CCR4 and CAF1 deadenylases have an intrinsic activity to remove the post-poly(A) sequence

Deadenylation of the internalized poly(A) sequence involves the CCR4–NOT complex. (A) Western blot analysis. CCR4 and CAF1 were significantly reduced by treatment of the corresponding dsRNA to S2 cells. (B) Deadenylation assay for Mini-let-7-A₂₀ and Mini-let-7-A₂₀N₁₀ with S2 cell lysate knocked down CAF1. While mock knockdown lysate effectively induced deadenylation for both reporter RNAs, CAF1 knockdown lysate failed to deadenylate. (C,D) Deadenylation assay for Mini-let-7-A₂₀ and Mini-let-7-A₂₀N₁₀ with S2 cell lysate knocked down CCR4. Compared to mock knockdown, deadenylation was retarded in CCR4 knockdown.