Distinct Developmental Functions of Prostasin (CAP1/PRSS8) Zymogen and Activated Prostasin

The study explored the distinct roles of prostasin (CAP1/PRSS8) in its zymogen and activated forms, particularly in epithelial development and homeostasis. Researchers found that while the zymogen form was crucial for maintaining epithelial integrity, the activated form regulated sodium balance and skin barrier function. Mice expressing only a zymogen-locked form of prostasin showed normal epidermal development but had defects in hair formation, indicating prostasin's non-proteolytic role in the epidermis and a proteolysis-dependent role in hair follicle development. The findings highlighted prostasin's dual functions and its involvement in a proteolytic cascade with matriptase, essential for hair morphogenesis.