RanGAP1 accumulates in stress-induced cytoplasmic compartments that are distinct from stress granules and P-bodies

Stress granules (SGs) and P-bodies are dynamic compartments in the cytoplasm of eukaryotic cells. SGs assemble in response to stress. The nuclear transport factor RanGAP1 is linked to the pathologies of several human diseases. RanGAP1 concentrates at nuclear pore complexes, but can also associate with cytoplasmic biomolecular condensates. The small molecule pifithrin-µ (PFT-µ) inhibits Hsp70 family members and has potential as a therapeutic agent. PFT-µ triggers SG formation in human cancer cells. This prompted us to evaluate the subcellular localization of RanGAP1 upon exposure to PFT-µ. We show that RanGAP1 accumulates in unique cytoplasmic compartments that do not colocalize with SGs or P-bodies.