Estrogen-related receptors stimulate pyruvate dehydrogenase kinase isoform 4 gene expression.
The pyruvate dehydrogenase complex (PDC) catalyzes the conversion of pyruvate to acetyl-CoA in mitochondria and is a key regulatory enzyme in the oxidation of glucose to acetyl-CoA. Phosphorylation of PDC by the pyruvate dehydrogenase kinases (PDK2 and PDK4) inhibits PDC activity. Expression of the PDK genes is elevated in diabetes, leading to the decreased oxidation of pyruvate to acetyl-CoA. In these studies we have investigated the transcriptional regulation of the PDK4 gene by the estrogen-related receptors (ERRalpha and ERRgamma). The ERRs are orphan nuclear receptors whose physiological roles include the induction of fatty acid oxidation in heart and muscle. Previously, we found that the peroxisome proliferator-activated receptor gamma coactivator (PGC-1alpha) stimulates the expression of PDK4. Here we report that ERRalpha and ERRgamma stimulate the PDK4 gene in hepatoma cells, suggesting a novel role for ERRs in controlling pyruvate metabolism. In addition, both ERR isoforms recruit PGC-1alpha to the PDK4 promoter. Insulin, which decreases the expression of the PDK4 gene, inhibits the induction of PDK4 by ERRalpha and ERRgamma. The forkhead transcription factor (FoxO1) binds the PDK4 gene and contributes to the induction of PDK4 by ERRs and PGC-1alpha. Insulin suppresses PDK4 expression in part through the dissociation of FoxO1 and PGC-1alpha from the PDK4 promoter. Our data demonstrate a key role for the ERRs in the induction of hepatic PDK4 gene expression.
Zhang
Yi
Y
Department of Pharmacology, College of Medicine, University of Tennessee Health Science Center, Memphis, Tennessee 38163, USA.
Ma
Ke
K
Sadana
Prabodh
P
Chowdhury
Farhana
F
Gaillard
Stephanie
S
Wang
Fang
F
McDonnell
Donald P
DP
Unterman
Terry G
TG
Elam
Marshall B
MB
Park
Edwards A
EA
D064413:3-Phosphoinositide-Dependent Protein Kinases; D000818:Animals; D006528:Carcinoma, Hepatocellular / Q000201:enzymology / Q000235:genetics; D002460:Cell Line; D045744:Cell Line, Tumor; D015971:Gene Expression Regulation, Enzymologic / Q000502:physiology*; D006801:Humans; D007527:Isoenzymes / Q000096:biosynthesis / Q000235:genetics; D008099:Liver / Q000201:enzymology / Q000378:metabolism; D008113:Liver Neoplasms / Q000201:enzymology / Q000235:genetics; D000071248:Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; D011401:Promoter Regions, Genetic; D011485:Protein Binding / Q000235:genetics; D011494:Protein Kinases / Q000096:biosynthesis* / Q000235:genetics* / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000096:biosynthesis / Q000235:genetics; D011773:Pyruvates / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000502:physiology; D051381:Rats; D018160:Receptors, Cytoplasmic and Nuclear / Q000378:metabolism / Q000502:physiology*; D011960:Receptors, Estrogen / Q000378:metabolism / Q000502:physiology*; D014157:Transcription Factors / Q000502:physiology; D000097983:ERRalpha Estrogen-Related Receptor
D064413:3-Phosphoinositide-Dependent Protein Kinases; D007527:Isoenzymes; D000071248:Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; D011494:Protein Kinases; D017346:Protein Serine-Threonine Kinases; D011773:Pyruvates; D016601:RNA-Binding Proteins; D018160:Receptors, Cytoplasmic and Nuclear; D011960:Receptors, Estrogen; D014157:Transcription Factors; D000097983:ERRalpha Estrogen-Related Receptor; C493778:Esrrg protein, rat; C501429:Ppargc1a protein, rat; C403287:pyruvate dehydrogenase kinase 4