Enables PDZ domain binding activity. Involved in cilium assembly and protein localization to ciliary membrane. Acts upstream of or within paraxial mesoderm formation. Located in growth cone membrane; microvillus; and myelin sheath abaxonal region. Is expressed in several structures, including central nervous system; extraembryonic component; ganglia; and retina. Orthologous to human EXOC4 (exocyst complex component 4). [provided by Alliance of Genome Resources, Apr 2022]