The data demonstrate that smooth muscle cells are targets for angiogenin and that both SAPK/JNK phosphorylation and nuclear translocation of the ligand are required for angiogenin to activate smooth muscle cells..     ///    Neomycin inhibits nuclear translocation of angiogenin and abolishes angiogenin-induced cell proliferation but does not inhibit SAPK/JNK phosphorylation.     ///    This activity of angiogenin depends on the cell density and requires nuclear translocation of the ligand as well as activation of SAPK/JNK MAP kinase.     ///    Angiogenin binds to a 170-kDa putative receptor on the cell surface and induces phosphorylation of SAPK/JNK. 