The cofilin phosphatase slingshot homolog 1 (SSH1) links NOD1 signaling to actin remodeling

Harald Bielig; Katja Lautz; Peter R Braun; Maureen Menning; Nikolaus Machuy; Christine Brügmann; Sandra Barisic; Stephan A Eisler; Maria Andree; Birte Zurek; Hamid Kashkar; Philippe J Sansonetti; Angelika Hausser; Thomas F Meyer; Thomas A Kufer

doi:10.1371/journal.ppat.1004351

The cofilin phosphatase slingshot homolog 1 (SSH1) links NOD1 signaling to actin remodeling

PLoS Pathog. 2014 Sep 4;10(9):e1004351. doi: 10.1371/journal.ppat.1004351. eCollection 2014 Sep.

Authors

Affiliations

¹ Institute for Medical Microbiology, Immunology and Hygiene, Cologne, Germany.
² Department of Molecular Biology, Max Planck Institute for Infection Biology, Berlin, Germany; Steinbeis-Innovationszentrum Center for Systems Biomedicine, Falkensee, Germany.
³ Department of Molecular Biology, Max Planck Institute for Infection Biology, Berlin, Germany.
⁴ Institute of Cell Biology and Immunology, University of Stuttgart, Stuttgart, Germany.
⁵ Unité de Pathogénie Microbienne Moléculaire, Institut Pasteur, Paris, France; INSERM U786, Institut Pasteur, Paris, France; Microbiologie et Maladies Infectieuses, Collège de France, Paris, France.
⁶ Institute for Medical Microbiology, Immunology and Hygiene, Cologne, Germany; University of Hohenheim, Institute of Nutritional Medicine, Stuttgart, Germany.

Abstract

NOD1 is an intracellular pathogen recognition receptor that contributes to anti-bacterial innate immune responses, adaptive immunity and tissue homeostasis. NOD1-induced signaling relies on actin remodeling, however, the details of the connection of NOD1 and the actin cytoskeleton remained elusive. Here, we identified in a druggable-genome wide siRNA screen the cofilin phosphatase SSH1 as a specific and essential component of the NOD1 pathway. We show that depletion of SSH1 impaired pathogen induced NOD1 signaling evident from diminished NF-κB activation and cytokine release. Chemical inhibition of actin polymerization using cytochalasin D rescued the loss of SSH1. We further demonstrate that NOD1 directly interacted with SSH1 at F-actin rich sites. Finally, we show that enhanced cofilin activity is intimately linked to NOD1 signaling. Our data thus provide evidence that NOD1 requires the SSH1/cofilin network for signaling and to detect bacterial induced changes in actin dynamics leading to NF-κB activation and innate immune responses.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Actins / chemistry
Actins / metabolism*
Blotting, Western
Cells, Cultured
Cofilin 1 / genetics
Cofilin 1 / metabolism*
Dysentery, Bacillary / microbiology*
Enzyme-Linked Immunosorbent Assay
Fluorescent Antibody Technique, Indirect
Gene Expression Regulation
HeLa Cells
High-Throughput Screening Assays
Humans
Immunoenzyme Techniques
Immunoprecipitation
Inflammation
Inflammation Mediators / metabolism
NF-kappa B / genetics
NF-kappa B / metabolism
Nod1 Signaling Adaptor Protein / antagonists & inhibitors
Nod1 Signaling Adaptor Protein / genetics
Nod1 Signaling Adaptor Protein / metabolism*
Phosphoprotein Phosphatases / genetics
Phosphoprotein Phosphatases / metabolism*
Phosphorylation
RNA, Messenger / genetics
RNA, Small Interfering / genetics
Real-Time Polymerase Chain Reaction
Reverse Transcriptase Polymerase Chain Reaction
Shigella flexneri / physiology*
Signal Transduction

Substances

Actins
Cofilin 1
Inflammation Mediators
NF-kappa B
NOD1 protein, human
Nod1 Signaling Adaptor Protein
RNA, Messenger
RNA, Small Interfering
Phosphoprotein Phosphatases
SSH1 protein, human

Grants and funding

This work was supported by grants of the DFG (SFB670) and the Koeln Fortune Program/Faculty of Medicine, University of Cologne to TAK and the Heidelberg Academy of Science and Humanities to AH (WIN-Kolleg). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.