Involved as a receptor for mab-20/sema-2a in the formation or stabilization of cell-cell contacts at several stages of epithelial morphogenesis. In early embryonic development, required for proper ventral closure of the epidermis. During male tail morphogenesis, involved in precursor cell sorting and in the formation of distinct sensory rays. Involved in axon guidance of SDQL neurons during neurogenesis. Interacts with mab-20. Belongs to the plexin family.