Expression and genetic loss of function analysis of the HAT/DESC cluster proteases TMPRSS11A and HAT.

Genome mining at the turn of the millennium uncovered a new family of type II transmembrane serine proteases (TTSPs) that comprises 17 members in humans and 19 in mice. TTSPs phylogenetically belong to one of four subfamilies: matriptase, hepsin/TMPRSS, corin and HAT/DESC. Whereas a wealth of information now has been gathered as to the physiological functions of members of the hepsin/TMPRSS, matriptase, and corin subfamilies of TTSPs, comparatively little is known about the functions of the HAT/DESC subfamily of proteases.

Matriptase initiates activation of epidermal pro-kallikrein and disease onset in a mouse model of Netherton syndrome.

Deficiency in the serine protease inhibitor LEKTI is the etiological origin of Netherton syndrome, which causes detachment of the stratum corneum and chronic inflammation. Here we show that the membrane protease matriptase initiates Netherton syndrome in a LEKTI-deficient mouse model by premature activation of a pro-kallikrein cascade. Auto-activation of pro-inflammatory pro-kallikrein-related peptidases that are associated with stratum corneum detachment was either low or undetectable, but they were efficiently activated by matriptase.