Mitochondrial-targeted aryl hydrocarbon receptor and the impact of 2,3,7,8-tetrachlorodibenzo-p-dioxin on cellular respiration and the mitochondrial proteome.
The aryl hydrocarbon receptor (AHR) is a ligand-activated transcription factor within the Per-Arnt-Sim (PAS) domain superfamily. Exposure to the most potent AHR ligand, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), is associated with various pathological effects including metabolic syndrome. While research over the last several years has demonstrated a role for oxidative stress and metabolic dysfunction in AHR-dependent TCDD-induced toxicity, the role of the mitochondria in this process has not been fully explored. Our previous research suggested that a portion of the cellular pool of AHR could be found in the mitochondria (mitoAHR). Using a protease protection assay with digitonin extraction, we have now shown that this mitoAHR is localized to the inter-membrane space (IMS) of the organelle. TCDD exposure induced a degradation of mitoAHR similar to that of cytosolic AHR. Furthermore, siRNA-mediated knockdown revealed that translocase of outer-mitochondrial membrane 20 (TOMM20) was involved in the import of AHR into the mitochondria. In addition, TCDD altered cellular respiration in an AHR-dependent manner to maintain respiratory efficiency as measured by oxygen consumption rate (OCR). Stable isotope labeling by amino acids in cell culture (SILAC) identified a battery of proteins within the mitochondrial proteome influenced by TCDD in an AHR-dependent manner. Among these, 17 proteins with fold changes≥2 are associated with various metabolic pathways, suggesting a role of mitochondrial retrograde signaling in TCDD-mediated pathologies. Collectively, these studies suggest that mitoAHR is localized to the IMS and AHR-dependent TCDD-induced toxicity, including metabolic dysfunction, wasting syndrome, and hepatic steatosis, involves mitochondrial dysfunction.
Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, United States; Center for Mitochondrial Science and Medicine, Michigan State University, East Lansing, MI 48824, United States.
Hye Jin
HJ
Hwang
Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, United States; Institute for Integrative Toxicology, Michigan State University, East Lansing, MI 48824-1319, United States.
Peter
P
Dornbos
Institute for Integrative Toxicology, Michigan State University, East Lansing, MI 48824-1319, United States; Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI 48824, United States.
Michelle
M
Steidemann
Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI 48824, United States.
Taylor K
TK
Dunivin
Institute for Integrative Toxicology, Michigan State University, East Lansing, MI 48824-1319, United States; Cell and Molecular Biology Graduate Program, Michigan State University, East Lansing, MI 48824, United States.
Mike
M
Rizzo
Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, United States; Center for Mitochondrial Science and Medicine, Michigan State University, East Lansing, MI 48824, United States. Electronic address: lapres@msu.edu.
John J
JJ
LaPres
D000818:Animals; D045744:Cell Line, Tumor; D019069:Cell Respiration / Q000187:drug effects; D018841:HSP90 Heat-Shock Proteins / Q000378:metabolism; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism; D026901:Membrane Transport Proteins / Q000378:metabolism; D051379:Mice; D008928:Mitochondria / Q000187:drug effects* / Q000378:metabolism; D000090622:Mitochondrial Precursor Protein Import Complex Proteins; D010101:Oxygen Consumption / Q000187:drug effects; D000072317:Polychlorinated Dibenzodioxins / Q000633:toxicity*; D020543:Proteome; D034741:RNA, Small Interfering; D018336:Receptors, Aryl Hydrocarbon / Q000096:biosynthesis* / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000378:metabolism
D018841:HSP90 Heat-Shock Proteins; D047908:Intracellular Signaling Peptides and Proteins; D026901:Membrane Transport Proteins; D000090622:Mitochondrial Precursor Protein Import Complex Proteins; D000072317:Polychlorinated Dibenzodioxins; D020543:Proteome; D034741:RNA, Small Interfering; D018336:Receptors, Aryl Hydrocarbon; D011956:Receptors, Cell Surface; C489997:Tomm20 protein, mouse; C103265:aryl hydrocarbon receptor-interacting protein
2,3,7,8-Tetrachlorodibenzo-p-dioxin, TCDD; Aryl hydrocarbon receptor; Mitochondria; Oxidative phosphorylation; Proteomics; SILAC