May be involved in regulated intramembrane proteolysis and the subsequent release of functional polypeptides from their membrane anchors. Cleaves type-1 transmembrane domains using a catalytic dyad composed of serine and histidine that are contributed by different transmembrane domains. At 8 dpc, expression is limited to the developing central nervous system (CNS). From 9 dpc on detected in the ventral forebrain, pretectum, dorsal diencephalon, metencephalon, the ventral spinal neural tube, in the ectoderm of the developing mandibular arches and the developing hindgut. Belongs to the peptidase S54 family.