DSMs are not involved in pkp4-facilitated E-cadherin clustering. Maximum-intensity projections of all x–y optical slices of αCat/pkp2/3-KO cells stained for pkp4 (green) and co-stained for the desmosomal marker, dsg2, or E-cadherin (Ecad), or F-actin (all in red). Only merged images are shown at low magnifications. Bar, 20 μm. Enlarged regions (indicated by white dashed boxes) are shown for both channels at the bottom. Bar, 10 μm. The boxed region within the enlarged F-actin image is further magnified in the insets (Bar, 7.5 μm). Note that cells form pkp4 clusters despite the complete absence of DSMs and α-catenin. Also note that the vast majority of pkp4 clusters are associated with actin-rich structures. αCat, α-catenin.