Epigenetic mechanisms and Sp1 regulate mitochondrial citrate carrier gene expression.
This study investigates the transcriptional role of the mitochondrial CIC proximal promoter. The wild-type (but not methylated) -335/-20 bp region of the CIC gene confers gene reporter activity, and the five wild-type (but not methylated) Sp1 binding elements in this region bind human recombinant Sp1. The DNA demethylating agent AzaC or the histone acetylating agent TSA increases CIC transcript and protein levels as well as the binding of Sp1 and of acetylated histones to the -335/-20 bp region of the CIC promoter in SK-N-SH cells but not in HepG2 cells; when untreated these cells exhibit low and high levels of gene expression, respectively. Finally, Sp1 silencing decreases proximal promoter-driven gene reporter activity as well as CIC mRNA and CIC protein in both untreated HepG2 cells and AzaC- and TSA-treated SK-N-SH cells. These results show that methylation, histone acetylation and Sp1 are important in the transcriptional regulation of the CIC proximal promoter.
Iacobazzi
Vito
V
Department of Pharmaco-Biology, Laboratory of Biochemistry and Molecular Biology, University of Bari, Via Orabona 4, Bari 70125, Italy.
Infantino
Vittoria
V
Palmieri
Ferdinando
F
D000107:Acetylation; D000818:Animals; D027321:Anion Transport Proteins / Q000235:genetics*; D001374:Azacitidine / Q000031:analogs & derivatives / Q000494:pharmacology; D001483:Base Sequence; D002460:Cell Line; D019175:DNA Methylation / Q000187:drug effects; D000077209:Decitabine; D044127:Epigenesis, Genetic; D015870:Gene Expression; D017930:Genes, Reporter; D006657:Histones / Q000378:metabolism; D006801:Humans; D006877:Hydroxamic Acids / Q000494:pharmacology; D051379:Mice; D024101:Mitochondrial Proteins / Q000235:genetics*; D027361:Organic Anion Transporters; D011401:Promoter Regions, Genetic / Q000187:drug effects; D051381:Rats; D016329:Sp1 Transcription Factor / Q000235:genetics / Q000378:metabolism*
D027321:Anion Transport Proteins; D006657:Histones; D006877:Hydroxamic Acids; D024101:Mitochondrial Proteins; D027361:Organic Anion Transporters; C532592:Slc25a1 protein, human; D016329:Sp1 Transcription Factor; C012589:trichostatin A; D000077209:Decitabine; D001374:Azacitidine