title: Thyroid hormone increases transcription of GA-binding protein/nuclear respiratory factor-2 alpha-subunit in rat liver.
abstract: Thyroid hormone (TH) regulates mitochondrial respiratory rate by activating coordinated transcription in the nucleus and mitochondria. Whereas TH activates transcription of mitochondrial genes directly, the activation of nuclear-encoded mitochondrial genes is probably executed by indirect unknown mechanisms. Nuclear respiratory factors (NRF)-1 and GA-binding protein (BP)/NRF-2 may function as transacting genes, but regulation of these genes by TH is not demonstrated. We show that TH administration to hypothyroid rats promptly increases GABP/NRF-2 alpha-subunit mRNA levels in the liver, without significant changes in beta, gamma subunits. In run-on and time-course experiments, the transcription rate and protein levels increased three-fold in response to TH, indicating GABP/NRF-2 transcriptional regulation. The results also support the notion that ATP synthase beta-subunit is regulated by TH through the indirect activation of GABP/NRF-2.
authors.affiliation: Instituto de Investigaciones Biomédicas Alberto Sols (CSIC-UAM), Arturo Duperier 4, 28029 Madrid, Spain.
authors.forename: Angeles
authors.initials: A
authors.lastname: Rodríguez-Peña
authors.forename: Héctor
authors.initials: H
authors.lastname: Escrivá
authors.forename: Ana C
authors.initials: AC
authors.lastname: Handler
authors.forename: Carmen G
authors.initials: CG
authors.lastname: Vallejo
mesh_terms: D025181:ATP Synthetase Complexes / Q000235:genetics / Q000378:metabolism; D000818:Animals; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D004334:Drug Administration Schedule; D051268:GA-Binding Protein Transcription Factor; D005786:Gene Expression Regulation / Q000187:drug effects / Q000502:physiology; D007037:Hypothyroidism / Q000188:drug therapy / Q000378:metabolism; D007274:Injections, Intraperitoneal; D008099:Liver / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D024101:Mitochondrial Proteins; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism; D021122:Protein Subunits; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D013997:Time Factors; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic / Q000187:drug effects*; D014284:Triiodothyronine / Q000008:administration & dosage*
chemical_list: D004268:DNA-Binding Proteins; D051268:GA-Binding Protein Transcription Factor; C495649:Gabpa protein, rat; C495653:Gabpb2 protein, rat; D024101:Mitochondrial Proteins; D009687:Nuclear Proteins; D021122:Protein Subunits; D012333:RNA, Messenger; C489030:Tfam protein, rat; D014157:Transcription Factors; C422562:mitochondrial transcription factor A; D014284:Triiodothyronine; D025181:ATP Synthetase Complexes