Enables apolipoprotein binding activity; receptor tyrosine kinase binding activity; and scaffold protein binding activity. Involved in dendrite morphogenesis and synapse organization. Located in several cellular components, including neuronal cell body; plasma membrane raft; and postsynaptic density. Human ortholog(s) of this gene implicated in Cenani-Lenz syndactyly syndrome; congenital myasthenic syndrome 17; and sclerosteosis 2. Orthologous to human LRP4 (LDL receptor related protein 4). [provided by Alliance of Genome Resources, Apr 2022]