环二鸟苷一磷酸(c-di-GMP)是细菌中调节多种生物学功能的第二信使,包括生物膜的形成,毒力,和细胞间通讯。然而,c-di-GMP信号在经济重要的丝状蓝细菌中几乎是未知的,节螺旋体。在这项研究中,我们预测31个基因编码GGDEF域蛋白从A.platensisNIES39作为潜在的二鸟苷酸环化酶(DGC)。系统发育分布分析显示,五个基因(RS09460,RS04865,RS26155,M01840和E02220)在25个节旋藻菌株中具有高度保守的分布。由RS09460编码的Adc1进一步表征为典型的DGC。通过建立节旋体的遗传转化体系,我们证明了Adc1的过表达促进了细胞外聚合物(EPS)的产生,这又导致了细丝的聚集。我们还证实RS04865和RS26155可以编码活性DGC,而酶活性测定表明,由M01840和E02220编码的蛋白质具有磷酸二酯酶(PDE)活性。Meta分析显示,RS09460和RS04865的表达谱在31个条件下不受影响,这表明它们可能作为保守基因在节旋体中维持c-di-GMP的基础水平。总之,本报告将为进一步研究节旋体中c-di-GMP信号提供依据。
Cyclic diguanosine monophosphate (c-di-GMP) is a second messenger in bacteria that regulates multiple biological functions, including biofilm formation, virulence, and intercellular communication. However, c-di-GMP signaling is virtually unknown in economically important filamentous cyanobacteria,
Arthrospira. In this study, we predicted 31 genes encoding GGDEF-domain proteins from A. platensis NIES39 as potential diguanylate cyclases (DGCs). Phylogenetic distribution analysis showed five genes (RS09460, RS04865, RS26155, M01840, and E02220) with highly conserved distribution across 25
Arthrospira strains. Adc1 encoded by RS09460 was further characterized as a typical DGC. By establishing the genetic transformation system of
Arthrospira, we demonstrated that the overexpression of Adc1 promoted the production of extracellular polymeric substances (EPS), which in turn caused the aggregation of filaments. We also confirmed that RS04865 and RS26155 may encode active DGCs, while enzymatic activity assays showed that proteins encoded by M01840 and E02220 have phosphodiesterase (PDE) activity. Meta-analysis revealed that the expression profiles of RS09460 and RS04865 were unaffected under 31 conditions, suggesting that they may function as conserved genes in maintaining the basal level of c-di-GMP in
Arthrospira. In summary, this report will provide the basis for further studies of c-di-GMP signal in
Arthrospira.