kadherin

Kadherin is typically a misspelling of cadherin, a family of calcium-dependent cell adhesion proteins found in animals. Cadherins are type I transmembrane glycoproteins that mediate homophilic cell-cell adhesion, contributing to tissue architecture and morphogenesis. They require extracellular calcium ions to maintain their adhesive conformation.

Structure: classical cadherins possess multiple extracellular cadherin (EC) repeats—typically five—along with a single span transmembrane region and a cytoplasmic tail that binds catenins. The cadherin-catenin complex anchors to the actin cytoskeleton and forms adherens junctions, coordinating cell adhesion with cytoskeletal dynamics. Non-classical cadherins include desmosomal cadherins (desmogleins and desmocollins), protocadherins and others, which contribute to specialized junctions and signaling.

Major vertebrate cadherins include E-cadherin (epithelial), N-cadherin (neural/fibroblast), P-cadherin (placental) and VE-cadherin (vascular endothelium). Cadherin specificity is generally homo-typic: E-cadherin binds E-cadherin on neighboring cells. Cadherin function is regulated by calcium levels, alternative splicing, phosphorylation, and interactions with catenins (α-, β-, and p120-catenin).

Role in development and disease: Cadherins are crucial for tissue morphogenesis, wound healing, and maintenance of epithelial sheets. Loss or downregulation of E-cadherin is associated with epithelial-to-mesenchymal transition (EMT) and cancer progression, including metastasis. The CDH1 gene encodes E-cadherin; mutations or promoter methylation can contribute to tumorigenesis. Cadherins also participate in signaling pathways, including sequestration of β-catenin away from Wnt signaling.

Note: The term kadherin is often a misspelling of cadherin; sources discussing kadherin may actually refer to cadherin proteins.