title: Hsp90 is involved in the formation of P-bodies and stress granules.
abstract: Previously, we found that treatment of cells with the Hsp90 inhibitor geldanamycin (GA) leads to a substantial reduction in the number of processing bodies (P-bodies), and also alters the size and subcellular localization of stress granules. These findings imply that the chaperone activity of Hsp90 is involved in the formation of P-bodies and stress granules. To verify these observations, we examined whether another Hsp90 inhibitor radicicol (RA) affected P-bodies and stress granules. Treatment with RA reduced the level of the Hsp90 client protein Argonaute 2 and the number of P-bodies. Although stress granules still assembled in RA-treated cells upon heat shock, they were smaller and more dispersed in the cytoplasm than those in untreated cells. Furthermore eIF4E and eIF4E-transporter were dissociated selectively from stress granules in RA-treated cells. These observations were comparable to those obtained upon treatment with GA in our previous work. Thus, we conclude that abrogation of the chaperone activity of Hsp90 affects P-body formation and the integrity of stress granules.
authors: Molecular Entomology Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan. matsumok@riken.jp
authors: Ken
authors: K
authors: Matsumoto
authors: Michiko
authors: M
authors: Minami
authors: Fumika
authors: F
authors: Shinozaki
authors: Yukari
authors: Y
authors: Suzuki
authors: Keiko
authors: K
authors: Abe
authors: Shuhei
authors: S
authors: Zenno
authors: Shogo
authors: S
authors: Matsumoto
authors: Yasufumi
authors: Y
authors: Minami
mesh_terms: D060565:Argonaute Proteins; D003594:Cytoplasmic Granules / Q000187:drug effects / Q000378:metabolism*; D015852:Eukaryotic Initiation Factor-2 / Q000037:antagonists & inhibitors / Q000378:metabolism; D018841:HSP90 Heat-Shock Proteins / Q000037:antagonists & inhibitors* / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D018942:Macrolides / Q000494:pharmacology*; D029543:Nucleocytoplasmic Transport Proteins / Q000378:metabolism
chemical_list: C466422:AGO2 protein, human; D060565:Argonaute Proteins; C411571:EIF4ENIF1 protein, human; D015852:Eukaryotic Initiation Factor-2; D018841:HSP90 Heat-Shock Proteins; D018942:Macrolides; D029543:Nucleocytoplasmic Transport Proteins; C035359:monorden