Becerra Gracia, Merchán Faustino, Blasco Rafael, Igeño M Isabel
Departamento de Bioquímica y Biología Molecular y Genética Facultad de Veterinaria, Universidad de Extremadura, Avenida de la Universidad s/n, 10003 Cáceres, Spain.
Departamento de Bioquímica y Biología Molecular y Genética Facultad de Veterinaria, Universidad de Extremadura, Avenida de la Universidad s/n, 10003 Cáceres, Spain.
J Biotechnol. 2014 Nov 20;190:2-10. doi: 10.1016/j.jbiotec.2014.03.030. Epub 2014 Apr 3.
The Fur protein is the main sensor of cellular iron status in bacteria. In the present study, we inactivated the fur gene of Pseudomonas pseudoalcaligenes CECT5344 and characterized the resulting mutant. Our findings provide experimental evidence that, cyanide generates an intracellular signal equivalent to that triggered by iron deprivation, as witnessed by the induction of prrF and fiuA (ferrichrome receptor) expression in the presence of cyanide. The fur mutant also displayed slow growth, especially in minimal culture medium, increased sensitivity to cyanide in LB medium and as expected, resistance to manganese ions. Moreover, the mutant exhibited enhanced iron accumulation and increased sensitivity to streptonigrin, as well as to some inducers of oxidative stress, such as paraquat and menadione, yet it remained resistant to hydrogen peroxide. Surprisingly, neither the wild type strain nor the fur mutant strain produced siderophores that could be detected using the universal CAS-agar method.
Fur蛋白是细菌细胞铁状态的主要传感器。在本研究中，我们使嗜碱假单胞菌CECT5344的fur基因失活，并对所得突变体进行了表征。我们的研究结果提供了实验证据，即氰化物产生的细胞内信号等同于铁缺乏触发的信号，这在氰化物存在下prrF和fiuA（高铁载体受体）表达的诱导中得到了证实。fur突变体也表现出生长缓慢，尤其是在基本培养基中，在LB培养基中对氰化物的敏感性增加，并且如预期的那样，对锰离子具有抗性。此外，该突变体表现出铁积累增强，对链黑菌素以及一些氧化应激诱导剂（如百草枯和甲萘醌）的敏感性增加，但它仍然对过氧化氢具有抗性。令人惊讶的是，野生型菌株和fur突变体菌株都没有产生可以使用通用CAS-琼脂法检测到的铁载体。
