Background
ADAMTS (a disintegrin and metalloproteinase domain with thrombospondin type-1 modules) is a family of zinc-dependent proteases that are implicated in a variety of normal and pathological conditions, including arthritis and cancer. ADAMTS protein family members contain an N-terminal propeptide domain, a metalloproteinase domain, a disintegrin-like domain and a C-terminus that contains a varying number of thrombospondin type-1 (TSP-1) motifs. ADAMTS genes are primarily expressed in fetal tissues, including lung, kidney and liver. ADAMTS-7 (ADAM metallopeptidase with thrombospondin type 1 motif, 7), also known as COMPase, is a 1,686 amino acid protein that exists as two alternatively spliced isoforms. Encoded by a gene that maps to human chromosome 15q25.1, ADAMTS-7 contains eight TSP-1 motifs and binds one zinc ion per subunit. ADAMTS-7 is expressed in heart, brain, placenta, lung, liver, skeletal muscle, kidney and pancreas. ADAMTS-7 is also located in meniscus, bone, tendon, cartilage, synovium, fat and ligaments, and is up-regulated in articular cartilage and synovium in arthritis patients. ADAMTS-7 functions as a metalloprotease and may play a role in the degradation of COMP. ADAMTS-7 is pH dependent, with optimum pH between 7.5 and 9.5.