Fig. 8. Rh50 acidic clusters interact with the ear domain of AP-1. The ability of the Rh50 cytoplasmic domain to interact with the -ear domain of AP-1 was tested in a yeast two-hybrid assay. Interaction of proteins was determined by measuring ß-galactosidase activity in liquid conditions. Results, expressed in arbitrary units, correspond to the average of three independent experiments. The s.e.m. was less than 5%. Both Ent3p and Rh50 proteins comparably interacted with the -ear domain of AP-1 in this assay but not with the µ1 subunit of the AP complex. Notably, mutation of either acidic cluster to alanine residues led to a dramatic reduction of the interaction between the -ear domain and Rh50.