Receptor for SEMA4D (PubMed:19788569). Plays a role in GABAergic synapse development (PubMed:23699507, PubMed:29981480). Mediates SEMA4A- and SEMA4D-dependent inhibitory synapse development (PubMed:23699507, PubMed:29981480). Plays a role in RHOA activation and subsequent changes of the actin cytoskeleton (By similarity). Plays a role in axon guidance, invasive growth and cell migration (By similarity). Monomer, and heterodimer with PLXNB2 after proteolytic processing (By similarity). Binds RAC1 that has been activated by GTP binding (By similarity). Interaction with SEMA4D promotes binding of cytoplasmic ligands (By similarity). Interacts with RRAS, ARHGEF11, ARHGEF12, ERBB2, MET, MST1R, RND1, RHOD, NRP1 and NRP2 (By similarity). Interacts with PLXNA1 (PubMed:12559962). Detected in brain, heart, lung, liver, kidney, stomach, testis, uterus and placenta (PubMed:12559962). Expressed in neurons and glia in the developing hippocampus (PubMed:29981480). Phosphorylated on tyrosine residues by ERBB2 and MET upon SEMA4D binding. Proteolytic processing favors heterodimerization with PLXNB2 and SEMA4D binding. Belongs to the plexin family.