<p>Mice tissues (n = 4) were isolated and the homogenates were generated as described in Experimental Procedures. The tissue lysates were incubated with UIM-agarose for ubiquitin affinity precipitation (AP). The proteins that interacted with polyubiquitin chains were analyzed by western blot using specific antibodies. <b>A.</b> GTPCH1 and polyubiquitin chains interaction in mouse heart and <b>B.</b> mouse lung. Control beads without UIM were used as a negative control are included in all experiments. The black triangle (▸) indicates the bound GTPCH1 by polyubiquitin chains and the asterisk (*) indicates a non-specific band. <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0043306#s3" target="_blank">Results</a> were obtained from four mice.</p
