Tensins

Tensins are a family of cytoskeletal proteins that help connect the actin cytoskeleton to integrin-based focal adhesions, playing a role in cell adhesion, shape, and movement. The family comprises four members: tensin-1 (TNS1), tensin-2 (TNS2), tensin-3 (TNS3), and CTEN, also known as tensin-4 (TNS4). These proteins are expressed in a variety of tissues and can show distinct expression patterns during development and in disease.

Structurally, tensins are modular proteins with an N-terminal actin-binding region that associates with F-actin and a C-terminal phosphotyrosine-binding (PTB) domain. The central portions of the proteins contain additional motifs that mediate interactions with other focal-adhesion components. The exact domain composition and splice variants differ among family members, contributing to their specific localization and functional nuances within cells.

Functionally, tensins contribute to the stabilization of focal adhesions and to the organization of the actin cytoskeleton. They participate in signaling related to integrin engagement and can influence cellular processes such as spreading, migration, and invasion. Through interactions with adapters and enzymes at focal adhesions, tensins may modulate pathways involving Rho family GTPases and other signaling cascades that control cytoskeletal dynamics and cell behavior.

Clinical and research relevance varies by context. Tensins have been studied in development, tissue remodeling, and cancer, where altered expression or activity can affect cell adhesion and motility. In some cancers, changes in tensin levels correlate with progression or metastatic potential, though the roles of each family member are context-dependent and an area of ongoing investigation.

Overall, tensins are important mediators at the interface between the actin cytoskeleton and cellular adhesion sites, contributing to how cells sense and respond to their mechanical and signaling environments.