Group of Biopolymer Analytics, University of Potsdam, Potsdam-Golm 14476, Germany.
Department of Biochemistry, Warsaw University of Life Sciences-SGGW, Warsaw 02-776, Poland.
Plant Cell Physiol. 2020 Feb 1;61(2):381-392. doi: 10.1093/pcp/pcz206.
Primary carbohydrate metabolism in plants includes several sugar and sugar-derivative transport processes. Over recent years, evidences have shown that in starch-related transport processes, in addition to glucose 6-phosphate, maltose, glucose and triose-phosphates, glucose 1-phosphate also plays a role and thereby increases the possible fluxes of sugar metabolites in planta. In this study, we report the characterization of two highly similar transporters, At1g34020 and At4g09810, in Arabidopsis thaliana, which allow the import of glucose 1-phosphate through the plasma membrane. Both transporters were expressed in yeast and were biochemically analyzed to reveal an antiport of glucose 1-phosphate/phosphate. Furthermore, we showed that the apoplast of Arabidopsis leaves contained glucose 1-phosphate and that the corresponding mutant of these transporters had higher glucose 1-phosphate amounts in the apoplast and alterations in starch and starch-related metabolism.
植物的初级碳水化合物代谢包括几种糖和糖衍生物的转运过程。近年来的证据表明，在与淀粉相关的转运过程中，除了葡萄糖 6-磷酸、麦芽糖、葡萄糖和三磷酸甘油醛外，葡萄糖 1-磷酸也发挥作用，从而增加了植物中糖代谢物的可能通量。在这项研究中，我们报告了拟南芥中两个高度相似的转运蛋白 At1g34020 和 At4g09810 的特征，它们允许葡萄糖 1-磷酸通过质膜进入。这两种转运蛋白都在酵母中表达，并进行了生化分析，以揭示葡萄糖 1-磷酸/磷酸的反向转运。此外，我们表明拟南芥叶片的质外体含有葡萄糖 1-磷酸，并且这些转运蛋白的相应突变体在质外体中有更高的葡萄糖 1-磷酸含量，并改变了淀粉和与淀粉相关的代谢。
