Fig. 3. Zic promotes degradation of the teneurin-2 intracellular domain. Western blot analysis of cell extracts of COS-7 cells transfected with teneurin-2 I (A, left side), the recombinant transcription factor BDAD (pBD-NFB) (B, left side) and zic (C and D, left side) alone and in combination, as indicated above the lanes (A-D right sides). Extracts of cells without lactacystin treatment were compared to extracts made from cells grown with the addition of lactacystin for the time periods indicated before harvesting. In A, the teneurin-2 intracellular domain was detected by anti-VSV, in B, BDAD was detected by anti-Gal4, and in C and D, zic was detected by anti-myc. Zic caused downregulation of the cotransfected teneurin-2 I but not of BDAD. Immunofluorescence staining of cells transfected with teneurin-2 I (anti-VSV antibody) and zic (anti-myc antibody) alone (E) and after co-transfection (F) revealed that the anti-VSV signal in PML bodies is lost in nuclei showing high expression levels of zic. Bar, 10 µm.