c-di-GMP对细菌胞外多糖合成与运输的调控

Regulation in EPS biosynthesis and transportation by cyclic diguanylate

环二鸟苷酸(Cyclic diguanylate,c-di-GMP)的发现已有29年。作为重要的细菌第二信使,c-di-GMP可参与调节细菌生物膜的合成与降解、运动、毒性、细胞周期、细胞分化等多种活动过程。胞外多糖(EPS)是细菌生物膜的主要组成成分,其合成和运输主要受c-di-GMP调控。目前细菌胞外多糖在医药、食品、农业、工业和环保等多个领域均有广泛的应用,其相关研究备受关注。本文旨在论述细菌中c-di-GMP合成与降解的调控,部分合成酶(Diguanylate cyclase,DGC)与降解酶(Phosphodiesterase,PDE)及其受体分子(Receptor)晶体结构等研究成果,并结合我们研究农杆菌ATCC31749中c-di-GMP对可德胶合成调控的基础上,重点阐述c-di-GMP对纤维素、藻酸盐、多聚氮乙酰葡萄糖胺(PNAG)和可德胶等EPS合成与运输的调控机制。

29 years have passed since the discovery of bis-（3＇,5＇） cyclic di-guanylate （c-di-GMP） which is a key bacterial second messenger involved in the regulation of many crucial bacterial processes including biofilm formation and disappearing, cell motility, virulence, cell cycle controlling, cell differentiation and aggregation as well. c-di-GMP plays an irreplaceable role in biosynthesis and transportation of bacterial extracellular polysaccharides （EPS）, which are major component of bacterial biofilm. Currently, due to its wide range of application in medicine, food processing, agriculture industries and environmental protection, it has gained more attention from medical and nutritional biochemistry researchers. In this paper we first reviewed recent achievements on crystal structure of c-di-GMP metabolic enzymes and its multiple receptor protein of c-di-GMP with emphasis on its in vivo concentration regulation; then combined with our researches on the regulation of curdlan, biosynthesis by c-di-GMP in Agrobacterium sp. ATCC31749, we further focus on the advancement of c-di-GMP regulation on the biosynthesis and transportation of bacterial extracellular polysaccharides （EPS）, such as cellulose, alginate, poly-N-acetylglucosamine （PNAG） and curdlan as well, which were widely used in industrial, pharmaceutical and food applications.