FIG. 6.
ITAM tyrosines direct G1 protein polyubiquitination and degradation. COS7 cells were transfected with ITAM (lanes 1 and 2), ITAM-FY (lanes 3 and 4), ITAM-YF (lanes 5 and 6), and ITAM-FF (lanes 7 and 8) constructs simultaneously with His6-ubiquitin in the presence (+) or absence (−) of the proteasome inhibitor ALLN. Cells were lysed, and equal amounts of total protein from straight lysates (A) or samples from Ni-NTA agarose pull-downs (B) were run on SDS-PAGE and were Western blotted (WB) with Gal4 antibody.