Nrd1 regulates stress granule assembly.

<p>(A) Effects of Nrd1 deletion on Pabp-positive granule formation after heat shock. Wild-type or the Δ<i>nrd1</i> cells expressing YFP-tagged Pabp were grown in normal medium or under the conditions indicated. Bar, 10 µm. Graphs showing the number of Pabp-positive granules per cell from each strain as a function of time. (B) Overproduction of Nrd1 induced Pabp-positive granules in the absence of stress. Cells expressing tdTomato-tagged Pabp transformed with pREP1-GFP-Nrd1 or pREP1-GFP-Nrd1^DD were grown in EMM (thiamine-free medium) for 16 h, 18 h, or 22 h to induce overproduction of GFP-Nrd1 or GFP-Nrd1^DD. Bar, 10 µm. (C) Wild-type cells transformed with control vector or containing the <i>nrd1⁺</i> gene, or the Δ<i>nrd1</i> cells transformed with control vector, were grown in EMM+thiamine at 27°C and were then spotted onto YES plates, or spotted onto YES plates with 0.3 mM arsenite, 4.0 mM H₂O₂, 0.3 mM CdCl₂, or 1.0 M KCl, and then incubated at temperatures indicated.