Enables apolipoprotein binding activity; lipoprotein particle binding activity; and low-density lipoprotein particle receptor binding activity. Involved in several processes, including cellular response to insulin stimulus; cellular response to starvation; and regulation of neuron apoptotic process. Acts upstream of or within several processes, including low-density lipoprotein receptor particle metabolic process; regulation of low-density lipoprotein particle receptor catabolic process; and triglyceride metabolic process. Located in COPII-coated ER to Golgi transport vesicle; endoplasmic reticulum; and extracellular space. Is expressed in several structures, including alimentary system; cerebellum; genitourinary system; liver; and telencephalon. Human ortholog(s) of this gene implicated in familial hypercholesterolemia and hypobetalipoproteinemia. Orthologous to human PCSK9 (proprotein convertase subtilisin/kexin type 9). [provided by Alliance of Genome Resources, Apr 2022]