FIGURE 8.

Association of specific mRNAs with cytoplasmic or ER-associated polyribosomes during mild hyperosmotic stress. A, MEFs were treated with 500 mosmol medium alone or in the presence of Sal (15 μm) for the indicated times, and the distribution of mRNAs in polysomes was analyzed using qRT-PCR. Equal volumes of cytoplasmic (Cyto) or ER-associated ribosomes were loaded on gradients. The mRNA in each fraction is expressed as the percentage of total mRNA (sum of all cytoplasmic + ER-associated fractions). B, quality control of cell fractionations by immunodetection of ER and cytoplasmic marker proteins. C, quantification of three independent experiments of ER-associated polysomes for the indicated mRNAs. Error bars represent mean ± S.E.