Tensin

Tensin refers to a small family of cytoplasmic proteins associated with focal adhesions that help connect the actin cytoskeleton to the extracellular matrix through integrin receptors. The best-known members are Tensin-1 (TNS1), Tensin-2 (TNS2), Tensin-3 (TNS3), and Tensin-4, also called CTEN (TNS4). They function as scaffolds that coordinate cytoskeletal organization and signaling at cell–matrix adhesion sites.

Most tensins share a C-terminal tensin homology (TH) domain, related to the PTEN tumor suppressor, and a phosphotyrosine-binding (PTB) domain. In many family members, an N-terminal actin-binding domain helps anchor the protein to F-actin, and a central coiled-coil region supports protein interactions and dimerization. CTEN (TNS4) is a shorter isoform that lacks the N-terminal actin-binding domain.

Localization at focal adhesions allows tensins to participate in integrin signaling, regulate adhesion turnover and actin dynamics, and influence downstream pathways involving Rho GTPases and other signaling nodes. Through their PTB domain and interaction partners, tensins can recruit kinases and adapters to adhesion sites and affect cell migration and morphology.

Clinical relevance: Altered expression or mutations of tensin genes have been linked to disease. TNS2 mutations have been associated with nephrotic syndrome in some cases. Overexpression of CTEN is reported in several cancers and is frequently associated with enhanced migratory and invasive properties, making it of interest as a potential oncogene or biomarker.

See also: tensin homology domain; focal adhesion; PTEN.