Figure 8.

Protein exchange controls adhesive state. Models illustrating how reduced protein exchange confers hyperadhesion. (A) Model illustrating dynamics of DP phosphorylation, protein exchange, and cadherin order in calcium-dependent adhesion (left) and hyperadhesion (right) with (top) and without (bottom) Ca²⁺. In calcium-dependent desmosomes with Ca²⁺, cadherins are ordered, and desmosomal proteins can diffuse in and out of the complex. In the absence of Ca²⁺, cadherin order is lost, proteins diffuse out but do not reenter, and desmosomes disassemble. In hyperadhesive desmosomes with Ca²⁺, cadherins are ordered, but desmosomal proteins are unable to diffuse in or out of the complex. In the absence of Ca²⁺, cadherin order is lost, but adhesion is maintained because proteins are unable to diffuse out of the complex. (B) We suggest that protein mobility is blocked by Gö6976 or DPS2849G though modulation of DP–keratin interactions via an inside-out mechanism. PM, plasma membrane.