A 45 kDa protein related to PPARgamma2, induced by peroxisome proliferators, is located in the mitochondrial matrix.
Besides their involvement in the control of nuclear gene expression by activating several peroxisome proliferator-activated receptors (PPARs), peroxisome proliferators influence mitochondrial activity. By analogy with the previous characterization of a mitochondrial T3 receptor (p43), we searched for the presence of a peroxisome proliferator target in the organelle. Using several antisera raised against different domains of PPARs, we demonstrated by Western blotting, immunoprecipitation and electron microscopy experiments, that a 45 kDa protein related to PPARgamma2 (mt-PPAR) is located in the matrix of rat liver mitochondria. In addition, we found that the amounts of mt-PPAR are increased by clofibrate treatment. Moreover, in EMSA experiments mt-PPAR bound to a DR2 sequence located in the mitochondrial D-loop, by forming a complex with p43. Last, studies of tissue-specific expression indicated that mt-PPAR is detected in mitochondria of all tissues tested except the brain in amounts positively related to p43 abundance. Besides their involvement in the control of nuclear gene expression by activating several peroxisome proliferator-activated receptors (PPARs), peroxisome proliferators influence mitochondrial activity. By analogy with the previous characterization of a mitochondrial T3 receptor (p43), we searched for the presence of a peroxisome proliferator target in the organelle. Using several antisera raised against different domains of PPARs, we demonstrated by Western blotting, immunoprecipitation and electron microscopy experiments, that a 45 kDa protein related to PPARgamma2 (mt-PPAR) is located in the matrix of rat liver mitochondria. In addition, we found that the amounts of mt-PPAR are increased by clofibrate treatment. Moreover, in EMSA experiments mt-PPAR bound to a DR2 sequence located in the mitochondrial D-loop, by forming a complex with p43. Last, studies of tissue-specific expression indicated that mt-PPAR is detected in mitochondria of all tissues tested except the brain in amounts positively related to p43 abundance.
UMR Differenciation Cellulaire et Croissance, Unité d'Endocrinologie Cellulaire, Institut National de la Recherche Agronomique, place Viala, 34060 Montpellier Cedex 1, France. casasf@ensam.inra.fr
F
F
Casas
L
L
Domenjoud
P
P
Rochard
R
R
Hatier
A
A
Rodier
L
L
Daury
A
A
Bianchi
P
P
Kremarik-Bouillaud
P
P
Becuwe
J
J
Keller
H
H
Schohn
C
C
Wrutniak-Cabello
G
G
Cabello
M
M
Dauça
D000818:Animals; D002994:Clofibrate / Q000494:pharmacology; D016384:Consensus Sequence / Q000235:genetics; D004272:DNA, Mitochondrial / Q000235:genetics / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000378:metabolism*; D008297:Male; D008854:Microscopy, Electron; D008930:Mitochondria, Liver / Q000737:chemistry* / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D008970:Molecular Weight; D009928:Organ Specificity; D020025:Peroxisome Proliferators / Q000494:pharmacology*; D020033:Protein Isoforms / Q000737:chemistry / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D018160:Receptors, Cytoplasmic and Nuclear / Q000737:chemistry*; D012045:Regulatory Sequences, Nucleic Acid / Q000235:genetics; D014157:Transcription Factors / Q000737:chemistry*; D015854:Up-Regulation / Q000187:drug effects*
D004272:DNA, Mitochondrial; D004268:DNA-Binding Proteins; D020025:Peroxisome Proliferators; D020033:Protein Isoforms; D018160:Receptors, Cytoplasmic and Nuclear; D014157:Transcription Factors; D002994:Clofibrate