Type II transmembrane serine proteases in development and disease

Recent advances in the mammalian genome projects have resulted in the identification of a surprisingly large number of genes encoding putative new members and even entire new families of proteolytic enzymes. In the past few years, one of these new families, type II transmembrane serine proteases (TTSPs), underwent a particularly rapid transformation from a group of predicted DNA and protein sequences into an established family of cell surface-associated proteases with important roles in the development and homeostasis of mammalian tissues such as heart, skin, inner ear, placenta, and digestive tract. Additionally, aberrant expression of TTSP genes appears to be involved in the aetiology of several human disorders, including cancer. This review presents our current knowledge of the biological functions of the individual TTSPs in mouse and human tissue development and disease.