Sorting of cadherin–catenin-associated proteins into individual clusters
Regina B. Troyanovsky, Alina P. Sergeeva, Indrajyoti Indra, Chi-Shuo Chen, Rei Kato, Lawrence Shapiro, Barry Honig, Sergey M. Troyanovsky
Abstract
Significance Cadherin–catenin complexes (CCCs) are a central component of adherens junctions. To produce an adhesive cell–cell contact, the CCC forms clusters, “E clusters,” driven by cooperative cis and trans interactions in the cadherin ectodomain and by α-catenin–actin interactions inside cells. We analyze whether E clustering is compatible with CCC-associated proteins (CAPs) and show that space constraints preclude the integration of many CAPs into E clusters. Using natural (scribble and erbin) and “artificial” (cadherin ectodomain antibodies) CAPs, we provide evidence that CAPs form separate “C clusters,” which are unable to intermix with E clusters. Our results thus suggest that CAP-dependent CCC clustering serves as a mechanism for sorting cellular proteins into distinct domains within cell–cell contacts.