Enables serine-type peptidase activity. Involved in proteolysis. Acts upstream of or within chorionic trophoblast cell differentiation; negative regulation of transmembrane receptor protein serine/threonine kinase signaling pathway; and placenta development. Located in collagen-containing extracellular matrix. Is expressed in several structures, including brain; limb; reproductive system; sensory organ; and skin. Human ortholog(s) of this gene implicated in CADASIL (multiple); hypertension; and macular degeneration (multiple). Orthologous to human HTRA1 (HtrA serine peptidase 1). [provided by Alliance of Genome Resources, Apr 2022]