The Collagen Suprafamily

Collagen, the predominant protein in mammals, serves as an essential structural component in various connective tissues such as skin, bones, tendons and ligaments. It imparts mechanical strength and structural integrity, crucial for supporting and protecting softer tissues and internal organs. Displaying significant heterogeneity, collagen encompasses 29 identified types, which form both fibrillar and non-fibrillar structures. Fibrillar collagens, such as types I, II, and III, are vital for connective tissue stability, while non-fibrillar collagens, including types IX and XVIII, fulfill specialized roles in anchoring and network formation. Collagen interacts with diverse receptors, including integrins, discoidin domain receptors (DDRs), glycoprotein VI (GPVI), and leukocyte-associated IG-like receptor-1 (LAIR-1), which are integral in regulating essential physiological processes such as cell adhesion, migration, and tissue remodeling. Mutations in collagen genes are associated with a range of disorders, including osteogenesis imperfecta (OI), Type II collagenopathies, Ehlers-Danlos Syndrome type IV, and Alport syndrome. Therefore, deepening our comprehension of collagen’s structural diversity and its biological interactions is imperative for elucidating its multifaceted roles and implications in pathology.