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Ghosh P, Roy Chowdhury D, Devgupta P, Chakraborti T. Averrhoa carambola Leaf Extract Induces Apoptosis-Like Death with Increased ROS Generation in Leishmania donovani. Acta Parasitol 2024; 69:1501-1516. [PMID: 39164544 DOI: 10.1007/s11686-024-00902-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2023] [Accepted: 07/30/2024] [Indexed: 08/22/2024]
Abstract
PURPOSE The parasitic disease leishmaniasis is responsible for high mortality and morbidity rates worldwide. The visceral form is the most severe form of leishmaniasis (or leishmaniosis), which is caused predominantly by Leishmania donovani. Currently, clinically recommended antileishmanial drugs are not convenient because of several medical complications and resistance issues. Phytocompounds are the best candidates in this regard. The present study aimed to evaluate the antileishmanial activity of Averrhoa carambola leaf extract. METHODS The antipromastigote activity and cytotoxicity were assessed using the MTT assay. Morphological distortions were determined using phase contrast microscopy and scanning electron microscopy (SEM). Reactive oxygen species (ROS) production, nonprotein thiol depletion and apoptotic death in promastigotes were determined via flow cytometry. UV-visible spectroscopy and energy dispersive X-ray (EDX) spectroscopy was performed for elemental analysis. Fourier-transform infrared spectroscopy (FTIR) and liquid chromatography‒mass spectrometry (LCMS) were used to characterize the phytocomponent(s) present in the extract. RESULTS The chloroform extract of Averrhoa carambola leaf (ACCEX) (IC50 = 50.76 ± 1.7 µg/mL) exhibited the highest activity, followed by the ethyl acetate, hexane, and methanol extracts. ACCEX has also exhibited lower toxicity towards host macrophages. ACCEX also induced morphological distortions in promastigotes, with significant generation of ROS and the concomitant apoptosis initiation followed by a decrease in the nonprotein thiol level. The major phytometabolites present in ACCEX were identified from the National Institute of Standards and Technology (NIST) database and from a literature review. CONCLUSIONS This study suggested that Averrhoa carambola leaf extracts are rich in some classes of biologically active phytocompounds and exhibit good antileishmanial activity.
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Affiliation(s)
- Priyanka Ghosh
- Department of Biochemistry and Biophysics, University of Kalyani, Kalyani, West Bengal, 741235, India
| | - Dibyapriya Roy Chowdhury
- Department of Biochemistry and Biophysics, University of Kalyani, Kalyani, West Bengal, 741235, India
| | - Pujayita Devgupta
- Department of Biochemistry and Biophysics, University of Kalyani, Kalyani, West Bengal, 741235, India
| | - Tapati Chakraborti
- Department of Biochemistry and Biophysics, University of Kalyani, Kalyani, West Bengal, 741235, India.
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2
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Nagel A, Cuss CW, Goss GG, Shotyk W, Glover CN. Effects of Acute and Subchronic Waterborne Thallium Exposure on Ionoregulatory Enzyme Activity and Oxidative Stress in Rainbow Trout (Oncorhynchus mykiss). ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2024; 43:87-96. [PMID: 37750573 DOI: 10.1002/etc.5756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 09/04/2023] [Accepted: 09/22/2023] [Indexed: 09/27/2023]
Abstract
The mechanisms of acute (96-hour) and subchronic (28-day) toxicity of the waterborne trace metal thallium (Tl) to rainbow trout (Oncorhynchus mykiss) were investigated. Specifically, effects on branchial and renal ionoregulatory enzymes (sodium/potassium adenosine triphosphatase [ATPase; NKA] and proton ATPase) and hepatic oxidative stress endpoints (protein carbonylation, glutathione content, and activities of catalase and glutathione peroxidase) were examined. Fish (19-55 g) were acutely exposed to 0 (control), 0.9 (regulatory limit), 2004 (half the acute median lethal concentration), or 4200 (acute median lethal concentration) µg Tl L-1 or subchronically exposed to 0, 0.9, or 141 (an elevated environmental concentration) µg Tl L-1 . The only effect following acute exposure was a stimulation of renal H+ -ATPase activity at the highest Tl exposure concentration. Similarly, the only significant effect of subchronic Tl exposure was an inhibition of branchial NKA activity at 141 µg Tl L-1 , an effect that may reflect the interaction of Tl with potassium ion handling. Despite significant literature evidence for effects of Tl on oxidative stress, there were no effects of Tl on any such endpoint in rainbow trout, regardless of exposure duration or exposure concentration. Elevated basal levels of antioxidant defenses may explain this finding. These data suggest that ionoregulatory perturbance is a more likely mechanism of Tl toxicity than oxidative stress in rainbow trout but is an endpoint of relevance only at elevated environmental Tl concentrations. Environ Toxicol Chem 2024;43:87-96. © 2023 SETAC.
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Affiliation(s)
- Andrew Nagel
- Department of Renewable Resources, University of Alberta, Edmonton, Alberta, Canada
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Chad W Cuss
- Department of Renewable Resources, University of Alberta, Edmonton, Alberta, Canada
- School of Science and the Environment, Memorial University Newfoundland-Grenfell Campus, Corner Brook, Newfoundland, Canada
| | - Greg G Goss
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - William Shotyk
- Department of Renewable Resources, University of Alberta, Edmonton, Alberta, Canada
| | - Chris N Glover
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
- Faculty of Science and Technology and Athabasca River Basin Research Institute, Athabasca University, Athabasca, Alberta, Canada
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3
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Leone FA, Fabri LM, Costa MIC, Moraes CM, Garçon DP, McNamara JC. Differential effects of cobalt ions in vitro on gill (Na +, K +)-ATPase kinetics in the Blue crab Callinectes danae (Decapoda, Brachyura). Comp Biochem Physiol C Toxicol Pharmacol 2023; 274:109757. [PMID: 37741603 DOI: 10.1016/j.cbpc.2023.109757] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Revised: 09/13/2023] [Accepted: 09/20/2023] [Indexed: 09/25/2023]
Abstract
We used the gill (Na+, K+)-ATPase as a molecular marker to provide a comprehensive kinetic analysis of the effects of Co2+in vitro on the modulation of K+-phosphatase activity in the Blue crab Callinectes danae. Co2+ can stimulate or inhibit K+-phosphatase activity. With Mg2+, K+-phosphatase activity is almost completely inhibited by Co2+. Co2+ stimulates K+-phosphatase activity similarly to Mg2+ although with a ≈4.5-fold greater affinity. At saturating Mg2+ concentrations, Mg2+ displaces bound Co2+ from the Mg2+-binding site in a concentration dependent manner, but Co2+ cannot displace Mg2+ from its binding site even at millimolar concentrations. Saturation by Co2+ of the Mg2+ binding site does not affect pNPP recognition by the enzyme. Substitution of Mg2+ by Co2+ slightly increases enzyme affinity for K+ and NH4+. Independently of Mg2+, inhibition by ouabain or sodium ions is unaffected by Co2+. Investigation of gill (Na+, K+)-ATPase K+-phosphatase activity provides a reliable tool to examine the kinetic effects of Co2+ with and without Na+ and ATP. Given that the toxic effects of Co2+ at the molecular level are poorly understood, these findings advance our knowledge of the mechanism of action of Co2+ on the crustacean gill (Na+, K+)-ATPase.
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Affiliation(s)
- Francisco A Leone
- Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil.
| | - Leonardo M Fabri
- Departamento de Bioquímica e Imunologia, Faculdade de Medicina de Ribeirão Preto, Brazil
| | - Maria I C Costa
- Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Cintya M Moraes
- Departamento de Bioquímica e Imunologia, Faculdade de Medicina de Ribeirão Preto, Brazil
| | | | - John C McNamara
- Departamento de Biologia, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil; Centro de Biologia Marinha, Universidade de São Paulo, São Sebastião, Brazil. https://twitter.com/@maracoani
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4
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Kruglov AG, Romshin AM, Nikiforova AB, Plotnikova A, Vlasov II. Warm Cells, Hot Mitochondria: Achievements and Problems of Ultralocal Thermometry. Int J Mol Sci 2023; 24:16955. [PMID: 38069275 PMCID: PMC10707128 DOI: 10.3390/ijms242316955] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Revised: 11/27/2023] [Accepted: 11/28/2023] [Indexed: 12/18/2023] Open
Abstract
Temperature is a crucial regulator of the rate and direction of biochemical reactions and cell processes. The recent data indicating the presence of local thermal gradients associated with the sites of high-rate thermogenesis, on the one hand, demonstrate the possibility for the existence of "thermal signaling" in a cell and, on the other, are criticized on the basis of thermodynamic calculations and models. Here, we review the main thermometric techniques and sensors developed for the determination of temperature inside living cells and diverse intracellular compartments. A comparative analysis is conducted of the results obtained using these methods for the cytosol, nucleus, endo-/sarcoplasmic reticulum, and mitochondria, as well as their biological consistency. Special attention is given to the limitations, possible sources of errors and ambiguities of the sensor's responses. The issue of biological temperature limits in cells and organelles is considered. It is concluded that the elaboration of experimental protocols for ultralocal temperature measurements that take into account both the characteristics of biological systems, as well as the properties and limitations of each type of sensor is of critical importance for the generation of reliable results and further progress in this field.
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Affiliation(s)
- Alexey G. Kruglov
- Institute of Theoretical and Experimental Biophysics of the Russian Academy of Sciences, 142290 Pushchino, Russia;
| | - Alexey M. Romshin
- Prokhorov General Physics Institute of the Russian Academy of Sciences, 119991 Moscow, Russia;
| | - Anna B. Nikiforova
- Institute of Theoretical and Experimental Biophysics of the Russian Academy of Sciences, 142290 Pushchino, Russia;
| | - Arina Plotnikova
- Institute for Physics and Engineering in Biomedicine, National Research Nuclear University MEPhI (Moscow Engineering Physics Institute MEPhI), 115409 Moscow, Russia;
| | - Igor I. Vlasov
- Prokhorov General Physics Institute of the Russian Academy of Sciences, 119991 Moscow, Russia;
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Yu Z, Ueno K, Funayama R, Sakai M, Nariai N, Kojima K, Kikuchi Y, Li X, Ono C, Kanatani J, Ono J, Iwamoto K, Hashimoto K, Kinoshita K, Nakayama K, Nagasaki M, Tomita H. Sex-Specific Differences in the Transcriptome of the Human Dorsolateral Prefrontal Cortex in Schizophrenia. Mol Neurobiol 2023; 60:1083-1098. [PMID: 36414910 DOI: 10.1007/s12035-022-03109-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Accepted: 10/20/2022] [Indexed: 11/24/2022]
Abstract
Schizophrenia presents clinical and biological differences between males and females. This study investigated transcriptional profiles in the dorsolateral prefrontal cortex (DLPFC) using postmortem data from the largest RNA-sequencing (RNA-seq) database on schizophrenic cases and controls. Data for 154 male and 113 female controls and 160 male and 93 female schizophrenic cases were obtained from the CommonMind Consortium. In the RNA-seq database, the principal component analysis showed that sex effects were small in schizophrenia. After we analyzed the impact of sex-specific differences on gene expression, the female group showed more significantly changed genes compared with the male group. Based on the gene ontology analysis, the female sex-specific genes that changed were overrepresented in the mitochondrion, ATP (phosphocreatine and adenosine triphosphate)-, and metal ion-binding relevant biological processes. An ingenuity pathway analysis revealed that the differentially expressed genes related to schizophrenia in the female group were involved in midbrain dopaminergic and γ-aminobutyric acid (GABA)-ergic neurons and microglia. We used methylated DNA-binding domain-sequencing analyses and microarray to investigate the DNA methylation that potentially impacts the sex differences in gene transcription using a maternal immune activation (MIA) murine model. Among the sex-specific positional genes related to schizophrenia in the PFC of female offspring from MIA, the changes in the methylation and transcriptional expression of loci ACSBG1 were validated in the females with schizophrenia in independent postmortem samples by real-time PCR and pyrosequencing. Our results reveal potential genetic risks in the DLPFC for the sex-dependent prevalence and symptomology of schizophrenia.
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Affiliation(s)
- Zhiqian Yu
- Department of Psychiatry, Graduate School of Medicine, Tohoku University, 1-1 Seiryo-Machi, Aoba-Ku, Sendai, 980-8574, Japan.
- Tohoku Medical Megabank Organization, Tohoku University, Sendai, Japan.
| | - Kazuko Ueno
- Tohoku Medical Megabank Organization, Tohoku University, Sendai, Japan
| | - Ryo Funayama
- Division of Cell Proliferation, United Centers for Advanced Research and Translational Medicine, Graduate School of Medicine, Tohoku University, Sendai, Japan
| | - Mai Sakai
- Department of Psychiatric Nursing, Graduate School of Medicine, Tohoku University, Sendai, Japan
| | - Naoki Nariai
- Tohoku Medical Megabank Organization, Tohoku University, Sendai, Japan
| | - Kaname Kojima
- Tohoku Medical Megabank Organization, Tohoku University, Sendai, Japan
| | - Yoshie Kikuchi
- Department of Psychiatry, Graduate School of Medicine, Tohoku University, 1-1 Seiryo-Machi, Aoba-Ku, Sendai, 980-8574, Japan
| | - Xue Li
- Department of Psychiatry, Graduate School of Medicine, Tohoku University, 1-1 Seiryo-Machi, Aoba-Ku, Sendai, 980-8574, Japan
| | - Chiaki Ono
- Department of Psychiatry, Graduate School of Medicine, Tohoku University, 1-1 Seiryo-Machi, Aoba-Ku, Sendai, 980-8574, Japan
| | - Junpei Kanatani
- Department of Psychiatry, Graduate School of Medicine, Tohoku University, 1-1 Seiryo-Machi, Aoba-Ku, Sendai, 980-8574, Japan
| | - Jiro Ono
- Department of Psychiatry, Graduate School of Medicine, Tohoku University, 1-1 Seiryo-Machi, Aoba-Ku, Sendai, 980-8574, Japan
| | - Kazuya Iwamoto
- Department of Molecular Brain Science, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
| | - Kenji Hashimoto
- Division of Clinical Neuroscience, Center for Forensic Mental Health, Chiba University, Chiba, Japan
| | - Kengo Kinoshita
- Tohoku Medical Megabank Organization, Tohoku University, Sendai, Japan
| | - Keiko Nakayama
- Division of Cell Proliferation, United Centers for Advanced Research and Translational Medicine, Graduate School of Medicine, Tohoku University, Sendai, Japan
| | - Masao Nagasaki
- Human Biosciences Unit for the Top Global Course Center for the Promotion of Interdisciplinary Education and Research, Kyoto University, Kyoto, Japan
- Center for Genomic Medicine, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Hiroaki Tomita
- Department of Psychiatry, Graduate School of Medicine, Tohoku University, 1-1 Seiryo-Machi, Aoba-Ku, Sendai, 980-8574, Japan
- Tohoku Medical Megabank Organization, Tohoku University, Sendai, Japan
- Department of Disaster Psychiatry, International Research Institute for Disaster Science, Tohoku University, Sendai, Japan
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6
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Xu N. Pumping Ratio of the Na +/K + Pump—A Further View. Bioelectricity 2022. [DOI: 10.1089/bioe.2022.0029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Affiliation(s)
- Ning Xu
- Department of Biomedical Engineering and Instrumentation, Tsinghua University, Beijing 100084, P.R. China
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7
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Xue YH, Jia T, Yang N, Sun ZX, Xu ZY, Wen XL, Feng LS. Transcriptome alterations in zebrafish gill after exposure to different sizes of microplastics. JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART A, TOXIC/HAZARDOUS SUBSTANCES & ENVIRONMENTAL ENGINEERING 2022; 57:347-356. [PMID: 35491826 DOI: 10.1080/10934529.2022.2064668] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Revised: 03/31/2022] [Accepted: 04/01/2022] [Indexed: 06/14/2023]
Abstract
Most studies on microplastics (MPs) focused on gut, liver, and brain, and MPs toxicity was size-dependent, but less has been reported on gill. Here, zebrafish were exposed to three sizes of MPs (45-53 μm, 90-106 μm, and 250-300 μm). Next, comparative transcriptome analysis and determination of physiological indices were performed in zebrafish gills to elucidate the size-associated toxicity of MPs to fish gills. Compared with the control, 60, 344, and 802 differentially expressed genes (DEGs) were identified after exposure to 45-53 μm, 90-106 μm, and 250-300 μm MPs for 5 days, respectively. More DEGs in treatment with bigger MPs suggested that bigger MPs might induce more changes in zebrafish gills than smaller ones. These DEGs were significantly enriched in the FoxO signaling, cellular senescence, circadian rhythm and p53 signaling pathways. Besides, 90-106 μm and 250-300 μm MPs treatments inhibited the cell cycle and prevented the apoptosis. The GSH content significantly increased after MPs exposure, suggesting the induction of oxidative stress. AChE and Na+/K+-ATPase activities were significantly lowered in all MPs treatments than in the control, suggesting the inhibition of neurotransmission and ion regulation. These changes might negatively influence the normal functioning of gills, such as osmoregulation, ion regulation, and respiration.
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Affiliation(s)
- Ying-Hao Xue
- College of Land and Environment, Shenyang Agricultural University, Shenyang, P.R. China
- Rural Energy and Environment Agency, Ministry of Agriculture and Rural Affairs, Beijing, P.R. China
| | - Tao Jia
- Rural Energy and Environment Agency, Ministry of Agriculture and Rural Affairs, Beijing, P.R. China
| | - Ning Yang
- Liaoning Academy of Agricultural Sciences, Shenyang, P.R. China
| | - Zhan-Xiang Sun
- Liaoning Academy of Agricultural Sciences, Shenyang, P.R. China
| | - Zhi-Yu Xu
- Rural Energy and Environment Agency, Ministry of Agriculture and Rural Affairs, Beijing, P.R. China
| | - Xin-Li Wen
- School of Ecology and Environment, Anhui Normal University, Wuhu, P.R. China
| | - Liang-Shan Feng
- Liaoning Academy of Agricultural Sciences, Shenyang, P.R. China
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8
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Garçon DP, Fabri LM, Moraes CM, Costa MIC, Freitas RS, McNamara JC, Leone FA. Effects of ammonia on gill (Na +, K +)-ATPase kinetics in a hololimnetic population of the Amazon River shrimp Macrobrachium amazonicum. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2022; 246:106144. [PMID: 35339850 DOI: 10.1016/j.aquatox.2022.106144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 03/04/2022] [Accepted: 03/12/2022] [Indexed: 06/14/2023]
Abstract
Water quality is essential for successful aquaculture. For freshwater shrimp farming, ammonia concentrations can increase considerably, even when culture water is renewed frequently, consequently increasing the risk of ammonia intoxication. We investigated ammonia lethality (LC50-96 h) in a hololimnetic population of the Amazon River shrimp Macrobrachium amazonicum from the Paraná/Paraguay River basin, including the effects of exposure to 4.93 mg L-1 total ammonia concentration on gill (Na+, K+)-ATPase activity. The mean LC50-96 h was 49.27 mg L-1 total ammonia, corresponding to 1.8 mg L-1 un-ionized ammonia. Except for NH4+ affinity that increased 2.5-fold, that of the gill (Na+, K+)-ATPase for ATP, Mg2+, Na+, K+ and ouabain was unchanged after ammonia exposure. Western blotting of gill microsomal preparations from fresh caught shrimps showed a single immunoreactive band of ≈110 kDa, corresponding to the gill (Na+, K+)-ATPase α-subunit. Ammonia exposure increased (Na+, K+)-ATPase activity by ≈25%, coincident with an additional 130 kDa α-subunit immunoreactive band, and increased K+-stimulated and V(H+)-ATPase activities by ≈2.5-fold. Macrobrachium amazonicum from the Paraná/Paraguay River basin is as tolerant to ammonia as are other Amazon River basins populations, showing toxicity comparable to that of marine crustaceans.
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Affiliation(s)
- Daniela P Garçon
- Campus Universitário de Iturama, Universidade Federal do Triângulo Mineiro, Iturama, MG, Brasil
| | - Leonardo M Fabri
- Departamento de Bioquímica e Imunologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil
| | - Cintya M Moraes
- Departamento de Bioquímica e Imunologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil
| | - Maria Izabel C Costa
- Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brasil
| | - Renata S Freitas
- Campus Universitário de Iturama, Universidade Federal do Triângulo Mineiro, Iturama, MG, Brasil
| | - John C McNamara
- Departamento de Biologia, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brasil; Centro de Biologia Marinha, Universidade de São Paulo, São Sebastião, SP, Brasil
| | - Francisco A Leone
- Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brasil.
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Liao B, Wang J, Xiao B, Yang X, Xie Z, Li D, Li C. Effects of acute microplastic exposure on physiological parameters in Tubastrea aurea corals. MARINE POLLUTION BULLETIN 2021; 165:112173. [PMID: 33621903 DOI: 10.1016/j.marpolbul.2021.112173] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2020] [Revised: 02/09/2021] [Accepted: 02/10/2021] [Indexed: 05/26/2023]
Abstract
Pollution of marine environments with microplastic particles has increased rapidly during the last few decades and its impact on marine lives have recently gained attention in both public and scientific community. Scleractinian corals are the foundation species of coral reef ecosystems that are greatly affected by the microplastics (MPs), yet little is known about the effects of microplastics on the coral azooxanthellate. In the present study, effects of the exposure and ingestion of polyvinyl chloride (PVC), polyethylene (PE), polyethylene terephthalate (PET), and polyamide 66 (PA66) were studied on the physiological responses of Tubastrea aurea. Our results shows that coral ingested microplastics in four treatment groups and the exposure of microplastics inhibited the antioxidant capacity, immune system, calcification and energy metabolism of the coral Tubastrea aurea. Superoxide dismutase (SOD), catalase (CAT), alkaline phosphatase (AKP), and total antioxidant capacity (TAC) were reduced by 29.4%, 35.5%, 73.9%, and 52.2% in the corals exposed to PVC, respectively. PET microplastics impacted more severely on pyruvate kinase (PK), Na, K-ATPase (Na, K-ATP), Ca-ATPase (Ca-ATP), Mg-ATPase (Mg-ATP), Ca-Mg-ATPase (Ca, Mg-ATP), and glutathione (GSH). Activity of these enzymes decreases to 89.6%, 66.7%, 63.6%, 60.4%, 48.4%, and 50.5% respectively. We anticipate that this work will provide important preliminary data for better understanding the effects of MPs on stony corals azooxanthellate.
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Affiliation(s)
- Baolin Liao
- Shenzhen Institute of Guangdong Ocean University, Shenzhen, Guangdong 518114, PR China
| | - Junjie Wang
- Shenzhen Institute of Guangdong Ocean University, Shenzhen, Guangdong 518114, PR China
| | - Baohua Xiao
- Shenzhen Institute of Guangdong Ocean University, Shenzhen, Guangdong 518114, PR China.
| | - Xiaodong Yang
- Shenzhen Institute of Guangdong Ocean University, Shenzhen, Guangdong 518114, PR China; School of Chemistry and Environment, Guangdong Ocean University, Zhanjiang 524088, China
| | - Ziqiang Xie
- Shenzhen Institute of Guangdong Ocean University, Shenzhen, Guangdong 518114, PR China
| | - Dongdong Li
- Shenzhen Institute of Guangdong Ocean University, Shenzhen, Guangdong 518114, PR China
| | - Chengyong Li
- Shenzhen Institute of Guangdong Ocean University, Shenzhen, Guangdong 518114, PR China; School of Chemistry and Environment, Guangdong Ocean University, Zhanjiang 524088, China.
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10
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Lucena MN, Garçon DP, Fontes CFL, Fabri LM, Moraes CM, McNamara JC, Leone FA. Dopamine binding directly up-regulates (Na +, K +)-ATPase activity in the gills of the freshwater shrimp Macrobrachium amazonicum. Comp Biochem Physiol A Mol Integr Physiol 2019; 233:39-47. [PMID: 30936021 DOI: 10.1016/j.cbpa.2019.03.018] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Revised: 03/20/2019] [Accepted: 03/25/2019] [Indexed: 01/11/2023]
Abstract
We examined the effects of exogenous dopamine on gill (Na+, K+)-ATPase activity in vitro in microsomal preparations from juvenile or adult freshwater shrimp, Macrobrachium amazonicum. Dopamine had no effect on enzyme activity in juveniles but stimulated activity in adult shrimp gills by ≈35%. Stimulation of the gill (Na+, K+)-ATPase in adult shrimps by 100 mmol L-1 dopamine was characterized kinetically by varying ATP, MgATP, and Na+ and K+ concentrations, together with inhibition by ouabain. Dopamine stimulated ATP hydrolysis by ≈40% obeying Michaelis-Menten kinetics, reaching VM = 190.5 ± 15.7 nmol Pi min-1 mg-1 protein, KM remaining unaltered. Stimulation by Na+ (≈50%) and K+ (≈25%) revealed distinct kinetic profiles: although KM values were similar, Na+ stimulation followed cooperative kinetics, contrasting with the Michaelian kinetics seen for K+. Stimulation by MgATP increased activity by ≈30% with little change in KM. Similar saturation profiles were seen for ouabain inhibition with very similar calculated KI values. Our findings suggest that dopamine may be involved in hemolymph sodium homeostasis by directly binding to the gill (Na+, K+)-ATPase at a site different from ouabain, thus stimulating enzyme activity in an ontogenetic stage-specific manner. However, dopamine binding does not affect enzyme affinity for cations and ouabain. This is the first report of the direct action of dopamine in stimulating the crustacean gill (Na+, K+)-ATPase.
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Affiliation(s)
- Malson N Lucena
- Departamento de Química - Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, 14040-901, SP, Brazil
| | - Daniela P Garçon
- Campus Universitário de Iturama, Universidade Federal do Triângulo Mineiro, 38280-000, MG, Brazil
| | - Carlos F L Fontes
- Instituto de Bioquímica Médica, Universidade Federal do Rio de Janeiro, 21941-590, RJ, Brazil
| | - Leonardo M Fabri
- Departamento de Química - Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, 14040-901, SP, Brazil
| | - Cintya M Moraes
- Departamento de Química - Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, 14040-901, SP, Brazil
| | - John C McNamara
- Departamento de Biologia - Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, 14040-901, SP, Brazil; Centro de Biologia Marinha, Universidade de São Paulo, São Sebastião, SP, Brazil
| | - Francisco A Leone
- Departamento de Química - Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, 14040-901, SP, Brazil.
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Huang F, Wang ZH, Cai YX, Chen SH, Tian JH, Cai KZ. Heavy metal bioaccumulation and cation release by growing Bacillus cereus RC-1 under culture conditions. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2018; 157:216-226. [PMID: 29625395 DOI: 10.1016/j.ecoenv.2018.03.077] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2018] [Revised: 03/25/2018] [Accepted: 03/27/2018] [Indexed: 06/08/2023]
Abstract
In an effort to explore the detoxifying mechanisms of B. cereus RC-1 under heavy metal stress, the bioaccumulation by growing cells under varying range of pH, culture time and initial metal concentration were investigated from a perspective of cation release. The maximum removal efficiencies were 16.7%, 38.3%, 81.4% and 40.3% for Cu2+, Zn2+, Cd2+ and Pb2+, respectively, with initial concentrations of 10 mg/L at pH 7.0. In presence of Cu2+ or Zn2+, large quantities of cations were released into the medium in descending order of Na+>K+>Ca2+>Mg2+, while bioremoval of the two essential metals Cd2+ and Pb2+ was accompanied with cellular Na+ and Mg2+ uptake from the medium, respectively. The relative mean contributions of intracellular accumulation to the total removal were approximately 19.6% for Cu2+, 12.8% for Zn2+, 51.1% for Cd2+, and only 4.6% for Pb2+. Following exposure at high concentration, B. cereus RC-1 could keep intracellular Cd2+ concentrations constant, possibly by means of a Cd-efflux system whose activity coincided with uptake of Na+, and reduce intracellular Pb2+ concentration due to the effect of Mg2+ on limiting Pb2+ access to the cells. Cellular morphology, surface functional groups and intracellular trace elements were further investigated by SEM-EDX, TEM-EDX, FTIR and ICP-MS analysis. The phenomena that removal of Cd2+ and Pb2+ coincided with uptake of Na+ and Mg2+, respectively, inspires a novel research perspective towards the study of protective mechanism of bacterial cells against the toxicity of heavy metals.
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Affiliation(s)
- Fei Huang
- Department of Ecology, College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China; Key Laboratory of Tropical Agro-Environment, Ministry of Agriculture, South China Agricultural University, Guangzhou 510642, China; Guangdong Engineering Research Center for Modern Eco-agriculture and Circular Agriculture, Guangzhou 510642, China.
| | - Ze-Huang Wang
- Department of Ecology, College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China
| | - Yi-Xia Cai
- Department of Ecology, College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China; Key Laboratory of Tropical Agro-Environment, Ministry of Agriculture, South China Agricultural University, Guangzhou 510642, China; Guangdong Engineering Research Center for Modern Eco-agriculture and Circular Agriculture, Guangzhou 510642, China
| | - Shao-Hua Chen
- Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou 510642, China
| | - Ji-Hui Tian
- Department of Ecology, College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China; Key Laboratory of Tropical Agro-Environment, Ministry of Agriculture, South China Agricultural University, Guangzhou 510642, China; Guangdong Engineering Research Center for Modern Eco-agriculture and Circular Agriculture, Guangzhou 510642, China
| | - Kun-Zheng Cai
- Department of Ecology, College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China; Key Laboratory of Tropical Agro-Environment, Ministry of Agriculture, South China Agricultural University, Guangzhou 510642, China; Guangdong Engineering Research Center for Modern Eco-agriculture and Circular Agriculture, Guangzhou 510642, China.
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12
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Data on RDM16 and STA1 regulate differential usage of exon/intron in RNA directed DNA Methylation pathway. Data Brief 2017; 12:261-268. [PMID: 28462364 PMCID: PMC5403763 DOI: 10.1016/j.dib.2017.03.050] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Revised: 03/16/2017] [Accepted: 03/31/2017] [Indexed: 11/21/2022] Open
Abstract
This article contains data on RDM16 and STA1 regulate differential usage of exon/intron in RNA directed DNA Methylation pathway (RdDM) (Sharma et al., 2016) [5]. This data include expression profiles of top 100 genes that has at least one exon or intron differentially expressed in three different contrast, i.e., WT (Wild type) vs RDM16, WT vs STA1, and RDM16 vs STA1. Also we included the alignment of MORC6 protein to the ATPase-C family members that have conserved three ATP binding sites and conserved Mg2+ binding sites in the spliced exon.
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Sharma RD, Bogaerts B, Goyal N. RDM16 and STA1 regulate differential usage of exon/intron in RNA directed DNA methylation pathway. Gene 2017; 609:62-67. [DOI: 10.1016/j.gene.2017.01.027] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Revised: 12/23/2016] [Accepted: 01/23/2017] [Indexed: 10/20/2022]
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Tejral G, Sopko B, Necas A, Schoner W, Amler E. Computer modelling reveals new conformers of the ATP binding loop of Na +/K +-ATPase involved in the transphosphorylation process of the sodium pump. PeerJ 2017; 5:e3087. [PMID: 28316890 PMCID: PMC5354106 DOI: 10.7717/peerj.3087] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Accepted: 02/14/2017] [Indexed: 01/02/2023] Open
Abstract
Hydrolysis of ATP by Na+/K+-ATPase, a P-Type ATPase, catalyzing active Na+ and K+ transport through cellular membranes leads transiently to a phosphorylation of its catalytical α-subunit. Surprisingly, three-dimensional molecular structure analysis of P-type ATPases reveals that binding of ATP to the N-domain connected by a hinge to the P-domain is much too far away from the Asp369 to allow the transfer of ATP’s terminal phosphate to its aspartyl-phosphorylation site. In order to get information for how the transfer of the γ-phosphate group of ATP to the Asp369 is achieved, analogous molecular modeling of the M4–M5 loop of ATPase was performed using the crystal data of Na+/K+-ATPase of different species. Analogous molecular modeling of the cytoplasmic loop between Thr338 and Ile760 of the α2-subunit of Na+/K+-ATPase and the analysis of distances between the ATP binding site and phosphorylation site revealed the existence of two ATP binding sites in the open conformation; the first one close to Phe475 in the N-domain, the other one close to Asp369 in the P-domain. However, binding of Mg2+•ATP to any of these sites in the “open conformation” may not lead to phosphorylation of Asp369. Additional conformations of the cytoplasmic loop were found wobbling between “open conformation” <==> “semi-open conformation <==> “closed conformation” in the absence of 2Mg2+•ATP. The cytoplasmic loop’s conformational change to the “semi-open conformation”—characterized by a hydrogen bond between Arg543 and Asp611—triggers by binding of 2Mg2+•ATP to a single ATP site and conversion to the “closed conformation” the phosphorylation of Asp369 in the P-domain, and hence the start of Na+/K+-activated ATP hydrolysis.
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Affiliation(s)
- Gracian Tejral
- Department of Biophysics, 2nd Faculty of Medicine, Charles University Prague, Prague, Czech Republic; Laboratory of Tissue Engineering, Institute of Experimental Medicine, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | - Bruno Sopko
- Department of Medical Chemistry and Clinical Biochemistry, 2nd Faculty of Medicine, Charles University Prague , Prague , Czech Republic
| | - Alois Necas
- Small Animal Clinic, Faculty of Veterinary Medicine, University of Veterinary and Pharmaceutical Science , Brno , Czech Republic
| | - Wilhelm Schoner
- Institute of Biochemistry and Endocrinology, University of Giessen , Giessen , Germany
| | - Evzen Amler
- Department of Biophysics, 2nd Faculty of Medicine, Charles University Prague, Prague, Czech Republic; Laboratory of Tissue Engineering, Institute of Experimental Medicine, Academy of Sciences of the Czech Republic, Prague, Czech Republic
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15
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Hudson NJ, Bottje WG, Hawken RJ, Kong B, Okimoto R, Reverter A. Mitochondrial metabolism: a driver of energy utilisation and product quality? ANIMAL PRODUCTION SCIENCE 2017. [DOI: 10.1071/an17322] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
High feed efficiency is a very desirable production trait as it positively influences resource utilisation, profitability and environmental considerations, albeit at the possible expense of product quality. The modern broiler is arguably the most illustrative model species as it has been transformed over the past half century into an elite feed converter. Some producers are currently reporting that 42-day-old birds gain 1 kg of wet weight for every 1.35 kg of dry weight consumed. Its large breast muscle is exclusively composed of large, low mitochondrial-content Type IIB fibres, which may contribute to low maintenance costs and high efficiency. In an effort to gain a better understanding of individual variation in chicken feed efficiency, our group has been exploring the biology of the mitochondrion at multiple levels of organisation. The mitochondrion is the organelle where much biochemical energy transformation occurs in the cell. Using Cobb-Vantress industrial birds as our primary experimental resource, we have explored the tissue content, structure and function of the mitochondrion and its relationship to growth, development, efficiency and genetic background. While much remains to be understood, recent highlights include (1) variation in muscle mitochondrial content that is associated with performance phenotypes, (2) altered muscle mitochondrial gene and protein expression in birds differing in feed efficiency, (3) variation in isolated mitochondrial function in birds differing in feed efficiency and (4) evidence for an unexpected role for the mitochondrially localised progesterone receptor in altering bird muscle metabolism. Mitochondrial function is largely conserved across the vertebrates, so the same metabolic principles appear to apply to the major production species, whether monogastric or ruminant. A speculative role for the mitochondria in aspects of meat quality and in influencing postmortem anaerobic metabolism will conclude the manuscript.
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16
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Properties of Na,K-ATPase in cerebellum of male and female rats: effects of acute and prolonged diabetes. Mol Cell Biochem 2016; 425:25-36. [DOI: 10.1007/s11010-016-2859-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Accepted: 10/22/2016] [Indexed: 02/07/2023]
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17
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A P-Loop NTPase Regulates Quiescent Center Cell Division and Distal Stem Cell Identity through the Regulation of ROS Homeostasis in Arabidopsis Root. PLoS Genet 2016; 12:e1006175. [PMID: 27583367 PMCID: PMC5008728 DOI: 10.1371/journal.pgen.1006175] [Citation(s) in RCA: 71] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Accepted: 06/15/2016] [Indexed: 01/03/2023] Open
Abstract
Reactive oxygen species (ROS) are recognized as important regulators of cell division and differentiation. The Arabidopsis thaliana P-loop NTPase encoded by APP1 affects root stem cell niche identity through its control of local ROS homeostasis. The disruption of APP1 is accompanied by a reduction in ROS level, a rise in the rate of cell division in the quiescent center (QC) and the promotion of root distal stem cell (DSC) differentiation. Both the higher level of ROS induced in the app1 mutant by exposure to methyl viologen (MV), and treatment with hydrogen peroxide (H2O2) rescued the mutant phenotype, implying that both the increased rate of cell division in the QC and the enhancement in root DSC differentiation can be attributed to a low level of ROS. APP1 is expressed in the root apical meristem cell mitochondria, and its product is associated with ATP hydrolase activity. The key transcription factors, which are defining root distal stem niche, such as SCARECROW (SCR) and SHORT ROOT (SHR) are both significantly down-regulated at both the transcriptional and protein level in the app1 mutant, indicating that SHR and SCR are important downstream targets of APP1-regulated ROS signaling to control the identity of root QC and DSCs. Reactive oxygen species (ROS) are recognized as important regulators of cell division and differentiation. In this study, we characterized an Arabidopsis thaliana P-loop NTPase encoded by APP1 regulates root stem cell niche identity through its control of local ROS homeostasis. The app1 mutant shows a reduction in ROS level, a rise in the rate of cell division in the quiescent center (QC) and the promotion of root distal stem cell (DSC) differentiation. The increased rate of cell division in the QC and the enhancement in root DSC differentiation in app1 can be attributed to a low level of ROS since both the exposure to methyl viologen (MV), and treatment with hydrogen peroxide (H2O2) rescued the mutant phenotype. APP1 is expressed in the root apical meristem cell mitochondria, and its product is associated with ATP hydrolase activity. The key transcription factors such as SCARECROW (SCR) and SHORT ROOT (SHR), which are defining root distal stem niche, are both greatly down-regulated at both the transcriptional and protein level in app1, indicating that SHR and SCR are important downstream targets of APP1-regulated ROS signaling to control the identity of root QC and DSCs.
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18
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Holm R, Toustrup-Jensen MS, Einholm AP, Schack VR, Andersen JP, Vilsen B. Neurological disease mutations of α3 Na +,K +-ATPase: Structural and functional perspectives and rescue of compromised function. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2016; 1857:1807-1828. [PMID: 27577505 DOI: 10.1016/j.bbabio.2016.08.009] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2016] [Revised: 08/19/2016] [Accepted: 08/25/2016] [Indexed: 11/26/2022]
Abstract
Na+,K+-ATPase creates transmembrane ion gradients crucial to the function of the central nervous system. The α-subunit of Na+,K+-ATPase exists as four isoforms (α1-α4). Several neurological phenotypes derive from α3 mutations. The effects of some of these mutations on Na+,K+-ATPase function have been studied in vitro. Here we discuss the α3 disease mutations as well as information derived from studies of corresponding mutations of α1 in the light of the high-resolution crystal structures of the Na+,K+-ATPase. A high proportion of the α3 disease mutations occur in the transmembrane sector and nearby regions essential to Na+ and K+ binding. In several cases the compromised function can be traced to disturbance of the Na+ specific binding site III. Recently, a secondary mutation was found to rescue the defective Na+ binding caused by a disease mutation. A perspective is that it may be possible to develop an efficient pharmaceutical mimicking the rescuing effect.
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Affiliation(s)
- Rikke Holm
- Department of Biomedicine, Aarhus University, 8000 Aarhus C, Denmark.
| | | | - Anja P Einholm
- Department of Biomedicine, Aarhus University, 8000 Aarhus C, Denmark.
| | - Vivien R Schack
- Department of Biomedicine, Aarhus University, 8000 Aarhus C, Denmark.
| | - Jens P Andersen
- Department of Biomedicine, Aarhus University, 8000 Aarhus C, Denmark.
| | - Bente Vilsen
- Department of Biomedicine, Aarhus University, 8000 Aarhus C, Denmark.
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Rui H, Artigas P, Roux B. The selectivity of the Na(+)/K(+)-pump is controlled by binding site protonation and self-correcting occlusion. eLife 2016; 5. [PMID: 27490484 PMCID: PMC5026471 DOI: 10.7554/elife.16616] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2016] [Accepted: 08/03/2016] [Indexed: 01/20/2023] Open
Abstract
The Na+/K+-pump maintains the physiological K+ and Na+ electrochemical gradients across the cell membrane. It operates via an 'alternating-access' mechanism, making iterative transitions between inward-facing (E1) and outward-facing (E2) conformations. Although the general features of the transport cycle are known, the detailed physicochemical factors governing the binding site selectivity remain mysterious. Free energy molecular dynamics simulations show that the ion binding sites switch their binding specificity in E1 and E2. This is accompanied by small structural arrangements and changes in protonation states of the coordinating residues. Additional computations on structural models of the intermediate states along the conformational transition pathway reveal that the free energy barrier toward the occlusion step is considerably increased when the wrong type of ion is loaded into the binding pocket, prohibiting the pump cycle from proceeding forward. This self-correcting mechanism strengthens the overall transport selectivity and protects the stoichiometry of the pump cycle. DOI:http://dx.doi.org/10.7554/eLife.16616.001 A protein called the sodium-potassium pump resides in the membrane that surrounds living cells. The role of this protein is to 'pump' sodium and potassium ions across the membrane to help restore their concentration inside and outside of the cell. About 25% of the body's energy is used to keep the pump going, rising to nearly 70% in the brain. Problems that affect the pump have been linked to several disorders, including heart, kidney and metabolic diseases, as well as severe neurological conditions. The sodium-potassium pump must be able to effectively pick out the correct ions to transport from a mixture of many different types of ions. However, it was not clear how the pump succeeds in doing this efficiently. Rui et al. have now used a computational method called molecular dynamics simulations to model how the sodium-potassium pump transports the desired ions across the cell membrane. The pump works via a so-called 'alternating-access' mechanism, repeatedly transitioning between inward-facing and outward-facing conformations. In each cycle, it binds three sodium ions from the cell’s interior and exports them to the outside. Then, the pump binds to two potassium ions from outside the cell and imports them inside. Although the bound sodium and potassium ions interact with similar binding sites in the pump, the pump sometimes preferentially binds sodium, and sometimes potassium. The study performed by Rui et al. shows that this preference is driven by how protons (hydrogen ions) bind to the amino acids that make up the binding site. The simulations also suggest that the pump uses a ‘self-correcting’ mechanism to prevent the pump from transporting the wrong types of ions. When incorrect ions are present at the binding sites, the pump cycle pauses temporarily until the ions detach from the pump. Only when the correct ions are bound will the pump cycle continue again. In the future, Rui et al. hope to use long time-scale molecular dynamics simulations to show the conformational transition in action. In addition, the 'self-correcting' mechanism will be directly tested by letting the wrong and correct ions compete for the binding sites to see whether the pump will transport only the correct ions. DOI:http://dx.doi.org/10.7554/eLife.16616.002
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Affiliation(s)
- Huan Rui
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, United States
| | - Pablo Artigas
- Department of Cell Physiology and Molecular Biophysics, Texas Tech University Health Sciences Center, Lubbock, United States
| | - Benoît Roux
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, United States
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20
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Zhang Q, Cao Z, Sun X, Zuang C, Huang W, Li Y. Aluminum Trichloride Induces Hypertension and Disturbs the Function of Erythrocyte Membrane in Male Rats. Biol Trace Elem Res 2016; 171:116-23. [PMID: 26354416 DOI: 10.1007/s12011-015-0504-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2015] [Accepted: 09/01/2015] [Indexed: 10/23/2022]
Abstract
Aluminum (Al) is the most abundant metal in the earth's crust. Al accumulates in erythrocyte and causes toxicity on erythrocyte membrane. The dysfunction of erythrocyte membrane is a potential risk to hypertension. The high Al content in plasma was associated with hypertension. To investigate the effect of AlCl3 on blood pressure and the function of erythrocyte membrane, the rats were intragastrically exposed to 0, 64(1/20 LD50), 128(1/10 LD50), and 256(1/5 LD50) mg/kg body weight AlCl3 in double distilled water for 120 days, respectively. Then, we determined the systolic and mean arterial blood pressures of rats, the osmotic fragility, the percentage of membrane proteins, the activities of Na(+)/K(+)-ATPase, Mg(2+)-ATPase, Ca(2+)-ATPase, catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GSH-pX), and malondialdehyde (MDA) content of the erythrocyte membrane in this experiment. The results showed that AlCl3 elevated the systolic and mean arterial blood pressure of rats, increased the osmotic fragility, decreased the percentage of membrane protein, inhibited the activities of Na(+)/K(+)-ATPase, Mg(2+)-ATPase, Ca(2+)-ATPase, CAT, SOD and GSH-pX, and increased the MDA content of erythrocyte membrane. These results indicate that AlCl3 may induce hypertension by disturbing the function of erythrocyte membrane.
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Affiliation(s)
- Qiuyue Zhang
- College of Veterinary Medicine, Northeast Agricultural University, Harbin, 150030, China
| | - Zheng Cao
- College of Veterinary Medicine, Northeast Agricultural University, Harbin, 150030, China
| | - Xudong Sun
- College of Veterinary Medicine, Northeast Agricultural University, Harbin, 150030, China
| | - Cuicui Zuang
- College of Veterinary Medicine, Northeast Agricultural University, Harbin, 150030, China
| | - Wanyue Huang
- College of Veterinary Medicine, Northeast Agricultural University, Harbin, 150030, China
| | - Yanfei Li
- College of Veterinary Medicine, Northeast Agricultural University, Harbin, 150030, China.
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Thabet R, Rouault JD, Ayadi H, Leignel V. Structural analysis of the α subunit of Na(+)/K(+) ATPase genes in invertebrates. Comp Biochem Physiol B Biochem Mol Biol 2016; 196-197:11-18. [PMID: 26812300 DOI: 10.1016/j.cbpb.2016.01.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2015] [Revised: 01/20/2016] [Accepted: 01/21/2016] [Indexed: 01/18/2023]
Abstract
The Na(+)/K(+) ATPase is a ubiquitous pump coordinating the transport of Na(+) and K(+) across the membrane of cells and its role is fundamental to cellular functions. It is heteromer in eukaryotes including two or three subunits (α, β and γ which is specific to the vertebrates). The catalytic functions of the enzyme have been attributed to the α subunit. Several complete α protein sequences are available, but only few gene structures were characterized. We identified the genomic sequences coding the α-subunit of the Na(+)/K(+) ATPase, from the whole-genome shotgun contigs (WGS), NCBI Genomes (chromosome), Genomic Survey Sequences (GSS) and High Throughput Genomic Sequences (HTGS) databases across distinct phyla. One copy of the α subunit gene was found in Annelida, Arthropoda, Cnidaria, Echinodermata, Hemichordata, Mollusca, Placozoa, Porifera, Platyhelminthes, Urochordata, but the nematodes seem to possess 2 to 4 copies. The number of introns varied from 0 (Platyhelminthes) to 26 (Porifera); and their localization and length are also highly variable. Molecular phylogenies (Maximum Likelihood and Maximum Parsimony methods) showed some clusters constituted by (Chordata/(Echinodermata/Hemichordata)) or (Plathelminthes/(Annelida/Mollusca)) and a basal position for Porifera. These structural analyses increase our knowledge about the evolutionary events of the α subunit genes in the invertebrates.
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Affiliation(s)
- Rahma Thabet
- University of Sfax, Laboratory of Biodiversity and Aquatic Ecosystems UR/11ES72, Ecology and Planktonology, Department of Life Sciences, Road Soukra Km 3.5, BP1171, 3000, Sfax, Tunisia
| | - J-D Rouault
- Laboratoire Evolution, Genomes et Speciation, UPR9034, CNRS, 91198 Gif-sur-Yvette, France
| | - Habib Ayadi
- University of Sfax, Laboratory of Biodiversity and Aquatic Ecosystems UR/11ES72, Ecology and Planktonology, Department of Life Sciences, Road Soukra Km 3.5, BP1171, 3000, Sfax, Tunisia
| | - Vincent Leignel
- Université du Maine, Laboratoire Mer Molecule Sante EA 2160 FR-CNRS 3473 IUML, 72085 Le Mans, France.
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Zhu W, Varga Z, Silva JR. Molecular motions that shape the cardiac action potential: Insights from voltage clamp fluorometry. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2015; 120:3-17. [PMID: 26724572 DOI: 10.1016/j.pbiomolbio.2015.12.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Revised: 11/11/2015] [Accepted: 12/16/2015] [Indexed: 01/04/2023]
Abstract
Very recently, voltage-clamp fluorometry (VCF) protocols have been developed to observe the membrane proteins responsible for carrying the ventricular ionic currents that form the action potential (AP), including those carried by the cardiac Na(+) channel, NaV1.5, the L-type Ca(2+) channel, CaV1.2, the Na(+)/K(+) ATPase, and the rapid and slow components of the delayed rectifier, KV11.1 and KV7.1. This development is significant, because VCF enables simultaneous observation of ionic current kinetics with conformational changes occurring within specific channel domains. The ability gained from VCF, to connect nanoscale molecular movement to ion channel function has revealed how the voltage-sensing domains (VSDs) control ion flux through channel pores, mechanisms of post-translational regulation and the molecular pathology of inherited mutations. In the future, we expect that this data will be of great use for the creation of multi-scale computational AP models that explicitly represent ion channel conformations, connecting molecular, cell and tissue electrophysiology. Here, we review the VCF protocol, recent results, and discuss potential future developments, including potential use of these experimental findings to create novel computational models.
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Affiliation(s)
- Wandi Zhu
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO, USA
| | - Zoltan Varga
- MTA-DE-NAP B Ion Channel Structure-Function Research Group, RCMM, University of Debrecen, Debrecen, Hungary
| | - Jonathan R Silva
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO, USA.
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23
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Wu R, Wang HL, Yu HL, Cui XH, Xu MT, Xu X, Gao JP. Doxorubicin toxicity changes myocardial energy metabolism in rats. Chem Biol Interact 2015; 244:149-58. [PMID: 26721193 DOI: 10.1016/j.cbi.2015.12.010] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2015] [Revised: 12/10/2015] [Accepted: 12/17/2015] [Indexed: 12/29/2022]
Abstract
BACKGROUND Doxorubicin (DOX) is an antitumor antibiotics used against malignancies. But its toxicity limits the therapy of DOX. OBJECTIVE The purpose of this study was to evaluate DOX toxicity and the alteration of energy metabolism after short term and long term treatment. METHODS Male Sprague-Dawley rats were randomly assigned to four groups: Short term control group, short term DOX treatment group, long term control group and long term DOX treatment group. In short term treated group, rats were injected with DOX i.p. at a dose of 2.5 mg/kg every 48 h for six equal injections. In long term, treated group, rats were tail-intravenously injected with DOX at a dose of 3 mg/kg once a week for four weeks. At the end of the experiment, histopathological changes, general blood biomarkers, endogenous antioxidant enzymes, cardiac energy metabolism and related mRNA expression of AMPK signal pathway were determined. RESULTS DOX induced prominent oxidative stress, a higher mortality rate, histological and ECG changes, obvious cardiac hypertrophy, acute cardiac damage and cardiac energy impairment in short term treatment rats. In long term treatment rats, DOX caused serious nephropathy and systolic dysfunction, terrible cardiac energy impairment, clear alteration of substrate utilization and AMPK signal pathway. CONCLUSION DOX treatment can induce different damages after short term and long term treatment. In short term treatment group, rats experienced a terrible mortality rate about 40%, the acute cardiac damage, cardiac energy impairment and an early heart failure which are potential connected with reduction of glucose utilization. In the long term treatment group, serious nephropathy and obvious changes of mRNA expressions of AMPK signal pathway were observed. Meanwhile, the serious cardiac energy impairment and substrate utilization alteration denote an obviously heart failure. This study could be helpful to develop therapy strategies of DOX complications for clinical application.
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Affiliation(s)
- Rong Wu
- Department of Pharmacology, School of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Hui-Lin Wang
- Department of Pharmacology, School of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Hai-Lun Yu
- School of Chemical and Environmental Engineering, Shanghai Institute of Technology, Shanghai 201418, China
| | - Xiao-Hua Cui
- Department of Pharmacology, School of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Meng-Ting Xu
- Department of Pharmacology, School of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Xu Xu
- School of Chemical and Environmental Engineering, Shanghai Institute of Technology, Shanghai 201418, China
| | - Jian-Ping Gao
- Department of Pharmacology, School of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China.
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SUN XUEFEI, MIN DONGYU, WANG YAN, HAO LIYING. Potassium aspartate inhibits SH-SY5Y cell damage and apoptosis induced by ouabain and H2O2. Mol Med Rep 2015; 12:2842-8. [DOI: 10.3892/mmr.2015.3741] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2014] [Accepted: 03/18/2015] [Indexed: 11/05/2022] Open
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Kaločayová B, Mézešová L, Barteková M, Vlkovičová J, Jendruchová V, Vrbjar N. Effect of duration of diabetes mellitus type 1 on properties of Na, K-ATPase in cerebral cortex. Mol Cell Biochem 2015; 405:41-52. [DOI: 10.1007/s11010-015-2394-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2014] [Accepted: 03/27/2015] [Indexed: 01/28/2023]
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26
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Ching B, Woo JM, Hiong KC, Boo MV, Choo CYL, Wong WP, Chew SF, Ip YK. Na+/K+-ATPase α-subunit (nkaα) isoforms and their mRNA expression levels, overall Nkaα protein abundance, and kinetic properties of Nka in the skeletal muscle and three electric organs of the electric eel, Electrophorus electricus. PLoS One 2015; 10:e0118352. [PMID: 25793901 PMCID: PMC4368207 DOI: 10.1371/journal.pone.0118352] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Accepted: 01/14/2015] [Indexed: 11/18/2022] Open
Abstract
This study aimed to obtain the coding cDNA sequences of Na+/K+-ATPase α (nkaα) isoforms from, and to quantify their mRNA expression in, the skeletal muscle (SM), the main electric organ (EO), the Hunter’s EO and the Sach’s EO of the electric eel, Electrophorus electricus. Four nkaα isoforms (nkaα1c1, nkaα1c2, nkaα2 and nkaα3) were obtained from the SM and the EOs of E. electricus. Based on mRNA expression levels, the major nkaα expressed in the SM and the three EOs of juvenile and adult E. electricus were nkaα1c1 and nkaα2, respectively. Molecular characterization of the deduced Nkaα1c1 and Nkaα2 sequences indicates that they probably have different affinities to Na+ and K+. Western blotting demonstrated that the protein abundance of Nkaα was barely detectable in the SM, but strongly detected in the main and Hunter’s EOs and weakly in the Sach’s EO of juvenile and adult E. electricus. These results corroborate the fact that the main EO and Hunter’s EO have high densities of Na+ channels and produce high voltage discharges while the Sach’s EO produces low voltage discharges. More importantly, there were significant differences in kinetic properties of Nka among the three EOs of juvenile E. electricus. The highest and lowest Vmax of Nka were detected in the main EO and the Sach’s EO, respectively, with the Hunter’s EO having a Vmax value intermediate between the two, indicating that the metabolic costs of EO discharge could be the highest in the main EO. Furthermore, the Nka from the main EO had the lowest Km (or highest affinity) for Na+ and K+ among the three EOs, suggesting that the Nka of the main EO was more effective than those of the other two EOs in maintaining intracellular Na+ and K+ homeostasis and in clearing extracellular K+ after EO discharge.
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Affiliation(s)
- Biyun Ching
- Department of Biological Sciences, National University of Singapore, Kent Ridge, Singapore, 117543, Republic of Singapore
| | - Jia M. Woo
- Department of Biological Sciences, National University of Singapore, Kent Ridge, Singapore, 117543, Republic of Singapore
| | - Kum C. Hiong
- Department of Biological Sciences, National University of Singapore, Kent Ridge, Singapore, 117543, Republic of Singapore
| | - Mel V. Boo
- Department of Biological Sciences, National University of Singapore, Kent Ridge, Singapore, 117543, Republic of Singapore
| | - Celine Y. L. Choo
- Department of Biological Sciences, National University of Singapore, Kent Ridge, Singapore, 117543, Republic of Singapore
| | - Wai P. Wong
- Department of Biological Sciences, National University of Singapore, Kent Ridge, Singapore, 117543, Republic of Singapore
| | - Shit F. Chew
- Natural Sciences and Science Education, National Institute of Education, Nanyang Technological University, 1 Nanyang Walk, Singapore, 637616, Republic of Singapore
| | - Yuen K. Ip
- Department of Biological Sciences, National University of Singapore, Kent Ridge, Singapore, 117543, Republic of Singapore
- The Tropical Marine Science Institute, National University of Singapore, Kent Ridge, Singapore, 119227, Republic of Singapore
- * E-mail:
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Effect of lysine acetylsalicylate on aluminium accumulation and (Na+/K+)ATPase activity in rat brain cortex synaptosomes after aluminium ingestion. Toxicol Lett 2015; 232:167-74. [DOI: 10.1016/j.toxlet.2014.10.014] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2014] [Revised: 10/09/2014] [Accepted: 10/09/2014] [Indexed: 11/21/2022]
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Mahmmoud YA, Kopec W, Khandelia H. K+ congeners that do not compromise Na+ activation of the Na+,K+-ATPase: hydration of the ion binding cavity likely controls ion selectivity. J Biol Chem 2014; 290:3720-31. [PMID: 25533461 DOI: 10.1074/jbc.m114.577486] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
The Na(+),K(+)-ATPase is essential for ionic homeostasis in animal cells. The dephosphoenzyme contains Na(+) selective inward facing sites, whereas the phosphoenzyme contains K(+) selective outward facing sites. Under normal physiological conditions, K(+) inhibits cytoplasmic Na(+) activation of the enzyme. Acetamidinium (Acet(+)) and formamidinium (Form(+)) have been shown to permeate the pump through the outward facing sites. Here, we show that these cations, unlike K(+), are unable to enter the inward facing sites in the dephosphorylated enzyme. Consistently, the organic cations exhibited little to no antagonism to cytoplasmic Na(+) activation. Na(+),K(+)-ATPase structures revealed a previously undescribed rotamer transition of the hydroxymethyl side chain of the absolutely conserved Thr(772) of the α-subunit. The side chain contributes its hydroxyl to Na(+) in site I in the E1 form and rotates to contribute its methyl group toward K(+) in the E2 form. Molecular dynamics simulations to the E1·AlF4 (-)·ADP·3Na(+) structure indicated that 1) bound organic cations differentially distorted the ion binding sites, 2) the hydroxymethyl of Thr(772) rotates to stabilize bound Form(+) through water molecules, and 3) the rotamer transition is mediated by water traffic into the ion binding cavity. Accordingly, dehydration induced by osmotic stress enhanced the interaction of the congeners with the outward facing sites and profoundly modified the organization of membrane domains of the α-subunit. These results assign a catalytic role for water in pump function, and shed light on a backbone-independent but a conformation-dependent switch between H-bond and dispersion contact as part of the catalytic mechanism of the Na(+),K(+)-ATPase.
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Affiliation(s)
- Yasser A Mahmmoud
- From the Department of Biomedicine, University of Aarhus, DK-8000 Aarhus C and
| | - Wojciech Kopec
- the MEMPHYS, Center for Biomembrane Physics, University of Southern Denmark, DK-5230 Odense M, Denmark
| | - Himanshu Khandelia
- the MEMPHYS, Center for Biomembrane Physics, University of Southern Denmark, DK-5230 Odense M, Denmark
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Larsen EH, Deaton LE, Onken H, O'Donnell M, Grosell M, Dantzler WH, Weihrauch D. Osmoregulation and Excretion. Compr Physiol 2014; 4:405-573. [DOI: 10.1002/cphy.c130004] [Citation(s) in RCA: 127] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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30
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Liu YR, Lei RY, Wang CE, Zhang BA, Lu H, Zhu HC, Zhang GB. Effects of catalpol on ATPase and amino acids in gerbils with cerebral ischemia/reperfusion injury. Neurol Sci 2014; 35:1229-33. [DOI: 10.1007/s10072-014-1687-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2013] [Accepted: 02/13/2014] [Indexed: 10/25/2022]
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31
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Modulation by K+ Plus NH4+ of microsomal (Na+, K+)-ATPase activity in selected ontogenetic stages of the diadromous river shrimp Macrobrachium amazonicum (Decapoda, Palaemonidae). PLoS One 2014; 9:e89625. [PMID: 24586919 PMCID: PMC3931822 DOI: 10.1371/journal.pone.0089625] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2013] [Accepted: 01/21/2014] [Indexed: 12/25/2022] Open
Abstract
We investigate the synergistic stimulation by K+ plus NH4+ of (Na+, K+)-ATPase activity in microsomal preparations of whole zoea I and decapodid III, and in juvenile and adult river shrimp gills. Modulation of (Na+, K+)-ATPase activity is ontogenetic stage-specific, and particularly distinct between juveniles and adults. Although both gill enzymes exhibit two different sites for K+ and NH4+ binding, in the juvenile enzyme, these two sites are equivalent: binding by both ions results in slightly stimulated activity compared to that of a single ionic species. In the adult enzyme, the sites are not equivalent: when one ion occupies its specific binding site, (Na+, K+)-ATPase activity is stimulated synergistically by ≈50% on binding of the complementary ion. Immunolocalization reveals the enzyme to be distributed predominantly throughout the intralamellar septum in the gill lamellae of juveniles and adults. Western blot analyses demonstrate a single immunoreactive band, suggesting a single (Na+, K+)-ATPase α-subunit isoform that is distributed into different density membrane fractions, independently of ontogenetic stage. We propose a model for the modulation by K+ and NH4+ of gill (Na+, K+)-ATPase activity. These findings suggest that the gill enzyme may be regulated by NH4+ during ontogenetic development in M. amazonicum.
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32
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Bonnaud L, Franko D, Vouillot L, Bouteau F. A study of the electrical polarization of Sepia officinalis yolk envelope, a role for Na(+)/K(+)-ATPases in osmoregulation? Commun Integr Biol 2013; 6:e26035. [PMID: 24505501 PMCID: PMC3913672 DOI: 10.4161/cib.26035] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2013] [Revised: 08/02/2013] [Accepted: 08/03/2013] [Indexed: 01/24/2023] Open
Abstract
The cuttlefish Sepia officinalis mate and spawn in the intertidal zone where eggs are exposed during low tide to osmotic stress. Embryonic outer yolk sac is a putative site for osmoregulation of young S. officinalis embryos. By using electrophysiological recordings and immunostaining we showed, (i) that the chorion is only a passive barrier for ions, since large molecules could not pass through it, (ii) that a complex transepithelial potential difference occurs through the yolk epithelium, (iii) that ionocyte-like cells and Na+/K+-ATPases were localized in the yolk epithelium and (iv) that ouabain sensitive Na+/K+-ATPase activity could participate to this yolk polarization. These data warrant further study on the role of ion transport systems of this epithelium in the osmoregulation processes in S. officinalis embryos.
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Affiliation(s)
- Laure Bonnaud
- Muséum National d'Histoire Naturelle DMPA; UMR BOREA MNHN-CNRS 7208-IRD 207-UPMC; Paris, France ; Univ. Paris Diderot; Sorbonne Paris Cité; Paris, France
| | - Delphine Franko
- Muséum National d'Histoire Naturelle DMPA; UMR BOREA MNHN-CNRS 7208-IRD 207-UPMC; Paris, France ; Univ. Paris Diderot; Sorbonne Paris Cité; Paris, France
| | - Léna Vouillot
- Muséum National d'Histoire Naturelle DMPA; UMR BOREA MNHN-CNRS 7208-IRD 207-UPMC; Paris, France
| | - François Bouteau
- Univ. Paris Diderot; Sorbonne Paris Cité, Institut des Energies de Demain (FRE 3597); Paris, France
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Chang YW, Mai RT, Fang WH, Lin CC, Chiu CC, Wu Lee YH. YB-1 disrupts mismatch repair complex formation, interferes with MutSα recruitment on mismatch and inhibits mismatch repair through interacting with PCNA. Oncogene 2013; 33:5065-77. [PMID: 24141788 DOI: 10.1038/onc.2013.450] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2013] [Revised: 09/04/2013] [Accepted: 09/20/2013] [Indexed: 12/17/2022]
Abstract
Y-box binding protein-1 (YB-1) is highly expressed in tumors and it participates in various cellular processes. Previous studies indicated that YB-1 binds to mispaired DNA and interacts with several mismatch repair (MMR)-related factors. However, its role in the MMR system remains undefined. Here, we found that YB-1 represses mutS homolog 6 (MSH6)-containing MMR complex formation and reduces MutSα mismatch binding activity by disrupting interactions among MMR-related factors. In an effort to elucidate how YB-1 exerts this inhibitory effect, we have identified two functional proliferating cell nuclear antigen (PCNA)-interacting protein (PIP)-boxes that mediate YB-1/PCNA interaction and locate within the C-terminal region of YB-1. This interaction is critical for the regulatory role of YB-1 in repressing MutSα mismatch binding activity, disrupting MutSα/PCNA/G/T heteroduplex ternary complex formation and inhibiting in vitro MMR activity. The differential regulation of 3' and 5' nick-directed MMR activity by YB-1 was also observed. Moreover, YB-1 overexpression is associated with the alteration of microsatellite pattern and the enhancement of N-methyl-N'-nitro-N-nitrosoguanidine (MNNG)-induced and spontaneous mutations. Furthermore, upregulation of other PIP-box-containing proteins, such as myeloid cell leukemia-1 (Mcl-1) and inhibitor of growth protein 1b (ING1b), has no impact on MMR complex formation and mutation accumulation, thus revealing the significant effect of YB-1 on regulating the MMR system. In conclusion, our study suggests that YB-1 functions as a PCNA-interacting factor to exert its regulatory role on the MMR process and involves in the induction of genome instability, which may partially account for the oncogenic potential of YB-1.
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Affiliation(s)
- Y-W Chang
- Institute of Biochemistry and Molecular Biology, School of Life Sciences, National Yang-Ming University, Taipei, Taiwan
| | - R-T Mai
- 1] Institute of Biochemistry and Molecular Biology, School of Life Sciences, National Yang-Ming University, Taipei, Taiwan [2] Department of Biological Science and Technology, College of Biological Science and Technology, National Chiao-Tung University, Hsinchu, Taiwan
| | - W-H Fang
- Department of Clinical Laboratory Sciences and Medical Biotechnology, National Taiwan University Hospital, Taipei, Taiwan
| | - C-C Lin
- Institute of Biochemistry and Molecular Biology, School of Life Sciences, National Yang-Ming University, Taipei, Taiwan
| | - C-C Chiu
- Institute of Biochemistry and Molecular Biology, School of Life Sciences, National Yang-Ming University, Taipei, Taiwan
| | - Y-H Wu Lee
- 1] Institute of Biochemistry and Molecular Biology, School of Life Sciences, National Yang-Ming University, Taipei, Taiwan [2] Department of Biological Science and Technology, College of Biological Science and Technology, National Chiao-Tung University, Hsinchu, Taiwan
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Uversky VN. The alphabet of intrinsic disorder: II. Various roles of glutamic acid in ordered and intrinsically disordered proteins. INTRINSICALLY DISORDERED PROTEINS 2013; 1:e24684. [PMID: 28516010 PMCID: PMC5424795 DOI: 10.4161/idp.24684] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/21/2013] [Revised: 03/27/2013] [Accepted: 04/12/2013] [Indexed: 11/19/2022]
Abstract
The ability of a protein to fold into unique functional state or to stay intrinsically disordered is encoded in its amino acid sequence. Both ordered and intrinsically disordered proteins (IDPs) are natural polypeptides that use the same arsenal of 20 proteinogenic amino acid residues as their major building blocks. The exceptional structural plasticity of IDPs, their capability to exist as heterogeneous structural ensembles and their wide array of important disorder-based biological functions that complements functional repertoire of ordered proteins are all rooted within the peculiar differential usage of these building blocks by ordered proteins and IDPs. In fact, some residues (so-called disorder-promoting residues) are noticeably more common in IDPs than in sequences of ordered proteins, which, in their turn, are enriched in several order-promoting residues. Furthermore, residues can be arranged according to their “disorder promoting potencies,” which are evaluated based on the relative abundances of various amino acids in ordered and disordered proteins. This review continues a series of publications on the roles of different amino acids in defining the phenomenon of protein intrinsic disorder and concerns glutamic acid, which is the second most disorder-promoting residue.
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Affiliation(s)
- Vladimir N Uversky
- Department of Molecular Medicine and USF Health Byrd Alzheimer's Research Institute; College of Medicine; University of South Florida; Tampa, FL USA.,Institute for Biological Instrumentation; Russian Academy of Sciences; Moscow, Russia
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35
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Petrović V, Čolović M, Krstić D, Vujačić A, Petrović S, Joksić G, Bugarčić Z, Vasić V. In vitro effects of some gold complexes on Na(+)/K(+) ATPase activity and cell proliferation. J Inorg Biochem 2013; 124:35-41. [PMID: 23591145 DOI: 10.1016/j.jinorgbio.2013.03.013] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2012] [Revised: 03/25/2013] [Accepted: 03/25/2013] [Indexed: 11/17/2022]
Abstract
The in vitro influence of gold(III) complexes, H[AuCl4], [Au(DMSO)2Cl2]Cl and [Au(bipy)Cl2]Cl (bipy = 2,2'-bipyridine), upon commercially available Na(+)/K(+) ATPase activity, purified from porcine brain cortex, was investigated. Additionally, the complexes were tested on human lymphocytes, and incidence of micronuclei and cell proliferation index was determined. Concentration-dependent inhibition of the enzyme for all three compounds was obtained, but with differing potencies. Calculated IC50 from Hill analysis were (in M): 5.75×10(-7), 5.50×10(-6) and 3.98×10(-5), for H[AuCl4], [Au(DMSO)2Cl2]Cl and [Au(bipy)Cl2]Cl, respectively, while Hill coefficient values, n, were above 1 in all cases. This inhibition can be prevented using -SH donating ligands such as L-Cys and glutathione, and these ligands can also cause a recovery of the enzyme activity after the induced inhibition. Kinetic analysis demonstrated that each of the studied gold(III) complexes affects Na(+)/K(+) ATPase reducing maximum enzymatic velocity, Vmax, but not significantly changing the affinity for the substrate (KM value), implying a noncompetitive mode of the interaction. Furthermore, among investigated gold(III) complexes, the [Au(bipy)Cl2]Cl complex exhibits a strong cytotoxic effect on human lymphocytes, which suggests its potential for use in antitumor therapy.
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Affiliation(s)
- Voin Petrović
- Department of Physical Chemistry, Vinča Institute of Nuclear Sciences, University of Belgrade, Belgrade, Serbia
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36
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Garçon DP, Lucena MN, Pinto MR, Fontes CFL, McNamara JC, Leone FA. Synergistic stimulation by potassium and ammonium of K(+)-phosphatase activity in gill microsomes from the crab Callinectes ornatus acclimated to low salinity: novel property of a primordial pump. Arch Biochem Biophys 2012; 530:55-63. [PMID: 23262318 DOI: 10.1016/j.abb.2012.12.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2012] [Revised: 11/28/2012] [Accepted: 12/04/2012] [Indexed: 11/16/2022]
Abstract
We provide an extensive characterization of the modulation by p-nitrophenylphosphate, Mg²⁺, Na⁺, K(+), Rb⁺, NH(4)(+) and pH of gill microsomal K⁺-phosphatase activity in the posterior gills of Callinectes ornatus acclimated to low salinity (21‰). The synergistic stimulation by K⁺ and NH(4)(+) of the K⁺-phosphatase activity is a novel finding, and may constitute a species-specific feature of K(+)/NH(4)(+) interplay that regulates crustacean gill (Na⁺, K⁺)-ATPase activity. p-Nitrophenylphosphate was hydrolyzed at a maximum rate (V) of 69.2 ± 2.8nmolPimin⁻¹mg⁻¹ with K(0.5)=2.3 ± 0.1mmolL(-1), obeying cooperative kinetics (n(H)=1.7). Stimulation by Mg²⁺ (V=70.1 ± 3.0nmolPimin⁻¹mg⁻¹, K(0.5)=0.88 ± 0.04mmolL⁻¹), K⁺ (V=69.6 ± 2.7nmolPimin⁻¹mg⁻¹, K(0.5)=1.60 ± 0.07mmolL⁻¹) and NH(4)(+) (V=90.8 ± 4.0nmolPimin⁻¹mg⁻¹, K(0.5)=9.2 ± 0.3mmol L⁻¹) all displayed site-site interaction kinetics. In the presence of NH(4)(+), enzyme affinity for K⁺ unexpectedly increased by 7-fold, while affinity for NH(4)(+) was 28-fold greater in the presence than absence of K⁺. Ouabain partially inhibited K⁺-phosphatase activity (K(I)=320 ± 14.0μmolL⁻¹), more effectively when NH(4)(+) was present (K(I)=240 ± 12.0μmolL⁻¹). We propose a model for the synergistic stimulation by K⁺ and NH(4)(+) of the K⁺-phosphatase activity of the (Na⁺, K⁺)-ATPase from C. ornatus posterior gill tissue.
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Affiliation(s)
- Daniela P Garçon
- Departamento de Biologia Molecular, Centro de Ciências Exatas e da Natureza, Universidade Federal da Paraíba, Brazil
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Schuck PF, De Assis DR, Viegas CM, Pereira TCB, Machado JL, Furlanetto CB, Bogo MR, Streck EL, Ferreira GC. Ethylmalonic acid modulates Na+, K(+)-ATPase activity and mRNA levels in rat cerebral cortex. Synapse 2012; 67:111-7. [PMID: 23161776 DOI: 10.1002/syn.21618] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2012] [Accepted: 10/25/2012] [Indexed: 02/05/2023]
Abstract
Ethylmalonic acid (EMA) accumulates in tissues of patients affected by short-chain acyl-CoA dehydrogenase deficiency and ethylmalonic encephalopathy, illnesses characterized by variable neurological symptoms. In this work, we investigated the in vitro and in vivo EMA effects on Na(+), K(+)-ATPase (NAK) activity and mRNA levels in cerebral cortex from 30-day-old rats. For in vitro studies, cerebral cortex homogenates were incubated in the presence of EMA at 0.5, 1, or 2.5 mM concentrations for 1 h. For in vivo experiments, animals received three subcutaneous EMA injections (6 μmol g(-1); 90-min interval) and were killed 60 min after the last injection. After that, NAK activity and its mRNA expression were measured. We observed that EMA did not affect this enzyme activity in vitro. In contrast, EMA administration significantly increased NAK activity and decreased mRNA NAK expression as assessed by semiquantitative reverse transcriptase polymerase chain reaction when compared with control group. Considering the high score of residues prone to phosphorylation on NAK, this profile can be associated with a possible regulation by specific phosphorylation sites of the enzyme. Altogether, the present results suggest that NAK alterations may be involved in the pathophysiology of brain damage found in patients in which EMA accumulates.
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Affiliation(s)
- Patrícia Fernanda Schuck
- Laboratório de Erros Inatos do Metabolismo, Programa de Pós-graduação em Ciências da Saúde, Unidade Acadêmica de Ciências da Saúde, Universidade do Extremo Sul Catarinense, Criciúma, SC, Brazil.
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38
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Mercury toxicity on sodium pump and organoseleniums intervention: a paradox. J Biomed Biotechnol 2012; 2012:924549. [PMID: 22927724 PMCID: PMC3425867 DOI: 10.1155/2012/924549] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2012] [Accepted: 07/01/2012] [Indexed: 12/21/2022] Open
Abstract
Mercury is an environmental poison, and the damage to living system is generally severe. The severity of mercury poisoning is consequent from the fact that it targets the thiol-containing enzymes, irreversibly oxidizing their critical thiol groups, consequently leading to an inactivation of the enzyme. The Na+/K+-ATPase is a sulfhydryl protein that is sensitive to Hg2+ assault. On the other hand, organoseleniums are a class of pharmacologically promising compounds with potent antioxidant effects. While Hg2+ oxidizes sulfhydryl groups of Na+/K+-ATPase under in vitro and in vivo conditions, the organoselenium compounds inhibit Na+/K+-ATPase in vitro but enhance its activities under in vivo conditions with concomitant increase in the level of endogenous thiols. Paradoxically, it appears that these two thiol oxidants can be used to counteract one another under in vivo conditions, and this hypothesis serves as the basis for this paper.
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39
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Leone FA, Masui DC, de Souza Bezerra TM, Garçon DP, Valenti WC, Augusto AS, McNamara JC. Kinetic analysis of gill (Na⁺,K⁺)-ATPase activity in selected ontogenetic stages of the Amazon River shrimp, Macrobrachium amazonicum (Decapoda, Palaemonidae): interactions at ATP- and cation-binding sites. J Membr Biol 2012; 245:201-15. [PMID: 22544049 DOI: 10.1007/s00232-012-9431-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2011] [Accepted: 04/09/2012] [Indexed: 11/26/2022]
Abstract
We investigated modulation by ATP, Mg²⁺, Na⁺, K⁺ and NH₄⁺ and inhibition by ouabain of (Na⁺,K⁺)-ATPase activity in microsomal homogenates of whole zoeae I and decapodid III (formerly zoea IX) and whole-body and gill homogenates of juvenile and adult Amazon River shrimps, Macrobrachium amazonicum. (Na⁺,K⁺)-ATPase-specific activity was increased twofold in decapodid III compared to zoea I, juveniles and adults, suggesting an important role in this ontogenetic stage. The apparent affinity for ATP (K(M) = 0.09 ± 0.01 mmol L⁻¹) of the decapodid III (Na⁺,K⁺)-ATPase, about twofold greater than the other stages, further highlights this relevance. Modulation of (Na⁺,K⁺-ATPase activity by K⁺ also revealed a threefold greater affinity for K⁺ (K₀.₅ = 0.91 ± 0.04 mmol L⁻¹) in decapodid III than in other stages; NH₄⁺ had no modulatory effect. The affinity for Na⁺ (K₀.₅ = 13.2 ± 0.6 mmol L⁻¹) of zoea I (Na⁺,K⁺)-ATPase was fourfold less than other stages. Modulation by Na⁺, Mg²⁺ and NH₄⁺ obeyed cooperative kinetics, while K⁺ modulation exhibited Michaelis-Menten behavior. Rates of maximal Mg²⁺ stimulation of ouabain-insensitive ATPase activity differed in each ontogenetic stage, suggesting that Mg²⁺-stimulated ATPases other than (Na⁺,K⁺)-ATPase are present. Ouabain inhibition suggests that, among the various ATPase activities present in the different stages, Na⁺-ATPase may be involved in the ontogeny of osmoregulation in larval M. amazonicum. The NH₄⁺-stimulated, ouabain-insensitive ATPase activity seen in zoea I and decapodid III may reflect a stage-specific means of ammonia excretion since functional gills are absent in the early larval stages.
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Affiliation(s)
- Francisco Assis Leone
- Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Avenida Bandeirantes, 3900 Ribeirão Prêto, SP 14040-901, Brazil.
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40
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Kaufman SB, González-Flecha FL, González-Lebrero RM. Opposing Effects of Na+ and K+ on the Thermal Stability of Na+,K+-ATPase. J Phys Chem B 2012; 116:3421-9. [DOI: 10.1021/jp2124108] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Affiliation(s)
- Sergio B. Kaufman
- Instituto
de Química y Fisicoquímica
Biológicas and Departamento de Química Biológica,
Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - F. Luis González-Flecha
- Instituto
de Química y Fisicoquímica
Biológicas and Departamento de Química Biológica,
Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Rodolfo M. González-Lebrero
- Instituto
de Química y Fisicoquímica
Biológicas and Departamento de Química Biológica,
Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires, Argentina
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41
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Garçon DP, Lucena MN, França JL, McNamara JC, Fontes CFL, Leone FA. Na⁺,K⁺-ATPase activity in the posterior gills of the blue crab, Callinectes ornatus (Decapoda, Brachyura): modulation of ATP hydrolysis by the biogenic amines spermidine and spermine. J Membr Biol 2011; 244:9-20. [PMID: 21972069 DOI: 10.1007/s00232-011-9391-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2011] [Accepted: 08/11/2011] [Indexed: 11/24/2022]
Abstract
We investigated the effect of the exogenous polyamines spermine, spermidine and putrescine on modulation by ATP, K⁺, Na⁺, NH₄⁺ and Mg²⁺ and on inhibition by ouabain of posterior gill microsomal Na⁺,K⁺-ATPase activity in the blue crab, Callinectes ornatus, acclimated to a dilute medium (21‰ salinity). This is the first kinetic demonstration of competition between spermine and spermidine for the cation sites of a crustacean Na⁺,K⁺-ATPase. Polyamine inhibition is enhanced at low cation concentrations: spermidine almost completely inhibited total ATPase activity, while spermine inhibition attained 58%; putrescine had a negligible effect on Na⁺,K⁺-ATPase activity. Spermine and spermidine affected both V and K for ATP hydrolysis but did not affect ouabain-insensitive ATPase activity. ATP hydrolysis in the absence of spermine and spermidine obeyed Michaelis-Menten behavior, in contrast to the cooperative kinetics seen for both polyamines. Modulation of V and K by K⁺, Na⁺, NH₄⁺ and Mg²⁺ varied considerably in the presence of spermine and spermidine. These findings suggest that polyamine inhibition of Na⁺,K⁺-ATPase activity may be of physiological relevance to crustaceans that occupy habitats of variable salinity.
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Affiliation(s)
- Daniela P Garçon
- Departamento de Química, Faculdade de Filosofia, Ciências e Letras da Universidade de São Paulo, Ribeirão Preto, Avenida Bandeirantes 3900, Ribeirão Preto, SP 14040-901, Brazil
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42
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Sodium or potassium efflux ATPase. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2010; 1798:1841-53. [DOI: 10.1016/j.bbamem.2010.07.009] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2010] [Revised: 07/06/2010] [Accepted: 07/13/2010] [Indexed: 12/20/2022]
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Einholm AP, Toustrup-Jensen MS, Holm R, Andersen JP, Vilsen B. The rapid-onset dystonia parkinsonism mutation D923N of the Na+, K+-ATPase alpha3 isoform disrupts Na+ interaction at the third Na+ site. J Biol Chem 2010; 285:26245-54. [PMID: 20576601 PMCID: PMC2924038 DOI: 10.1074/jbc.m110.123976] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2010] [Revised: 05/31/2010] [Indexed: 11/06/2022] Open
Abstract
Rapid-onset dystonia parkinsonism (RDP), a rare neurological disorder, is caused by mutation of the neuron-specific alpha3-isoform of Na(+), K(+)-ATPase. Here, we present the functional consequences of RDP mutation D923N. Relative to the wild type, the mutant exhibits a remarkable approximately 200-fold reduction of Na(+) affinity for activation of phosphorylation from ATP, reflecting a defective interaction of the E(1) form with intracellular Na(+). This is the largest effect on Na(+) affinity reported so far for any Na(+), K(+)-ATPase mutant. D923N also affects the interaction with extracellular Na(+) normally driving the E(1)P to E(2)P conformational transition backward. However, no impairment of K(+) binding was observed for D923N, leading to the conclusion that Asp(923) is specifically associated with the third Na(+) site that is selective toward Na(+). The crystal structure of the Na(+), K(+)-ATPase in E(2) form shows that Asp(923) is located in the cytoplasmic half of transmembrane helix M8 inside a putative transport channel, which is lined by residues from the transmembrane helices M5, M7, M8, and M10 and capped by the C terminus, recently found involved in recognition of the third Na(+) ion. Structural modeling of the E(1) form of Na(+), K(+)-ATPase based on the Ca(2+)-ATPase crystal structure is consistent with the hypothesis that Asp(923) contributes to a site binding the third Na(+) ion. These results in conjunction with our previous findings with other RDP mutants suggest that a selective defect in the handling of Na(+) may be a general feature of the RDP disorder.
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Affiliation(s)
- Anja Pernille Einholm
- From the Centre for Membrane Pumps in Cells and Disease-PUMPKIN, Danish National Research Foundation, Department of Physiology and Biophysics, Aarhus University, DK-8000 Aarhus C, Denmark
| | - Mads S. Toustrup-Jensen
- From the Centre for Membrane Pumps in Cells and Disease-PUMPKIN, Danish National Research Foundation, Department of Physiology and Biophysics, Aarhus University, DK-8000 Aarhus C, Denmark
| | - Rikke Holm
- From the Centre for Membrane Pumps in Cells and Disease-PUMPKIN, Danish National Research Foundation, Department of Physiology and Biophysics, Aarhus University, DK-8000 Aarhus C, Denmark
| | - Jens Peter Andersen
- From the Centre for Membrane Pumps in Cells and Disease-PUMPKIN, Danish National Research Foundation, Department of Physiology and Biophysics, Aarhus University, DK-8000 Aarhus C, Denmark
| | - Bente Vilsen
- From the Centre for Membrane Pumps in Cells and Disease-PUMPKIN, Danish National Research Foundation, Department of Physiology and Biophysics, Aarhus University, DK-8000 Aarhus C, Denmark
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Vedovato N, Gadsby DC. The two C-terminal tyrosines stabilize occluded Na/K pump conformations containing Na or K ions. ACTA ACUST UNITED AC 2010; 136:63-82. [PMID: 20548052 PMCID: PMC2894553 DOI: 10.1085/jgp.201010407] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Interactions of the three transported Na ions with the Na/K pump remain incompletely understood. Na/K pump crystal structures show that the extended C terminus of the Na,K-adenosine triphosphatase (ATPase) alpha subunit directly contacts transmembrane helices. Deletion of the last five residues (KETYY in almost all Na/K pumps) markedly lowered the apparent affinity for Na activation of pump phosphorylation from ATP, a reflection of cytoplasmic Na affinity for forming the occluded E1P(Na3) conformation. ATPase assays further suggested that C-terminal truncations also interfere with low affinity Na interactions, which are attributable to extracellular effects. Because extracellular Na ions traverse part of the membrane's electric field to reach their binding sites in the Na/K pump, their movements generate currents that can be monitored with high resolution. We report here electrical measurements to examine how Na/K pump interactions with extracellular Na ions are influenced by C-terminal truncations. We deleted the last two (YY) or five (KESYY) residues in Xenopus laevis alpha1 Na/K pumps made ouabain resistant by either of two kinds of point mutations and measured their currents as 10-mM ouabain-sensitive currents in Xenopus oocytes after silencing endogenous Xenopus Na/K pumps with 1 microM ouabain. We found the low affinity inhibitory influence of extracellular Na on outward Na/K pump current at negative voltages to be impaired in all of the C-terminally truncated pumps. Correspondingly, voltage jump-induced transient charge movements that reflect pump interactions with extracellular Na ions were strongly shifted to more negative potentials; this signals a several-fold reduction of the apparent affinity for extracellular Na in the truncated pumps. Parallel lowering of Na affinity on both sides of the membrane argues that the C-terminal contacts provide important stabilization of the occluded E1P(Na3) conformation, regardless of the route of Na ion entry into the binding pocket. Gating measurements of palytoxin-opened Na/K pump channels additionally imply that the C-terminal contacts also help stabilize pump conformations with occluded K ions.
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Affiliation(s)
- Natascia Vedovato
- Laboratory of Cardiac/Membrane Physiology, The Rockefeller University, New York, NY 10065, USA
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Structural changes in the catalytic cycle of the Na+,K+-ATPase studied by infrared spectroscopy. Biophys J 2009; 96:3433-42. [PMID: 19383486 DOI: 10.1016/j.bpj.2009.01.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2008] [Revised: 12/20/2008] [Accepted: 01/02/2009] [Indexed: 11/23/2022] Open
Abstract
Pig kidney Na(+),K(+)-ATPase was studied by means of reaction-induced infrared difference spectroscopy. The reaction from E1Na(3)(+) to an E2P state was initiated by photolysis of P(3)-1-(2-nitrophenyl)ethyl ATP (NPE caged ATP) in samples that contained 3 mM free Mg(2+) and 130 mM NaCl at pH 7.5. Release of ATP from caged ATP produced highly detailed infrared difference spectra indicating structural changes of the Na(+),K(+)-ATPase. The observed transient state of the enzyme accumulated within seconds after ATP release and decayed on a timescale of minutes at 15 degrees C. Several controls ensured that the observed difference signals were due to structural changes of the Na(+),K(+)-ATPase. Samples that additionally contained 20 mM KCl showed similar spectra but less intense difference bands. The absorbance changes observed in the amide I region, reflecting conformational changes of the protein backbone, corresponded to only 0.3% of the maximum absorbance. Thus the net change of secondary structure was concluded to be very small, which is in line with movement of rigid protein segments during the catalytic cycle. Despite their small amplitude, the amide I signals unambiguously reveal the involvement of several secondary structure elements in the conformational change. Similarities and dissimilarities to corresponding spectra of the Ca(2+)-ATPase and H(+),K(+)-ATPase are discussed, and suggest characteristic bands for the E1 and E2 conformations at 1641 and 1661 cm(-1), respectively, for alphabeta heterodimeric ATPases. The spectra further indicate the participation of protonated carboxyl groups or lipid carbonyl groups in the reaction from E1Na(3)(+) to an E2P state. A negative band at 1730 cm(-1) is in line with the presence of a protonated Asp or Glu residue that coordinates Na(+) in E1Na(3)(+). Infrared signals were also detected in the absorption regions of ionized carboxyl groups.
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Morth JP, Poulsen H, Toustrup-Jensen MS, Schack VR, Egebjerg J, Andersen JP, Vilsen B, Nissen P. The structure of the Na+,K+-ATPase and mapping of isoform differences and disease-related mutations. Philos Trans R Soc Lond B Biol Sci 2009; 364:217-27. [PMID: 18957371 DOI: 10.1098/rstb.2008.0201] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The Na+,K+-ATPase transforms the energy of ATP to the maintenance of steep electrochemical gradients for sodium and potassium across the plasma membrane. This activity is tissue specific, in particular due to variations in the expressions of the alpha subunit isoforms one through four. Several mutations in alpha2 and 3 have been identified that link the specific function of the Na+,K+-ATPase to the pathophysiology of neurological diseases such as rapid-onset dystonia parkinsonism and familial hemiplegic migraine type 2. We show a mapping of the isoform differences and the disease-related mutations on the recently determined crystal structure of the pig renal Na+,K+-ATPase and a structural comparison to Ca2+-ATPase. Furthermore, we present new experimental data that address the role of a stretch of three conserved arginines near the C-terminus of the alpha subunit (Arg1003-Arg1005).
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Affiliation(s)
- J Preben Morth
- Centre for Membrane Pumps in Cells and Disease-PUMPKIN, Danish National Research Foundation, University of Aarhus, Gustav Wieds Vej 10C, Aarhus C, Denmark
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Chen W, Zhang Z, Huang F. Synchronization of Na/K pump molecules by an oscillating electric field. J Bioenerg Biomembr 2008; 40:347-57. [DOI: 10.1007/s10863-008-9150-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2007] [Accepted: 06/28/2008] [Indexed: 10/21/2022]
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48
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Jorgensen PL. Importance for Absorption of Na+ from Freshwater of Lysine, Valine and Serine Substitutions in the α1a-Isoform of Na,K-ATPase in the Gills of Rainbow Trout (Oncorhynchus mykiss) and Atlantic Salmon (Salmo salar). J Membr Biol 2008; 223:37-47. [DOI: 10.1007/s00232-008-9111-y] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2008] [Accepted: 05/14/2008] [Indexed: 11/24/2022]
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Effect of dietary protein level and origin on the redox status in the digestive tract of mice. Int J Mol Sci 2008; 9:464-475. [PMID: 19325762 PMCID: PMC2635687 DOI: 10.3390/ijms9040464] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2008] [Revised: 03/11/2008] [Accepted: 03/14/2008] [Indexed: 11/16/2022] Open
Abstract
The present study was undertaken to evaluate the effects of high protein (soybean protein or casein) on the balance between production of free radicals and antioxidant level in digestive organs of mice. For this purpose, male (C57BL/6J) mice were adapted to experimental diets containing soybean protein or casein with 20% (normal protein diets, NPDs) or 60% (high protein diets, HPDs), and HPDs supplemented with 0.06g/kg cysteamine. After two weeks of feeding, oxidative and antioxidative parameters in duodenum, liver and pancreas were measured. The results show that ingestion of high protein markedly increased contents of superoxide anion and malondialdehyde (MDA), decreased activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), catalase (CAT) and Na+ K+-ATPase, and content of reduced glutathione (GSH) in digestive organs of mice (P<0.05). Levels of oxidative parameters were lower and antioxidant capacity of both enzyme and non-enzyme was higher in mice fed with soybean protein than those fed with casein. In groups fed HPDs supplemented with cysteamine, oxidative stress was mitigated. However, oxidative parameter levels were still higher than those of NPD-fed groups. The present study indicates that ingestion of high protein diets could result in an imbalance between oxidant and antioxidant, and thus induce oxidative stress in digestive organs of mice. The oxidative damage was smaller in mice fed with high level of soy protein in comparison with casein.
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50
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Regulation and Function of Lysine-Substituted Na,K Pumps in Salt Adaptation of Artemia franciscana. J Membr Biol 2007; 221:39-49. [DOI: 10.1007/s00232-007-9083-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2007] [Accepted: 10/19/2007] [Indexed: 12/01/2022]
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