FIG. 3.

ORF1p is targeted to stress granules in both unstressed and stressed teratocarcinoma cells. The distribution of tagged or endogenous ORF1p in teratocarcinoma cells was compared with that of endogenous marker proteins of PBs (A and B) and SGs (C to H) and a Cy3-labeled poly(dT) probe that detects polyadenylated RNA (I to K). Enlarged images of individual cytoplasmic foci are shown beside panel B and above panel C. The poly(dT)-Cy3 probe clearly detects polyadenylated RNA in stressed (J and K) but not unstressed (I) cells. Some cell groups were chemically stressed by treatment with sodium (meta)arsenite (0.75 mM; 50 min) or thapsigargin (1.5 μM; 2 h) immediately prior to fixation. Bar, 10 μm.