Figure 3.

AtNTF2a and AtNTF2b bind to Arabidopsis, human, and yeast Ran. A yeast two-hybrid assay was used to examine the interaction between AtNTF2a, AtNTF2b, and Ran. Each of the AtNTF proteins was expressed as an activation domain fusion as described in “Materials and Methods.” Ran proteins were expressed as DNA-binding domain fusion proteins. Interactions with Arabidopsis (AtRAN1), human (hRAN), and yeast (yRAN) Ran were examined for AtNTF2a (top) and AtNTF2b (bottom). As a negative control, interaction with vector alone was also examined. In this two-hybrid system, activation domain fusion proteins are expressed under a Gal-inducible promoter; thus, interactions should only occur in the presence of Gal. As indicated by the blue color indicative of β-galactosidase expression, both AtNTF2a and AtNTF2b interact with Ran from all species tested.