Figure 2.

The hepatocyte tight junction complex. (A) Electron micrograph of the bile canaliculus formed between two adjacent hepatocytes and whose lumen is filled with microvilli and sealed by the tight junctions (arrows). (B) Schematic of the tight junction complex showing that occludins and claudins are transmembrane proteins forming the junction seal, whereas zonula occluden proteins 1 and 2 (Z01 and Z02) are cytoplasmic proteins that may serve as anchors for occludins. The latter protein forms the interconnecting strands illustrated in the freeze fracture in Figure 3. See Ref. (384) for more details of tight junction anatomy. Reprinted, with permission, from Ref. (76).