What does alpha catenin do?
α-Catenin is an F-actin-binding protein and vinculin homologue and has been long appreciated to play an indispensible role in cell–cell adhesion by forming an essential link between the cadherin/β-catenin and the underlying actin cytoskeleton (Maiden & Hardin, 2011).
What is the difference between alpha catenin and beta catenin?
The first two catenins that were identified became known as α-catenin and β-catenin. α-Catenin can bind to β-catenin and can also bind filamentous actin (F-actin). β-Catenin binds directly to the cytoplasmic tail of classical cadherins. Additional catenins such as γ-catenin and δ-catenin have been identified.
What is the function of vinculin?
Vinculin is a cytoskeletal protein associated with cell-cell and cell-matrix junctions, where it is thought to function as one of several interacting proteins involved in anchoring F-actin to the membrane.
What is the function of E cadherin?
E-cadherin is thought to prevent the initial dissociation of epithelial cells from the original tumor mass, and loss of cell-cell adhesion and cell junctions allows cells to invade surrounding tissues and migrate to distant sites.
Where are adhesion junctions found?
Adherens junctions (or zonula adherens, intermediate junction, or “belt desmosome”) are protein complexes that occur at cell–cell junctions, cell–matrix junctions in epithelial and endothelial tissues, usually more basal than tight junctions.
Which adhesion complexes would be disrupted if mutated alpha catenin?
In Drosophila melanogaster, cell adhesion is disrupted when α-catenin contains a mutation in the binding site for Armadillo, which is the D. melanogastor homologue of β-catenin.
What dual roles does β-catenin play in epithelial cells?
β-catenin is a dual function protein, involved in regulation and coordination of cell–cell adhesion and gene transcription.
What is the role of vinculin and talin in cell?
At cell–matrix adhesions, talin is subject to tension which exposes binding sites for vinculin [25]. Stretching of talin induces vinculin conformational changes that reinforce F-actin anchoring, thereby allowing for the establishment of additional linkages between integrins and the actin cytoskeleton [52].
Where is vinculin found in the cell?
adherens junctions
3.4 Vinculin. Vinculin is an actin-binding protein present in cell–matrix adhesions and adherens junctions. In adherens junctions, it binds α- and β-catenin (Fig. 2.1); it might be recruited to adherens junction by β-catenin and at an earlier stage of contact maturation by myosin VI (Maddugoda et al., 2007).
What are cadherins made of?
The cadherins are calcium-dependent homotypic cell–cell receptors. The classic cadherin family members include N, P, R, B, and E cadherins, each of which contains 100 common amino acid repeats in their large extracellular domain.
What is the function of alpha catenin in the body?
Alpha-catenin was proposed to function as a linking protein between cadherins and actin-containing filaments of the cytoskeleton.
How is alpha catenin related to cadherin and actin?
Alpha-catenin was proposed to function as a linking protein between cadherins and actin-containing filaments of the cytoskeleton. It has been reported that the actin binding proteins vinculin and alpha-actinin can bind to alpha-catenin. However, a protein complex including a cadherin, actin, beta-catenin and alpha-catenin has not been isolated.
Is the alpha catenin gene similar to vinculin?
Alpha catenin exhibits significant protein dynamics. The amino acid sequence of alpha-catenin has sequence similarity to that of vinculin. Three alpha-catenin genes are expressed in humans: ^ Cooper, Geoffrey M. (2000).
How is alpha catenin related to actin filament assembly?
It has been observed that when alpha-catenin is not in a molecular complex with beta-catenin, it dimerizes and functions to regulate actin filament assembly, possibly by competing with Arp2/3 protein. Alpha catenin exhibits significant protein dynamics.