Lopinavir impairs protein synthesis and induces eEF2 phosphorylation via the activation of AMP-activated protein kinase

Ly Q. Hong-Brown, C. Randell Brown, Danuta S. Huber, Charles H. Lang

Research output: Contribution to journalArticle

12 Citations (Scopus)

Abstract

HIV anti-retroviral drugs decrease protein synthesis, although the underlying regulatory mechanisms of this process are not fully established. Therefore, we investigated the effects of the HIV protease inhibitor lopinavir (LPV) on protein metabolism. We also characterized the mechanisms that mediate the effects of this drug on elongation factor-2 (eEF2), a key component of the translational machinery. Treatment of C2C12 myocytes with LPV produced a dose-dependent inhibitory effect on protein synthesis. This effect was observed at 15 min and was maintained for at least 4 h. Mechanistically, LPV increased the phosphorylation of eEF2 and thereby decreased the activity of this protein. Increased phosphorylation of eEF2 was associated with increased activity of its upstream regulators AMP-activated protein kinase (AMPK) and eEF2 kinase (eEF2K). Both AMPK and eEF2K directly phosphorylated eEF2 in an in vitro kinase assay suggesting two distinct paths lead to eEF2 phosphorylation. To verify this connection, myocytes were treated with the AMPK inhibitor compound C. Compound C blocked eEF2K and eEF2 phosphorylation, demonstrating that LPV affects eEF2 activity via an AMPK-eEF2K dependent pathway. In contrast, incubation of myocytes with rottlerin suppressed eEF2K, but not eEF2 phosphorylation, suggesting that eEF2 can be regulated independent of eEF2K. Finally, LPV did not affect PP2A activity when either eEF2 or peptide was used as the substrate. Collectively, these results indicate that LPV decreases protein synthesis, at least in part, via inhibition of eEF2. This appears regulated by AMPK which can act directly on eEF2 or indirectly via the action of eEF2K.

Original languageEnglish (US)
Pages (from-to)814-823
Number of pages10
JournalJournal of Cellular Biochemistry
Volume105
Issue number3
DOIs
StatePublished - Oct 15 2008

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Lopinavir
Phosphorylation
AMP-Activated Protein Kinases
Chemical activation
Phosphotransferases
Muscle Cells
Proteins
Peptide Elongation Factor 2
HIV Protease Inhibitors
Anti-HIV Agents
Protein Kinase Inhibitors
Metabolism
Pharmaceutical Preparations
Machinery
Assays
Peptides
Substrates
AMP-activated protein kinase kinase

All Science Journal Classification (ASJC) codes

  • Biochemistry
  • Cell Biology
  • Molecular Biology

Cite this

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abstract = "HIV anti-retroviral drugs decrease protein synthesis, although the underlying regulatory mechanisms of this process are not fully established. Therefore, we investigated the effects of the HIV protease inhibitor lopinavir (LPV) on protein metabolism. We also characterized the mechanisms that mediate the effects of this drug on elongation factor-2 (eEF2), a key component of the translational machinery. Treatment of C2C12 myocytes with LPV produced a dose-dependent inhibitory effect on protein synthesis. This effect was observed at 15 min and was maintained for at least 4 h. Mechanistically, LPV increased the phosphorylation of eEF2 and thereby decreased the activity of this protein. Increased phosphorylation of eEF2 was associated with increased activity of its upstream regulators AMP-activated protein kinase (AMPK) and eEF2 kinase (eEF2K). Both AMPK and eEF2K directly phosphorylated eEF2 in an in vitro kinase assay suggesting two distinct paths lead to eEF2 phosphorylation. To verify this connection, myocytes were treated with the AMPK inhibitor compound C. Compound C blocked eEF2K and eEF2 phosphorylation, demonstrating that LPV affects eEF2 activity via an AMPK-eEF2K dependent pathway. In contrast, incubation of myocytes with rottlerin suppressed eEF2K, but not eEF2 phosphorylation, suggesting that eEF2 can be regulated independent of eEF2K. Finally, LPV did not affect PP2A activity when either eEF2 or peptide was used as the substrate. Collectively, these results indicate that LPV decreases protein synthesis, at least in part, via inhibition of eEF2. This appears regulated by AMPK which can act directly on eEF2 or indirectly via the action of eEF2K.",
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Lopinavir impairs protein synthesis and induces eEF2 phosphorylation via the activation of AMP-activated protein kinase. / Hong-Brown, Ly Q.; Brown, C. Randell; Huber, Danuta S.; Lang, Charles H.

In: Journal of Cellular Biochemistry, Vol. 105, No. 3, 15.10.2008, p. 814-823.

Research output: Contribution to journalArticle

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T1 - Lopinavir impairs protein synthesis and induces eEF2 phosphorylation via the activation of AMP-activated protein kinase

AU - Hong-Brown, Ly Q.

AU - Brown, C. Randell

AU - Huber, Danuta S.

AU - Lang, Charles H.

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