Skip to main content
NCBI home page
NIHPA Author Manuscripts logoLink to NIHPA Author Manuscripts
. Author manuscript; available in PMC: 2020 Dec 1.
Published in final edited form as: Curr Opin Biomed Eng. 2019 Sep 28;12:43–50. doi: 10.1016/j.cobme.2019.08.006

Single-molecule studies of classical and desmosomal cadherin adhesion

Andrew Vae Priest 1,2,#, Ramesh Koirala 1,2,#, Sanjeevi Sivasankar 1,*
PMCID: PMC6859941  NIHMSID: NIHMS1542484  PMID: 31742239

Abstract

Classical cadherin and desmosomal cadherin cell-cell adhesion proteins play essential roles in tissue morphogenesis and in maintaining tissue integrity. Deficiencies in cadherin adhesion are hallmarks of diseases like cancers, skin diseases and cardiomyopathies. Structural studies and single molecule biophysical measurements have revealed critical similarities and surprising differences between these key adhesion proteins. This review summarizes our current understanding of the biophysics of classical and desmosomal cadherin adhesion and the molecular basis for their cross-talk. We focus on recent single molecule measurements, highlight key insights into the adhesion of cadherin extracellular regions and their relation to associated diseases, and identify major open questions in this exciting area of research.

Graphical Abstract

graphic file with name nihms-1542484-f0001.jpg

1. INTRODUCTION

Tissue formation and integrity relies on the ability of cells to sense, transmit and respond to mechanical forces; cadherin cell-cell adhesion proteins are integral to these functions. While the extracellular region of cadherins form load-bearing complexes that mechanically link cells to each other, their intracellular regions interact with the cytoskeleton and regulatory proteins [Figure 1]. The cadherin superfamily of cell-cell adhesion proteins are composed of four major subfamilies: classical cadherins, desmosomal cadherins, protocadherins and atypical cadherins [1]. Of these proteins, classical and desmosomal cadherins are essential for the maintenance of tissue integrity. While classical cadherins mediate cell-cell adhesion in all soft tissue and play critical roles in tissue morphogenesis, desmosomal cadherins mediate robust cell-cell adhesion in tissues like the epidermis and heart that are exposed to significant levels of mechanical stress [1, 2]. Mutations in classical cadherins and down regulation of their expression have been implicated in several cancers [3]. Similarly desmosomal cadherin mutations and autoantibodies that target desmosomal proteins result in arrhythmogenic cardiomyopathies and skin blistering diseases, respectively [2]. Recently, single molecule biophysical measurements have resolved the mechanistic links between classical and desmosomal cadherin structure and adhesion; these studies have revealed several critical similarities and a few surprising differences between these essential adhesion proteins. We critically review these measurements and discuss major open questions and future directions in this exciting area of research.

Figure 1: Classical and desmosomal cadherin adhesive complexes.

Figure 1:

Open in a new tab

Cadherin ectodomains from opposing cells adhere to each other while intracellular regions interact with the cytoskeleton through effector proteins. (A) Classical cadherins form homodimers and associate with filamentous actin (F-actin) via β-catenin, α-catenin p120 catenin, and vinculin. (B) In contrast, desmosomal cadherins (Dsc and Dsg) typically form heterodimers and associate with intermediate filaments via plakoglobin, plakophilins and desmoplakin.

2. CLASSICAL CADHERINS

Classical cadherins are single-pass transmembrane proteins that mediate the integrity of all soft tissue, play essential roles in tissue morphogenesis and wound healing. Deficiencies in classical cadherin adhesion correlate with several cancers. Classical cadherins have extracellular regions (or ectodomains) that are comprised of five tandemly repeated extracellular (EC1–5) domains with three calcium binding sites in each interdomain linker [4]. Cadherins from opposing cells mediate adhesion by binding in ‘trans’ conformations [Figure 2A] while cadherins on the same cell surface associate laterally in a ‘cis’ orientation [5, 6]. Here, we only focus on the trans binding between cadherin ectodomains; cis dimerization has been reviewed elsewhere [4].

Figure 2: Structure and biomechanics of E-cadherin trans dimers.

Figure 2:

Open in a new tab

(A) E-cadherin monomers from opposing cells (red and blue) bind in a strand-swap dimer conformation. (B) Strand-swap dimers are formed by the exchange of conserved W2 residues between opposing EC1 domains (PDB: 3Q2V). Bound Ca2+ are denoted by gray spheres. (C) X-dimer interface consists of noncovalent surface interactions (hydrogen bonds and a salt bridge) between EC1 and EC2 domains near the Ca2+ binding site (PDB: 3LNH). (D) E-cadherins interconvert convert between an X-dimer (left) and strand-swap dimer (right) via an intermediate state (middle; simulated structure and interconversion pathway from reference [18]). (E) X-dimers form catch bonds. Catch bonds initially strengthen before weakening beyond a critical pulling force. (F) Strand-swap dimers form slip bonds. The lifetime of slip bonds decrease rapidly with force. (G-H) E-cadherin X-dimer before (G) and after (H) application of force. Tensile force flexes the interacting ectodomains such that hydrogen-bond donor and acceptor amino acids (cyan residues on blue monomer and orange residues on red monomer) are brought into registry. Panels (G, H) are adapted from reference [17]. Panel (F) is adapted from reference [18].

2.1. CLASSICAL CADHERIN TRANS INTERACTIONS

Classical cadherins from opposing cells bind in two Ca2+ dependent trans adhesive conformations: strand-swap dimers [Figure 2B] and X-dimers [Figure 2C]. Strand-swap dimers are the primary cadherin adhesive conformation and are formed by the exchange of a conserved Tryptophan (W2) residue between the outermost (EC1) domains of opposing proteins [5, 7] [Figure 2B]. Single-molecule force [8] and Förster resonance energy transfer (FRET) [9, 10] experiments have mapped the domains of classical cadherin involved in strand-swap dimer formation and the Ca2+ dependence of the dimerization process. While strand swap dimers are crucial for robust cell-cell adhesion, mutating the conserved W2 to alanine (W2A) does not completely abolish adhesion [11, 12]. Single molecule FRET and atomic force microscopy (AFM) measurements show that the W2A mutant forms a weak complex that does not involve strand swapping [10]. Structural studies show that this mutant is trapped in an X-dimer conformation, which is formed by extensive surface interactions between the outer two (EC1–2) domains [13] [Figure 2C]. Mutating Lys14 to Glutamic acid (K14E), which compromises X-dimer formation, slows W2 strand-swapping but does not affect the dimerization affinity of the swapped dimer [13]. These studies demonstrate that X-dimers serve as an intermediate during the formation and rupture of strand-swap dimers [10, 13, 14].

Single-molecule AFM experiments have also elucidated the force-induced changes in the binding kinetics of X-dimers and strand-swap dimers formed by E-cadherin– a classical cadherin found in epithelial cells. W2A mutants, which are trapped in an X-dimer conformation, exhibit a catch bond relationship between lifetime and force: the bond lifetimes initially increases with force before decreasing [Figure 2E] [15]. This data can be fit to a sliding-rebinding model [16], where interacting ectodomains slide past each other in the presence of a force and form noncovalent interactions which strengthens the bond. Indeed, AFM, Molecular Dynamics (MD) and Steered MD (SMD) simulations have shown that X-dimer catch bonds are Ca2+ dependent and are formed by the force-induced rearrangement of X-dimers, which results in the formation of several de-novo hydrogen bonds [Figure 2G, H] that lock the X-dimer into tighter contact [17]. In contrast to X-dimers, K14E strand-swap dimers, show slip bond behavior; their bond lifetimes decreased with increasing tensile force [Figure 2F] [15]. Importantly, consistent with X-dimers being a weaker adhesive structure than strand-swap dimers, X-dimer catch bonds are shorter lived than strand-swap dimer slip bonds [Figure 2E, F]. Recent single molecule AFM measurements and computer simulations show that wild type E-cadherin interconverts between X-dimers and strand-swap dimers; along the transition pathway for interconversion, the proteins adopt a metastable intermediate state [Figure 2D] [18]. Consequently, by switching between strand-swap and X-dimer conformations, E-cadherins are able to strengthen or weaken their adhesion.

The two distinct trans conformations adopted by classical cadherins may play important roles in phenomenon such as collective cell migration, which is a hallmark of tissue remodeling, morphogenesis and wound repair [19]. While collectively migrating cells use cytoskeletal protrusions and guidance cues that are similar to those used by single migratory cells, the presence of cadherin cell-cell adhesion junctions result in ‘supra-cellular’ properties, such as collective polarization and force generation, and, eventually, complex tissue organization [19]. An intriguing possibility is that strand-swap dimers interactions may be formed by leader cells that require more stable cell-cell contacts with follower cells. In contrast, the cells deep within the cell monolayer, which require more dynamic contacts, may form X-dimers. However, the molecular mechanisms by which formation of X-dimers and strand-swap dimers are regulated by cells, and the physiological roles of these conformations in collective cell migration, is still unknown.

2.2. ROLE OF CYTOPLASMIC ADAPTOR PROTEINS IN REGULATING CADHERIN ADHESION

The cytoplasmic tail of classical cadherins associate with intracellular p120-catenin and β-catenin which in turn recruit the actin binding and bundling protein α-catenin [Figure 1A]. Binding of p120-catenin to the cadherin cytoplasmic domain stabilizes the cadherin complex by preventing cadherin internalization and degradation [20]. The cadherin-catenin complex links to filamentous actin either by the direct binding of α-catenin and F-actin or by indirect association of α-catenin and F-actin via vinculin [Figure 1A] [21]. Adhesive forces transmitted across intercellular junctions by cadherins, induce conformational changes in α-catenin [22] which recruits vinculin to the site of force application [23]. These force-induced changes modulate adhesion by mediating cytoskeletal rearrangements [24]. Additionally, recent studies show that β-catenin directly binds to vinculin [25] and forms an alternate bypass connection from cadherin to the actin cytoskeleton.

Recent studies demonstrate that E-cadherin adhesion is regulated by the phosphorylation state of p120-catenin: dephosphorylation of p120-catenin strengthens adhesion while p120-catenin phosphorylation weakens E-cadherin binding [26, 27]. Biophysical studies also show that binding of α-catenin [28, 29] and vinculin [30] is obligatory in strengthening E-cadherin adhesion. These findings suggest that association of p120-catenin, α-catenin and vinculin to the cadherin cytoplasmic tail, allosterically regulate ectodomain conformation, and consequently cadherin adhesion. However, the ‘inside out’ molecular mechanisms by which regulatory events within the cell allosterically control the conformation of the extracellular region is still a mystery.

2.3. CLASSICAL CADHERINS IN CANCER

Experimental studies show that E-cadherin acts as a tumor suppressor – re-expression of E-cadherin in cadherin deficient cancer cells can prevent tumor progression and invasion [31]. Similarly, reduced expression of N-cadherin–– a classical cadherin found in neurons, strongly correlates with metastasis in neuroblastoma [32] . The role of classical cadherins, as a cancer marker has been reviewed recently [3]. However, several studies show that E-cadherin is often expressed in metastatic tumor cells [33, 34] indicating that E-cadherin expressing tumor cells can downregulate adhesion without affecting E-cadherin expression levels on the cell surface. A recent study showed that dephosphorylation of p120-catenin (which is known to strengthen adhesion) significantly reduced the number of cells metastasized from the mammary gland to the lung [35]. Furthermore, several point mutations in the E-cadherin ectodomain that are prevalent in hereditary diffuse gastric cancer, selectively interfere with the inside-out regulation of E-cadherin adhesion, rather than the ability of E-cadherin to adhere [35]. This suggests that inside-out regulation of E-cadherin plays an important role in cancer progression. However, the conformational states adopted by E-cadherin in these mutations, is still an open question.

3. DESMOSOMAL CADHERINS

Desmosomal cadherins form the desmosome, a vital intercellular adhesive junction found in the skin and heart that links to the intermediate filament (IF) cytoskeleton and mechanically couples cells [Figure 1B]. There are two types of desmosomal cadherins: desmoglein (Dsg) and desmocollin (Dsc), which are organized into four Dsg isoforms (Dsg1–4) and three Dsc isoforms (Dsc1–3) that show tissue and differentiation specific expression patterns [2]. Desmosome linkage to intermediate filaments is facilitated by binding of desmosomal cadherins to armadillo proteins plakoglobin (PG) and plakophilin (PKP) which in turn are linked to IFs by desmoplakin (DP) [Figure 1B].

3.1. DESMOSOMAL CADHERIN TRANS INTERACTIONS

The extracellular region of desmosomal cadherins contain four cadherin homology repeats and an anchor domain [36]. While co-expression of both Dsg and Dsc are needed for intercellular adhesion [2, 37], the types of trans interactions that occur between Dsg and Dsc are only partially understood. Single molecule AFM experiments demonstrate that Dsg2 and Dsc2 interact to form robust heterophilic (Dsc2:Dsg2) dimers while Dsc2 also forms weak homophilic (Dsc2:Dsc2) dimers [38, 39]. These findings are supported by solution binding and structural assays, which demonstrate that while all isoforms of Dsg and Dsc form heterophilic dimers, homophilic interactions are either weak or non-existent [36]. Analysis of surface charges of residues along the interaction interface reveal that Dsc and Dsg have complementary charges suggesting an electrostatic mechanism for preferential heterophilic binding [36]. Affinities for the heterodimers match their role and expression levels in stratified epithelia -Dsg1:Dsc1 and Dsg4:Dsc1, which are found in the most differentiated or outermost layers of human skin, have the highest affinities while Dsg3:Dsc3, which are found in the basal layers of the epidermis, are the weakest binding pairs [36]. However, other single molecule AFM studies show homophilic interactions between Dsc3 and between Dsg1–3 [40, 41]. An AFM study performed on live cells also suggests that Dsg3 primarily forms homodimers on keratinocytes [41]. Consequently, the precise molecular mechanisms and roles that homo- and heterodimers play in desmosome adhesion remain unresolved.

3.2. DESMOSOMAL CADHERINS IN SKIN AND HEART DISEASE

Autoimmune skin blistering diseases pemphigus vulgaris (PV) and pemphigus foliaceus (PF) result from autoantibodies developed primarily against Dsg1 and Dsg3 [2]. These antibodies impair normal adhesion causing painful blisters to form on the skin and mucous membranes [2, 42, 43]. Pemphigus pathogenesis has been studied using single molecule AFM in cell-free and keratinocyte monolayer conditions, where it was show that PV and PF autoantibodies inhibit Dsg3 binding but do not affect Dsg1 adhesion [44]. These AFM studies along with cell biological assays show that intracellular signaling affected by pemphigus autoantibodies regulates desmosome adhesion and may also play a role in pemphigus pathogenesis [44].

Dsg2 and Dsc2 are the only desmosomal cadherins found in cardiac tissue and mutations in Dsg2 and Dsc2 have been associated with arrhythmogenic right ventricular cardiomyopathy (ARVC) [45, 46]. This disease is marked by fatty deposits and fibrosis in the right ventricle and leads to ventricular arrhythmias and sudden cardiac failure [2]. Recently, two mutations in Dsg2 ectodomains, associated with ARVC were studied with single molecule AFM and cell dissociation assays [40]. These studies showed that the binding kinetics of homophilic Dsg2 interactions were significantly different between wild type Dsg2 and the two ARVC mutants. Both mutants had a lower off-rate but a higher KD than wild type, suggesting that these ARVC mutations may affect desmosomal integrity [40]. However, since the AFM measurements tested only homophilic Dsg2 interactions, how these mutations affect adhesion, and consequently ARVC, in desmosomes —where heterophilic binding likely occurs— remains to be seen. A comprehensive review of desmosomes and their diseases can be found elsewhere [2].

4. CROSS TALK BETWEEN CLASSICAL AND DESMOSOMAL CADHERINS

Several studies have also shown a cross-talk between classical and desmosomal cadherins suggesting that classical cadherins are needed to facilitate desmosome assembly in vivo. Immuno-electron micrographs demonstrate that E-cadherin localizes to the intercellular region of desmosomes [47] and that blocking E-cadherin adhesion with antibodies delays desmosome formation [48]. Studies also show that desmosome formation in keratinocytes requires junctional initiation by E- or P-cadherin, a classical cadherin expressed in the placenta and myoepithelial cells [49]. E- and P-cadherin deficient mice show defective desmosome assembly [50]. However, the precise molecular mechanisms by which classical cadherins promote desmosome formation are unknown. Recently, the role of the E-cadherin ectodomain at different stages of desmosome formation was characterized using an integrated structure/function analysis that combined single molecule force measurements with an AFM, super resolution imaging and confocal fluorescence microscopy [39]. These studies identified a novel Ca2+- independent direct interaction between E-cadherin and Dsg2 that is mediated by a conserved Leu 175 on E-cadherin; previous structural studies have shown that L175 mediates homophilic E-cadherin cis dimerization [6]. The data suggests that desmosome assembly is initiated in two stages: a first stage that requires stable E-cadherin trans-homodimerization and a second stage characterized by the direct heterophilic binding between E-cadherin and Dsg2 that facilitates further desmosome assembly [Figure 3] [39]. The interactions between E-cadherin and Dsg2 are short-lived and as desmosomes mature, Dsg2 dissociates from E-cadherin and forms stable bonds with Dsc2 to mediate robust adhesion [Figure 3] [39].

Figure 3: Model for desmosome assembly.

Figure 3:

Open in a new tab

Dsg2 (PDB code: 5ERD) and Ecad (PDB code: 3Q2V) initially interact to form a low-lifetime Ecad:Dsg2 complex. This requires prior formation of Ecad trans-homodimers. The Ecad:Dsg2 complex is then incorporated in the nascent desmosome that contains the weak Dsc2:Dsc2 homodimer (Dsc2 was constructed from PDB codes: 5ERP and 5J5J). Ecad:Dsg2 and Dsc2:Dsc2 complexes dissociate as the desmosome matures and a robust adhesive complex of trans Dsg2:Dsc2 heterodimers is formed. Figure was generated by positioning Ecad, Dsg2 and Dsc2 ectodomain structures in PyMOL based on model proposed in reference [41]. Lipid bilayer coordinates were obtained from reference [51]. Note: Only cadherin ectodomains are displayed in the figure.

5. FUTURE DIRECTIONS

While the unique conformations adopted by classical cadherins and the distinct adhesive properties of these conformations are well established, how these structures are utilized and regulated in the context of cell function are unknown. Analogous to the case of integrins where adhesion is regulated from the inside-out, classical and desmosomal cadherin adhesion is also regulated by cytoplasmic proteins. However, the biophysical mechanisms that underlie the regulation of classical and desmosomal cadherin conformation (and consequently adhesion) are still unclear. Resolving this question will likely require the development of single molecule AFM based techniques to study the biomechanics of single cadherins on live-cell surfaces.

While classical cadherin junctions are among the most investigated cell-cell adhesion complexes, desmosomes are among the most poorly understood adhesive organelle. Consequently, several fundamental biophysical questions on desmosome structure-function remain unanswered. For instance, the force dependent kinetic properties of desmosomal cadherins and the range of conformations that these proteins can adopt in the presence of mechanical stress are unknown. Furthermore, the unique functional roles of each desmosomal cadherin isoform are not understood. Addressing these questions are essential to advancing our understanding of desmosome function in healthy and disease states.

Acknowledgements:

This research was supported in part by the National Science Foundation (PHY-1607550) and National Institute of General Medical Sciences of the National Institutes of Health (R01GM121885).

Footnotes

Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Conflict of Interest: The authors declare no conflict of interest.

References

  • 1.Brasch J, Harrison OJ, Honig B, and Shapiro L, Thinking outside the cell: how cadherins drive adhesion. Trends in Cell Biology, 2012. 22(6): p. 299–310. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 2.Najor NA, Desmosomes in Human Disease. Annual Review of Pathology: Mechanisms of Disease, 2018. 13(1): p. 51–70. [DOI] [PubMed] [Google Scholar]
  • 3.Mendonsa AM, Na T-Y, and Gumbiner BM, E-cadherin in contact inhibition and cancer. Oncogene, 2018. 37(35): p. 4769–4780. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 4.Priest AV, Shafraz O, and Sivasankar S, Biophysical basis of cadherin mediated cell-cell adhesion. Experimental Cell Research, 2017. 358(1): p. 10–13. [DOI] [PubMed] [Google Scholar]
  • 5.Boggon TJ, Murray J, Chappuis-Flament S, Wong E, Gumbiner BM, and Shapiro L, C-cadherin ectodomain structure and implications for cell adhesion mechanisms. Science, 2002. 296(5571): p. 1308–1313. [DOI] [PubMed] [Google Scholar]
  • 6.Harrison OJ, Jin X, Hong S, Bahna F, Ahlsen G, Brasch J, Wu Y, Vendome J, Felsovalyi K, Hampton CM, Troyanovsky RB, Ben-Shaul A, Frank J, Troyanovsky SM, Shapiro L, and Honig B, The extracellular architecture of adherens junctions revealed by crystal structures of type I cadherins. Structure, 2011. 19(2): p. 244–256. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 7.Häussinger D, Ahrens T, Aberle T, Engel J, Stetefeld J, and Grzesiek S, Proteolytic E-cadherin activation followed by solution NMR and X-ray crystallography. The EMBO Journal, 2004. 23(8): p. 1699–1708. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 8.Chien Y-H, Jiang N, Li F, Zhang F, Zhu C, and Leckband D, Two stage cadherin kinetics require multiple extracellular domains but not the cytoplasmic region. The Journal of Biological Chemistry, 2008. 283(4): p. 1848–1856. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 9.Zhang Y, Sivasankar S, Nelson WJ, and Chu S, Resolving cadherin interactions and binding cooperativity at the single-molecule level. Proceedings of the National Academy of Sciences of the United States of America, 2009. 106(1): p. 109–114. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 10.Sivasankar S, Zhang Y, Nelson WJ, and Chu S, Characterizing the initial encounter complex in cadherin adhesion. Structure, 2009. 17(8): p. 1075–1081. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 11.Kitagawa M, Natori M, Murase S, Hirano S, Taketani S, and Suzuki ST, Mutation analysis of cadherin-4 reveals amino acid residues of EC1 important for the structure and function. Biochemical and Biophysical Research Communications, 2000. 271(2): p. 358–363. [DOI] [PubMed] [Google Scholar]
  • 12.Prakasam A, Chien YH, Maruthamuthu V, and Leckband DE, Calcium site mutations in cadherin: impact on adhesion and evidence of cooperativity. Biochemistry, 2006. 45(22): p. 6930–6939. [DOI] [PubMed] [Google Scholar]
  • 13.Harrison OJ, Bahna F, Katsamba PS, Jin X, Brasch J, Vendome J, Ahlsen G, Carroll KJ, Price SR, Honig B, and Shapiro L, Two-step adhesive binding by classical cadherins. Nature Structural & Molecular Biology, 2010. 17(3): p. 348–357. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 14.Hong S, Troyanovsky RB, and Troyanovsky SM, Cadherin exits the junction by switching its adhesive bond. The Journal of Cell Biology, 2011. 192(6): p. 1073–1083. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 15.Rakshit S, Zhang Y, Manibog K, Shafraz O, and Sivasankar S, Ideal, catch, and slip bonds in cadherin adhesion. Proceedings of the National Academy of Sciences of the United States of America, 2012. 109(46): p. 18815–18820. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 16.Lou J and Zhu C, A structure-based sliding-rebinding mechanism for catch bonds. Biophysical Journal, 2007. 92(5): p. 1471–1485. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 17.Manibog K, Li H, Rakshit S, and Sivasankar S, Resolving the molecular mechanism of cadherin catch bond formation. Nature Communications, 2014. 5: p. 3941. [DOI] [PubMed] [Google Scholar]
  • (o)18.Manibog K, Sankar K, Kim S-A, Zhang Y, Jernigan RL, and Sivasankar S, Molecular determinants of cadherin ideal bond formation: Conformation-dependent unbinding on a multidimensional landscape. Proceedings of the National Academy of Sciences of the United States of America, 2016. 113(39): p. E5711–20. [DOI] [PMC free article] [PubMed] [Google Scholar]; Single-molecule AFM measurements and computer simulations were used to map the transition pathway for interconversion between X-dimers and strand-swap dimers .
  • 19.Friedl P and Gilmour D, Collective cell migration in morphogenesis, regeneration and cancer. Nature Reviews Molecular Cell Biology, 2009. 10: p. 445. [DOI] [PubMed] [Google Scholar]
  • 20.Xiao K, Allison DF, Buckley KM, Kottke MD, Vincent PA, Faundez V, and Kowalczyk AP, Cellular levels of p120 catenin function as a set point for cadherin expression levels in microvascular endothelial cells. The Journal of Cell Biology, 2003. 163(3): p. 535–545. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 21.Ratheesh A and Yap AS, A bigger picture: classical cadherins and the dynamic actin cytoskeleton. Nature Reviews. Molecular Cell Biology, 2012. 13(10): p. 673–679. [DOI] [PubMed] [Google Scholar]
  • 22.Kim T-J, Zheng S, Sun J, Muhamed I, Wu J, Lei L, Kong X, Leckband Deborah E., and Wang Y, Dynamic Visualization of α-Catenin Reveals Rapid, Reversible Conformation Switching between Tension States. Current Biology, 2015. 25(2): p. 218–224. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 23.Yao M, Qiu W, Liu R, Efremov AK, Cong P, Seddiki R, Payre M, Lim CT, Ladoux B, Mège R-M, and Yan J, Force-dependent conformational switch of α-catenin controls vinculin binding. Nature Communications, 2014. 5: p. 4525. [DOI] [PubMed] [Google Scholar]
  • 24.le Duc Q, Shi Q, Blonk I, Sonnenberg A, Wang N, Leckband D, and de Rooij J, Vinculin potentiates E-cadherin mechanosensing and is recruited to actin-anchored sites within adherens junctions in a myosin II–dependent manner. The Journal of Cell Biology, 2010. 189(7): p. 1107. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 25.Peng X, Cuff LE, Lawton CD, and DeMali KA, Vinculin regulates cell-surface E-cadherin expression by binding to β-catenin. Journal of Cell Science, 2010. 123(4): p. 567. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 26.Petrova YI, Spano MM, and Gumbiner BM, Conformational epitopes at cadherin calcium-binding sites and p120-catenin phosphorylation regulate cell adhesion. Molecular Biology of the Cell, 2012. 23(11): p. 2092–2108. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 27.Shashikanth N, Petrova YI, Park S, Chekan J, Maiden S, Spano M, Ha T, Gumbiner BM, and Leckband DE, Allosteric Regulation of E-Cadherin Adhesion. The Journal of Biological Chemistry, 2015. 290(35): p. 21749–21761. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 28.Bajpai S, Correia J, Feng Y, Figueiredo J, Sun SX, Longmore GD, Suriano G, and Wirtz D, {alpha}-Catenin mediates initial E-cadherin-dependent cell-cell recognition and subsequent bond strengthening. Proceedings of the National Academy of Sciences of the United States of America, 2008. 105(47): p. 18331–18336. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 29.Bajpai S, Feng Y, Krishnamurthy R, Longmore GD, and Wirtz D, Loss of alpha-catenin decreases the strength of single E-cadherin bonds between human cancer cells. The Journal of Biological Chemistry, 2009. 284(27): p. 18252–18259. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 30.Thomas WA, Boscher C, Chu Y-S, Cuvelier D, Martinez-Rico C, Seddiki R, Heysch J, Ladoux B, Thiery JP, Mege R-M, and Dufour S, α-Catenin and vinculin cooperate to promote high E-cadherin-based adhesion strength. The Journal of Biological Chemistry, 2013. 288(7): p. 4957–4969. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 31.Navarro P, Gómez M, Pizarro A, Gamallo C, Quintanilla M, and Cano A, A role for the E-cadherin cell-cell adhesion molecule during tumor progression of mouse epidermal carcinogenesis. The Journal of Cell Biology, 1991. 115(2): p. 517–533. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 32.Lammens T, Swerts K, Derycke L, De Craemer A, De Brouwer S, De Preter K, Van Roy N, Vandesompele J, Speleman F, Philippé J, Benoit Y, Beiske K, Bracke M, and Laureys G, N-cadherin in neuroblastoma disease: expression and clinical significance. Plos One, 2012. 7(2): p. e31206. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 33.Lou Y, Preobrazhenska O, auf dem Keller U, Sutcliffe M, Barclay L, McDonald PC, Roskelley C, Overall CM, and Dedhar S, Epithelial-mesenchymal transition (EMT) is not sufficient for spontaneous murine breast cancer metastasis. Developmental Dynamics, 2008. 237(10): p. 2755–2768. [DOI] [PubMed] [Google Scholar]
  • 34.Fischer KR, Durrans A, Lee S, Sheng J, Li F, Wong STC, Choi H, El Rayes T, Ryu S, Troeger J, Schwabe RF, Vahdat LT, Altorki NK, Mittal V, and Gao D, Epithelial-to-mesenchymal transition is not required for lung metastasis but contributes to chemoresistance. Nature, 2015. 527(7579): p. 472–476. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • (oo)35.Petrova YI, Schecterson L, and Gumbiner BM, Roles for E-cadherin cell surface regulation in cancer. Molecular Biology of the Cell, 2016. 27(21): p. 3233–3244. [DOI] [PMC free article] [PubMed] [Google Scholar]; Demonstrates that p120-catenin mediated inside-out regulation of E-cadherin adhesion is important in hereditary diffuse gastric cancer. Cancer-associated E-cadherin ectodomain mutations selectively affect inside-out regulation of adhesion without inhibiting basic E-cadherin adhesion function
  • (oo)36.Harrison OJ, Brasch J, Lasso G, Katsamba PS, Ahlsen G, Honig B, and Shapiro L, Structural basis of adhesive binding by desmocollins and desmogleins. Proceedings of the National Academy of Sciences of the United States of America, 2016. 113(26): p. 7160–7165. [DOI] [PMC free article] [PubMed] [Google Scholar]; Cell-free binding assays demonstrate family-wise heterophilic specificity between Dscs and Dsgs. X-ray crystallography shows that heterophilic binding likely occurs through a strand-swap mechanism similar to that of homophilic classical cadherins.
  • 37.Chitaev NA and Troyanovsky SM, Direct Ca2+ -dependent Heterophilic Interaction between Desmosomal Cadherins, Desmoglein and Desmocollin, Contributes to Cell–Cell Adhesion. The Journal of Cell Biology, 1997. 138(1): p. 193–201. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 38.Lowndes M, Rakshit S, Shafraz O, Borghi N, Harmon RM, Green KJ, Sivasankar S, and Nelson WJ, Different roles of cadherins in the assembly and structural integrity of the desmosome complex. Journal of Cell Science, 2014. 127(Pt 10): p. 2339–2350. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • (oo)39.Shafraz O, Rübsam M, Stahley SN, Caldara AL, Kowalczyk AP, Niessen CM, and Sivasankar S, E-cadherin binds to desmoglein to facilitate desmosome assembly. eLife, 2018. 7. [DOI] [PMC free article] [PubMed] [Google Scholar]; Single molecule AFM force measurements, super-resolution imaging and confocal imaging were used to establish that E-cadherin trans interactions at nascent cell-cell contacts initiate the recruitment of Dsg2 through direct cis interactions with E-cadherin which facilitates desmosome assembly.
  • (o)40.Dieding M, Debus JD, Kerkhoff R, Gaertner-Rommel A, Walhorn V, Milting H, and Anselmetti D, Arrhythmogenic cardiomyopathy related DSG2 mutations affect desmosomal cadherin binding kinetics. Scientific reports, 2017. 7(1): p. 13791. [DOI] [PMC free article] [PubMed] [Google Scholar]; AFM and cell dissociation assays show that two mutations associated with ARVC affect homophilic Dsg2 interactions.
  • (o)41.Vielmuth F, Wanuske M-T, Radeva MY, Hiermaier M, Kugelmann D, Walter E, Buechau F, Magin TM, Waschke J, and Spindler V, Keratins Regulate the Adhesive Properties of Desmosomal Cadherins through Signaling. The Journal of Investigative Dermatology, 2018. 138(1): p. 121–131. [DOI] [PubMed] [Google Scholar]; Demonstrates inside-out regulation of Dsg3 adhesion strength by p38 mitogen-activated protein kinase activity
  • 42.Chan PT, Ohyama B, Nishifuji K, Yoshida K, Ishii K, Hashimoto T, and Amagai M, Immune response towards the amino-terminus of desmoglein 1 prevails across different activity stages in nonendemic pemphigus foliaceus. British Journal of Dermatology, 2010. 162(6): p. 1242–1250. [DOI] [PubMed] [Google Scholar]
  • 43.Ohyama B, Nishifuji K, Chan PT, Kawaguchi A, Yamashita T, Ishii N, Hamada T, Dainichi T, Koga H, Tsuruta D, Amagai M, and Hashimoto T, Epitope Spreading Is Rarely Found in Pemphigus Vulgaris by Large-Scale Longitudinal Study Using Desmoglein 2–Based Swapped Molecules. Journal of Investigative Dermatology, 2012. 132(4): p. 1158–1168. [DOI] [PubMed] [Google Scholar]
  • (o)44.Walter E, Vielmuth F, Rotkopf L, Sárdy M, Horváth ON, Goebeler M, Schmidt E, Eming R, Hertl M, Spindler V, and Waschke J, Different signaling patterns contribute to loss of keratinocyte cohesion dependent on autoantibody profile in pemphigus. Scientific reports, 2017. 7(1): p. 3579. [DOI] [PMC free article] [PubMed] [Google Scholar]; Single molecule AFM and cell biological assays show that pemphigus autoantibodies eliminate desmoglein adhesion and alter intracellular signaling pathways.
  • 45.Pilichou K, Nava A, Basso C, Beffagna G, Bauce B, Lorenzon A, Frigo G, Vettori A, Valente M, Towbin J, Thiene G, Danieli Gian A, and Rampazzo A, Mutations in Desmoglein-2 Gene Are Associated With Arrhythmogenic Right Ventricular Cardiomyopathy. Circulation, 2006. 113(9): p. 1171–1179. [DOI] [PubMed] [Google Scholar]
  • 46.Syrris P, Ward D, Evans A, Asimaki A, Gandjbakhch E, Sen-Chowdhry S, and McKenna WJ, Arrhythmogenic right ventricular dysplasia/cardiomyopathy associated with mutations in the desmosomal gene desmocollin-2. American Journal of Human Genetics, 2006. 79(5): p. 978–984. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 47.Jones JC, Characterization of a 125K glycoprotein associated with bovine epithelial desmosomes. Journal of Cell Science, 1988. 89 ( Pt 2): p. 207–216. [DOI] [PubMed] [Google Scholar]
  • 48.Lewis JE, Jensen PJ, and Wheelock MJ, Cadherin function is required for human keratinocytes to assemble desmosomes and stratify in response to calcium. The Journal of Investigative Dermatology, 1994. 102(6): p. 870–877. [DOI] [PubMed] [Google Scholar]
  • 49.Michels C, Buchta T, Bloch W, Krieg T, and Niessen CM, Classical cadherins regulate desmosome formation. The Journal of Investigative Dermatology, 2009. 129(8): p. 2072–2075. [DOI] [PubMed] [Google Scholar]
  • 50.Tinkle CL, Pasolli HA, Stokes N, and Fuchs E, New insights into cadherin function in epidermal sheet formation and maintenance of tissue integrity. Proceedings of the National Academy of Sciences of the United States of America, 2008. 105(40): p. 15405–15410. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 51.Tieleman DP and Berendsen HJ: A molecular dynamics study of the pores formed by Escherichia coli OmpF porin in a fully hydrated palmitoyloleoylphosphatidylcholine bilayer. Biophysical journal 1998, 74:2786–2801. [DOI] [PMC free article] [PubMed] [Google Scholar]

RESOURCES