Role of FOXA in mitochondrial citrate carrier gene expression and insulin secretion.
In this study, we have investigated the transcriptional role of the FOXA site present in the promoter of the mitochondrial citrate carrier (CIC) gene. We have shown that wild-type (but not mutated) CIC FOXA site cloned in front of the luciferase promoter confers transcriptional activation of the gene reporter, particularly in cells overexpressing FOXA1. We have also demonstrated that overexpression and silencing of FOXA increases and reduces CIC transcript and protein levels, respectively. In addition, FOXA1 silencing in INS-1 cells decreases not only CIC mRNA and protein but also the amount of citrate in the cytosol and glucose-stimulated insulin secretion. These results show that FOXA plays a role in the transcriptional regulation of CIC and in insulin secretion.
Iacobazzi
Vito
V
Department of Pharmaco-Biology, Laboratory of Biochemistry and Molecular Biology, University of Bari, Bari, Italy.
Infantino
Vittoria
V
Bisaccia
Faustino
F
Castegna
Alessandra
A
Palmieri
Ferdinando
F
D027321:Anion Transport Proteins / Q000235:genetics*; D001483:Base Sequence; D001665:Binding Sites; D002460:Cell Line; D005786:Gene Expression Regulation; D051541:Hepatocyte Nuclear Factor 3-alpha / Q000378:metabolism*; D006801:Humans; D007328:Insulin / Q000378:metabolism*; D000078790:Insulin Secretion; D050417:Insulin-Secreting Cells / Q000378:metabolism*; D024101:Mitochondrial Proteins / Q000235:genetics*; D027361:Organic Anion Transporters; D014158:Transcription, Genetic
D027321:Anion Transport Proteins; C496499:FOXA1 protein, human; D051541:Hepatocyte Nuclear Factor 3-alpha; D007328:Insulin; D024101:Mitochondrial Proteins; D027361:Organic Anion Transporters; C532592:Slc25a1 protein, human