Adherens junction

Classical and desmosomal cadherins are constituents of different types of intercellular junctions. E-cadherin, the classical cadherin of epithelial cells, is part of the adherens junction (zonula adherens), which is attached to a belt of actin via the catenins. As the name says, desmosomal cadherins are part of the desmosomes, which are rivet-like structures that make focal connections between cells. Desmosomes are characterized by a... 

Yet another family of junction adhesion molecules (JAMs) was recently located at the tight junctions of both endothelial and epithelial cells. The intracellular domain of JAM-1 also interacts with structural and signaling proteins, such as ZO-1 and cingulin. Lastly, the molecular organization of the endothelial cell junctions includes two other cell-cell contact Ca2+-dependent cadherin-catenin systems. These make up the adherens junction common to all endothelial cell junctions. 

A recent crystal structure based model [20] for the structure of C-cadherin postulates that the five extracellular domains EC1-EC5 protrude from the cell surface as a curved rod. The structural analysis of C-cadherin reveals that the molecules facing each other across apposed cell surfaces are antiparallel to one another, forming a dimeric interaction termed a strand dimer (Fig. 7-5). This forms the functional unit that is likely to mediate adhesion between cell surfaces. The structure from this recent paper allows the prediction of both cis and trans interfaces that together result in a lattice and not, as previously believed, an adhesion zipper. This new model allows for a mechanism by which adhesion plates or puncta might be generated, such as are formed at CNS synapses [21, 22], adherens junctions and desmosomes [23], all cadherin based organelles. 

These complex elements expand the function of this neural adherens junction . 

Fannon,A.M.,Sherman,D.L.,Ilyina-Gragerova,G.,Brophy, P. J., Friedrich, V. L. Jr and Colman, D. R. Novel E-cadherin mediated adhesion in peripheral nerve Schwann cell architecture is stabilized by intracellular signals elicited by autotypic adherens junctions. J. Cell Biol. 129 189-202, 1995. 

Alveolar epithelial cells (AECs) are connected with each other by various epithelial cell-cell contacts (i.e., tight junctions, adherens junctions and others). These contacts comprise several groups of proteins, such as occludin, zonula occludens (ZO-1, -2, -3), claudins, tricellulin, E-cadherin and intercellular adhesion molecule-1 (ICAM-1) [13-15], Their regulation and interplay, which has influence on epithelial barrier properties, however, is largely unknown to date. 

Peters NS, Severs NJ, Rothery SM, Lincoln C, Yacoub MH, Green CR Spatiotemporal relation between gap junctions and fascia adherens junctions during postnatal development of human ventricular myocardium. Circulation 1994 90 713-725. 

Figure 32-2 A pair of epithelial cells of Drosophila. The apical surface (top), e.g., of epithelial cells of the gut, faces the external surface, while the basolateral surface (bottom) binds to a basal membrane. Adheren junctions (AJ) and septate junctions (SJ) are shown between the cells. From Peifer and Tepass.84 Drawing by S. Whitfield.

Cadherins are calcium-dependent and establish molecular links between adjacent cells. They include neural cadherins (NC), epithelial cadherins (EC), placental cadherins (PC), protocadherins and desmosomal cadherins. Cadherins mediate homophilic interactions and form zipper-like structures at adherens junctions and... 

Plakoglobin is /3-catenin s nearest relative, and is a constituent of both adherens junctions and desmosomes (Zhurinsky et al, 2000). Its central... 

The cortical region of many cells is enriched in actin and associated actin-binding proteins, which function in motility, cell shape maintenance, and membrane protein distribution in polarized cells. In some cases, discrete structures anchor actin to the membrane, as is the case for intercellular adherens junctions and cell-substrate focal contacts. In certain special cell types, the fundamental blueprint for an adherens junction is taken to a new structural level, serving as scaffolding for cell-type specific complexes, such as the dystrophin-associated protein complex (DPC) in striated muscle. Although for years morphological studies have described a close association with IF with the actin-rich cortex, recent advances in methods to study protein-protein interactions have provided new insight into the intimate structural and functional relationship between IFs and these membrane domains. 

Hatzfeld, M., Green, K. J., and Sauter, H. (2003). Targeting of p0071 to desmosomes and adherens junctions is mediated by different protein domains. I. Cell Sri. 116, 1219-1233. 

Miravet, S., Piedra, J., Castano, J., Raurell, I., Franci, C., Dunach, M., and Garcia de Herreros, A. (2003). Tyrosine phosphorylation of plakoglobin causes contrary effects on its association with desmosomes and adherens junction components and modulates beta-catenin-mediated transcription. Mol. Cell. Biol. 23, 7391-7402. 

Roper, K., and Brown, N. H. (2003). Maintaining epithelial integrity A function for gigantic spectraplakin isoforms in adherens junctions. / Cell Biol. 162, 1305-1315. Roper, K., Gregory, S. L., and Brown, N. H. (2002). The spectraplakins Cytoskeletal giants with characteristics of both spectrin and plakin families. /. Cell Sci. 115, 4215-4225. 

Careful observation at the borders of the enterocytes reveals a close juxtaposition of the membranes of adjacent epithelial cells, identified as zonulae occludens, located at the apical neck of the epithelial cells [168], The zonulae occludens is composed of apical complex the tight junctions and more basal structure underneath, the adherens junctions (also referred to as intermediate junctions) [169,170]. The adherens junctions are linked to the actomyosin ring at the cell circumference. This actin cytoskeleton, which forms a perijunctional area at the apical neck of the epithelial cells, is the cause for their polarized nature (Figure 1.12). The classical functions of tight junctions are the regulation of paracellular permeability and the restriction of apical basolateral intramembrane diffusion of lipids (cell polarity housekeeping). 

Yolberg, T., et al. 1986. Changes in membrane microfilament interaction in intercellular adherens junctions upon removal of extracellular Ca2+ ions. J Cell Biol 102 1832. 

Volk, T., and B. Geiger. 1986. A-CAM A 135-KD receptor of intercellular adherens junctions. II. Antibody mediated modulation of junction formation. J Cell Biol 103 1451. 

The junctional complexes between endothelial cells consist of adherens junctions (AJ) where cadherin proteins span the extracellular space and are linked into the cell cytoplasm by the scaffolding proteins alpha, beta, and gamma catenin. These adherens junctions are... 

Yamada A, Irie K, Hirota T, Ooshio T, Fukuhara A, Takai Y. 2005. Involvement of the annexin II-S100A10 complex in the formation of E-cadherin-based adherens junctions in Madin-Darby canine kidney cells. J Biol Chem 280(7) 6016-6027. 

Shay-Salit, A., Shushy, M., Wolfovitz, E., Yahav, H., Breviario, F., et al. 2002. VEGF receptor 2 and the adherens junction as a mechanical transducer in vascular endothelial cells. Proc. Natl. Acad. Sci. USA 99 9462-9467. 

The contacts between two adjoining cell membranes are stabilized by specific cell adhesion molecules (CAMs), which include the Ca+2-dependent cadherins. These molecules appear to lead the way for cell-cell communications and are involved in mechanochemical transduction via cell-cell interactions. In some cell types, cadherins are concentrated within adherens junctions that are stretch-sensitive and their extracellular domains interact with cadherins on adjacent cells whereas their cytoplasmic domains provide attachment to the actin cytoskeleton via catenins and other cytoskeletal proteins. The Rho family is required for the establishment and maintenance of cadherin-based adherens junctions. The type of cadherin expressed in a cell can affect the specificity and the physiological properties of cell-cell interactions. 

Ragsdale GK, Phelps J, Luby-Phelps K. Viscoelastic response of fibroblasts to tension transmitted through adherens junctions. Biophys J. 1997 73 2798-2808. 

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