Loss of kinesin-1 or -2 results in weakened cell–cell adhesion. (A) Confluent monolayers of Scc9 keratinocytes after 72-h siRNA transfection with either kinesin-1 (KHC) or kinesin-2 (KIF3A) or doubly silenced for kinesin-1/Dsg2, kinesin-1/Dsc2, kinesin-2/Dsg2, or kinesin-2/Dsc2 were subjected to a dispase mechanical dissociation assay in triplicate. Cells were incubated with dispase enzyme to lift the cells from the dish, and the intact monolayer was subjected to mechanical stress. Increasing amounts of fragments indicate the loss of cell–cell adhesion. (B) Bar graphs show quantification of fragmentation as an average from at least three experiments. ***, P < 0.001 for pairs siKHC/siKHC+siDsc2, siKHC+siDsg2/siKHC+siDsc2, siKIF3A/siKIF3A+siDsg2, and siKIF3A+siDsc2/siKIF3A+siDsg2. P < 0.01 for pairs nontargeting (NT) siRNA/siKHC and nontargeting siRNA/siKIF3A. P < 0.05 for the pair siKHC/siKIF3A. (C) Level of Dsg2 and Dsc2 knockdowns (KD) in dispase experiments shown by Western blots (compiled data from the same blots). Level of knockdown for Dsg2 was ∼70% (*, P < 0.05) and ∼90% for Dsc2 (***, P < 0.001; n = 3 for both). The protein expression levels of the partner desmosomal cadherins and E-cadherin (E-cad) were unchanged. Levels of KHC and KIF3A knockdowns were comparable with that shown in Fig. 2 F and Fig. 5 D. Black lines indicate that intervening lanes have been spliced out. GAPDH, glyceraldehyde 3-phosphate dehydrogenase.