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Metazoan Stress Granule Assembly Is Mediated By P-Eif2alpha-Dependent And -Independent Mechanisms, Natalie Farny, Nancy Kedersha, Pamela Silver

Natalie G. Farny

Stress granules (SGs) are cytoplasmic bodies wherein translationally silenced mRNAs are recruited for triage in response to environmental stress. We report that Drosophila cells form SGs in response to arsenite and heat shock. Drosophila SGs, like mammalian SGs, are distinct from but adjacent to processing bodies (PBs, sites of mRNA silencing and decay), require polysome disassembly, and are in dynamic equilibrium with polysomes. We further examine the role of the two Drosophila eIF2alpha kinases, PEK and GCN2, in regulating SG formation in response to heat and arsenite stress. While arsenite-induced SGs are dependent upon eIF2alpha phosphorylation, primarily via PEK, heat-induced …