Chen Xianyi, Qu Shaoxuan, Luo Xin, Lu Shi-En, Liu Youzhou, Li Huiping, Hou Lijuan, Lin Jinsheng, Jiang Ning, Ma Lin
Jiangsu Key Laboratory for Horticultural Crop Genetic Improvement, Institute of Vegetable Crops, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China.
Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology, Mississippi State University, Starkville, MS 39762, USA.
Microorganisms. 2022 Nov 26;10(12):2342. doi: 10.3390/microorganisms10122342.
Cyclic dimeric guanosine monophosphate (c-di-GMP) is synthesized by diguanylate cyclase (DGC) with the GGDEF domain. As a ubiquitous bacterial second messenger, it regulates diverse life-activity phenotypes in some bacteria. Although 38 genes encoding GGDEF-domain-containing proteins have been identified in the genome of the strain MS82, whether c-di-GMP functions as a facilitator or repressor of life-activity phenotypes is poorly understood. In this study, one of the 38 genes containing a GGDEF domain in MS82, was investigated to explore its regulatory function in bacterial life activities. The deletion mutant Δ and reversion mutant -comp were constructed by the method of biparental conjugation and homologous recombination. The life activities of the mutants, such as antifungal activity, biofilm formation ability, polysaccharide content, and motor behavior, were explored. The results showed that all life-activity phenotypes were significantly reduced after knocking out , whereas all were significantly restored to a similar level to that of MS82 after the complementation of . These results suggested that plays an important role in the regulation of a range of cellular activities by c-di-GMP in MS82.
环二鸟苷单磷酸（c-di-GMP）由具有GGDEF结构域的二鸟苷酸环化酶（DGC）合成。作为一种普遍存在的细菌第二信使，它在某些细菌中调节多种生命活动表型。尽管在菌株MS82的基因组中已鉴定出38个编码含GGDEF结构域蛋白的基因，但c-di-GMP作为生命活动表型的促进剂还是抑制剂，目前了解甚少。在本研究中，对MS82中38个含GGDEF结构域的基因之一进行了研究，以探索其在细菌生命活动中的调控功能。通过双亲接合和同源重组的方法构建了缺失突变体Δ和回复突变体-comp。对突变体的生命活动进行了探索，如抗真菌活性、生物膜形成能力、多糖含量和运动行为。结果表明，敲除后所有生命活动表型均显著降低，而在-comp互补后所有表型均显著恢复到与MS82相似的水平。这些结果表明，在MS82中，在c-di-GMP对一系列细胞活动的调控中发挥着重要作用。
