Migrating Krt6a/Krt6b-null keratinocytes show disrupted cell–cell adhesion, and loss of DP promotes collective keratinocyte migration. (A) Schematic of the experiment. The rectangular area (with dashed lines) shows area adjacent to migration front. (B and C) In the absence of K6a/K6b proteins, the amount of DP at cell–cell adhesion (B′, B″, C′, and C″) was reduced, and DP localized to the nucleus of keratinocytes on type I collagen. Asterisks mark the gaps between keratinocyte sheets. Arrowheads point to nuclear DP. Bars: 50 µm (B, B′, C, and C′); 10 µm (B″ and C″). (D) The percentage of cells that showed a distinct nuclear localization of DP is presented as the mean + SEM of three biological replicates. (E) Western blot analysis of whole-cell lysates harvested from 6-d skin explant culture showed that Krt6a/Krt6b-null keratinocytes had a reduced level of DP and increased level of plakophilin 1. β-Actin was used as a loading control. n = six biological repeats. (F) Quantification of Western blot results of six biological replicates. Data represent the mean + SEM. (G) The overexpressing of DP-GFP in Krt6a/Krt6b-null keratinocytes led to a reduction in migration area. Data represent the mean + SEM of five biological replicates. (H) Adenovirus delivered Cre (Ad-Cre)–induced Dsp deletion in WT keratinocytes resulted in an increase in migration area (Video 7). Data represent the mean + SEM of three biological replicates. *, P < 0.05; **, P < 0.01, Student’s two-tailed t test.