Fig. 3. Colocalization and subcellular co-distribution of epiplakin with keratin aggregates after OA-induced filament disruption in wild-type (+/+) and epiplakin-deficient (–/–) keratinocytes. (A) Primary mouse keratinocytes, treated with OA for 2, 4 and 6 hours were immunolabeled using antibodies as indicated. Merged images show complete colocalization of epiplakin with keratin. Compare with untreated cells (negative control) shown in Fig. 1A. Scale bar: 10 µm. (B) Immunoblotting (upper four panels) of soluble and insoluble cell fractions obtained from 2, 4 and 6 hour OA-treated keratinocytes using antibodies to epiplakin, tubulin, and phospho (p)-K5. Coomassie Blue staining of high salt-extracted keratins is shown in bottom panel.