Proc. Natl Acad. Sci. USA 109, 1506–1511 (2012)

Credit: © 2012 NAS

The extracellular matrix (ECM) is a dynamic, heterogeneous scaffold known to regulate many aspects of cellular behaviour, such as cell shape, cell migration, stem-cell differentiation, and cell–cell junction remodelling. Now, experiments show that the spatial distribution of the ECM can also regulate the positioning of cells. By imaging cell doublets (formed by daughter cells after mitosis) placed on predesigned ECM micropatterns, Qingzong Tseng and colleagues found that the cells move so as to place their intercellular junction above regions deprived of ECM. Moreover, traction-force measurements revealed that the ECM also controls the magnitude of intra- and intercellular forces. Using numerical simulations of a model of cell adhesion and contractility, the authors suggest that cells organize their relative position to minimize tension. Although the mechanism by which the ECM modulates such forces still needs to be determined, ECM-induced cell–cell junction positioning could explain processes occurring during the morphogenesis of (cell-packed) epithelial tissues, such as the relocalization of intercellular junctions away from the ECM in tubulogenesis.