Tension-Dependent Stretching Activates ZO-1 to Control the Junctional Localization of Its Interactors
| Autor: | Jie Yan, Domenica Spadaro, Thierry Laroche, Isabelle Méan, Sandra Citi, Lionel Jond, Shimin Le |
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| Rok vydání: | 2017 |
| Předmět: |
0301 basic medicine
Magnetic tweezers Morphogenesis Biology Spodoptera Occludin General Biochemistry Genetics and Molecular Biology Cell Line 03 medical and health sciences Mice Sf9 Cells Animals Humans Transcription factor Barrier function Tight junction Actin cytoskeleton Actin Cytoskeleton 030104 developmental biology Membrane protein Gene Expression Regulation Biophysics Zonula Occludens-1 Protein Female General Agricultural and Biological Sciences Signal Transduction |
| Zdroj: | Current biology : CB. 27(24) |
| ISSN: | 1879-0445 |
| Popis: | Summary Tensile forces regulate epithelial homeostasis, but the molecular mechanisms behind this regulation are poorly understood. Using structured illumination microscopy and proximity ligation assays, we show that the tight junction protein ZO-1 exists in stretched and folded conformations within epithelial cells, depending on actomyosin-generated force. We also show that ZO-1 and ZO-2 regulate the localization of the transcription factor DbpA and the tight junction membrane protein occludin in a manner that depends on the organization of the actin cytoskeleton, myosin-II activity, and substrate stiffness, resulting in modulation of gene expression, cell proliferation, barrier function, and cyst morphogenesis. Pull-down experiments show that interactions between N-terminal (ZPSG) and C-terminal domains of ZO-1 prevent binding of DbpA to the ZPSG, suggesting that force-dependent intra-molecular interactions regulate ZPSG binding to ligands within cells. In vivo and in vitro experiments also suggest that ZO-1 heterodimerization with ZO-2 promotes the stretched conformation and ZPSG interaction with ligands. Magnetic tweezers single-molecule experiments suggest that pN-scale tensions (∼2–4 pN) are sufficient to maintain the stretched conformation of ZO-1, while keeping its structured domains intact, and that 5–20 pN force is required to disrupt the interaction between the extreme C-terminal and the ZPSG domains of ZO-1. We propose that tensile forces regulate epithelial homeostasis by activating ZO proteins through stretching, to control the junctional recruitment and downstream signaling of their interactors. |
| Databáze: | OpenAIRE |
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