TY - JOUR
T1 - Different roles of cadherins in the assembly and structural integrity of the desmosome complex
AU - Lowndes, Molly
AU - Rakshit, Sabyasachi
AU - Shafraz, Omer
AU - Borghi, Nicolas
AU - Harmon, Robert M.
AU - Green, Kathleen J.
AU - Sivasankar, Sanjeevi
AU - Nelson, W. James
PY - 2014
Y1 - 2014
N2 - Adhesion between cells is established by the formation of specialized intercellular junctional complexes, such as desmosomes. Desmosomes contain isoforms of two members of the cadherin superfamily of cell adhesion proteins, desmocollins (Dsc) and desmogleins (Dsg), but their combinatorial roles in desmosome assembly are not understood. To uncouple desmosome assembly from other cell-cell adhesion complexes, we used micro-patterned substrates of Dsc2aFc and/or Dsg2Fc and collagen IV; we show that Dsc2aFc, but not Dsg2Fc, was necessary and sufficient to recruit desmosome-specific desmoplakin into desmosome puncta and produce strong adhesive binding. Single-molecule force spectroscopy showed that monomeric Dsc2a, but not Dsg2, formed Ca2+-dependent homophilic bonds, and that Dsg2 formed Ca2+- independent heterophilic bonds with Dsc2a. A W2A mutation in Dsc2a inhibited Ca2+-dependent homophilic binding, similar to classical cadherins, and Dsc2aW2A, but not Dsg2W2A, was excluded from desmosomes in MDCK cells. These results indicate that Dsc2a, but not Dsg2, is required for desmosome assembly through homophilic Ca2+- and W2-dependent binding, and that Dsg2 might be involved later in regulating a switch to Ca2+-independent adhesion in mature desmosomes.
AB - Adhesion between cells is established by the formation of specialized intercellular junctional complexes, such as desmosomes. Desmosomes contain isoforms of two members of the cadherin superfamily of cell adhesion proteins, desmocollins (Dsc) and desmogleins (Dsg), but their combinatorial roles in desmosome assembly are not understood. To uncouple desmosome assembly from other cell-cell adhesion complexes, we used micro-patterned substrates of Dsc2aFc and/or Dsg2Fc and collagen IV; we show that Dsc2aFc, but not Dsg2Fc, was necessary and sufficient to recruit desmosome-specific desmoplakin into desmosome puncta and produce strong adhesive binding. Single-molecule force spectroscopy showed that monomeric Dsc2a, but not Dsg2, formed Ca2+-dependent homophilic bonds, and that Dsg2 formed Ca2+- independent heterophilic bonds with Dsc2a. A W2A mutation in Dsc2a inhibited Ca2+-dependent homophilic binding, similar to classical cadherins, and Dsc2aW2A, but not Dsg2W2A, was excluded from desmosomes in MDCK cells. These results indicate that Dsc2a, but not Dsg2, is required for desmosome assembly through homophilic Ca2+- and W2-dependent binding, and that Dsg2 might be involved later in regulating a switch to Ca2+-independent adhesion in mature desmosomes.
KW - Adhesion
KW - Desmocollin
KW - Desmoglein
KW - Desmosome
UR - http://www.scopus.com/inward/record.url?scp=84900808778&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84900808778&partnerID=8YFLogxK
U2 - 10.1242/jcs.146316
DO - 10.1242/jcs.146316
M3 - Article
C2 - 24610950
AN - SCOPUS:84900808778
SN - 0021-9533
VL - 127
SP - 2339
EP - 2350
JO - Journal of cell science
JF - Journal of cell science
IS - 10
ER -