Acts upstream of or within blood vessel lumenization. Predicted to be located in early endosome and membrane. Predicted to be active in cytoplasm; glutamatergic synapse; and presynapse. Is expressed in blood island; notochord; posterior lateral mesoderm; and vasculature. Orthologous to human SH3GL3 (SH3 domain containing GRB2 like 3, endophilin A3).