Figure 4.

TAMPs demonstrate unique interactions with each other and ZO-1. (A) Coimmunoprecipitation of TAMPs from Caco-2 lysates reveals interactions among marvelD3, tricellulin, and occludin. The data are consistent with a model of TAMP interaction, where marvelD3 physically associates with both occludin and tricellulin, but the latter two TAMPs do not interact. (B) TAMP cytoplasmic tails were expressed as GST fusion constructs, and equal quantities of each were loaded onto GST-agarose, as confirmed by the Coomassie blue–stained gel. Pulldown experiments using VSVG-ZO-1-GuK as prey demonstrate interaction with the carboxy-terminal tail of occludin (immunoblot). In contrast, neither cytoplasmic tails of tricellulin nor marvelD3 were able to pull down VSVG-ZO-1-GuK. Data are representative of ≥2 experiments, each in duplicate, with similar results.