Partial rescue of geldanamycin-induced TrkA depletion by a proteasome inhibitor in PC12 cells
| Autor: | Mónika Vecsernyés, Oktavia Tarjanyi, Gergely Berta, József Szeberényi, Marianna Pap, András Balogh, György Sétáló, Alexandra Harci |
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| Rok vydání: | 2013 |
| Předmět: |
Leupeptins
Lactams Macrocyclic Blotting Western DNA Fragmentation Tropomyosin receptor kinase A PC12 Cells AKT3 chemistry.chemical_compound Nerve Growth Factor Benzoquinones Low-affinity nerve growth factor receptor Animals Immunoprecipitation Enzyme Inhibitors Receptor trkA Protein kinase A Molecular Biology Protein kinase B Neurons Microscopy Confocal biology Akt/PKB signaling pathway General Neuroscience Geldanamycin Hsp90 Rats chemistry biology.protein Cancer research Neurology (clinical) Proteasome Inhibitors Developmental Biology Signal Transduction |
| Zdroj: | Brain research. 1520 |
| ISSN: | 1872-6240 |
| Popis: | In this work we tried to identify mechanisms that could explain how chemical inhibition of heat-shock protein 90 reduces nerve growth factor signaling in rat pheochromocytoma PC12 cells. Geldanamycin is an antibiotic originally discovered based on its ability to bind heat-shock protein 90. This interaction can lead to the disruption of heat-shock protein 90-containing multimolecular complexes. It can also induce the inhibition or even degradation of partner proteins dissociated from the 90 kDa chaperone and, eventually, can cause apoptosis, for instance, in PC12 cells. Before the onset of initial apoptotic events, however, a marked decrease in the activity of extracellular signal-regulated kinases ERK 1/2 and protein kinase B/Akt can be observed together with reduced expression of the high affinity nerve growth factor receptor, tropomyosine-related kinase, TrkA, in this cell type. The proteasome inhibitor MG-132 can effectively counteract the geldanamycin-induced reduction of TrkA expression and it can render TrkA and ERK1/2 phosphorylation but not that of protein kinase B/Akt by nerve growth factor again inducible. We have found altered intracellular distribution of TrkA in geldanamycin-treated and proteasome-inhibited PC12 cells that may, at least from the viewpoint of protein localization explain why nerve growth factor remains without effect on protein kinase B/Akt. The lack of protein kinase B/Akt stimulation by nerve growth factor in turn reveals why nerve growth factor treatment cannot save PC12 cells from geldanamycin-induced programmed cell death. Our observations can help to better understand the mechanism of action of geldanamycin, a compound with strong human therapeutical potential. |
| Databáze: | OpenAIRE |
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