This gene encodes a calcium-dependent serine endoprotease that proteolytically activates different proprotein substrates traversing the secretory pathway. The encoded protein undergoes proteolytic autoactivation during which an N-terminal propeptide is cleaved to generate the mature protein. Mice lacking the encoded protein die at an embryonic stage and display hemodynamic insufficiency, cardiac ventral closure defect, axial rotation defect and abnormal yolk sac vasculature. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Jul 2015]