Type XII collagen is a protein that belongs to the collagen family, specifically, the fibril-associated collagens with interrupted triple helices (FACIT) group. It is encoded by the COL12A1 gene and primarily expressed in various connective tissues, including cartilage, tendons, ligaments, and the extracellular matrix of developing bones. Type XII collagen plays a crucial role in maintaining the structural integrity and strength of these tissues.
As a non-fibrillar collagen, type XII collagen acts as a regulator and organizer of collagen fibrillogenesis. It interacts with other collagen types, such as types I, II, and IX, to regulate fibril assembly and maturation. It functions as a molecular bridge linking the fibrils to other components of the extracellular matrix, including proteoglycans and glycoproteins.
Deficiencies or mutations of type XII collagen can lead to various connective tissue disorders, such as osteoarthritis, tendinopathy, and joint laxity. These conditions are characterized by impaired tissue strength, reduced structural integrity, and altered biomechanical properties.
Research on type XII collagen is ongoing to explore its clinical significance and potential therapeutic applications. Understanding its role in tissue development, maintenance, and repair may open avenues for novel treatments for connective tissue disorders and injuries.
In summary, type XII collagen is a non-fibrillar collagen that regulates collagen fibrillogenesis and plays a crucial role in maintaining the structural integrity of connective tissues. Its interactions with other collagen types and extracellular matrix components are essential for tissue strength and function.
