SERPINB5 binds to DSP preferably at the rod and tail domains. (a) Western blot showing migration of DSG2 and DSP upon treatment with PNGaseF in sgNT1 versus sgDPM1 HaCaT keratinocytes. (b) Heat map showing differential protein expression profiles in sgNT1 and sgDPM1 HaCaT keratinocytes from three biological replicates. Color scale represents log₂ fold change of intensity values. (c) Principal component (PC) analysis of the samples used in b. (d) Immunoprecipitation (I.P.) assay showing DSP pulldown in sgNT1 and sgDPM1 cells. IgG used as negative control. Panel shows representative of two biological replicates. (e) Schematic depicting the different truncated DSP constructs fused with GFP at the C-terminus. (f and g) Coimmunoprecipitation assay showing SERPINB5 binding to respective DSP truncated-GFP mutants expressed in HaCaT sgDSP cells. Quantification of SERPINB5 in I.P. samples normalized to the respective amounts of GFP immunoprecipitated. One-way ANOVA, Dunnett’s multiple comparison test, from three independent biological replicates. (h and i) Western blot and corresponding quantification of SERPINB5 expression in sgDPM1 HaCaT keratinocytes. N = 4, unpaired Student’s t test. (j and k) Images and quantification of SERPINB5 immunostainings in sgNT1 and sgDPM1 HaCaT keratinocytes. Scale bar: 10 µm distance. Panel represents three biological replicates. Unpaired Student’s t test (N = 3). (l) qPCR analysis of relative expression of SERPINB5 transcripts in sgNT1 and sgDPM1 cells. GAPDH used as housekeeping control and SERPINB5 transcript expression normalized to GAPDH. Each dot represents individual biological replicates, Unpaired Student’s t test. Source data are available for this figure: SourceData FS2.