Figure 5.

Detection of XAP-binding activities in extracts. (A) Radioactively labeled, uncapped (indicated by ∗) XAP1, V_GG, V_TL, and V_GUG were incubated with increasing amounts (lanes 1, 7 μg; lanes 5, 35 μg) of oocyte nuclear extracts (NXT), and specific complexes formed (cplx) were analyzed on nondenaturing acrylamide gels. (B) RNA competition. Oocyte NXT (15 μg) was preincubated with increasing amounts (lanes 1, 170 pmol; lanes 5, 850 pmol) of unlabeled XAP1, V_GG, and V_TL for 20 min at 20°. Radioactively labeled XAP1* was added and incubated for an additional 15 min at 20°, and complexes formed (cplx) were analyzed on nondenaturing acrylamide gels. (C) Same as in B, but with HeLa NXT (15 μg).