Figure 7. Sdk specificity could be accentuated by competition between cis and trans interactions.
(A) Schematic of two neighboring cells expressing Sdk1 showing the competition between homophilic Ig1–4-mediated dimer interactions in cis and in trans. The six immunoglobulin domains (Ig) are represented as numbered ovals and the thirteen extracellular fibronectin type III (FNIII), whose arrangement is unknown, are represented as dashed lines. (B) Schematic of two neighboring cells, one expressing Sdk1 and one expressing Sdk2, showing the competition between the stronger homophilic dimer interactions in cis and the weaker heterophilic dimer interactions in trans.