Discovery of a Novel Inner Membrane-Associated Bacterial Structure Related to the Flagellar Type III Secretion System
- Creators
- Kaplan, Mohammed
- Oikonomou, Catherine M.
- Wood, Cecily R.
- Chreifi, Georges
- Ghosal, Debnath
- Dobro, Megan J.
- Yao, Qing
- Pal, Ritesh Ranjan
- Baidya, Amit K.
- Liu, Yuxi
- Maggi, Stefano
- McDowall, Alasdair W.
- Ben-Yehuda, Sigal
- Rosenshine, Ilan
- Briegel, Ariane
- Beeby, Morgan
- Chang, Yi-Wei
- Shaffer, Carrie L.
- Jensen, Grant J.
Abstract
The bacterial flagellar type III secretion system (fT3SS) is a suite of membrane-embedded and cytoplasmic proteins responsible for building the flagellar motility machinery. Homologous nonflagellar (NF-T3SS) proteins form the injectisome machinery that bacteria use to deliver effector proteins into eukaryotic cells, and other family members were recently reported to be involved in the formation of membrane nanotubes. Here, we describe a novel, evolutionarily widespread, hat-shaped structure embedded in the inner membranes of bacteria, of yet-unidentified function, that is present in species containing fT3SS. Mutant analysis suggests a relationship between this novel structure and the fT3SS, but not the NF-T3SS. While the function of this novel structure remains unknown, we hypothesize that either some of the fT3SS proteins assemble within the hat-like structure, perhaps including the fT3SS core complex, or that fT3SS components regulate other proteins that form part of this novel structure.
Additional Information
© 2022 Kaplan et al. This is an open-access article distributed under the terms of the Creative Commons Attribution 4.0 International license. Received: 19 April 2022. Accepted: 30 May 2022. Published online: 18 July 2022. This project was funded by the NIH (grant R01 AI127401 to G.J.J., and grant P20 GM130456 to C.L.S.) and the European Research Council (ERC) Synergy grant (no. 810186 awarded to S.B.Y. and I.R.). M.K. acknowledges a Baxter postdoctoral fellowship from Caltech. Cryo-ET work was done in the Beckman Institute Resource Center for Transmission Electron Microscopy at the California Institute of Technology. We are grateful to Marc Erhardt (Humboldt-Universität zu Berlin) for critically reading an initial version of this work. We thank Elitza I. Tocheva for collecting the A. tumefaciens data, Jian Shi for collecting the H. neptunium data, and Martin Pilhofer for collecting the P. luteoviolacea data. We thank Dianne Newman's lab for providing the P. aeruginosa transposon mutant. We are grateful to the lab of Robert Heinzen at the National Institute of Allergy and Infectious Diseases in Montana for growing the Coxiella burnetii cells. The authors declare no conflict of interest.Attached Files
Supplemental Material - jb.00144-22-s0001.pdf
Supplemental Material - jb.00144-22-s0002.mov
Published - jb.00144-22.pdf
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Additional details
- Eprint ID
- 115975
- DOI
- 10.1128/jb.00144-22
- Resolver ID
- CaltechAUTHORS:20220729-894327000
- PMCID
- PMC9380563
- R01 AI127401
- NIH
- P20 GM130456
- NIH
- 810186
- European Research Council (ERC)
- Baxter Foundation
- Created
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2022-08-01Created from EPrint's datestamp field
- Updated
-
2022-08-24Created from EPrint's last_modified field
- Caltech groups
- Division of Biology and Biological Engineering