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Biochimica Et Biophysica Acta.... Jul 2020The classic view is that iron regulatory proteins operate at the post-transcriptional level. Iron Regulatory Protein 1 (IRP1) shifts between an apo-form that binds mRNAs... (Review)
Review
The classic view is that iron regulatory proteins operate at the post-transcriptional level. Iron Regulatory Protein 1 (IRP1) shifts between an apo-form that binds mRNAs and a holo-form that harbors a [4Fe4S] cluster. The latter form is not considered relevant to iron regulation, but rather thought to act as a non-essential cytosolic aconitase. Recent work in Drosophila, however, shows that holo-IRP1 can also translocate to the nucleus, where it appears to downregulate iron metabolism genes, preparing the cell for a decline in iron uptake. The shifting of IRP1 between states requires a functional mitoNEET pathway that includes a glycogen branching enzyme for the repair or disassembly of IRP1's oxidatively damaged [3Fe4S] cluster. The new findings add to the notion that glucose metabolism is modulated by iron metabolism. Furthermore, we propose that ferritin ferroxidase activity participates in the repair of the IRP1 [3Fe4S] cluster leading to the hypothesis that cytosolic ferritin directly contributes to cellular iron sensing.
Topics: Aconitate Hydratase; Cell Nucleus; Ceruloplasmin; Cytosol; Ferritins; Gene Expression Regulation; Iron; Iron Regulatory Protein 1; Iron-Regulatory Proteins; Iron-Sulfur Proteins; Oxidation-Reduction; RNA, Messenger
PubMed: 32199885
DOI: 10.1016/j.bbamcr.2020.118705 -
Mitochondrion Jun 2005Human prostate secretory epithelial cells have the uniquely specialized function of accumulating and secreting extremely high levels of citrate. This is achieved by... (Review)
Review
Human prostate secretory epithelial cells have the uniquely specialized function of accumulating and secreting extremely high levels of citrate. This is achieved by their ability to accumulate high cellular levels of zinc that inhibit citrate oxidation. This process of net citrate production requires unique metabolic/bioenergetic mitochondrial relationships. In prostate cancer, the malignant cells undergo a metabolic transformation from zinc-accumulating citrate-producing sane cells to citrate-oxidizing malignant cells that lost the ability to accumulate zinc. This review describes the metabolic/bioenergetic, zinc and mitochondrial relationships involved in normal and malignant prostate. Hopefully, this report will generate much needed interest and research in this neglected, but critically important, area of investigation.
Topics: Aconitate Hydratase; Apoptosis; Citrates; Citric Acid Cycle; Energy Metabolism; Epithelial Cells; Humans; Male; Mitochondria; Models, Biological; Oxidation-Reduction; Prostate; Prostatic Neoplasms; Zinc
PubMed: 16050980
DOI: 10.1016/j.mito.2005.02.001 -
Scientific Reports Oct 2021Catabolite control protein C (CcpC) belongs to the LysR-type transcriptional regulator (LTTR) family, which regulates the transcription of genes encoding the...
Catabolite control protein C (CcpC) belongs to the LysR-type transcriptional regulator (LTTR) family, which regulates the transcription of genes encoding the tricarboxylic acid branch enzymes of the TCA cycle by responding to a pathway-specific metabolite, citrate. The biological function of CcpC has been characterized several times, but the structural basis for the molecular function of CcpC remains elusive. Here, we report the characterization of a full-length CcpC from Bacillus amyloliquefaciens (BaCcpC-FL) and a crystal structure of the C-terminal inducer-binding domain (IBD) complexed with citrate. BaCcpC required both dyad symmetric regions I and II to recognize the citB promoter, and the presence of citrate reduced citB promoter binding. The crystal structure of CcpC-IBD shows two subdomains, IBD-I and IBD-II, and a citrate molecule buried between them. Ile100, two arginines (Arg147 and Arg260), and three serines (Ser129, Ser189, and Ser191) exhibit strong hydrogen-bond interactions with citrate molecules. A structural comparison of BaCcpC-IBD with its homologues showed that they share the same tail-to-tail dimer alignment, but the dimeric interface and the rotation between these molecules exhibit significant differences. Taken together, our results provide a framework for understanding the mechanism underlying the functional divergence of the CcpC protein.
Topics: Aconitate Hydratase; Arginine; Bacillus amyloliquefaciens; Bacillus subtilis; Bacterial Proteins; Citrates; Citric Acid; Citric Acid Cycle; Crystallography, X-Ray; Cyclic AMP Receptor Protein; DNA-Binding Proteins; Dimerization; Gene Expression Regulation, Bacterial; Hydrogen Bonding; Molecular Dynamics Simulation; Promoter Regions, Genetic; Protein Binding; Protein Conformation; Repressor Proteins
PubMed: 34645869
DOI: 10.1038/s41598-021-99552-x -
Annals of Clinical and Translational... Jun 2020We describe the clinical characteristics and genetic etiology of several new cases within the ACO2-related disease spectrum. Mitochondrial aconitase (ACO2) is a...
OBJECTIVE
We describe the clinical characteristics and genetic etiology of several new cases within the ACO2-related disease spectrum. Mitochondrial aconitase (ACO2) is a nuclear-encoded tricarboxylic acid cycle enzyme. Homozygous pathogenic missense variants in the ACO2 gene were initially associated with infantile degeneration of the cerebrum, cerebellum, and retina, resulting in profound intellectual and developmental disability and early death. Subsequent studies have identified a range of homozygous and compound heterozygous pathogenic missense, nonsense, frameshift, and splice-site ACO2 variants in patients with a spectrum of clinical manifestations and disease severities.
METHODS
We describe a cohort of five novel patients with biallelic pathogenic variants in ACO2. We review the clinical histories of these patients as well as the molecular and functional characterization of the associated ACO2 variants and compare with those described previously in the literature.
RESULTS
Two siblings with relatively mild symptoms presented with episodic ataxia, mild developmental delays, severe dysarthria, and behavioral abnormalities including hyperactivity and depressive symptoms with generalized anxiety. One patient presented with the classic form with cerebellar hypoplasia, ataxia, seizures, optic atrophy, and retinitis pigmentosa. Another unrelated patient presented with ataxia but developed severe progressive spastic quadriplegia. Another patient demonstrated a spinal muscular atrophy-like presentation with severe neonatal hypotonia, diminished reflexes, and poor respiratory drive, leading to ventilator dependence until death at the age of 9 months.
INTERPRETATION
In this study, we highlight the importance of recognizing milder forms of the disorder, which may escape detection due to atypical disease presentation.
Topics: Aconitate Hydratase; Adolescent; Adult; Child; Cohort Studies; Female; Humans; Infant; Male; Nervous System Diseases; Pedigree; Phenotype
PubMed: 32519519
DOI: 10.1002/acn3.51074 -
Nature Communications May 2017Mammalian A-type proteins, ISCA1 and ISCA2, are evolutionarily conserved proteins involved in iron-sulfur cluster (Fe-S) biogenesis. Recently, it was shown that ISCA1...
Mammalian A-type proteins, ISCA1 and ISCA2, are evolutionarily conserved proteins involved in iron-sulfur cluster (Fe-S) biogenesis. Recently, it was shown that ISCA1 and ISCA2 form a heterocomplex that is implicated in the maturation of mitochondrial FeS proteins. Here we report that mouse ISCA1 and ISCA2 are FeS-containing proteins that combine all features of Fe-S carrier proteins. We use biochemical, spectroscopic and in vivo approaches to demonstrate that despite forming a complex, ISCA1 and ISCA2 establish discrete interactions with components of the late Fe-S machinery. Surprisingly, knockdown experiments in mouse skeletal muscle and in primary cultures of neurons suggest that ISCA1, but not ISCA2, is required for mitochondrial FeS proteins biogenesis. Collectively, our data suggest that cellular processes with different requirements for ISCA1, ISCA2 and ISCA1-ISCA2 complex seem to exist.
Topics: Aconitate Hydratase; Animals; Binding Sites; Cloning, Molecular; Escherichia coli; Female; Gene Expression; Genetic Vectors; Iron-Sulfur Proteins; Male; Mice; Mice, Inbred C57BL; Mitochondrial Proteins; Muscle, Skeletal; Primary Cell Culture; Protein Binding; Protein Interaction Domains and Motifs; Protein Multimerization; Recombinant Proteins; Sensory Receptor Cells; Spectroscopy, Mossbauer
PubMed: 28492233
DOI: 10.1038/ncomms15124 -
Microbes and Infection May 2004Xanthomonas campestris pathovar campestris is the causal agent of black rot disease of cruciferous plants. A cell-cell signalling system encoded by genes within the rpf... (Review)
Review
Xanthomonas campestris pathovar campestris is the causal agent of black rot disease of cruciferous plants. A cell-cell signalling system encoded by genes within the rpf cluster is required for the full virulence of this plant pathogen. This system has recently been implicated in regulation of the formation and dispersal of Xanthomonas biofilms.
Topics: Aconitate Hydratase; Bacterial Proteins; Biofilms; Gene Expression Regulation, Bacterial; Plant Diseases; Polysaccharides, Bacterial; Signal Transduction; Virulence Factors; Xanthomonas campestris
PubMed: 15158198
DOI: 10.1016/j.micinf.2004.01.013 -
Microbial Cell Factories Dec 2022Itaconic acid, an unsaturated C5 dicarbonic acid, has significant market demand and prospects. It has numerous biological functions, such as anti-cancer,...
BACKGROUND
Itaconic acid, an unsaturated C5 dicarbonic acid, has significant market demand and prospects. It has numerous biological functions, such as anti-cancer, anti-inflammatory, and anti-oxidative in medicine, and is an essential renewable platform chemical in industry. However, the development of industrial itaconic acid production by Aspergillus terreus, the current standard production strain, is hampered by the unavoidable drawbacks of that species. Developing a highly efficient cell factory is essential for the sustainable and green production of itaconic acid.
RESULTS
This study employed combinatorial engineering strategies to construct Escherichia coli cells to produce itaconic acid efficiently. Two essential genes (cis-aconitate decarboxylase (CAD) encoding gene cadA and aconitase (ACO) encoding gene acn) employed various genetic constructs and plasmid combinations to create 12 recombination E. coli strains to be screened. Among them, E. coli BL-CAC exhibited the highest titer with citrate as substrate, and the induction and reaction conditions were further systematically optimized. Subsequently, employing enzyme evolution to optimize rate-limiting enzyme CAD and synthesizing protein scaffolds to co-localize ACO and CAD were used to improve itaconic acid biosynthesis efficiency. Under the optimized reaction conditions combined with the feeding control strategy, itaconic acid titer reached 398.07 mM (51.79 g/L) of engineered E. coli BL-CAR470E-DS/A-CS cells as a catalyst with the highest specific production of 9.42 g/g among heterologous hosts at 48 h.
CONCLUSIONS
The excellent catalytic performance per unit biomass shows the potential for high-efficiency production of itaconic acid and effective reduction of catalytic cell consumption. This study indicates that it is necessary to continuously explore engineering strategies to develop high-performance cell factories to break through the existing bottleneck and achieve the economical commercial production of itaconic acid.
Topics: Metabolic Engineering; Escherichia coli; Succinates; Aconitate Hydratase
PubMed: 36577997
DOI: 10.1186/s12934-022-02001-1 -
PloS One 2023Acute kidney injury (AKI) is a serious and frequently observed disease associated with high morbidity and mortality. Weighted gene co-expression network analysis (WGCNA)...
Acute kidney injury (AKI) is a serious and frequently observed disease associated with high morbidity and mortality. Weighted gene co-expression network analysis (WGCNA) is a research method that converts the relationship between tens of thousands of genes and phenotypes into the association between several gene sets and phenotypes. We screened potential target genes related to AKI through WGCNA to provide a reference for the diagnosis and treatment of AKI. Key biomolecules of AKI were investigated based on transcriptome analysis. RNA sequencing data from 39 kidney biopsy specimens of AKI patients and 9 normal subjects were downloaded from the GEO database. By WGCNA, the top 20% of mRNAs with the largest variance in the data matrix were used to construct a gene co-expression network with a p-value < 0.01 as a screening condition, showing that the blue module was most closely associated with AKI. Thirty-two candidate biomarker genes were screened according to the threshold values of |MM|≥0.86 and |GS|≥0.4, and PPI and enrichment analyses were performed. The top three genes with the most connected nodes, alanine-glyoxylate aminotransferase 2(AGXT2), serine hydroxymethyltransferase 1(SHMT1) and aconitase 2(ACO2), were selected as the central genes based on the PPI network. A rat AKI model was constructed, and the mRNA and protein expression levels of the central genes in the model and control groups were verified by PCR and immunohistochemistry experiments. The results showed that the relative mRNA expression and protein levels of AGXT2, SHMT1 and ACO2 showed a decrease in the model group. In conclusion, we inferred that there is a close association between AGXT2, SHMT1 and ACO2 genes and the development of AKI, and the down-regulation of their expression levels may induce AKI.
Topics: Animals; Rats; Acute Kidney Injury; Biomarkers; Gene Expression Profiling; Gene Regulatory Networks; Glycine Hydroxymethyltransferase; RNA, Messenger; Aconitate Hydratase
PubMed: 36735737
DOI: 10.1371/journal.pone.0281439 -
Metabolic Engineering Sep 2022The chemolithotroph Cupriavidus necator H16 is known as a natural producer of the bioplastic-polymer PHB, as well as for its metabolic versatility to utilize different...
The chemolithotroph Cupriavidus necator H16 is known as a natural producer of the bioplastic-polymer PHB, as well as for its metabolic versatility to utilize different substrates, including formate as the sole carbon and energy source. Depending on the entry point of the substrate, this versatility requires adjustment of the thermodynamic landscape to maintain sufficiently high driving forces for biological processes. Here we employed a model of the core metabolism of C. necator H16 to analyze the thermodynamic driving forces and PHB yields from formate for different metabolic engineering strategies. For this, we enumerated elementary flux modes (EFMs) of the network and evaluated their PHB yields as well as thermodynamics via Max-min driving force (MDF) analysis and random sampling of driving forces. A heterologous ATP:citrate lyase reaction was predicted to increase driving force for producing acetyl-CoA. A heterologous phosphoketolase reaction was predicted to increase maximal PHB yields as well as driving forces. These enzymes were then verified experimentally to enhance PHB titers between 60 and 300% in select conditions. The EFM analysis also revealed that PHB production from formate may be limited by low driving forces through citrate lyase and aconitase, as well as cofactor balancing, and identified additional reactions associated with low and high PHB yield. Proteomics analysis of the engineered strains confirmed an increased abundance of aconitase and cofactor balancing. The findings of this study aid in understanding metabolic adaptation. Furthermore, the outlined approach will be useful in designing metabolic engineering strategies in other non-model bacteria.
Topics: Aconitate Hydratase; Cupriavidus necator; Formates; Fructose; Hydroxybutyrates; Polyesters; Thermodynamics
PubMed: 35987434
DOI: 10.1016/j.ymben.2022.08.005 -
Archives of Biochemistry and Biophysics Dec 2016The human prostate gland contains extremely high zinc levels; which is due to the specialized zinc-accumulating acinar epithelial of the peripheral zone. These cells... (Review)
Review
The human prostate gland contains extremely high zinc levels; which is due to the specialized zinc-accumulating acinar epithelial of the peripheral zone. These cells evolved for their unique capability to produce and secrete extremely levels of citrate, which is achieved by the high cellular zinc level effects on the cell metabolism. This review highlights the specific functional and metabolic alterations that result from the accumulation of the high zinc levels, especially its effects on mitochondrial citrate metabolism and terminal oxidation. The implications of zinc in the development and progression of prostate cancer are described, which is the most consistent hallmark characteristic of prostate cancer. The requirement for decreased zinc resulting from down regulation of ZIP1 to prevent zinc cytotoxicity in the malignant cells is described as an essential early event in prostate oncogenesis. This provides the basis for the concept that an agent (such as the zinc ionophore, clioquinol) that facilitates zinc uptake and accumulation in ZIP1-deficient prostate tumors cells will markedly inhibit tumor growth. In the current absence of an efficacious chemotherapy for advanced prostate cancer, and for prevention of early development of malignancy; a zinc treatment regimen is a plausible approach that should be pursued.
Topics: Aconitate Hydratase; Animals; Biological Transport; Cation Transport Proteins; Citrates; Disease Progression; Epithelial Cells; Humans; Ligands; Male; Mitochondria; Prolactin; Prostate; Prostatic Neoplasms; Testosterone; Zinc
PubMed: 27132038
DOI: 10.1016/j.abb.2016.04.014