Procollagen Genes: Further Sequence Studies and Interspecies Comparisons

Abstract

Collagen is the most abundant protein in higher vertebrates. It constitutes as much as 60% of the protein in tissues such as bone and cartilage and is present in small amounts in most tissues in the body (Eyre 1980). In invertebrates, although less abundant, it is found in almost every metazoan phylum studied (Adams 1978). The genetic diversity of collagen within a single species has only come to light within the last decade. There are at least five different types of collagen and at least nine genetically distinct polypeptide chains. Of these different types, types I, II, and III make up the fibrillar collagens found in skin, bone, tendon, and cartilage, whereas types IV and V are nonfibrillar and are found in basement lamina and pericellular locations, respectively. Following appropriate posttranslational modification, these molecules become the dominant building blocks of tissues and give form and shape to the changing matrix...