Rimicaris exoculata (Decapoda: Bresiliidae) is one of the dominant species among hydrothermal vent communities along the Mid-Atlantic Ridge. This shrimp can tolerate high concentrations of heavy metals such as iron, but the mechanisms used for detoxification and utilization of excess metals remain largely unknown. Ferritin is a major iron storage protein in most living organisms. The central heavy subunit of ferritin (H-ferritin) possesses ferroxidase activity and converts iron from Fe2+ to Fe3+, the non-toxic form used for storage. In the present study, the H-ferritin RexFrtH was identified in the hydrothermal vent shrimp R. exoculata, and found to be highly expressed in the gill, the main organ involved in bioaccumulation of metals, at both RNA and protein levels. Accumulation of RexFrtH decreased from efferent to afferent vessels, coinciding with the direction of water flow through the gills. Fe3+ was localized with RexFrtH, and in vitro iron-binding and ferroxidase assays using recombinant RexFrtH confirmed the high affinity for iron. Based on these results, we propose a model of iron metabolism in R. exoculata gills; ferrous iron from ambient hydrothermal water accumulates and is converted and stored in ferric form by RexFrtH as an iron reservoir when needed for metabolism, or excreted as an intermediate to prevent iron overload. The findings expand our understanding of the adaptation strategies used by shrimps inhabiting extreme hydrothermal vents to cope with extremely high heavy metal concentrations.

中文翻译：

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来自热液喷发虾虾Ri的H-铁蛋白及其在铁代谢中的潜在作用。

Rimicaris exoculata（Decapoda：Bresiliidae）是大西洋中脊热液喷口群落中的优势种之一。这种虾可以忍受高浓度的重金属，例如铁，但是用于排毒和利用多余金属的机制仍然未知。铁蛋白是大多数活生物体中主要的铁存储蛋白。铁蛋白的中央重亚基（H-铁蛋白）具有铁氧化酶活性，可将铁从Fe2 +转化为Fe3 +（用于储存的无毒形式）。在本研究中，H-铁蛋白RexFrtH在热液对虾R. exoculata中被鉴定出，并在RNA和蛋白质水平上在ill（一种参与金属生物积累的主要器官）中高表达。RexFrtH的积累从传出血管减少到传出血管，与通过through的水流方向一致。Fe3 +用RexFrtH定位，并且使用重组RexFrtH进行的体外铁结合和铁氧化酶测定证实了对铁的高亲和力。基于这些结果，我们提出了一种在罗非鱼。中铁代谢的模型。RexFrtH会从周围的热水中收集亚铁，然后以三价铁的形式转化和存储，作为新陈代谢所需的铁储存器，或作为中间体排出以防止铁超载。这些发现扩大了我们对居住在极端热液喷口处的虾应对极高重金属浓度所采用的适应策略的理解。重组RexFrtH的体外铁结合和亚铁氧化酶测定证实了对铁的高度亲和力。基于这些结果，我们提出了一种在罗非鱼g中铁代谢的模型。RexFrtH会从周围的热水中收集亚铁，然后以三价铁的形式转化和存储，作为新陈代谢所需的铁储存器，或作为中间体排出以防止铁超载。这些发现扩大了我们对居住在极端热液喷口中的虾应对极高重金属浓度所采用的适应策略的理解。重组RexFrtH的体外铁结合和亚铁氧化酶测定证实了对铁的高度亲和力。基于这些结果，我们提出了一种在罗非鱼。中铁代谢的模型。RexFrtH会从周围的热水中收集亚铁，然后以三价铁的形式转化和存储，作为新陈代谢所需的铁储存器，或作为中间体排出以防止铁超载。这些发现扩大了我们对居住在极端热液喷口中的虾应对极高重金属浓度所采用的适应策略的理解。或作为中间体排泄，以防止铁超载。这些发现扩大了我们对居住在极端热液喷口中的虾应对极高重金属浓度所采用的适应策略的理解。或作为中间体排泄，以防止铁超载。这些发现扩大了我们对居住在极端热液喷口中的虾用于应对极高重金属浓度的适应策略的理解。