Western blot analysis of protein extracts from isogenic K8 and K18 cell lines.

<p>Tracks: (1) K8 WT cells; (2) K8 G62C cells; (3) K8 K464N cells; (4) K18 WT cells; (5) K18 S230T cells. Total protein extracts (10 µg) from selected clones were run on a 5% denaturing polyacrylamide gel, transferred to a PVDF membrane, and incubated with antibodies against K8 (M20), K18 (LDK-18) and phosphorylated keratin (LJ4) protein. As shown, K8 and K18 expression levels are very similar between the selected clones, while phosphorylated keratin levels are altered in the mutants, up-regulated in the K8 G62C (track 2) and K8 K464N (track 3) cells and down-regulated in the K18 S230T cells (track 5).