Domínguez-Martín María Agustina, López-Lozano Antonio, Rangel-Zúñiga Oriol Alberto, Díez Jesús, García-Fernández José Manuel
Departamento de Bioquímica y Biología Molecular, Campus Universitario de Excelencia ceiA3, Universidad de Córdoba.
FEMS Microbiol Lett. 2018 Feb 1;365(3). doi: 10.1093/femsle/fnx278.
The abundance and significant contribution to global primary production of the marine cyanobacterium Prochlorococcus have made it one of the main models in marine ecology. Several conditions known to cause strong effects on the regulation of N-related enzymes in other cyanobacteria lacked such effect in Prochlorococcus. Prochlorococcus sp. strain MIT9313 is one of the most early-branching strains among the members of this genus. In order to further understand the C/N control system in this cyanobacterium, we studied the effect of the absence of three key elements in the ocean, namely N, P and Fe, as well as the effect of inhibitors of the N assimilation or photosynthesis on the N metabolism of this strain. Furthermore, we focused our work in the effect of ageing, as the age of cultures has clear effects on the regulation of some enzymes in Prochlorococcus. To reach this goal, expression of the main three regulators involved in N assimilation in cyanobacteria, namely ntcA, glnB and pipX, as well as that of icd (encoding for isocitrate dehydrogenase) were analysed. Our results show that the control of the main proteins involved in the C/N balance in strain MIT9313 differs from other model Prochlorococcus strains.
海洋蓝细菌原绿球藻在全球初级生产中的丰富度及其重大贡献使其成为海洋生态学的主要模式生物之一。已知一些对其他蓝细菌中氮相关酶调控有强烈影响的条件在原绿球藻中却没有这种作用。原绿球藻MIT9313菌株是该属成员中最早分支的菌株之一。为了进一步了解这种蓝细菌中的碳/氮控制系统，我们研究了海洋中三种关键元素（即氮、磷和铁）缺失的影响，以及氮同化或光合作用抑制剂对该菌株氮代谢的影响。此外，由于培养物的年龄对原绿球藻中某些酶的调控有明显影响，我们重点研究了老化的影响。为实现这一目标，我们分析了蓝细菌中参与氮同化的三个主要调节因子（即ntcA、glnB和pipX）以及icd（编码异柠檬酸脱氢酶）的表达。我们的结果表明，MIT9313菌株中参与碳/氮平衡的主要蛋白质的调控与其他模式原绿球藻菌株不同。
