Fig. 1. Epiplakin binds to keratins via multiple sites. (A) Double immunofluorescence microscopy of primary keratinocytes and primary hepatocytes using antibodies as indicated. Inserts show twofold magnifications of boxed areas; localization of epiplakin dot-like structures along a keratin filament is indicated by arrows. Scale bar: 10 µm. (B) Domain structure of mouse epiplakin (Spazierer et al., 2003) showing 16 repeat domains, linkers (white bars) and modules (grey ellipses). Modules that are virtually identical are shown in light gray, those with lower homology in dark gray. (C,D) Blot overlay of keratins (isolated from mouse keratinocytes) with 10 µg/ml of the protein indicated. Positions of K5 and K14 (arrows) and of size markers (bars) are indicated. PRD, plakin-repeat domain; Li, linker; M, module. Note that M8 and M9 have identical amino acid sequence. (E) Co-sedimentation of K5 and K14 with epiplakin-GST fusion proteins. Proteins bound to epiplakin-GST-Sepharose beads were analyzed by immunoblotting (IB) using antibodies to K5 and K14; GST coupled to Sepharose beads was used as negative control. For IB, keratinocyte protein lysates were used as positive controls (lysate).