Figure 4.

Models of EpCAM homo-oligomerization and formation of adhesion units. (a) The initial cis-dimer/trans-tetramer and cis-tetramer/trans-octamer hypotheses proposed in 2001 (left and center, respectively) and the experimental structure of EpCAM dimer from 2014 (right). (b) The symmetry of EpCAM cis-dimer in two different orientations, depicted as ribbons and molecular surface. Axis of rotation (C2) is shown as a dashed line. (c) Potential clustering of EpCAM adhesion units due to inherent symmetry implying lateral extension in both directions (dots). (d) Adaptation of the trans-tetramer model presented by Pavšič et al. in 2014 [11] with three C2 axes indicated by black dotted lines or a white dot.