Fig. 1. PDZ domains 2 and 3 of Baz bind directly to the C-terminal PDZ-binding motif of PTEN2 in the yeast 2-hybrid system. (A) In the yeast 2-hybrid screen using the three PDZ domains of Baz as bait, we isolated three independent clones corresponding to the C terminus of PTEN2. One clone contains amino acids 316-511 and two clones contain amino acids 297-511 of PTEN2. A deletion mutant lacking the three C-terminal amino acid residues of PTEN2 did not bind to the PDZ domains of Baz, nor did PTEN isoform 3, which differs only at the C terminus from PTEN2 and lacks the PDZ-binding motif. (B) Different regions of Baz were tested for interaction with the C terminus of PTEN2 and with the C-terminal deletion mutant of PTEN2 lacking the PDZ-binding motif. The smallest fragment that interacted with PTEN2, but not with the mutant lacking the PDZ-binding motif, contained PDZ domains 2 and 3.