Spatial Gradients of E-Cadherin and Fibronectin in TGF-β1-Treated Epithelial Colonies Are Independent of Fibronectin Fibril Assembly.

Epithelial to Mesenchymal Transition (EMT) is a dynamic, morphogenetic process characterized by a phenotypic shift in epithelial cells towards a motile and often invasive mesenchymal phenotype. We have previously demonstrated that EMT is associated with an increase in assembly of the extracellular matrix protein fibronectin (FN) into insoluble, viscoelastic fibrils. We have also demonstrated that Transforming Growth Factor-β1 (TGF-β1) localizes to FN fibrils, and disruption of FN assembly or disruption of TGF-β1 localization to FN fibrils attenuates EMT.

A hybrid model of intercellular tension and cell-matrix mechanical interactions in a multicellular geometry.

Epithelial cells form continuous sheets of cells that exist in tensional homeostasis. Homeostasis is maintained through cell-to-cell junctions that distribute tension and balance forces between cells and their underlying matrix. Disruption of tensional homeostasis can lead to epithelial-mesenchymal transition (EMT), a transdifferentiation process in which epithelial cells adopt a mesenchymal phenotype, losing cell-cell adhesion and enhancing cellular motility.

Fibronectin fibrils regulate TGF-β1-induced Epithelial-Mesenchymal Transition.

Epithelial-Mesenchymal Transition (EMT) is a dynamic process through which epithelial cells transdifferentiate from an epithelial phenotype into a mesenchymal phenotype. Previous studies have demonstrated that both mechanical signaling and soluble growth factor signaling facilitate this process. One possible point of integration for mechanical and growth factor signaling is the extracellular matrix.

The YsrS Paralog DygS Has the Capacity To Activate Expression of the Yersinia enterocolitica Ysa Type III Secretion System.

Unlabelled: The Yersinia enterocolitica Ysa type III secretion system (T3SS) is associated with intracellular survival, and, like other characterized T3SSs, it is tightly controlled. Expression of the ysa genes is only detected following growth at low temperatures (26°C) and in high concentrations of sodium chloride (290 mM) in the medium. The YsrSTR phosphorelay (PR) system is required for ysa expression and likely responds to NaCl.