Figure 5.

Smg7/Ebs1p physically interacts with Upf1 proteins in a partially RNA-dependent manner. (A) Myc tagged Ebs1p was immunoprecipitated from cell lysates prepared from strains expressing Upf1p-GFP. Lysates were treated with RNase or left untreated. Western blots were performed using anti-myc and anti-GFP antibodies. (B) Protein extracts were prepared form HeLa cells and treated with RNase or left untreated. Human Upf1 was immunoprecipitated using goat polyclonal antibodies and western blot analysis was performed using rabbit polyclonal antibodies raised against human Smg7, Upf2 and Upf3 and goat polyclonal antibodies raised against Upf1. As a control for IP specificity, α-Tubulin does not co-immunoprecipitate with Upf1.