HSP90 protein stabilizes unloaded argonaute complexes and microscopic P-bodies in human cells.
Key components of the miRNA-mediated gene regulation pathway are localized in cytoplasmic processing bodies (P-bodies). Mounting evidence suggests that the presence of microscopic P-bodies are not always required for miRNA-mediated gene regulation. Here we have shown that geldanamycin, a well-characterized HSP90 inhibitor, abolishes P-bodies and significantly reduces Argonaute and GW182 protein levels but does not affect the miRNA level and the efficiency of miRNA-mediated gene repression; however, it significantly impairs siRNA loading and the efficacy of exogenous siRNA. Our data suggests that HSP90 protein chaperones Argonautes before binding RNA and may facilitate efficient loading of small RNA.
Johnston
Michael
M
Wellcome Trust Centre for Gene Regulation and Expression, College of Life Sciences, University of Dundee, Dundee DD1 5EH, United Kingdom.
Geoffroy
Marie-Claude
MC
Sobala
Andrew
A
Hay
Ron
R
Hutvagner
Gyorgy
G
D060565:Argonaute Proteins; D001324:Autoantigens / Q000235:genetics / Q000378:metabolism; D016227:Benzoquinones / Q000494:pharmacology; D015152:Blotting, Northern; D015153:Blotting, Western; D002460:Cell Line; D045744:Cell Line, Tumor; D003594:Cytoplasmic Granules / Q000187:drug effects / Q000378:metabolism*; D015852:Eukaryotic Initiation Factor-2 / Q000235:genetics / Q000378:metabolism*; D015870:Gene Expression; D018841:HSP90 Heat-Shock Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D047029:Lactams, Macrocyclic / Q000494:pharmacology; D008156:Luciferases / Q000235:genetics / Q000378:metabolism; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism; D008856:Microscopy, Fluorescence; D011485:Protein Binding; D034622:RNA Interference; D016601:RNA-Binding Proteins; D015398:Signal Transduction / Q000187:drug effects; D014162:Transfection
C466422:AGO2 protein, human; D060565:Argonaute Proteins; D001324:Autoantigens; D016227:Benzoquinones; D015852:Eukaryotic Initiation Factor-2; D018841:HSP90 Heat-Shock Proteins; D047029:Lactams, Macrocyclic; D035683:MicroRNAs; D016601:RNA-Binding Proteins; C465663:TNRC6A protein, human; D008156:Luciferases; C001277:geldanamycin