Rei1 is functionally linked to the shuttling factors Arx1 and Tif6. (A) In the absence of Rei1, Arx1 and Tif6 are redistributed to the cytoplasm. The localization of Arx1-GFP, Tif6-GFP, or Rlp24-TAP was observed after the growth of rei1Δ or wild-type strains for 8 h in minimal medium at 23°C. (B) Rei1 is required for the binding of Arx1 to pre-60S complexes. rei1Δ or wild-type strains expressing ARX1-GFP or TIF6-GFP were grown for 8 h at 23°C, and whole cell extracts were prepared. The extracts were separated on sucrose gradients and analyzed as described in Fig. 1 C. The immunoblots, which were performed using antibodies against GFP, are displayed below the corresponding profile.