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.
Pubmed ID: 29199076 RIS Download
Publication data is provided by the National Library of Medicine ® and PubMed ®. Data is retrieved from PubMed ® on a weekly schedule. For terms and conditions see the National Library of Medicine Terms and Conditions.
Software for image processing, analysis, and editing. The software includes features such as touch capabilities, a customizable toolbar, 2D and 3D image merging, and Cloud access and options.
View all literature mentionsThis unknown targets Goat IgG (H+L)
View all literature mentionsThis unknown targets Rat IgG (H+L)
View all literature mentionsThis polyclonal targets Mouse IgG (H+L)
View all literature mentionsThis polyclonal targets IgG (H+L)
View all literature mentionsThis unknown targets Mouse IgG (H+L)
View all literature mentionsThis polyclonal secondary targets IgG (H+L)
View all literature mentionsThis polyclonal targets Phospho-Myosin Light Chain 2 (Thr18/Ser19)
View all literature mentionsThis polyclonal targets Ki67 antibody - Proliferation Marker
View all literature mentionsThis monoclonal targets beta Tubulin
View all literature mentionsThis unknown targets Occludin
View all literature mentionsThis unknown targets ZO-2
View all literature mentionsThis unknown targets ZONAB
View all literature mentionsThis unknown targets ZO-1
View all literature mentionsThis monoclonal targets ZO-1
View all literature mentionsThis polyclonal targets AVI Tag
View all literature mentionsThis polyclonal targets His-probe (H-15)
View all literature mentionsThis polyclonal targets VSV-G Tag
View all literature mentionsThis polyclonal targets HA-probe
View all literature mentionsThis monoclonal targets HA Tag
View all literature mentions