Figure 1.

Actin reorganization during cell–cell junction formation in cell culture. Actin is shown in red, cadherin in green. (A) Before cell–cell contact, epithelial cells extend protrusions (lamellipodia and membrane ruffles). (B) Cadherin puncta form at the tips of these projections and are connected to the circumferential actin cable via radial actin bundles. (B, bottom) Contacting keratinocytes adopt an intermediate configuration known as the “adhesion zipper” as a consequence of myosin-mediated tension pulling inward on cadherin puncta. (C) As cell–cell contacts expand and mature, actin arcs focus on the edges of the contact. Actin remodeling along the contact results in formation of the adhesion belt.