Ferritin is widely acknowledged as a conservative iron storage protein found in almost all living kingdoms. Apostichopus japonicus (Selenka) is among the oldest echinoderm fauna and has unique ...regenerative potential, but the catalytic mechanism of iron oxidation in A. japonicus ferritin (AjFER) remains elusive. We previously identified several potential metal-binding sites at the ferroxidase center, the three- and four-fold channels in AjFER. Herein, we prepared AjFER, AjFER-E25A/E60A/E105A, AjFER-D129A/E132A, and AjFER-E168A mutants, investigated their structures, and functionally characterized these ferritins with respect to Fesup.2+ uptake using X-ray techniques together with biochemical analytical methods. A crystallographic model of the AjFER-D129A/E132A mutant, which was solved to a resolution of 1.98 Å, suggested that the substitutions had a significant influence on the quaternary structure of the three-fold channel compared to that of AjFER. The structures of these ferritins in solution were determined based on the molecular envelopes of AjFER and its variants by small-angle X-ray scattering, and the structures were almost consistent with the characteristics of well-folded and globular-shaped proteins. Comparative biochemical analyses indicated that site-directed mutagenesis of metal-binding sites in AjFER presented relatively low rates of iron oxidation and thermostability, as well as weak iron-binding affinity, suggesting that these potential metal-binding sites play critical roles in the catalytic activity of ferritin. These findings provide profound insight into the structure-function relationships related to marine invertebrate ferritins.
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Nowadays cancer represents a prominent challenge in clinics. Main achievements in cancer management would be the development of highly accurate and specific diagnostic tools for early ...detection of cancer onset, and the generation of smart drug delivery systems for targeted chemotherapy release in cancer cells. In this context, protein-based nanocages hold a tremendous potential as devices for theranostics purposes. In particular, ferritin has emerged as an excellent and promising protein-based nanocage thanks to its unique architecture, surface properties and high biocompatibility. By exploiting natural recognition of the Transferrin Receptor 1, which is overexpressed on tumor cells, ferritin nanocages may ensure a proper drug delivery and release. Moreover, researchers have applied surface functionalities on ferritin cages for further providing active tumor targeting. Encapsulation strategies of non metal-containing drugs within ferritin cages have been explored and successfully performed with encouraging results. Various preclinical studies have demonstrated that nanoformulation within ferritin nanocages significantly improved targeted therapy and accurate imaging of cancer cells. Aims of this review are to describe structure and functions of ferritin nanocages, and to provide an overview about the nanotechnological approaches implemented for applying them to cancer diagnosis and treatment.
Iron is an essential nutrient for mitochondrial metabolic processes, including mitochondrial respiration. Ferritin complexes store excess iron and protect cells from iron toxicity. Therefore, iron ...stored in the ferritin complex might be utilized under iron-depleted conditions. In this study, we show that the inhibition of lysosome-dependent protein degradation by bafilomycin A1 and the knockdown of NCOA4, an autophagic receptor for ferritin, reduced mitochondrial respiration, respiratory chain complex assembly, and membrane potential under iron-sufficient conditions. However, autophagy did not contribute to degradation of the ferritin complex under iron-sufficient conditions. Knockout of the ferritin light chain, a subunit of the ferritin complex, inhibited ferritin degradation by decreasing interactions with NCOA4. However, ferritin light chain knockout did not affect mitochondrial functions under iron-sufficient conditions, and ferritin light chain knockout cells showed a rapid reduction of mitochondrial functions compared with wild-type cells under iron-depleted conditions. These results indicate that the constitutive degradation of the ferritin complex contributes to the maintenance of mitochondrial functions.
Serum ferritin: Past, present and future Wang, Wei; Knovich, Mary Ann; Coffman, Lan G. ...
Biochimica et biophysica acta,
08/2010, Letnik:
1800, Številka:
8
Journal Article
Recenzirano
Odprti dostop
Serum ferritin was discovered in the 1930s, and was developed as a clinical test in the 1970s. Many diseases are associated with iron overload or iron deficiency. Serum ferritin is widely used in ...diagnosing and monitoring these diseases.
In this chapter, we discuss the role of serum ferritin in physiological and pathological processes and its use as a clinical tool.
Although many aspects of the fundamental biology of serum ferritin remain surprisingly unclear, a growing number of roles have been attributed to extracellular ferritin, including newly described roles in iron delivery, angiogenesis, inflammation, immunity, signaling and cancer.
Serum ferritin remains a clinically useful tool. Further studies on the biology of this protein may provide new biological insights.
Ferritinophagy is the process of autophagic degradation of ferritin that participates in the regulation of cellular iron homeostasis. This process was shown to be mediated by the selective ...cargo-receptor Nuclear Receptor Coactivator-4 (NCOA4) that binds ferritin and targets it to emerging autophagosome. To characterize some of the biochemical properties of the interaction between the two proteins we cloned and expressed in E. coli the ferritin-binding domain of human NCOA4, fragment 383–522. It was purified and subjected to biochemical analysis. The NCOA4(383–522) fragment was expressed in soluble and dimeric form, and CD spectra indicated low level of secondary structure. The Ferritin binding activity of the fragment was investigated by developing an electrophoretic mobility shift and an ELISA assays. They showed that the NCOA4 fragment binds the H-ferritin with an affinity in the nM range, but not the R23A H-ferritin mutant and the L-ferritin chain, confirming the high specificity for the H-chain. The H-ferritin could bind up to 24 NCOA4(383–522) fragments forming highly stable and insoluble complexes. The binding was partially inhibited only by Fe(II) among the various divalent metal ions analyzed. The iron-dependent, highly-specific formation of the remarkably stable H-ferritin-NCOA4 complex shown in this work may be important for the characterization of the mechanism of ferritinophagy.
•The recombinant ferritin binding domain of NCOA4 (residues 383-522) was expressed in E. coli and purified.•The domain binds ferritin H-chain with high affinity, but not its mutant Arg23Ala and ferritin L-chain•Electro mobility shift assay showed that H-ferritin binds up to 24 NCOA4 domains forming a highly stable complex•ELISA assay showed that the complex formation is partially inhibited by Fe(II) but not by other divalent metal ions.
The Ferritins are part of the extensive ‘Ferritin-like superfamily’ which have diverse functions but are linked by the presence of a common four-helical bundle domain. The role performed by Ferritins ...as the cellular repository of excess iron is unique. In many ways Ferritins act as tiny organelles in their ability to secrete iron away from the delicate machinery of the cell, and then to release it again in a controlled fashion avoiding toxicity. The Ferritins are ancient proteins, being common in all three domains of life. This ubiquity reflects the key contribution that Ferritins provide in achieving iron homeostasis.
This review compares the features of the different Ferritins and considers how they, and other members of the Ferritin-like superfamily, have evolved. It also considers relevant features of the eleven other known families within the Ferritin-like superfamily, particularly the highly diverse rubrerythrins.
The Ferritins have travelled a considerable evolutionary journey, being derived from far more simplistic rubrerythrin-like molecules which play roles in defence against toxic oxygen species. The forces of evolution have moulded such molecules into three distinct types of iron storing (or detoxifying) protein: the classical and universal 24-meric ferritins; the haem-containing 24-meric bacterioferritins of prokaryotes; and the prokaryotic 12-meric Dps proteins. These three Ferritin types are similar, but also possess unique properties that distinguish them and enable then to achieve their specific physiological purposes.
A wide range of biological functions have evolved from a relatively simple structural unit.
Chemistry and biology of ferritin Plays, Marina; Müller, Sebastian; Rodriguez, Raphaël
Metallomics,
05/2021, Letnik:
13, Številka:
5
Journal Article
Recenzirano
Odprti dostop
Iron is an essential element required by cells and has been described as a key player in ferroptosis. Ferritin operates as a fundamental iron storage protein in cells forming multimeric assemblies ...with crystalline iron cores. We discuss the latest findings on ferritin structure and activity and its link to cell metabolism and ferroptosis. The chemistry of iron, including its oxidation states, is important for its biological functions, its reactivity, and the biology of ferritin. Ferritin can be localized in different cellular compartments and secreted by cells with a variety of functions depending on its spatial context. Here, we discuss how cellular ferritin localization is tightly linked to its function in a tissue-specific manner, and how impairment of iron homeostasis is implicated in diseases, including cancer and coronavirus disease 2019. Ferritin is a potential biomarker and we discuss latest research where it has been employed for imaging purposes and drug delivery.
Ferritin molecular cages are marvelous 24-mer supramolecular architectures that enable massive iron storage (>2000 iron atoms) within their inner cavity. This cavity is connected to the outer ...environment by two channels at C3 and C4 symmetry axes of the assembly. Ferritins can also be exploited as carriers for in vivo imaging and therapeutic applications, owing to their capability to effectively protect synthetic non-endogenous agents within the cage cavity and deliver them to targeted tissue cells without stimulating adverse immune responses. Recently, X-ray crystal structures of Fe2+-loaded ferritins provided important information on the pathways followed by iron ions toward the ferritin cavity and the catalytic centers within the protein. However, the specific mechanisms enabling Fe2+ uptake through wild-type and mutant ferritin channels is largely unknown. To shed light on this question, we report extensive molecular dynamics simulations, site-directed mutagenesis, and kinetic measurements that characterize the transport properties and translocation mechanism of Fe2+ through the two ferritin channels, using the wild-type bullfrog Rana catesbeiana H′ protein and some of its variants as case studies. We describe the structural features that determine Fe2+ translocation with atomistic detail, and we propose a putative mechanism for Fe2+ transport through the channel at the C3 symmetry axis, which is the only iron-permeable channel in vertebrate ferritins. Our findings have important implications for understanding how ion permeation occurs, and further how it may be controlled via purposely engineered channels for novel biomedical applications based on ferritin.
Natural human ferritin generally contains 24 subunits with different ratios of heavy chain to light chain, and the ratio of both subunits varies depending on tissue distribution and pathological ...conditions. However, the production of recombinant hybrid ferritin with both subunits is more challenging.
This study aimed to prepare the recombinant hybrid ferritin for prokaryotic expression and characterize its structure and physicochemical properties.
A prokaryotic expression vector of pACYCDuet-1 harboring the two individual genes of human ferritin heavy chain and light chain (FTH/FTL-pACYCDuet-1) was constructed and transfected into Escherichia coli bacteria. Then the genes were co-induced by IPTG to express.
The ferritin was purified by hydrophobic interaction chromatography combining size exclusion chromatography and verified by mass spectrometry and characterized by spectral and morphological analysis.
FTH and FTL subunits were successfully co-assembled into a hybrid ferritin nanoparticle (rhFTH/L). The structure of rhFTH/L was demonstrated highly ordered and fairly compact. Besides, the hybrid rhFTH/L nanoparticle was shown more sensitive to thermal stress and reduced stability when compared with that of both individual rhFTH and rhFTL.
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