Fig. 5. SUMO is sufficient to increase binding of MEP-1 to LIN-1. The association of MEP-1 with the indicated LA fusion proteins was monitored using the yeast two-hybrid system. Bars represent the average LexA-dependent ß-galactosidase activity from three independent yeast transformants grown to logarithmic phase in selective media, and lines indicate the standard deviation. The values were normalized by setting the interaction of each protein with LA:LIN-1(1-64) to 100 RLU. The LA fusion proteins were expressed at similar levels as determined by western blotting (data not shown).