The Collagen Superfamily: Everything You Always Wanted to Know

Collagens are the most abundant extracellular matrix proteins in multicellular organisms. In humans, the collagen superfamily counts 28 proteins encoded by 44 genes whose functions are far from being completely elucidated. Their primary function is to provide structural support and strength to cells in order to maintain the biomechanical integrity of tissues. However, collagens are no longer considered just as structural proteins and there is an extensive literature that documents the high diversity of collagens’ functions in cell behavior, integrity, and tissue homeostasis. A number of common diseases are directly linked to an imbalance between collagen synthesis and degradation that leads to tissue dysfunction. In addition, collagens are associated with a broad spectrum of heritability-related diseases known as “collagenopathies” that affect a multitude of organs and tissues including sensory organs. However, the particular complexity and diversity of the collagen nomenclature, structure, biosynthesis, and molecular assembly often repel scientists and clinicians who are not in the field. This chapter aims at providing a glossary of the collagen superfamily that allows readers to locate the piece of information they need without alienating them.