Fig. 4. Comparison of deadenylation end-points in ccr4 point mutants. Shown are polyacrylamide northern gels for the MFA2pG transcript in (A) ccr4Δ strains or (B) ccr4Δ/pan2Δ strains, containing either a vector control, Flag-Ccr4p wild-type plasmid (pRP1045) or Flag-Ccr4p plasmids containing specific point mutants (pRP1046–1049) as indicated (see Materials and methods). Steady-state mRNA samples were resolved on 6% polyacrylamide/8 M urea northern gels, with or without removal of poly(A) tails with RNase H and oligo(dT) (lane 1). (C) Western analysis of extracts from ccr4Δ strains harboring both wild-type and mutant forms of the CCR4 plasmid. Probing with anti-Flag antibodies indicates that each mutant produces a full-length Ccr4p.