Fig. 2.

Representation of the matriptase transmembrane protein product, with domains labeled with their first and last amino acids. Sites of cleavage required for matriptase activation are shown below the domains. Mutations in the ST14 gene causing IHS are displayed at their corresponding sites of effect on matriptase at the amino acid level (boxed). The currently reported mutation is exhibited in red at the first LDLR-A domain. SEA, sea urchin sperm protein-enteropeptidase-agrin; CUB, C1r/C1s, urchin embryonic growth factor bone morphogenic protein; LDLRA; low density lipoprotein receptor class A