Figure 4.

Red1 localizes to cleavage bodies in mitotically dividing cells and cooperates with polyadenylation factors to hyperadenylate meiotic mRNAs. (A) Red1 dots co-localize with cleavage factor, Pcf11; the canonical poly(A) polymerase, Pla1; a nuclear exosome subunit, Rrp6; and a nuclear poly(A)-binding protein, Pab2. Microscopic images of strains expressing both Red1-tdTomato and either Pcf11-, Pla1-, Rrp6-, or Pab2-GFP are shown. Bars, 2 μm. (B) Red1 co-immunoprecipitates with Pla1 and Rrp6. Total cell extracts prepared from strains expressing both Red1-FLAG and Rrp6/Pla1-myc were subjected to immunoprecipitation, followed by western blotting. (C) Meiotic mRNAs in red1Δ do not have highly elongated poly(A) tails. Northern blotting was performed to analyse rec8⁺ and spo5⁺ mRNAs in wild type (WT), red1Δ, rrp6Δ, and red1Δrrp6Δ. The same blots were stained with methylene blue to visualize ribosomal RNAs (rRNA), which serve as a loading control.