Bacteria respond to changes in environmental conditions through adaptation to external cues. Frequently, bacteria employ nucleotide signaling molecules to mediate a specific, rapid response. Cyclic di-AMP (c-di-AMP) was recently discovered to be a bacterial second messenger that is essential for viability in many species. In this review, we highlight recent work that has described the roles of c-di-AMP in bacterial responses to various stress conditions. These studies show that depending on the lifestyle and environmental niche of the bacterial species, the c-di-AMP signaling network results in diverse outcomes, such as regulating osmolyte transport, controlling plant attachment, or providing a checkpoint for spore formation. c-di-AMP achieves this signaling specificity through expression of different classes of synthesis and catabolic enzymes as well as receptor proteins and RNAs, which will be summarized.

中文翻译：

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细菌第二信使环双-AMP在适应压力提示中的许多作用。

细菌通过适应外部线索来响应环境条件的变化。通常，细菌会利用核苷酸信号分子来介导特定的快速反应。最近发现，环二AMP（c-di-AMP）是细菌的第二信使，对许多物种的生存能力至关重要。在这篇综述中，我们重点介绍了最近的工作，该工作描述了c-di-AMP在细菌对各种胁迫条件的反应中的作用。这些研究表明，取决于细菌物种的生活方式和环境环境，c-di-AMP信号网络可产生多种结果，例如调节渗透液运输，控制植物附着或提供孢子形成检查点。