Transcription factor activator protein-1 expressed by kainate treatment can bind to the non-coding region of mitochondrial genome in murine hippocampus.
We have demonstrated previously that the transcription factor activator protein-1 (AP-1) complex is translocated into mitochondria into the nucleus in murine hippocampus after systemic kainate injection (Ogita et al. [2002] J. Neurosci. 22:2561-2570). The present study investigates whether the mitochondrial AP-1 complex translocated in response to kainate treatment binds to AP-1-like sites located at the non-coding region of the mitochondrial genome in mouse hippocampus. There are 10 sites with sequences similar to the nuclear AP-1 site in the non-coding region. Of 10 pieces (MT-1-MT-10) of synthesized double-stranded oligonucleotides, each containing a mitochondrial AP-1-like site, MT-3, MT-4, and MT-9 were effective in inhibiting mitochondrial AP-1 DNA binding enhanced by kainate. Electrophoresis mobility shift analysis using radiolabeled MT-3 and MT-9 probes demonstrated marked enhancement with binding of these 2 probes in hippocampal mitochondrial extracts prepared 2-6 hr after kainate treatment. Unlabeled AP-1 probe was more potent than unlabeled MT-9 probe in inhibiting the mitochondrial MT-9 binding. Supershift analysis revealed participation of particular Fos/Jun family proteins, such as c-Fos, Fos-B, c-Jun, Jun-B, and Jun-D, in MT-9 binding in hippocampal mitochondrial extracts prepared 4 hr after kainate treatment. Immunoprecipitation analysis using anti-c-Fos antibody demonstrated that c-Fos associated with the mitochondrial genome in hippocampal mitochondria prepared from kainate-treated animals. These results suggest that the AP-1 complex expressed by in vivo kainate treatment would bind to AP-1-like sites in the non-coding region of the mitochondrial genome after translocation into mitochondria from murine hippocampus.
Ogita
Kiyokazu
K
Department of Pharmacology, Faculty of Pharmaceutical Sciences, Setsunan University, Hirakata, Osaka, Japan. ogita@pharm.setsunan.ac.jp
Fujinami
Yoshiaki
Y
Kitano
Masahiro
M
Yoneda
Yukio
Y
D000818:Animals; D000906:Antibodies / Q000378:metabolism; D019540:Area Under Curve; D001665:Binding Sites / Q000187:drug effects / Q000502:physiology; D001667:Binding, Competitive / Q000187:drug effects; D004268:DNA-Binding Proteins / Q000276:immunology / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D024202:Electrophoretic Mobility Shift Assay / Q000379:methods; D018690:Excitatory Amino Acid Agonists / Q000008:administration & dosage / Q000494:pharmacology; D005095:Exoribonucleases / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects*; D016678:Genome; D006624:Hippocampus / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D007608:Kainic Acid / Q000008:administration & dosage / Q000494:pharmacology*; D008297:Male; D000090023:Metallothionein 3; D051379:Mice; D008815:Mice, Inbred Strains; D008928:Mitochondria / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D016133:Polymerase Chain Reaction / Q000379:methods; D011233:Precipitin Tests; D011401:Promoter Regions, Genetic; D017385:Sequence Homology; D013997:Time Factors; D018808:Transcription Factor AP-1 / Q000378:metabolism*
D000906:Antibodies; D004268:DNA-Binding Proteins; D018690:Excitatory Amino Acid Agonists; D000090023:Metallothionein 3; C000715430:Mt3 protein, mouse; D018808:Transcription Factor AP-1; D005095:Exoribonucleases; C065486:oligonucleotidase; D007608:Kainic Acid