Abstract
Proteolytic processing and degradation plays an important role in modulating the generation and bioactivity of neuroendocrine peptide mediators, a class of key molecules in cutaneous biology. Accordingly, the cellular localization and expression, and the molecular biology and structural properties of selected intracellular prohormone convertases and ectopically expressed zinc-binding metalloendoproteases are discussed. A special reference will be made to the physiologic and pathophysiologic significance of these endopeptidases in cutaneous immunobiology. Because of the number of pathologically relevant changes in inflammation and tumor progression that can be directly attributed to neprilysin and angiotensin-converting enzyme, a particular focus will be on the role of these enzymes in modulating innate and adaptive immune responses in the skin.