Intermembrane crosstalk drives inner-membrane protein organization in Escherichia coli.
Fiche publication
Date publication
mars 2018
Journal
Nature communications
Auteurs
Membres identifiés du Cancéropôle Est :
Dr RASSAM Patrice
Tous les auteurs :
Rassam P, Long KR, Kaminska R, Williams DJ, Papadakos G, Baumann CG, Kleanthous C
Lien Pubmed
Résumé
Gram-negative bacteria depend on energised protein complexes that connect the two membranes of the cell envelope. However, β-barrel outer-membrane proteins (OMPs) and α-helical inner-membrane proteins (IMPs) display quite different organisation. OMPs cluster into islands that restrict their lateral mobility, while IMPs generally diffuse throughout the cell. Here, using live cell imaging of Escherichia coli, we demonstrate that when transient, energy-dependent transmembrane connections are formed, IMPs become subjugated by the inherent organisation of OMPs and that such connections impact IMP function. We show that while establishing a translocon for import, the colicin ColE9 sequesters the IMPs of the proton motive force (PMF)-linked Tol-Pal complex into islands mirroring those of colicin-bound OMPs. Through this imposed organisation, the bacteriocin subverts the outer-membrane stabilising role of Tol-Pal, blocking its recruitment to cell division sites and slowing membrane constriction. The ordering of IMPs by OMPs via an energised inter-membrane bridge represents an emerging functional paradigm in cell envelope biology.
Mots clés
Bacterial Outer Membrane Proteins, metabolism, Cell Membrane, metabolism, Escherichia coli, metabolism, Escherichia coli Proteins, metabolism, Protein Binding, physiology, Protein Transport, physiology
Référence
Nat Commun. 2018 03 14;9(1):1082