Figure 1. Summary of the yeast two-hybrid analysis using PITX2A and PITX2C as “bait.” EFEMP2 was identified as a novel PITX2-interacting protein by independent yeast two-hybrid (Y2H) analysis with two commonly expressed PITX2 isoforms. Y2H screening with PITX2A resulted in 14 EFEMP2 cDNAs from approximately 250,000 yeast clones while 12 EFEMP2 cDNAs were derived from screening approximately one million yeast clones with PITX2C. Combining all positives, the largest EFEMP2 clone lacks the NH₂-terminal 36 amino acid residues while the smallest EFEMP2 clone lacks the NH₂-terminal 134 amino acid residues. A schematic representation of EFEMP2 protein therefore shows that the PITX2 interacting domain in EFEMP2 lies between the second EGF-like module and the COOH-terminal fibulin-like module (135 to 443 amino acid residues).