Fig. 6. Models for cadherin-based cell-cell junctions in epithelia (left) and in heart (right panel). In the heart, T-catenin recruits desmosomal proteins to hybrid adhering junctions (top drawings), thereby forming, together with desmosomes (see below), an area composita, which is an enforced, mixed-type junctional structure attached to both the actin cytoskeleton and the intermediate filaments. By contrast, epithelial tissues do not express T-catenin, and therefore their adherens junctions are not attached to the intermediate filaments. The composition of typical desmosomes (drawings at the bottom) is largely similar in the two tissue types. Although desmosomes are shown here as containing simultaneously all three types of plakophilins as well as heterophilically binding desmosomal cadherins, we are not aware of evidence for such high complexity in individual desmosomes.