Cell surface receptor for SEMA4A and for class 3 semaphorins, such as SEMA3A, SEMA3C and SEMA3E. Plays an important role in cell-cell signaling, and in regulating the migration of a wide spectrum of cell types. Regulates the migration of thymocytes in the medulla. Regulates endothelial cell migration. Plays an important role in ensuring the specificity of synapse formation. Mediates anti-angiogenic signaling in response to SEMA3E. Required for normal development of the heart and vasculature. Interacts with NRP1 and SEMA4A (PubMed:15239958, PubMed:17318185). Interacts with SH3BP1; they dissociate upon SEMA3E binding to PLXND1 allowing SH3BP1 to transduce downstream signal through RAC1 inactivation (By similarity). Detected in embryonic heart and vascular endothelium, brain, dorsal root ganglia, adrenal gland, lung mesenchyme, small intestine and in the ossification centers of vertebral bodies. Neonate lethality, due to defects in the development of the heart outflow tract and in aortic arch patterning, plus defects in peripheral vasculature. Mice also display skeletal defects, but these may be caused by defects in the embryonic vasculature. Belongs to the plexin family.