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1.
Int J Mol Sci ; 22(12)2021 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-34203920

RESUMO

The negatively charged Asp325 residue has proved to be essential for iron export by human (HsFPN1) and primate Philippine tarsier (TsFpn) ferroportin, but its exact role during the iron transport cycle is still to be elucidated. It has been posited as being functionally equivalent to the metal ion-coordinating residue His261 in the C-lobe of the bacterial homolog BbFpn, but the two residues arise in different sequence motifs of the discontinuous TM7 transmembrane helix. Furthermore, BbFpn is not subject to extracellular regulation, contrary to its mammalian orthologues which are downregulated by hepcidin. To get further insight into the molecular mechanisms related to iron export in mammals in which Asp325 is involved, we investigated the behavior of the Asp325Ala, Asp325His, and Asp325Asn mutants in transiently transfected HEK293T cells, and performed a comparative structural analysis. Our biochemical studies clearly distinguished between the Asp325Ala and Asp325His mutants, which result in a dramatic decrease in plasma membrane expression of FPN1, and the Asp325Asn mutant, which alters iron egress without affecting protein localization. Analysis of the 3D structures of HsFPN1 and TsFpn in the outward-facing (OF) state indicated that Asp325 does not interact directly with metal ions but is involved in the modulation of Cys326 metal-binding capacity. Moreover, models of the architecture of mammalian proteins in the inward-facing (IF) state suggested that Asp325 may form an inter-lobe salt-bridge with Arg40 (TM1) when not interacting with Cys326. These findings allow to suggest that Asp325 may be important for fine-tuning iron recognition in the C-lobe, as well as for local structural changes during the IF-to-OF transition at the extracellular gate level. Inability to form a salt-bridge between TM1 and TM7b during iron translocation could lead to protein instability, as shown by the Asp325Ala and Asp325His mutants.


Assuntos
Ácido Aspártico/metabolismo , Proteínas de Transporte de Cátions/química , Proteínas de Transporte de Cátions/metabolismo , Sítios de Ligação , Transporte Biológico , Membrana Celular/metabolismo , Células HEK293 , Humanos , Ferro/metabolismo , Estrutura Secundária de Proteína , Relação Estrutura-Atividade
2.
Int J Mol Sci ; 22(12)2021 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-34203933

RESUMO

Natural resistance-associated macrophage proteins (Nramps) are specific metal transporters in plants with different functions among various species. The evolutionary and functional information of the Nramp gene family in Spirodela polyrhiza has not been previously reported in detail. To identify the Nramp genes in S. polyrhiza, we performed genome-wide identification, characterization, classification, and cis-elements analysis among 22 species with 138 amino acid sequences. We also conducted chromosomal localization and analyzed the synteny relationship, promoter, subcellular localization, and expression patterns in S. polyrhiza. ß-Glucuronidase staining indicated that SpNramp1 and SpNramp3 mainly accumulated in the root and joint between mother and daughter frond. Moreover, SpNramp1 was also widely displayed in the frond. SpNramp2 was intensively distributed in the root and frond. Quantitative real-time PCR results proved that the SpNramp gene expression level was influenced by Cd stress, especially in response to Fe or Mn deficiency. The study provides detailed information on the SpNramp gene family and their distribution and expression, laying a beneficial foundation for functional research.


Assuntos
Araceae/genética , Cádmio/toxicidade , Proteínas de Transporte de Cátions/genética , Regulação da Expressão Gênica de Plantas , Genoma de Planta , Família Multigênica , Proteínas de Plantas/genética , Estresse Fisiológico/genética , Motivos de Aminoácidos , Sequência de Aminoácidos , Araceae/efeitos dos fármacos , Proteínas de Transporte de Cátions/química , Proteínas de Transporte de Cátions/metabolismo , Cromossomos de Plantas/genética , Sequência Conservada , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Genes de Plantas , Filogenia , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Regiões Promotoras Genéticas/genética , Estresse Fisiológico/efeitos dos fármacos , Sintenia/genética
3.
Int J Mol Sci ; 22(12)2021 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-34198528

RESUMO

Intracellular free zinc ([Zn2+]i) is mobilized in neuronal and non-neuronal cells under physiological and/or pathophysiological conditions; therefore, [Zn2+]i is a component of cellular signal transduction in biological systems. Although several transporters and ion channels that carry Zn2+ have been identified, proteins that are involved in Zn2+ supply into cells and their expression are poorly understood, particularly under inflammatory conditions. Here, we show that the expression of Zn2+ transporters ZIP8 and ZIP14 is increased via the activation of hypoxia-induced factor 1α (HIF-1α) in inflammation, leading to [Zn2+]i accumulation, which intrinsically activates transient receptor potential ankyrin 1 (TRPA1) channel and elevates basal [Zn2+]i. In human fibroblast-like synoviocytes (FLSs), treatment with inflammatory mediators, such as tumor necrosis factor-α (TNF-α) and interleukin-1α (IL-1α), evoked TRPA1-dependent intrinsic Ca2+ oscillations. Assays with fluorescent Zn2+ indicators revealed that the basal [Zn2+]i concentration was significantly higher in TRPA1-expressing HEK cells and inflammatory FLSs. Moreover, TRPA1 activation induced an elevation of [Zn2+]i level in the presence of 1 µM Zn2+ in inflammatory FLSs. Among the 17 out of 24 known Zn2+ transporters, FLSs that were treated with TNF-α and IL-1α exhibited a higher expression of ZIP8 and ZIP14. Their expression levels were augmented by transfection with an active component of nuclear factor-κB P65 and HIF-1α expression vectors, and they could be abolished by pretreatment with the HIF-1α inhibitor echinomycin (Echi). The functional expression of ZIP8 and ZIP14 in HEK cells significantly increased the basal [Zn2+]i level. Taken together, Zn2+ carrier proteins, TRPA1, ZIP8, and ZIP14, induced under HIF-1α mediated inflammation can synergistically change [Zn2+]i in inflammatory FLSs.


Assuntos
Proteínas de Transporte de Cátions/genética , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Inflamação/genética , Sinoviócitos/metabolismo , Canal de Cátion TRPA1/genética , Regulação para Cima/genética , Zinco/metabolismo , Proteínas de Transporte de Cátions/metabolismo , Fibroblastos/metabolismo , Fibroblastos/patologia , Humanos , Inflamação/patologia , Espaço Intracelular/metabolismo , Sinoviócitos/patologia , Canal de Cátion TRPA1/metabolismo
4.
Int J Mol Sci ; 22(12)2021 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-34204327

RESUMO

Despite its abundance in the environment, iron is poorly bioavailable and subject to strict conservation and internal recycling by most organisms. In vertebrates, the stability of iron concentration in plasma and extracellular fluid, and the total body iron content are maintained by the interaction of the iron-regulatory peptide hormone hepcidin with its receptor and cellular iron exporter ferroportin (SLC40a1). Ferroportin exports iron from duodenal enterocytes that absorb dietary iron, from iron-recycling macrophages in the spleen and the liver, and from iron-storing hepatocytes. Hepcidin blocks iron export through ferroportin, causing hypoferremia. During iron deficiency or after hemorrhage, hepcidin decreases to allow iron delivery to plasma through ferroportin, thus promoting compensatory erythropoiesis. As a host defense mediator, hepcidin increases in response to infection and inflammation, blocking iron delivery through ferroportin to blood plasma, thus limiting iron availability to invading microbes. Genetic diseases that decrease hepcidin synthesis or disrupt hepcidin binding to ferroportin cause the iron overload disorder hereditary hemochromatosis. The opposite phenotype, iron restriction or iron deficiency, can result from genetic or inflammatory overproduction of hepcidin.


Assuntos
Proteínas de Transporte de Cátions/metabolismo , Hepcidinas/metabolismo , Homeostase , Ferro/metabolismo , Animais , Comunicação Autócrina , Transporte Biológico , Proteínas de Transporte de Cátions/química , Suscetibilidade a Doenças , Hepcidinas/química , Humanos , Ligantes , Redes e Vias Metabólicas , Comunicação Parácrina , Ligação Proteica , Transdução de Sinais , Distribuição Tecidual
5.
Int J Mol Sci ; 22(10)2021 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-34069632

RESUMO

In tobacco, the efficiency of Zn translocation to shoots depends on Zn/Cd status. Previous studies pointed to the specific contribution of root parts in the regulation of this process, as well as the role of NtZIP4A/B (from the ZIP family; Zrt Irt-like Proteins). Here, to verify this hypothesis, NtZIP4A/B RNAi lines were generated. Then, in plants exposed to combinations of Zn and Cd concentrations in the medium, the consequences of NtZIP4A/B suppression for the translocation of both metals were determined. Furthermore, the apical, middle, and basal root parts were examined for accumulation of both metals, for Zn localization (using Zinpyr-1), and for modifications of the expression pattern of ZIP genes. Our results confirmed the role of NtZIP4A/B in the control of Zn/Cd-status-dependent transfer of both metals to shoots. Furthermore, they indicated that the middle and basal root parts contributed to the regulation of this process by acting as a reservoir for excess Zn and Cd. Expression studies identified several candidate ZIP genes that interact with NtZIP4A/B in the root in regulating Zn and Cd translocation to the shoot, primarily NtZIP1-like in the basal root part and NtZIP2 in the middle one.


Assuntos
Proteínas de Transporte de Cátions/metabolismo , Tabaco/metabolismo , Zinco/metabolismo , Adenosina Trifosfatases/metabolismo , Transporte Biológico/genética , Cádmio/metabolismo , Proteínas de Transporte de Cátions/genética , Regulação da Expressão Gênica de Plantas/genética , Homeostase , Proteínas de Plantas/genética , Raízes de Plantas/genética , Raízes de Plantas/metabolismo , Brotos de Planta/metabolismo , Plantas Geneticamente Modificadas/metabolismo , Tabaco/genética
6.
Nat Commun ; 12(1): 4028, 2021 06 29.
Artigo em Inglês | MEDLINE | ID: mdl-34188059

RESUMO

CNNM/CorB proteins are a broadly conserved family of integral membrane proteins with close to 90,000 protein sequences known. They are associated with Mg2+ transport but it is not known if they mediate transport themselves or regulate other transporters. Here, we determine the crystal structure of an archaeal CorB protein in two conformations (apo and Mg2+-ATP bound). The transmembrane DUF21 domain exists in an inward-facing conformation with a Mg2+ ion coordinated by a conserved π-helix. In the absence of Mg2+-ATP, the CBS-pair domain adopts an elongated dimeric configuration with previously unobserved domain-domain contacts. Hydrogen-deuterium exchange mass spectrometry, analytical ultracentrifugation, and molecular dynamics experiments support a role of the structural rearrangements in mediating Mg2+-ATP sensing. Lastly, we use an in vitro, liposome-based assay to demonstrate direct Mg2+ transport by CorB proteins. These structural and functional insights provide a framework for understanding function of CNNMs in Mg2+ transport and associated diseases.


Assuntos
Proteínas de Transporte de Cátions/metabolismo , Hydrogenophilaceae/metabolismo , Magnésio/metabolismo , Methanomicrobiaceae/metabolismo , Sequência de Aminoácidos , Proteínas de Transporte de Cátions/genética , Cristalografia por Raios X , Medição da Troca de Deutério , Simulação de Dinâmica Molecular , Conformação Proteica , Domínios Proteicos
7.
Int J Mol Sci ; 22(6)2021 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-33804198

RESUMO

Body iron levels are regulated by hepcidin, a liver-derived peptide that exerts its function by controlling the presence of ferroportin (FPN), the sole cellular iron exporter, on the cell surface. Hepcidin binding leads to FPN internalization and degradation, thereby inhibiting iron release, in particular from iron-absorbing duodenal cells and macrophages involved in iron recycling. Disruption in this regulatory mechanism results in a variety of disorders associated with iron-deficiency or overload. In recent years, increasing evidence has emerged to indicate that, in addition to its role in systemic iron metabolism, FPN may play an important function in local iron control, such that its dysregulation may lead to tissue damage despite unaltered systemic iron homeostasis. In this review, we focus on recent discoveries to discuss the role of FPN-mediated iron export in the microenvironment under both physiological and pathological conditions.


Assuntos
Proteínas de Transporte de Cátions/genética , Microambiente Celular/genética , Hepcidinas/genética , Ferro/metabolismo , Proteínas de Transporte de Cátions/metabolismo , Hepcidinas/metabolismo , Homeostase/genética , Humanos , Fígado/metabolismo , Macrófagos/metabolismo , Ligação Proteica
8.
Int J Mol Sci ; 22(9)2021 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-33925597

RESUMO

Iron is a critical metal for several vital biological processes. Most of the body's iron is bound to hemoglobin in erythrocytes. Iron from senescent red blood cells is recycled by macrophages in the spleen, liver and bone marrow. Dietary iron is taken up by the divalent metal transporter 1 (DMT1) in enterocytes and transported to portal blood via ferroportin (FPN), where it is bound to transferrin and taken up by hepatocytes, macrophages and bone marrow cells via transferrin receptor 1 (TfR1). While most of the physiologically active iron is bound hemoglobin, the major storage of most iron occurs in the liver in a ferritin-bound fashion. In response to an increased iron load, hepatocytes secrete the peptide hormone hepcidin, which binds to and induces internalization and degradation of the iron transporter FPN, thus controlling the amount of iron released from the cells into the blood. This review summarizes the key mechanisms and players involved in cellular and systemic iron regulation.


Assuntos
Ferro/metabolismo , Ferro/fisiologia , Animais , Proteínas de Transporte de Cátions/genética , Proteínas de Transporte de Cátions/metabolismo , Enterócitos/metabolismo , Ferritinas/metabolismo , Hemoglobinas/metabolismo , Hepatócitos/metabolismo , Humanos , Ferro na Dieta/metabolismo , Fígado/metabolismo , Receptores da Transferrina/metabolismo , Baço/metabolismo , Transferrina/metabolismo
9.
Int J Mol Sci ; 22(9)2021 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-33925953

RESUMO

In the last years, research has shown that zinc ions play an essential role in the physiology of brain function. Zinc acts as a potent neuromodulatory agent and signaling ions, regulating healthy brain development and the function of both neurons and glial cells. Therefore, the concentration of zinc within the brain and its cells is tightly controlled. Zinc transporters are key regulators of (extra-) cellular zinc levels, and deregulation of zinc homeostasis and zinc transporters has been associated with neurodegenerative and neuropsychiatric disorders. However, to date, the presence of specific family members and their subcellular localization within brain cells have not been investigated in detail. Here, we analyzed the expression of all zinc transporters (ZnTs) and Irt-like proteins (ZIPs) in the rat brain. We further used primary rat neurons and rat astrocyte cell lines to differentiate between the expression found in neurons or astrocytes or both. We identified ZIP4 expressed in astrocytes but significantly more so in neurons, a finding that has not been reported previously. In neurons, ZIP4 is localized to synapses and found in a complex with major postsynaptic scaffold proteins of excitatory synapses. Synaptic ZIP4 reacts to short-term fluctuations in local zinc levels. We conclude that ZIP4 may have a so-far undescribed functional role at excitatory postsynapses.


Assuntos
Proteínas de Transporte/metabolismo , Neurônios/metabolismo , Zinco/metabolismo , Animais , Astrócitos/metabolismo , Encéfalo/metabolismo , Proteínas de Transporte/fisiologia , Proteínas de Transporte de Cátions/genética , Proteínas de Transporte de Cátions/metabolismo , Linhagem Celular , Feminino , Expressão Gênica/genética , Homeostase/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Tecido Nervoso/metabolismo , Gravidez , Cultura Primária de Células , Ratos , Ratos Sprague-Dawley , Transcriptoma/genética
10.
Int J Mol Sci ; 22(9)2021 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-33925013

RESUMO

Understanding of the immediate mechanisms of Mn-induced neurotoxicity is rapidly evolving. We seek to provide a summary of recent findings in the field, with an emphasis to clarify existing gaps and future research directions. We provide, here, a brief review of pertinent discoveries related to Mn-induced neurotoxicity research from the last five years. Significant progress was achieved in understanding the role of Mn transporters, such as SLC39A14, SLC39A8, and SLC30A10, in the regulation of systemic and brain manganese handling. Genetic analysis identified multiple metabolic pathways that could be considered as Mn neurotoxicity targets, including oxidative stress, endoplasmic reticulum stress, apoptosis, neuroinflammation, cell signaling pathways, and interference with neurotransmitter metabolism, to name a few. Recent findings have also demonstrated the impact of Mn exposure on transcriptional regulation of these pathways. There is a significant role of autophagy as a protective mechanism against cytotoxic Mn neurotoxicity, yet also a role for Mn to induce autophagic flux itself and autophagic dysfunction under conditions of decreased Mn bioavailability. This ambivalent role may be at the crossroad of mitochondrial dysfunction, endoplasmic reticulum stress, and apoptosis. Yet very recent evidence suggests Mn can have toxic impacts below the no observed adverse effect of Mn-induced mitochondrial dysfunction. The impact of Mn exposure on supramolecular complexes SNARE and NLRP3 inflammasome greatly contributes to Mn-induced synaptic dysfunction and neuroinflammation, respectively. The aforementioned effects might be at least partially mediated by the impact of Mn on α-synuclein accumulation. In addition to Mn-induced synaptic dysfunction, impaired neurotransmission is shown to be mediated by the effects of Mn on neurotransmitter systems and their complex interplay. Although multiple novel mechanisms have been highlighted, additional studies are required to identify the critical targets of Mn-induced neurotoxicity.


Assuntos
Intoxicação por Manganês/metabolismo , Animais , Proteínas de Transporte de Cátions/metabolismo , Humanos , Manganês/toxicidade , Doenças Neurodegenerativas/induzido quimicamente , Transmissão Sináptica/efeitos dos fármacos
11.
EMBO Rep ; 22(5): e51532, 2021 05 05.
Artigo em Inglês | MEDLINE | ID: mdl-33822458

RESUMO

Ferroptosis has recently attracted much interest because of its relevance to human diseases such as cancer and ischemia-reperfusion injury. We have reported that prolonged severe cold stress induces lipid peroxidation-dependent ferroptosis, but the upstream mechanism remains unknown. Here, using genome-wide CRISPR screening, we found that a mitochondrial Ca2+ uptake regulator, mitochondrial calcium uptake 1 (MICU1), is required for generating lipid peroxide and subsequent ferroptosis under cold stress. Furthermore, the gatekeeping activity of MICU1 through mitochondrial calcium uniporter (MCU) is suggested to be indispensable for cold stress-induced ferroptosis. MICU1 is required for mitochondrial Ca2+ increase, hyperpolarization of the mitochondrial membrane potential (MMP), and subsequent lipid peroxidation under cold stress. Collectively, these findings suggest that the MICU1-dependent mitochondrial Ca2+ homeostasis-MMP hyperpolarization axis is involved in cold stress-induced lipid peroxidation and ferroptosis.


Assuntos
Proteínas de Transporte de Cátions , Ferroptose , Cálcio/metabolismo , Proteínas de Ligação ao Cálcio/metabolismo , Proteínas de Transporte de Cátions/metabolismo , Resposta ao Choque Frio , Humanos , Potencial da Membrana Mitocondrial , Proteínas de Transporte da Membrana Mitocondrial/genética , Proteínas de Transporte da Membrana Mitocondrial/metabolismo
12.
Int J Mol Sci ; 22(6)2021 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-33806756

RESUMO

The popularity of fasting and restricted food intake is increasing. While the body's adaptability to dietary insufficiency is crucial for health, molecular mechanisms of adaptive changes are not well understood. Here, we compared the effects of fasting and exercise on the expression of leukocyte genes and proteins involved in the storage, export, and acquisition of iron, an essential element with physiological roles. Healthy men participated in the study (age, 30-70 years; body weight, 60-100 kg; body mass index, 20-29.9 kg/m2). The participants performed an exercise test with a gradually increasing intensity until the individual maximum exercise capacity was reached, before and after 8-d fast. Blood samples were collected before, immediately after, and 3 h after exercise. Gene expression was analyzed by reverse-transcription quantitative polymerase chain reaction and protein levels were analyzed by immunobloting. Eight days of total starvation diet affected the body composition and decreased exercise capacity. Further, fasting decreased the expression of genes associated with iron storage and export, and increased the expression of genes involved in iron acquisition. Conversely, only PCBP2 protein increased after fasting; however, an upward trend was apparent for all proteins. In conclusion, the body adapts to starvation by adjusting iron economy.


Assuntos
Proteínas de Transporte de Cátions/genética , Jejum , Regulação da Expressão Gênica , Ferro/metabolismo , Leucócitos/metabolismo , Adulto , Proteínas de Transporte de Cátions/metabolismo , Jejum/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Estresse Oxidativo , Fatores Sexuais , Fatores de Tempo
13.
Biochemistry (Mosc) ; 86(2): 168-178, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33832415

RESUMO

Monocytes and muscles demonstrate functionally contrasting behavior under conditions of zinc deficiency with relation to zinc storage system (muscle retain zinc in contrast to monocytes). We aimed to understand the effects of zinc status and HIV-1 Tat mediated inflammation on expression of zinc transporters in these types of cells. Expression of zinc transporters [ZnTs, ZIPs, and metallothionein (MT)] was quantified by qRT-PCR in RD, THP-1 cells separately and in co-cultured THP-1-RD cells. ZnT1 protein expression levels were confirmed by Western blot. Significant increase of MT and ZnT1 mRNA in response to zinc supplementation and decrease during zinc deficiency indicates significance of the genes encoding transporters in maintaining zinc homeostasis in these tissues. In the RD cells ZIP10 exhibited inverse relation to zinc status whereas no correlation was found in the THP-1 cells. Tat-induced inflammation resulted in the significant elevation of MT, IL6, ZIP7, ZIP8, ZIP9 transcripts in the co-cultured RD cells, whereas THP-1 cells demonstrated increased IL-1ß levels and reduced levels of ZIP7 and ZIP14. Zinc status and HIV-1Tat induced inflammation appear to influence differential expression of MT, ZnTs, and ZIPs in the muscle and monocyte cells.


Assuntos
Proteínas de Transporte de Cátions/genética , Inflamação , Monócitos/metabolismo , Músculos/metabolismo , Zinco/metabolismo , Proteínas de Transporte de Cátions/metabolismo , Linhagem Celular Tumoral , Regulação da Expressão Gênica , HIV-1 , Humanos , Metalotioneína/genética , Monócitos/virologia , Músculos/virologia , RNA Mensageiro , Células THP-1 , Produtos do Gene tat do Vírus da Imunodeficiência Humana
14.
J Chem Inf Model ; 61(5): 2407-2417, 2021 05 24.
Artigo em Inglês | MEDLINE | ID: mdl-33886304

RESUMO

The CorA family of proteins plays a housekeeping role in the homeostasis of divalent metal ions in many bacteria and archaea as well as in mitochondria of eukaryotes, rendering it an important target to study the mechanisms of divalent transport and regulation across different life domains. Despite numerous studies, the mechanistic details of the channel gating and the transport of the metal ions are still not entirely understood. Here, we use all-atom and coarse-grained molecular dynamics simulations combined with in vitro experiments to investigate the influence of divalent cations on the function of CorA. Simulations reveal pronounced asymmetric movements of monomers that enable the rotation of the α7 helix and the cytoplasmic subdomain with the subsequent formation of new interactions and the opening of the channel. These computational results are functionally validated using site-directed mutagenesis of the intracellular cytoplasmic domain residues and biochemical assays. The obtained results infer a complex network of interactions altering the structure of CorA to allow gating. Furthermore, we attempt to reconcile the existing gating hypotheses for CorA to conclude the mechanism of transport of divalent cations via these proteins.


Assuntos
Proteínas de Transporte de Cátions , Simulação de Dinâmica Molecular , Proteínas de Bactérias/metabolismo , Proteínas de Transporte de Cátions/genética , Proteínas de Transporte de Cátions/metabolismo , Magnésio/metabolismo , Mutagênese Sítio-Dirigida
15.
Int J Mol Sci ; 22(4)2021 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-33672907

RESUMO

HKT channels are a plant protein family involved in sodium (Na+) and potassium (K+) uptake and Na+-K+ homeostasis. Some HKTs underlie salt tolerance responses in plants, while others provide a mechanism to cope with short-term K+ shortage by allowing increased Na+ uptake under K+ starvation conditions. HKT channels present a functionally versatile family divided into two classes, mainly based on a sequence polymorphism found in the sequences underlying the selectivity filter of the first pore loop. Physiologically, most class I members function as sodium uniporters, and class II members as Na+/K+ symporters. Nevertheless, even within these two classes, there is a high functional diversity that, to date, cannot be explained at the molecular level. The high complexity is also reflected at the regulatory level. HKT expression is modulated at the level of transcription, translation, and functionality of the protein. Here, we summarize and discuss the structure and conservation of the HKT channel family from algae to angiosperms. We also outline the latest findings on gene expression and the regulation of HKT channels.


Assuntos
Proteínas de Transporte de Cátions/metabolismo , Proteínas de Plantas/metabolismo , Potássio/metabolismo , Sódio/metabolismo , Simportadores/metabolismo , Proteínas de Transporte de Cátions/classificação , Proteínas de Transporte de Cátions/genética , Regulação da Expressão Gênica de Plantas , Transporte de Íons , Magnoliopsida/genética , Magnoliopsida/metabolismo , Microalgas/genética , Microalgas/metabolismo , Filogenia , Proteínas de Plantas/genética , Simportadores/classificação , Simportadores/genética
16.
Int J Nanomedicine ; 16: 1709-1724, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33688187

RESUMO

Background: Manganese Ferrite Nanoparticles (Mn-IONPs) are widely used in biomedical field and their cytotoxicity has been initially explored, but the mechanism remains obscure. The nano-bio interactions are believed to be crucial for cytotoxicity mechanism, while little data have been acquired. Methods: Mn-IONPs were synthesized by thermal decomposition of acetylacetonate precursor. After physicochemical characterization, we analyzed the metabolic conversion and removal of Mn-IONPs in RAW264.7 cells by Prussian blue staining, TEM, HRTEM and elemental quantitative analysis, followed by gene expression evaluation using quantitative RT-PCR. Results: Mn-IONPs were successfully synthesized. Both the uptake and cytotoxicity of Mn-IONPs on RAW264.7 cells were time- and dose-dependent. After internalized, Mn-IONPs were passed to daughter cells with passages on. Meanwhile, Mn-IONPs were exocytosed and digested to metal ions and further excreted out, resulted in the labeling rate and ions contents decreased gradually. As ion influx related genes, the expressions of ZIP14, IRP2, FtH and DMT1 were suppressed within 24 hours but overexpressed to a plateau at the 48th hour in a dose-dependent manner. At the 72nd hour, ZIP14 and DMT1 mRNA levels decreased toward normal, while IRP2 and FtH kept up-regulated. As efflux related genes, FPN, SLC30A10 and Hamp2 genes were up-regulated within 24-72 hours; SPCA1 was suppressed at the 24th and 72nd hour, while overexpressed at the 48th hour. All the efflux related genes' mRNA had a dose-dependent increasing manner at the corresponding time points. Conclusion: Mn-IONPs showed time- and dose-dependent cytotoxicity and cell labeling rate in RAW264.7 cells. Accompanying with the intracellular catabolic breakdown and exocytosis of Mn-IONPs, RAW264.7 cells also secreted and re-uptook manganese and iron ions to maintain intracellular homeostasis in the succeeding passages. And the metabolic conversion of Mn-IONPs in RAW264.7 cells can affect the expression of ZIP14, DMT1, FPN, SLC30A10, IRP2, FtH, Hamp2 and SPCA1 genes.


Assuntos
Proteínas de Transporte de Cátions/genética , Compostos Férricos/metabolismo , Regulação da Expressão Gênica , Compostos de Manganês/metabolismo , Nanopartículas/química , Animais , Proteínas de Transporte de Cátions/metabolismo , Morte Celular/genética , Proliferação de Células/genética , Camundongos , Nanopartículas/ultraestrutura , Tamanho da Partícula , Células RAW 264.7
17.
Nutrients ; 13(3)2021 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-33673530

RESUMO

Anemia is a frequent finding in children with celiac disease but the detailed pathophysiological mechanisms in the intestine remain obscure. One possible explanation could be an abnormal expression of duodenal iron transport proteins. However, the results have so far been inconsistent. We investigated this issue by comparing immunohistochemical stainings of duodenal cytochrome B (DCYTB), divalent metal transporter 1 (DMT1), ferroportin, hephaestin and transferrin receptor 1 (TfR1) in duodenal biopsies between 27 children with celiac disease and duodenal atrophy, 10 celiac autoantibody-positive children with potential celiac disease and six autoantibody-negative control children. Twenty out of these 43 subjects had anemia. The expressions of the iron proteins were investigated with regard to saturation and the percentage of the stained area or stained membrane length of the enterocytes. The results showed the stained area of ferroportin to be increased and the saturation of hephaestin to be decreased in celiac disease patients compared with controls. There were no differences in the transporter protein expressions between anemic and non-anemic patients. The present results suggest an iron status-independent alteration of ferroportin and hephaestin proteins in children with histologically confirmed celiac disease.


Assuntos
Antígenos CD/metabolismo , Proteínas de Transporte de Cátions/metabolismo , Doença Celíaca/metabolismo , Grupo dos Citocromos b/metabolismo , Proteínas de Membrana/metabolismo , Oxirredutases/metabolismo , Receptores da Transferrina/metabolismo , Fatores de Transcrição/metabolismo , Adolescente , Anemia Ferropriva/complicações , Anemia Ferropriva/metabolismo , Antígenos CD/genética , Proteínas de Transporte de Cátions/genética , Doença Celíaca/complicações , Criança , Pré-Escolar , Grupo dos Citocromos b/genética , Feminino , Regulação da Expressão Gênica/fisiologia , Humanos , Masculino , Proteínas de Membrana/genética , Oxirredutases/genética , Receptores da Transferrina/genética , Fatores de Transcrição/genética
18.
Aging (Albany NY) ; 13(6): 8737-8761, 2021 03 10.
Artigo em Inglês | MEDLINE | ID: mdl-33714956

RESUMO

Lung cancer morbidity and mortality remain the leading causes of tumor-associated death worldwide. The discovery of early diagnostic and prognostic markers of lung cancer could significantly improve the survival rate and decrease the mortality rate. FPN1 is the only known mammalian iron exporter. However, the molecular and biological functions of FPN1 in lung cancer remain unclear. Here, FPN1 mRNA expression in lung cancer was estimated using the TCGA, Oncomine, TIMER, and UALCAN databases. The prognostic role of FPN1 was evaluated using Kaplan-Meier plotter and PrognoScan. Associations between FPN1 and immune infiltration in lung cancer were evaluated by the TIMER and CIBERSORT algorithms. FPN1 mRNA and protein expressions were significantly downregulated in lung cancer. Low FPN1 expression was strongly related to worse prognosis in patients with lung cancer. GO and KEGG analyses and GSEA suggested that FPN1 was remarkably related to iron homeostasis and immunity. Importantly, FPN1 was remarkably associated with the infiltrating abundance of multiple immune cells. Moreover, FPN1 displayed a strong correlation with various immune marker sets. We investigated the clinical application value of FPN1 and provided a basis for the sensitive diagnosis, prognostication and targeted therapy of lung cancer.


Assuntos
Biomarcadores Tumorais/metabolismo , Proteínas de Transporte de Cátions/metabolismo , Neoplasias Pulmonares/patologia , Linfócitos do Interstício Tumoral/patologia , Regulação para Baixo , Humanos , Neoplasias Pulmonares/imunologia , Neoplasias Pulmonares/metabolismo , Prognóstico
19.
PLoS Pathog ; 17(3): e1009399, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33720977

RESUMO

Trypanosoma cruzi is a protist parasite and the causative agent of American trypanosomiasis or Chagas disease. The parasite life cycle in its mammalian host includes an intracellular stage, and glycosylated proteins play a key role in host-parasite interaction facilitating adhesion, invasion and immune evasion. Here, we report that a Golgi-localized Mn2+-Ca2+/H+ exchanger of T. cruzi (TcGDT1) is required for efficient protein glycosylation, host cell invasion, and intracellular replication. The Golgi localization was determined by immunofluorescence and electron microscopy assays. TcGDT1 was able to complement the growth defect of Saccharomyces cerevisiae null mutants of its ortholog ScGDT1 but ablation of TcGDT1 by CRISPR/Cas9 did not affect the growth of the insect stage of the parasite. The defect in protein glycosylation was rescued by Mn2+ supplementation to the growth medium, underscoring the importance of this transition metal for Golgi glycosylation of proteins.


Assuntos
Proteínas de Transporte de Cátions/metabolismo , Doença de Chagas/metabolismo , Interações Hospedeiro-Parasita/fisiologia , Manganês/metabolismo , Proteínas de Protozoários/metabolismo , Trypanosoma cruzi/fisiologia , Animais , Chlorocebus aethiops , Glicosilação , Complexo de Golgi/metabolismo , Células Vero , Internalização do Vírus , Replicação Viral/fisiologia
20.
Biochem Biophys Res Commun ; 550: 30-36, 2021 04 23.
Artigo em Inglês | MEDLINE | ID: mdl-33677133

RESUMO

The extracellular matrix (ECM) degradation of nucleus pulposus cells (NPCs) is mainly induced by metalloproteinases (MMPs). Zn2+ is an essential component of MMPs, but the effect of Zn2+ importers in controlling ECM metabolism remains unclear. The purpose of this research was to identify the involvement of Zn2+ importers in ECM degradation induced by inflammatory stimuli and excessive mechanical stressing. In this study, NPCs from Sprague-Dawley (SD) rats were separated and cultured. FluoZin-3 AM staining was applied to detect [Zn2+]i in NPCs treated with Interleukin-1ß (IL-1ß) or cyclic tensile strain (CTS) with a Flexcell Strain Unit. We found that intracellular Zn2+ concentration ([Zn2+]i) elevated dramatically, and ZIP8 is the predominant Zn2+ importer among all importers in senescent NPCs. The [Zn2+]i and MMP expression level both increased in IL-1ß and CTS treated NPCs. Furthermore, the expression of ZIP8 was also markedly increased. However, knockdown of ZIP8 with siRNA alleviated ECM degradation induced by inflammatory stimuli and CTS. Both stimuli activated NF-κB signaling pathway, and knockdown of ZIP8 effectively inhibited NF-κB signaling pathway activation. In conclusion, knockdown of ZIP8 can alleviate NPCs' ECM degradation caused by inflammatory stimuli and excessive mechanical stressing.


Assuntos
Proteínas de Transporte de Cátions/metabolismo , Matriz Extracelular/metabolismo , NF-kappa B/metabolismo , Núcleo Pulposo/metabolismo , Transdução de Sinais , Animais , Proteínas de Transporte de Cátions/deficiência , Proteínas de Transporte de Cátions/genética , Colágeno Tipo II/metabolismo , Técnicas de Silenciamento de Genes , Inflamação/metabolismo , Masculino , Núcleo Pulposo/citologia , Ratos , Zinco/metabolismo
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