Abstract
Heat shock protein-90 (Hsp90) buffers cells from genetic mutations and environmental stresses. To test if this capability reflects a normal physiological function of Hsp90 to buffer cellular signals, the effects of Hsp90 inhibition were measured on activation of Akt. Inhibition of Hsp90 with geldanamycin amplified Akt phosphorylation induced by insulin-like growth factor-1 (IGF-1) or insulin, indicating that Hsp90 normally buffers these signals. Furthermore, with IGF-1 stimulation Hsp90 inhibition increased p38 activation, produced additive activation of p90RSK, and slightly increased the duration of ERK1/2 activation. Hsp90 dampened Akt signaling by facilitating phosphatase-mediated dephosphorylation of Akt. Thus, Hsp90 not only buffers the cellular effects of mutations and stresses, but also buffers the magnitude and duration of activation of proliferative and survival-promoting signaling responses.
Original language | English (US) |
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Pages (from-to) | 181-186 |
Number of pages | 6 |
Journal | FEBS letters |
Volume | 574 |
Issue number | 1-3 |
DOIs | |
State | Published - Sep 10 2004 |
Externally published | Yes |
Keywords
- Akt
- Heat shock protein-90
- Insulin
- Insulin-like growth factor-1
- Protein kinase B
ASJC Scopus subject areas
- Biochemistry
- Biophysics
- Molecular Biology