Multi-omics analysis reveals dermokine as a regulator of keratinocyte differentiation and adhesion.

22 Impaired adhesion and differentiation of keratinocytes is a hallmark of several skin diseases, but only some of 23 the factors that regulate these processes have been identified. Here, we studied the role of isoform -rich 24 dermokine – a wound- and tumor-regulated protein – in keratinocytes using a combination of multi-omics and 25 functional approaches. CRISPR/Cas9 -induced knockout of dermokine isoforms in human keratinocytes 26 inhibited differentiation of these cells in three-dimensional organotypic skin cultures, which was confirmed by 27 quantitative proteomics. In two -dimensional monocultures, dermokine deficiency affected the proteome and 28 phosphoproteome as revealed by mass spectrometry. We found reduced abundance of differentiation-specific 29 proteins and increased p hosphorylation of cell adhesion protein p120 (cateninδ1). The adhesive strength of 30 dermokine knockout keratinocytes was impaired, which was rescued by p120 knock-down or ROCK inhibition. 31 Finally, we verified the correlation between decreased dermokine expr ession and increased p120 32 phosphorylation in human non-healing wounds. These results identify dermokine as regulator of keratinocyte 33 adhesion and differentiation, involving at least in part its effect on p120 phosphorylation and ROCK. Our data 34 point to a function of dermokine in the pathogenesis of chronic wounds. 35 36 3