Fig. 7. CNF-1 disrupts morphological localization of a TJ-associated pool of phosphorylated MLC. In control T84 monolayers double-labeled with antibodies to ZO-1 (a; green) and p-MLC (b; red), extensive co-localization (c; yellow) was observed in the TJ plane. In monolayers treated apically for 24 hours with CNF toxin, ZO-1 (d) and p-MLC (e) were also seen to co-localize (f). However, monolayers treated basolaterally with CNF-1 for the same time period displayed not only profound disruption of ZO-1 staining (g) but also p-MLC (h) in the TJ plane. Fragments of each protein from the disassembled ring structures co-localized in a punctate pattern (i). Bar10 µm.