Following iinduction of apoptosis in epithelial cells, tight junction are disrupted. Tight junction proteins, including the the transmembrane protein occludin and the cytoplasmic adaptor proteins ZO-1 and ZO-2 are fragmented by caspase cleavage (Bojarski et al., 2004). Inhibition of caspase-3 prevents cleavage of occludin, implicating caspase-3 as the responsible endopeptidase (Bojarski et al. 2004).
cysteine-type endopeptidase activity of Caspase-3 [cytosol]