Characterization of the plastidial pyruvate transporting mechanism

丙酮酸是植物体内多种叶绿体定位代谢途径的重要代谢物，包括C4光合作用的CO浓缩机制。尽管丙酮酸输入到叶绿体中起着至关重要的作用，但调节丙酮酸运输的分子仍不清楚。通过对黄花属植物C3和C4的差异转录组分析，我们发现了一个新的胆汁酸转运蛋白基因，命名为BASS2：钠转运蛋白家族蛋白2，该基因在具有钠依赖型丙酮酸转运蛋白的C4植物中含量丰富。重组BASS2具有钠依赖的丙酮酸摄取活性。

Pyruvate is an essential metabolite for multiple plastid-localized metabolic pathways of plants, including the C4 photosynthetic CO, -concentrating mechanism. Despite the crucial role of pyruvate import into plastids, the molecule mediating pyruvate transport is still unknown. Using differential transcriptome analyses of the C3 and C4 plants of the genus Flaveria, we have identified a novel plastid-localized transporter gene, named BASS2, for bile acid : sodium symporter family protein 2, the transcript of which is abundant in C4 plants that have the sodium-dependent pyruvate transporter. Recombinant BASS2 shows sodium-dependent pyruvate uptake activity.