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FEBS Open Bio Jun 2024The mitochondrial intermembrane space hosts a machinery for oxidative protein folding, the mitochondrial disulfide relay. This machinery imports a large number of... (Review)
Review
The mitochondrial intermembrane space hosts a machinery for oxidative protein folding, the mitochondrial disulfide relay. This machinery imports a large number of soluble proteins into the compartment, where they are retained through oxidative folding. Additionally, the disulfide relay enhances the stability of many proteins by forming disulfide bonds. In this review, we describe the mitochondrial disulfide relay in human cells, its components, and their coordinated collaboration in mechanistic detail. We also discuss the human pathologies associated with defects in this machinery and its protein substrates, providing a comprehensive overview of its biological importance and implications for health.
PubMed: 38867508
DOI: 10.1002/2211-5463.13839 -
Journal of Agricultural and Food... Jun 2024β-Alanine, a valuable β-type amino acid, is experiencing increased demand due to its multifaceted applications in food flavoring, nutritional supplements,...
β-Alanine, a valuable β-type amino acid, is experiencing increased demand due to its multifaceted applications in food flavoring, nutritional supplements, pharmaceuticals, and the chemical industry. Nevertheless, the sustainable biosynthesis of β-alanine currently faces challenges due to the scarcity of robust strains, attributed to the complexities of modulating multiple genes and the inherent physiological constraints. Here, systems metabolic engineering was implemented in to overcome these limitations. First, an efficient l-aspartate-α-decarboxylase (ADC) was recruited for β-alanine biosynthesis. To conserve phosphoenolpyruvate flux, we subsequently modified the endogenous glucose assimilation system by inactivating the phosphotransferase system (PTS) and introducing an alternative non-PTS system, which increased β-alanine production to 1.70 g/L. The supply of key precursors, oxaloacetate and l-aspartate, was synergistically improved through comprehensive modulation, including strengthening main flux and blocking bypass metabolism, which significantly increased the β-alanine titer to 3.43 g/L. Next, the expression of ADC was optimized by promoter and untranslated region (UTR) engineering. Further transport engineering, which involved disrupting β-alanine importer CycA and heterologously expressing β-alanine exporter NCgI0580, improved β-alanine production to 8.48 g/L. Additionally, corn steep liquor was used to develop a cost-effective medium. The final strain produced 74.03 g/L β-alanine with a yield of 0.57 mol/mol glucose during fed-batch fermentation.
Topics: beta-Alanine; Escherichia coli; Metabolic Engineering; Glucose; Fermentation; Escherichia coli Proteins; Glutamate Decarboxylase
PubMed: 38867465
DOI: 10.1021/acs.jafc.4c03492 -
Cell Death and Differentiation Jun 2024Cancer cells rely on metabolic reprogramming to sustain the prodigious energetic requirements for rapid growth and proliferation. Glutamine metabolism is frequently...
Cancer cells rely on metabolic reprogramming to sustain the prodigious energetic requirements for rapid growth and proliferation. Glutamine metabolism is frequently dysregulated in cancers and is being exploited as a potential therapeutic target. Using CRISPR/Cas9 interference (CRISPRi) screening, we identified TARBP1 (TAR (HIV-1) RNA Binding Protein 1) as a critical regulator involved in glutamine reliance of cancer cell. Consistent with this discovery, TARBP1 amplification and overexpression are frequently observed in various cancers. Knockout of TARBP1 significantly suppresses cell proliferation, colony formation and xenograft tumor growth. Mechanistically, TARBP1 selectively methylates and stabilizes a small subset of tRNAs, which promotes efficient protein synthesis of glutamine transporter-ASCT2 (also known as SLC1A5) and glutamine import to fuel the growth of cancer cell. Moreover, we found that the gene expression of TARBP1 and ASCT2 are upregulated in combination in clinical cohorts and their upregulation is associated with unfavorable prognosis of HCC (hepatocellular carcinoma). Taken together, this study reveals the unexpected role of TARBP1 in coordinating the tRNA availability and glutamine uptake during HCC progression and provides a potential target for tumor therapy.
PubMed: 38867004
DOI: 10.1038/s41418-024-01323-4 -
The FEBS Journal Jun 2024Hemoglobins, with heme as a cofactor, are functional proteins that have extensive applications in the fields of artificial oxygen carriers and foods. Although...
Hemoglobins, with heme as a cofactor, are functional proteins that have extensive applications in the fields of artificial oxygen carriers and foods. Although Saccharomyces cerevisiae is an ideal host for hemoglobin synthesis, it lacks a suitable transport system to utilize additional heme for active expression of hemoglobins, resulting in the cellular aggregation and degradation of the latter. Here, an effective heme importer, heme-responsive gene 4 (Hrg-4), was selected from six candidates through the comparison of effects on the growth rates of Δhem1 S. cerevisiae strain and the activities of various hemoglobins when supplemented with 5 mg·L exogenous heme. Additionally, to counter the instability of plasmid-based expression and the metabolic burden introduced from overexpressing Hrg-4, a series of hrg-4 integrated strains were constructed and the best engineered strain with five copies of hrg-4 was chosen. We found that this engineered strain was associated with an increased binding rate of heme in monomeric leghemoglobin and multimeric human hemoglobin (76.3% and 16.5%, respectively), as well as an enhanced expression of both hemoglobins (52.8% and 17.0%, respectively). Thus, the engineered strain with improved heme uptake can be used to efficiently synthesize other heme-binding proteins and enzymes in S. cerevisiae.
PubMed: 38865576
DOI: 10.1111/febs.17199 -
Proceedings of the National Academy of... Jun 2024Pyruvate lies at a pivotal node of carbon metabolism in eukaryotes. It is involved in diverse metabolic pathways in multiple organelles, and its interorganelle shuttling...
Pyruvate lies at a pivotal node of carbon metabolism in eukaryotes. It is involved in diverse metabolic pathways in multiple organelles, and its interorganelle shuttling is crucial for cell fitness. Many apicomplexan parasites harbor a unique organelle called the apicoplast that houses metabolic pathways like fatty acid and isoprenoid precursor biosyntheses, requiring pyruvate as a substrate. However, how pyruvate is supplied in the apicoplast remains enigmatic. Here, deploying the zoonotic parasite as a model apicomplexan, we identified two proteins residing in the apicoplast membranes that together constitute a functional apicoplast pyruvate carrier (APC) to mediate the import of cytosolic pyruvate. Depletion of APC results in reduced activities of metabolic pathways in the apicoplast and impaired integrity of this organelle, leading to parasite growth arrest. APC is a pyruvate transporter in diverse apicomplexan parasites, suggesting a common strategy for pyruvate acquisition by the apicoplast in these clinically relevant intracellular pathogens.
Topics: Apicoplasts; Toxoplasma; Pyruvic Acid; Protozoan Proteins; Animals; Membrane Transport Proteins; Biological Transport; Metabolic Networks and Pathways
PubMed: 38865262
DOI: 10.1073/pnas.2314314121 -
Biochemical Society Transactions Jun 2024Mitochondria are essential organelles of eukaryotic cells and thus mitochondrial proteome is under constant quality control and remodelling. Yme1 is a multi-functional... (Review)
Review
Mitochondria are essential organelles of eukaryotic cells and thus mitochondrial proteome is under constant quality control and remodelling. Yme1 is a multi-functional protein and subunit of the homo-hexametric complex i-AAA proteinase. Yme1 plays vital roles in the regulation of mitochondrial protein homeostasis and mitochondrial plasticity, ranging from substrate degradation to the regulation of protein functions involved in mitochondrial protein biosynthesis, energy production, mitochondrial dynamics, and lipid biosynthesis and signalling. In this mini review, we focus on discussing the current understanding of the roles of Yme1 in mitochondrial protein import via TIM22 and TIM23 pathways, oxidative phosphorylation complex function, as well as mitochondrial lipid biosynthesis and signalling, as well as a brief discussion of the role of Yme1 in modulating mitochondrial dynamics.
Topics: Humans; Oxidative Phosphorylation; Mitochondrial Proteins; Mitochondria; Mitochondrial Dynamics; Animals; Proteostasis; Protein Transport; ATPases Associated with Diverse Cellular Activities; Lipids; Lipid Metabolism; Homeostasis; Signal Transduction; ATP-Dependent Proteases
PubMed: 38864432
DOI: 10.1042/BST20240450 -
BMC Complementary Medicine and Therapies Jun 2024Endometrial cancer (EC) is an oestrogen-dependent tumour, the occurrence of which is closely related to an imbalance of oestrogen homeostasis. Our previous studies...
OBJECTIVE
Endometrial cancer (EC) is an oestrogen-dependent tumour, the occurrence of which is closely related to an imbalance of oestrogen homeostasis. Our previous studies explored the effects of Resveratrol(Res) on oestrogen metabolism. However, systematic research on the exact mechanism of action of Res is still lacking. Based on network pharmacology, molecular docking and animal experiments, the effects and molecular mechanisms of Res on endometrial cancer were investigated.
METHODS
The target of Res was obtained from the high-throughput experiment and reference-guided database of TCM (HERB) and the Encyclopedia of Traditional Chinese Medicine (ETCM) databases, and the target of endometrial cancer was obtained by using the Genecards database. Venny map was used to obtain the intersection target of Res in the treatment of endometrial cancer, and the protein interaction network of the intersection target was constructed by importing the data into the STRING database. Then, the drug-disease-target interaction network was constructed based on Cytoscape 3.9.1 software. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were performed for intersection targets using the OmicShare cloud platform. Res and core targets were analysed by molecular docking. EC model mice induced by MNNG were randomly divided into the control group, Res group, MNNG group, MNNG + Res group, and MNNG + Res + MAPK/ERKi group. The protein levels of ERK and p-ERK in the mouse uterus were detected by Western blot. The levels of E1, E2, E3, 16-epiE3, 17-epiE3, 2-MeOE1, 4-MeOE1, 2-MeOE2, 4-MeOE2, 3-MeOE1, 2-OHE1, 4-OHE1, 2-OHE2, 4-OHE2, and 16α-OHE1 in the serum and endometrial tissue of mice were measured by LC‒MS/MS.
RESULTS
A total of 174 intersection targets of Res anti-endometrial cancer were obtained. The signalling pathways analysed by KEGG enrichment included the AGE-RAGE signalling pathway in diabetic complications, the PI3K-Akt signalling pathway and the MAPK signalling pathway. The top 10 core targets were MAPK3, JUN, TP53, CASP3, TNF, IL1B, AKT1, FOS, VEGFA and INS. Molecular docking showed that in addition to TNF, other targets had good affinity for Res, and the binding activity with MAPK3 was stable. Western blot results showed that Res increased the phosphorylation level of ERK and that MAPK/ERKi decreased ERK activation. In the LC-MS/MS analysis, the levels of 2-MeOE1, 2-MeOE2 and 4-MeOE1 in serum and uterine tissue showed a significantly decreasing trend in the MNNG group, while that of 4-OHE2 was increased (P < 0.05). The concentrations of 4-MeOE1 in serum and 2-MeOE1 and 2-MeOE2 in the endometrial tissue of mice were significantly increased after Res treatment, and those of 4-OHE2 in the serum and uterus of mice were significantly decreased (P < 0.05). Meanwhile, in the MAPK/ERKi intervention group, the effect of Res on the reversal of oestrogen homeostasis imbalance was obviously weakened.
CONCLUSION
Res has multiple targets and multiple approaches in the treatment of endometrial cancer. In this study, it was found that Res regulates oestrogen metabolism by activating the MAPK/ERK pathway. This finding provides a new perspective for subsequent research on the treatment of endometrial cancer.
Topics: Female; Endometrial Neoplasms; Animals; Resveratrol; Mice; MAP Kinase Signaling System; Estrogens; Molecular Docking Simulation; Humans; Mice, Inbred BALB C; Network Pharmacology; Protein Interaction Maps
PubMed: 38862934
DOI: 10.1186/s12906-024-04509-y -
Proceedings of the National Academy of... Jun 2024The nematode intestine is the primary site for nutrient uptake and storage as well as the synthesis of biomolecules; lysosome-related organelles known as gut granules...
The nematode intestine is the primary site for nutrient uptake and storage as well as the synthesis of biomolecules; lysosome-related organelles known as gut granules are important for many of these functions. Aspects of intestine biology are not well understood, including the export of the nutrients it imports and the molecules it synthesizes, as well as the complete functions and protein content of the gut granules. Here, we report a mass spectrometry (MS)-based proteomic analysis of the intestine of the and of its gut granules. Overall, we identified approximately 5,000 proteins each in the intestine and the gonad and showed that most of these proteins can be detected in samples extracted from a single worm, suggesting the feasibility of individual-level genetic analysis using proteomes. Comparing proteomes and published transcriptomes of the intestine and the gonad, we identified proteins that appear to be synthesized in the intestine and then transferred to the gonad. To identify gut granule proteins, we compared the proteome of individual intestines deficient in gut granules to the wild type. The identified gut granule proteome includes proteins known to be exclusively localized to the granules and additional putative gut granule proteins. We selected two of these putative gut granule proteins for validation via immunohistochemistry, and our successful confirmation of both suggests that our strategy was effective in identifying the gut granule proteome. Our results demonstrate the practicability of single-tissue MS-based proteomic analysis in small organisms and in its future utility.
Topics: Animals; Caenorhabditis elegans; Caenorhabditis elegans Proteins; Proteomics; Lysosomes; Proteome; Intestines; Intestinal Mucosa; Gonads; Mass Spectrometry; Organelles
PubMed: 38861598
DOI: 10.1073/pnas.2322588121 -
The FEBS Journal Jun 2024Almost all mitochondrial proteins are encoded by nuclear genes and synthesized in the cytosol as precursor proteins. Signals in the amino acid sequence of these... (Review)
Review
Almost all mitochondrial proteins are encoded by nuclear genes and synthesized in the cytosol as precursor proteins. Signals in the amino acid sequence of these precursors ensure their targeting and translocation into mitochondria. However, in many cases, only a certain fraction of a specific protein is transported into mitochondria, while the rest either remains in the cytosol or undergoes reverse translocation to the cytosol, and can populate other cellular compartments. This phenomenon is called dual localization which can be instigated by different mechanisms. These include alternative start or stop codons, differential transcripts, and ambiguous or competing targeting sequences. In many cases, dual localization might serve as an economic strategy to reduce the number of required genes; for example, when the same groups of enzymes are required both in mitochondria and chloroplasts or both in mitochondria and the nucleus/cytoplasm. Such cases frequently employ ambiguous targeting sequences to distribute proteins between both organelles. However, alternative localizations can also be used for signaling, for example when non-imported precursors serve as mitophagy signals or when they represent transcription factors in the nucleus to induce the mitochondrial unfolded stress response. This review provides an overview regarding the mechanisms and the physiological consequences of dual targeting.
PubMed: 38857249
DOI: 10.1111/febs.17191 -
Biochemical Genetics Jun 2024Patients with chronic pelvic inflammation (CPI) experience irregular menstrual, ectopic pregnancy, and infertility. Yiyi Baijiang Decoction attenuates CPI in patients...
Patients with chronic pelvic inflammation (CPI) experience irregular menstrual, ectopic pregnancy, and infertility. Yiyi Baijiang Decoction attenuates CPI in patients with uncovered mechanisms. CPI therapeutic targets intersected with those of Yiyi Baijiang Decoction, followed by importing into STRING to obtain protein-target interaction. "Drug-component-disease-target" interaction was constructed by Cytoscape. mRNA and protein levels were detected by real-time quantitative PCR (RT-qPCR) and western blot. Yiyi Baijiang Decoction contained 199 active ingredients. There were 1071 drug targets for Yiyi Baijiang Decoction and 1622 therapeutic targets for CPI. The GO functional enrichment analysis revealed 3445 biological processes, and the KEGG pathway enrichment analysis screened 67 signal pathways. Decreased ALB, increased protein kinase B (AKT1), interleukin (IL)-6, vascular endothelial growth factor A (VEGFA), and phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K/AKT)-extracellular-regulated protein kinases (ERK)1/2 activation in CPI mice were abolished by Yiyi Baijiang Decoction. Yiyi Baijiang Decoction attenuates CPI by inactivating PI3K/AKT and ERK1/2 and regulating ALB, VEGFA, AKT1, and IL-6.
PubMed: 38856955
DOI: 10.1007/s10528-024-10843-0