Etomoxir repurposed as a promiscuous fatty acid mimetic chemoproteomic probe

Joseph Choi; Danielle M. Smith; Ye Jin Lee; Danfeng Cai; Mohammad J. Hossain; Tamara J. O’Connor; Pragney Deme; Norman J. Haughey; Susanna Scafidi; Ryan C. Riddle; Michael J. Wolfgang

iScience (Sep 2024)

Etomoxir repurposed as a promiscuous fatty acid mimetic chemoproteomic probe

Joseph Choi,
Danielle M. Smith,
Ye Jin Lee,
Danfeng Cai,
Mohammad J. Hossain,
Tamara J. O’Connor,
Pragney Deme,
Norman J. Haughey,
Susanna Scafidi,
Ryan C. Riddle,
Michael J. Wolfgang

Affiliations

Joseph Choi: Department of Physiology, The Johns Hopkins University School of Medicine, Baltimore, MD, USA; Department of Biological Chemistry, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
Danielle M. Smith: Department of Physiology, The Johns Hopkins University School of Medicine, Baltimore, MD, USA; Department of Biological Chemistry, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
Ye Jin Lee: Department of Biochemistry and Molecular Biology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
Danfeng Cai: Department of Biochemistry and Molecular Biology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
Mohammad J. Hossain: Department of Biological Chemistry, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
Tamara J. O’Connor: Department of Biological Chemistry, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
Pragney Deme: Department of Neurology, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
Norman J. Haughey: Department of Neurology, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
Susanna Scafidi: Department of Anesthesiology and Critical Care Medicine, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
Ryan C. Riddle: Department of Orthopaedics, University of Maryland School of Medicine, Baltimore, MD, USA; Research and Development Service, Baltimore VA Medical Center, Baltimore, MD, USA
Michael J. Wolfgang: Department of Physiology, The Johns Hopkins University School of Medicine, Baltimore, MD, USA; Department of Biological Chemistry, The Johns Hopkins University School of Medicine, Baltimore, MD, USA; Department of Pharmacology and Molecular Sciences, The Johns Hopkins University School of Medicine, Baltimore, MD, USA; Corresponding author

Journal volume & issue: Vol. 27, no. 9
p. 110642

Abstract

Read online

Summary: Etomoxir has been used for decades as a popular small molecule inhibitor of carnitine palmitoyltransferase I, Cpt1, to block mitochondrial fatty acid β-oxidation. To test the specificity of etomoxir, we generated click chemistry–enabled reagents to label etomoxir binding proteins in situ. Etomoxir bound to Cpt1, but also bound to a large array of diverse proteins that metabolize and transport fatty acids in the cytoplasm, peroxisome, and mitochondria. Many of the most abundant proteins identified in primary hepatocytes were peroxisomal proteins. The loss of Pex5, required for the import of peroxisomal matrix proteins, eliminated many of these etomoxir-labeled proteins. By utilizing the promiscuous, covalent, and fatty acid mimetic properties of etomoxir, etomoxir targets of fatty acid ω-oxidation were revealed following the loss of Pex5. These data demonstrate that etomoxir is not specific for Cpt1 and is not appropriate as a tool to distinguish the biological effects of fatty acid oxidation.

Published in iScience

ISSN: 2589-0042 (Online)
Publisher: Elsevier
Country of publisher: United States
LCC subjects: Science
Website: http://www.cell.com/iscience/home

About the journal

Abstract

Keywords