Figure 3. Regulation of hepcidin expression by matriptase-2.
Matriptase-2 prevents hepcidin overexpression by degrading hemojuvelin (HJV), which acts as a co-receptor for BMP to promote Hamp gene expression (panel A). In matriptase-2 deficiency (panel B), high levels of HJV enhances the BMP signaling pathway, leading to overexpression of hepcidin. Hepcidin inhibits iron absorption, release and recycling, thereby causing IRIDA.