Fig. 3. JAM associates with ASIP generated in COS-7 cells. COS-7 cells were transiently transfected with either an irrelevant expression vector encoding bacterial alkaline phosphatase (mock), N-terminal T7 tag-fused ASIP expression constructs that encode full-length ASIP (ASIP fl) or deletion mutants comprising amino acid residues 583–1337 (ASIP 583) or 258–936 (ASIP 258). Lysates from transfected cells were incubated with GST–JAM, GST–JAMΔ3 or GST alone, immobilized on G–Sepharose beads. The resulting complexes were analysed by immunoblotting with a mAb directed against the T7 tag. Arrowheads indicate the positions of the recombinant ASIP molecules. Both full-length ASIP and ASIP deletion mutant ASIP 258 were efficiently affinity isolated with GST–JAM, whereas the ASIP mutant lacking the first PDZ domain (ASIP 583) was only poorly affinity isolated.