Fig. 2. Yeast two-hybrid interactions of BICD2. (A) Structure of the yeast two-hybrid constructs. The domain structure of BICD2, p150Glued, dynamitin, Arp1 and p24, including coiled-coil regions (hatched boxes) and microtubule-binding motif (black box), are shown. The position of the protein fragments used in the yeast two-hybrid assay is indicated with horizontal lines below the respective diagrams. (B and C) Yeast two-hybrid analysis. Different segments of BICD2 were tested for BICD2 self-association (B), or for interaction with components of the dynactin complex (C). Protein segments were either fused to AD or DNA-BD of GAL4. The β-galactosidase activity in the yeast lysate is a measure of reporter gene activation. Enzymatic activity is expressed as (++), which indicates high activity (50–100 U); (+), which indicates moderate activity (5–50 U); and (–), which indicates low or no activity (0–5 U).