Figure 3. Whi3 nucleates stress granules during mild heat shock.

(A) Cells coexpressing Whi3FL-3xGFP and P-body marker Edc3-mCh were incubated at various temperatures for 15 minutes. Whi3 does not colocalize with P-bodies during non-stress conditions (30°C). As temperatures increase, both Whi3 and Edc3 form foci. Though some Whi3 foci are distinct from Edc3 foci (arrowheads), colocalization between Whi3 and Edc3 increases as temperature increases. Scale bar represents 5 µm. (B) The experiment described in (A) was repeated in cells coexpressing Whi3FL-3xGFP and stress granule marker Pub1-mCh. Though Whi3 begins localizing to foci at 37°C, Pub1 foci do not form until 42°C. Pub1 and Whi3 foci colocalize at temperatures at or above 42°C.