "2018",
month = "5",
day = "1",
doi = "10.1371/journal.ppat.1007094",
language = "English (US)",
volume = "14",
journal = "PLoS Pathogens",
issn = "1553-7366",
publisher = "Public Library of Science",
number = "5",

}

Faralla, C, Bastounis, EE, Ortega, FE, Light, SH, Rizzuto, G, Nocadello, S, Anderson, WF, Robbins, JR, Theriot, JA & Bakardjiev, AI 2018, 'Listeria monocytogenes InlP interacts with afadin and facilitates basement membrane crossing', PLoS pathogens, vol. 14, no. 5, e1007094. https://doi.org/10.1371/journal.ppat.1007094

Listeria monocytogenes InlP interacts with afadin and facilitates basement membrane crossing. / Faralla, Cristina; Bastounis, Effie E.; Ortega, Fabian E.; Light, Samuel H.; Rizzuto, Gabrielle; Nocadello, Salvatorre; Anderson, Wayne F; Robbins, Jennifer R.; Theriot, Julie A.; Bakardjiev, Anna I.

In: PLoS pathogens, Vol. 14, No. 5, e1007094, 01.05.2018.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Listeria monocytogenes InlP interacts with afadin and facilitates basement membrane crossing

AU - Faralla, Cristina

AU - Bastounis, Effie E.

AU - Ortega, Fabian E.

AU - Light, Samuel H.

AU - Rizzuto, Gabrielle

AU - Nocadello, Salvatorre

AU - Anderson, Wayne F

AU - Robbins, Jennifer R.

AU - Theriot, Julie A.

AU - Bakardjiev, Anna I.

PY - 2018/5/1

Y1 - 2018/5/1

N2 - During pregnancy, the placenta protects the fetus against the maternal immune response, as well as bacterial and viral pathogens. Bacterial pathogens that have evolved specific mechanisms of breaching this barrier, such as Listeria monocytogenes, present a unique opportunity for learning how the placenta carries out its protective function. We previously identified the L. monocytogenes protein Internalin P (InlP) as a secreted virulence factor critical for placental infection. Here, we show that InlP, but not the highly similar L. monocytogenes internalin Lmo2027, binds to human afadin (encoded by AF-6), a protein associated with cell-cell junctions. A crystal structure of InlP reveals several unique features, including an extended leucine-rich repeat (LRR) domain with a distinctive Ca 2+ -binding site. Despite afadin’s involvement in the formation of cell-cell junctions, MDCK epithelial cells expressing InlP displayed a decrease in the magnitude of the traction stresses they could exert on deformable substrates, similar to the decrease in traction exhibited by AF-6 knock-out MDCK cells. L. monocytogenes ΔinlP mutants were deficient in their ability to form actin-rich protrusions from the basal face of polarized epithelial monolayers, a necessary step in the crossing of such monolayers (transcytosis). A similar phenotype was observed for bacteria expressing an internal in-frame deletion in inlP (inlP ΔLRR5) that specifically disrupts its interaction with afadin. However, afadin deletion in the host cells did not rescue the transcytosis defect. We conclude that secreted InlP targets cytosolic afadin to specifically promote L. monocytogenes transcytosis across the basal face of epithelial monolayers, which may contribute to the crossing of the basement membrane during placental infection.

AB - During pregnancy, the placenta protects the fetus against the maternal immune response, as well as bacterial and viral pathogens. Bacterial pathogens that have evolved specific mechanisms of breaching this barrier, such as Listeria monocytogenes, present a unique opportunity for learning how the placenta carries out its protective function. We previously identified the L. monocytogenes protein Internalin P (InlP) as a secreted virulence factor critical for placental infection. Here, we show that InlP, but not the highly similar L. monocytogenes internalin Lmo2027, binds to human afadin (encoded by AF-6), a protein associated with cell-cell junctions. A crystal structure of InlP reveals several unique features, including an extended leucine-rich repeat (LRR) domain with a distinctive Ca 2+ -binding site. Despite afadin’s involvement in the formation of cell-cell junctions, MDCK epithelial cells expressing InlP displayed a decrease in the magnitude of the traction stresses they could exert on deformable substrates, similar to the decrease in traction exhibited by AF-6 knock-out MDCK cells. L. monocytogenes ΔinlP mutants were deficient in their ability to form actin-rich protrusions from the basal face of polarized epithelial monolayers, a necessary step in the crossing of such monolayers (transcytosis). A similar phenotype was observed for bacteria expressing an internal in-frame deletion in inlP (inlP ΔLRR5) that specifically disrupts its interaction with afadin. However, afadin deletion in the host cells did not rescue the transcytosis defect. We conclude that secreted InlP targets cytosolic afadin to specifically promote L. monocytogenes transcytosis across the basal face of epithelial monolayers, which may contribute to the crossing of the basement membrane during placental infection.

UR - http://www.scopus.com/inward/record.url?scp=85048015437&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85048015437&partnerID=8YFLogxK

U2 - 10.1371/journal.ppat.1007094

DO - 10.1371/journal.ppat.1007094

M3 - Article

C2 - 29847585

AN - SCOPUS:85048015437

VL - 14

JO - PLoS Pathogens

JF - PLoS Pathogens

SN - 1553-7366

IS - 5

M1 - e1007094

ER -

Faralla C, Bastounis EE, Ortega FE, Light SH, Rizzuto G, Nocadello S et al. Listeria monocytogenes InlP interacts with afadin and facilitates basement membrane crossing. PLoS pathogens. 2018 May 1;14(5). e1007094. https://doi.org/10.1371/journal.ppat.1007094