disease:Overexpressed and constitutively tyrosine phosphorylated in colon, liver, pancreas and gastric carcinoma cell lines. Overexpression increases MET activation and promotes invasive growth.,function:Receptor for SEMA4D. Plays a role in RHOA activation and subsequent changes of the actin cytoskeleton. Plays a role in axon guidance, invasive growth and cell migration.,PTM:Phosphorylated on tyrosine residues by ERBB2 and MET upon SEMA4D binding.,PTM:Proteolytic processing favors heterodimerization with PLXNB2 and SEMA4D binding.,similarity:Belongs to the plexin family.,similarity:Contains 1 Sema domain.,similarity:Contains 3 IPT/TIG domains.,subunit:Monomer, and heterodimer with PLXNB2 after proteolytic processing. Binds RAC1 that has been activated by GTP binding. Interaction with SEMA4D promotes binding of cytoplasmic ligands. Binds PLXNA1 (By similarity). Binds ARHGEF11, ARHGEF12, ERBB2, MET, MST1R, RND1, NRP1 and NRP2.,tissue specificity:Highly expressed in fetal kidney, and at slightly lower levels in fetal brain, lung and liver.,