植物磷酸烯醇式丙酮酸羧化酶的功能及其在基因工程中的应用

Functions of plant phosphoenolpyruvate carboxylase and its applications for genetic engineering

摘要:

植物磷酸烯醇式丙酮酸羧化酶 (Phosphoenolpyruvate carboxylase，PEPC，EC 4.1.1.31) 是广泛存在的一种细胞质酶，催化磷酸烯醇式丙酮酸 (PEP) 和 HCO3-生成草酰乙酸 (OAA)，后者可转化生成三羧酸循环的多种中间产物。PEPC在植物细胞中参与植物的光合碳同化等重要代谢途径，并且在不同组织中具有多种生理功能。PEPC同时也参与调控植物种子的营养物质合成与代谢过程，控制糖类物质流向脂肪酸合成或蛋白质合成途径。以下介绍了植物PEPC的种类、蛋白质结构特点及其在植物组织中的调控方式，并重点论述了PEPC在生物基因工程中的应用方面的进展，随着对其功能机制和应用研究的深入，将有助于植物PEPC在高产优质农作物育种、能源植物和工业微生物等的开发利用等方面得到更好的发展与应用。

Abstract:

Phosphoenolpyruvate carboxylase (PEPC, EC 4.1.1.31) is an important ubiquitous cytosol enzyme that fixes HCO3- together with phosphoenolpyruvate (PEP) and yields oxaloacetate that can be converted to intermediates of the citric acid cycle. In plant cells, PEPC participates in CO2 assimilation and other important metabolic pathways, and it has broad functions in different plant tissues. PEPC is also involved in the regulation of storage product synthesis and metabolism in seeds, such as affecting the metabolic fluxes from sugars/starch towards the synthesis of fatty acids or amino acids and proteins. In this review, we introduced the progress in classification, structure and regulation of PEPC in plant tissues. We discussed the potential applications of plant PEPCs in genetic engineering. The researches in functions and regulation mechanism of plant PEPCs will provide beneficial approaches to applications of plant PEPCs in high-yield crops breeding, energy crop and microbe genetic engineering.