As a second messenger widely present in bacteria, cyclic diguanosine monophosphate (c-di-GMP) can act on different receptors to regulate various physiological functions of bacteria, including biofilm formation, bacterial motility, bacterial virulence, cell cycle and differentiation. The enzymes responsible for the synthesis and degradation of c - di - GMP are diguanylate cyclases (DGCs) and phosphodiesterases (PDEs), respectively. The diguanylate cyclase contains a GGDEF conserved domain, and the phosphodiesterase contains an EAL conserved domain or an HD-GYP domain. The level of intracellular c-di-GMP is dependent on the activity of diguanylate cyclase and phosphodiesterase, and proteins containing the GGDEF and EAL/ HD-GYP domains are often linked to the signal-sensing regulatory domain at the N-terminus, such as PAS domain and REC domain. These regulatory domains are able to sense intracellular and extracellular signals to regulate intracellular c-di-GMP levels. In addition, protein interactions between c-diGMP synthesis and degrading enzymes and interactions with other proteins can also regulate. This paper reviews the mechanism of the second messenger c-di-GMP synthesis degradation and regulation mechanism, and summarizes the latest research progress.

环二鸟苷酸(cyclic diguanosine monophosphate, c-di-GMP)作为细菌中广泛存在的第二信使,能够作用于 不同的受体调控细菌的多种生理功能,包括生物膜的形成、细菌运动、细菌毒力、细胞周期与分化等。 负责合成和降解 c-di-GMP 的酶分别为二鸟苷酸环化酶(diguanylate cyclases, DGCs)和磷酸二酯酶(phosphodiesterases, PDEs),二鸟苷 酸环化酶含有 GGDEF 保守结构域,磷酸二酯酶含有 EAL 保守结构域或 HD-GYP 结构域。 胞内 c-di-GMP 的水平依 赖于二鸟苷酸环化酶和磷酸二酯酶的活性,含有 GGDEF 和 EAL / HD-GYP 结构域的蛋白在 N 端经常会连接信号感应 调控结构域,如 PAS 结构域和 REC 结构域。 这些调控结构域能够感知胞内外信号,从而调控胞内 c-di-GMP 的水平; 此外,c-di-GMP 合成和降解酶之间的蛋白互作及与其他蛋白之间的互作也能够调节胞内 c-di-GMP 的水平。 本文综 述了第二信使 c-di-GMP 合成降解的机制以及调节机制,并总结了其最新研究进展。