α-Catenin-Vinculin Interaction Functions to Organize the Apical Junctional Complex in Epithelial Cells

Abstract

αE-catenin, a cadherin-associated protein, is required for tight junction (TJ) organization, but its role is poorly understood. We transfected an αE-catenin–deficient colon carcinoma line with a series of αE-catenin mutant constructs. The results showed that the amino acid 326–509 domain of this catenin was required to organize TJs, and its COOH-terminal domain was not essential for this process. The 326–509 internal domain was found to bind vinculin. When an NH2-terminal αE-catenin fragment, which is by itself unable to organize the TJ, was fused with the vinculin tail, this chimeric molecule could induce TJ assembly in the αE-catenin–deficient cells. In vinculin-null F9 cells, their apical junctional organization was impaired, and this phenotype was rescued by reexpression of vinculin. These results indicate that the αE-catenin-vinculin interaction plays a role in the assembly of the apical junctional complex in epithelia.

α-Catulin, a Rho signalling component, can regulate NF-κB through binding to IKK-β, and confers resistance to apoptosis

“…a-Catenin is a component of the cadherin-catenin complex involved in cell-cell contacts and focal adhesions (Aberle et al, 1996). It links the adhesion complex to the actin cytoskeleton by binding several actin-binding proteins including a-actinin, vinculin and ZO-1 (Itoh et al, 1993; a-Catulin links NF-jB and Rho signalling C Wiesner et al Knudsen et al, 1995;Watabe-Uchida et al, 1998). a-Catenin has been proposed to modulate actin polymerization states locally at cadherin-mediated cell-cell junctions Yamada et al, 2005).…”

Blockade of cadherin‐6B activity perturbs the distribution of PSD‐95 family proteins in retinal neurones

“…through some cytoskeletal elements. In epithelial cells, cadherin-mediated adherens junctions are a prerequisite for normal assembly of the tight junctions located next to the former (Watabe- Uchida et al 1998). A similar structural relationship may exist between the cadherin system and the active zone junction in synapses.…”

Similar and differential behaviour between the nectin‐afadin‐ponsin and cadherin‐catenin systems during the formation and disruption of the polarized junctional alignment in epithelial cells

“…The cadherin-catenin system plays essential roles in the formation and maintenance of cell-cell AJs (Takeichi 1988(Takeichi , 1991Gumbiner 1996). Evidence is accumulating that the cadherincatenin system is also required for the organization of tight junctions (Gumbiner & Simons 1986;Gumbiner et al 1988;Watabe-Uchida et al 1998). However, little is still known about the mechanism of how the cadherin-catenin system is involved in the formation of the polarized junctional alignment in epithelial cells.…”