Figure 1

Discontinuous adherens junctions (AJs) in confluent human umbilical vein endothelial cells (HUVECs) described by Millán et al[6]. (a-c) Discontinuous AJs form separated clusters of vascular endothelial (VE)-cadherin-based junctions at the ends of F-actin-based stress fibers that are oriented more or less orthogonal to the adjacent cell membranes (boxed in (c) and marked with arrows). There they appear to connect stress fibers between adjacent cells (insert 1 in (a)). Discontinuous AJs contain aside from VE-cadherin, both α-catenin and β-catenin (c, d) and a number of additional junctional proteins such as zona occludens (ZO)-1, plakoglobin and junctional adhesion molecule A (JAM-A) (c), p120-catenin, and CD99. Discontinuous AJs attached to stress fibers did not colocalize with the focal adhesion (FA) components, focal adhesion kinase (P-FAK) (d), paxillin, or talin, indicating that FAs and discontinuous AJs are distinct, separate structures. Fluorescent images (a, c, d), ultrastructure (b). All images are taken from Millán et al. [6].