FIG. 4.

Effects of Nop58p depletion on Nop56p association with the snoRNAs and Nop1p. Immunoprecipitation on IgG-agarose was performed on lysates from a strain expressing ProtA-Nop56ΔKKE in the presence (0 h) or absence (20 h) of Nop58p. Total protein and RNA were extracted from equivalent amounts of total (T), supernatant (S), and pellet (P) fractions. (A) Northern blot hybridization with probes directed against box C+D snoRNAs. (B) Western blot decorated with anti-Nop1p antibodies (mA66); these cross-react with the ProtA tag on Nop56p. Several degradation products of ProtA-Nop56ΔKKE were observed, including one (∗) migrating slightly faster than Nop1p (15).