Enables aminopeptidase activity. Involved in negative regulation of cold-induced thermogenesis. Acts upstream of or within SMAD protein signal transduction and protein catabolic process. Located in cytoplasmic vesicle membrane; perinuclear region of cytoplasm; and plasma membrane. Is expressed in extraembryonic component; labyrinthine zone; and placenta. Orthologous to human LNPEP (leucyl and cystinyl aminopeptidase). [provided by Alliance of Genome Resources, Apr 2022]