Brault Ariane, Mbuya Berthy, Labbé Simon
Département de Biochimie et de Génomique Fonctionnelle, Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, Sherbrooke, QC, Canada.
Front Microbiol. 2022 Jul 19;13:962853. doi: 10.3389/fmicb.2022.962853. eCollection 2022.
Although is unable to produce siderophores, this fungal organism can assimilate iron bound to the hydroxamate-type siderophore ferrichrome (Fc) produced and secreted by other microbes. Fc can enter cells Arn1. Unlike , synthesizes and secretes Fc. The and genes encode, respectively, a Fc synthetase and an ornithine-N-oxygenase, which are required for Fc production. When both genes were expressed in , cross-feeding experiments revealed that Δ Δ cells expressing Arn1 could grow in the vicinity of under low-iron conditions. In contrast, deletion of and produced a defect in the ability of to keep cells alive when Fc is used as the sole source of iron. Further analysis identified a gene designated that encodes an N-transacetylase required for Fc production in . The Δ mutant strain exhibited a severe growth defect in iron-poor media, and it was unable to promote Fc-dependent growth of cells. Microscopic analyses of cells expressing a functional Sib3-GFP protein revealed that Sib3 was localized throughout the cells, with a proportion of Sib3 being colocalized with Sib1 and Sib2 within the cytosol. Collectively, these results describe the first example of a one-way cross-feeding interaction, with providing Fc that enables to grow when Fc is used as the sole source of iron.
尽管[具体真菌名称]无法产生铁载体，但这种真菌生物体能够同化与其他微生物产生并分泌的异羟肟酸型铁载体铁色素（Fc）结合的铁。Fc可通过Arn1进入[具体真菌名称]细胞。与[具体真菌名称]不同，[另一种真菌名称]合成并分泌Fc。[另一种真菌名称]的[具体基因名称1]和[具体基因名称2]基因分别编码一种Fc合成酶和一种鸟氨酸 - N - 加氧酶，它们是Fc产生所必需的。当这两个基因在[具体真菌名称]中表达时，交叉喂养实验表明，表达Arn1的Δ[具体基因名称1]Δ[具体基因名称2]细胞在低铁条件下能够在[另一种真菌名称]附近生长。相比之下，缺失[具体基因名称1]和[具体基因名称2]会导致[另一种真菌名称]在以Fc作为唯一铁源时维持[具体真菌名称]细胞存活的能力出现缺陷。进一步分析鉴定出一个名为[具体基因名称3]的基因，它编码[另一种真菌名称]中Fc产生所需的N - 转乙酰酶。Δ[具体基因名称3]突变株在缺铁培养基中表现出严重的生长缺陷，并且无法促进[具体真菌名称]细胞依赖Fc的生长。对表达功能性Sib3 - GFP蛋白的[另一种真菌名称]细胞进行显微镜分析发现，Sib3定位于整个细胞中，其中一部分Sib3与胞质溶胶中的Sib1和Sib2共定位。总体而言，这些结果描述了单向交叉喂养相互作用的首个例子，即[另一种真菌名称]提供Fc，使[具体真菌名称]在以Fc作为唯一铁源时能够生长。
