Fig. 2.

hUpf1 is associated with nuclear complexes together with ADAR1. (A) Nuclear complexes sedimenting at 70S were immunoprecipitated by anti-hUpf1 antibodies, and the precipitated and unbound proteins were analyzed by SDS/PAGE and probed by anti-ADAR1 antibodies (lanes 1 and 4, respectively). Controls: lane 2, no antibody; lane 3, no sample. (B) Nuclear complexes sedimenting at the top of the gradient were immunoprecipitated as described in A (lanes in B as in A). (C) HeLa cell NE and nuclear complexes sedimenting at the top of the gradient at 70S and at 200S were immunoprecipitated by a nonrelevant antibody, preimmune anti-rabbit IgG, and were Western blotted by anti-ADAR1 (Left) and anti-hUpf1 (Right) antibodies.