生物细胞中颗粒状多聚磷酸盐细胞器的结构与功能

Structure and function of granular polyphosphate organelle in biological cells

摘要:

多聚磷酸盐(polyphosphat，poly P)是一种由数十个或上百个磷酸根聚合而成的生物大分子，以颗粒状、胶体状和溶解状等多种状态存在于各类生物细胞中。生物体中的poly P能够通过分解提供能量；鳌合金属离子来调节细胞内渗透压，维持质膜稳定；与蛋白质或DNA结合稳定其结构，减轻细胞应激损伤。颗粒状多聚磷酸盐细胞器主要指细胞中用于贮存颗粒状poly P、金属阳离子以及蛋白质、氨基酸和少量水等物质的细胞器。在寄生虫细胞中颗粒状聚磷细胞器常称为酸性钙体，而细菌或者其他微生物细胞中则称为异染颗粒，但是随着研究的不断深入，发现酸性钙体和异染颗粒都具有相似的结构特征，遂将其统一定义为颗粒状多聚磷酸盐细胞器。颗粒状聚磷细胞器的发现拓展了生物共同祖先(last universal common ancestor，LUCA)的学说，丰富了原核生物细胞器认知，我们相信该细胞器在生命起源、抗环境胁迫、生物互作和代谢调控等方面具有重要功能，在疾病治疗以及磷生物地球化学循环过程中发挥重要作用。

Abstract:

Polyphosphate (poly P) is a polymer of tens to hundreds of phosphate residues, which is found in various biological cells in granular, colloidal, and dissolved forms. It has been verified that poly P can be an energy source and regulate intracellular osmotic pressure to maintain the stability of membrane. In addition, it binds to protein and DNA to stabilize them and protects cells from stress injury. Granular poly P organelle stores poly P granules, metal cations, proteins, amino acids, and water in cells. The poly P granules in the parasite are called acidocalcisomes and those in bacteria or other microorganisms are named metachromatic granules. Further research shows that they have similar structures and thus they are both called granular poly P organelles. Crucially, this organelle is thought to be the only one preserved from prokaryotes to humans and may even be last universal common ancestor (LUCA). It is crucial for the origin of life, anti-stress, biological interaction, and metabolism regulation. It is meaningful to develop this organelle in pharmaceutical research and biogeochemical cycle of phosphorus.