Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P02794 (ferritin)
 17,525 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

An iron-rich protein was isolated from the Archaeon Halobacterium salinarum sharing a sequence identity of 35% with the starvation-induced DNA-binding protein, DpsA, of Synechecoccus sp. PCC 7942. It consists of 20 kDa subunits, forming a dodecameric structure. The protein exhibits a ferric iron loading of up to 103 Fe ions/mol of holoprotein. CD spectra are consistent with an alpha-helical contribution of 58%. The UV/visible spectrum provides no evidence for the presence of haem groups. This protein exhibits features of a non-haem-type bacterial ferritin although it shares only little sequence homology with non-haem bacterial ferritin.
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PMID:Characterization of a non-haem ferritin of the Archaeon Halobacterium salinarum, homologous to Dps (starvation-induced DNA-binding protein). 1219 73

In this article, we demonstrate the connection between intracellular iron storage and oxidative stress response in cyanobacteria. Iron is essential for the survival of all organisms. However, the redox properties that make iron a valuable cofactor also lead to oxidative interactions, resulting in the formation of harmful radicals. Therefore, iron accumulation in cells should be tightly regulated, a process in which ferritin family proteins play an important role. Synechocystis sp. PCC 6803 contains two ferritin-type storage complexes, bacterioferritin and MrgA. Previous studies demonstrated the role of bacterioferritin and MrgA in iron storage. In addition, MrgA was found to play a key role in oxidative stress response. Here, we examined the dual role of the ferritin family proteins using physiological and transcriptomic approaches. Microarray analysis of iron-limited wild-type and DeltamrgA cultures revealed a substantial up-regulation of oxidative stress-related genes in mutant cells. The PerR regulator was found to play an important role in that process. Furthermore, we were able to demonstrate the connection between internal iron quota, the presence of the two storage complexes, and the sensitivity to externally applied oxidative stress. These data suggest a pivotal role for the ferritin-type proteins of Synechocystis sp. PCC 6803 in coordinating iron homeostasis and in oxidative stress response. The combined action of the two complexes allows for the safe accumulation and release of iron from storage by minimizing damage resulting from interactions between reduced iron and the oxygen radicals that are produced in abundance by the photosynthetic apparatus.
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PMID:The mechanism of iron homeostasis in the unicellular cyanobacterium synechocystis sp. PCC 6803 and its relationship to oxidative stress. 1956 Nov 20

Knowledge on the regulatory mechanisms controlling iron homeostasis in cyanobacteria is limited. In Anabaena sp. PCC 7120, the ferric uptake regulator FurA is a constitutive and essential protein whose expression is induced under iron deprivation. Our previous analyses have shown that this protein acts as a global transcriptional regulator, controlling the expression of several genes belonging to different functional categories, including schT, a gene coding for a TonB-dependent schizokinen transporter. In the present study we analysed the impact of FurA overexpression and iron availability on the transcriptional modulation of a broad range of Anabaena iron uptake, transport, storage and cellular iron utilization mechanisms, including enzymes involved in siderophore biosynthesis, TonB-dependent siderophore outer membrane transporters, siderophore periplasmic binding proteins, ABC inner membrane permeases, ferritin Dps family proteins, and enzymes involved in tetrapyrrole biosynthesis. By combining reverse transcription-PCR analyses, electrophoretic mobility shift assays and DNase I footprinting experiments, we defined a variety of novel direct iron-dependent transcriptional targets of this metalloregulator, including genes encoding at least five enzymes involved in the tetrapyrrole biosynthesis pathway. The results unravel the role of FurA as the master regulator of iron homeostasis in Anabaena sp. PCC 7120, providing new insights into the Fur regulons in cyanobacteria.
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PMID:FurA is the master regulator of iron homeostasis and modulates the expression of tetrapyrrole biosynthesis genes in Anabaena sp. PCC 7120. 2306 98