Hurtaud C, Gelly C, Chen Z, Lévi-Meyrueis C, Bouillaud F
BIOTRAM UPR9078, CNRS, Université Paris Descartes, Faculté de Médecine Necker Enfants Malades, 156 rue de Vaugirard, 75730 Paris, France.
Cell Mol Life Sci. 2007 Jul;64(14):1853-60. doi: 10.1007/s00018-007-7039-5.
Uncoupling protein 2 (UCP2) belongs to a family of transporters/exchangers of the mitochondrial inner membrane. Using cell lines representing natural sites of UCP2 expression (macrophages, colonocytes, pancreatic beta cells), we show that UCP2 expression is stimulated by glutamine at physiological concentrations. This control is exerted at the translational level. We demonstrate that the upstream open reading frame (ORF1) in the 5' untranslated region (5'UTR) of the UCP2 mRNA is required for this stimulation to take place. Cloning of the 5' UTR of the UCP2 mRNA in front of a GFP cDNA resulted in a reporter gene with which GFP expression could be induced by glutamine. An effect of glutamine on translation of a given mRNA has not been identified before, and this is the first evidence for a link between UCP2 and glutamine, an amino acid oxidized by immune cells or intestinal epithelium and playing a role in the control of insulin secretion.
解偶联蛋白2（UCP2）属于线粒体内膜转运蛋白/交换蛋白家族。利用代表UCP2天然表达位点的细胞系（巨噬细胞、结肠上皮细胞、胰腺β细胞），我们发现生理浓度的谷氨酰胺可刺激UCP2的表达。这种调控作用于翻译水平。我们证明，UCP2 mRNA 5'非翻译区（5'UTR）中的上游开放阅读框（ORF1）是这种刺激发生所必需的。将UCP2 mRNA的5'UTR克隆到GFP cDNA之前，得到了一个报告基因，谷氨酰胺可诱导该报告基因表达GFP。此前尚未发现谷氨酰胺对特定mRNA翻译的影响，这是UCP2与谷氨酰胺之间存在联系的首个证据，谷氨酰胺是一种被免疫细胞或肠上皮细胞氧化的氨基酸，在胰岛素分泌的调控中发挥作用。
