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Zhao Z, Qin P, Huang YW. Lysosomal ion channels involved in cellular entry and uncoating of enveloped viruses: Implications for therapeutic strategies against SARS-CoV-2. Cell Calcium 2021; 94:102360. [PMID: 33516131 PMCID: PMC7825922 DOI: 10.1016/j.ceca.2021.102360] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 01/13/2021] [Accepted: 01/15/2021] [Indexed: 12/21/2022]
Abstract
Ion channels are necessary for correct lysosomal function including degradation of cargoes originating from endocytosis. Almost all enveloped viruses, including coronaviruses (CoVs), enter host cells via endocytosis, and do not escape endosomal compartments into the cytoplasm (via fusion with the endolysosomal membrane) unless the virus-encoded envelope proteins are cleaved by lysosomal proteases. With the ongoing outbreak of severe acute respiratory syndrome (SARS)-CoV-2, endolysosomal two-pore channels represent an exciting and emerging target for antiviral therapies. This review focuses on the latest knowledge of the effects of lysosomal ion channels on the cellular entry and uncoating of enveloped viruses, which may aid in development of novel therapies against emerging infectious diseases such as SARS-CoV-2.
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Affiliation(s)
- Zhuangzhuang Zhao
- Key Laboratory of Animal Virology of Ministry of Agriculture, Institute of Preventive Veterinary Medicine, Department of Veterinary Medicine, Zhejiang University, Hangzhou 310058, China
| | - Pan Qin
- Key Laboratory of Animal Virology of Ministry of Agriculture, Institute of Preventive Veterinary Medicine, Department of Veterinary Medicine, Zhejiang University, Hangzhou 310058, China
| | - Yao-Wei Huang
- Key Laboratory of Animal Virology of Ministry of Agriculture, Institute of Preventive Veterinary Medicine, Department of Veterinary Medicine, Zhejiang University, Hangzhou 310058, China.
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2
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Yu ZC, Wang TQ, Luo YN, Zheng XT, He W, Chen LB, Peng CL. Overexpression of the V-ATPase c subunit gene from Antarctic notothenioid fishes enhances freezing tolerance in transgenic Arabidopsis plants. Plant Physiol Biochem 2021; 160:365-376. [PMID: 33550177 DOI: 10.1016/j.plaphy.2021.01.038] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Accepted: 01/23/2021] [Indexed: 05/23/2023]
Abstract
Theoretical and experimental studies have demonstrated that temperature is an important environmental factor that affects the regional distribution of plants. However, how to modify the distribution pattern of plants in different regions is a focus of current research. Obtain the information of cold tolerance genes from cold tolerance species, cloning genes with real cold tolerance effects is one of the most important ways to find the genes related to cold tolerance. In this study, we investigated whether transferring the VHA-c gene from Antarctic notothenioid fishes into Arabidopsis enhances freezing tolerance of Arabidopsis. The physiological response and molecular changes of VHA-c overexpressing pedigree and wildtype Arabidopsis were studied at -20 °C. The results showed that the malondialdehyde (MDA) and membrane leakage rates of WT plants were significantly higher than those of VHA-c8 and VHA-c11 plants, but the soluble sugar, soluble protein, proline and ATP contents of WT plants were significantly lower than those of VHA-c8 and VHA-c11 plants under -20 °C freezing treatment. The survival rate, VHA-c gene expression level and VHA-c protein contents of WT plants were significantly lower than those of VHA-c8 and VHA-c11 plants under -20 °C freezing treatment. Correlation analysis showed that ATP content was significantly negatively correlated with MDA and membrane leakage rate, and positively correlated with soluble sugar, soluble protein and proline content under -20 °C freezing treatment. These results demonstrated that overexpression of the VHA-c gene provided strong freezing tolerance to Arabidopsis by increasing the synthesis of ATP and improved the adaptability of plants in low temperature environment.
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Affiliation(s)
- Zheng-Chao Yu
- Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Sciences, South China Normal University, Guangzhou, 510631, China
| | - Ting-Qin Wang
- College of Coastal Agricultural Sciences, Guangdong Ocean University, Zhanjiang, 524088, China
| | - Yan-Na Luo
- Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Sciences, South China Normal University, Guangzhou, 510631, China
| | - Xiao-Ting Zheng
- Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Sciences, South China Normal University, Guangzhou, 510631, China
| | - Wei He
- Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Sciences, South China Normal University, Guangzhou, 510631, China
| | - Liang-Biao Chen
- Internal Joint Research Center for Marine Biosciences (Ministry of Science and Technology), College of Fisheries and Life Science, Shanghai Ocean University, Shanghai, 201306, China.
| | - Chang-Lian Peng
- Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Sciences, South China Normal University, Guangzhou, 510631, China.
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Wang P, Guo Y, Wang Y, Gao C. Vacuolar membrane H +-ATPase c`` subunit gene (ThVHAc``1) from Tamarix hispida Willd improves salt stress tolerance. Plant Physiol Biochem 2020; 157:370-378. [PMID: 33190056 DOI: 10.1016/j.plaphy.2020.10.039] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Accepted: 10/29/2020] [Indexed: 05/15/2023]
Abstract
The plant vacuolar H+-ATPase (V-ATPase) is a multisubunit complex. In addition to performing basic housekeeping functions, this complex is also involved in abiotic stress resistance in plants. In this study, a V-ATPase c`` subunit gene (ThVHAc``1) from Tamarix hispida Willd was cloned with a 534-bp ORF. Sequence analysis showed that the ThVHAc``1 protein contains four transmembrane helices and lacks a signal peptide. qRT-PCR results showed that ThVHAc``1 was primarily induced by treatments of NaCl, NaHCO3, PEG6000, CdCl2 or ABA in roots, stems and leaves of T. hispida. The expression pattern of ThVHAc``1 was significantly different from that of ThVHAc1 (a V-ATPase c subunit in T. hispida). Furthermore, the cell survival rates and density (OD600) results showed that the transgenic yeast overexpressing ThVHAc``1 exhibited increased tolerance to the above-mentioned abiotic stresses. In addition, the overexpression of ThVHAc``1 confers salt tolerance to transgenic Arabidopsis plants by improving the ROS content and decreasing the accumulation of O2- and H2O2. Similarly, the homologous transformation of the ThVHAc``1 gene into T. hispida also improved salt tolerance. Our results suggest that the ThVHAc``1 gene plays an important role in plant stress tolerance.
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Affiliation(s)
- Peilong Wang
- State Key Laboratory of Tree Genetics and Breeding (Northeast Forestry University), Harbin, 150040, China
| | - Yucong Guo
- State Key Laboratory of Tree Genetics and Breeding (Northeast Forestry University), Harbin, 150040, China
| | - Yuanyuan Wang
- State Key Laboratory of Tree Genetics and Breeding (Northeast Forestry University), Harbin, 150040, China
| | - Caiqiu Gao
- State Key Laboratory of Tree Genetics and Breeding (Northeast Forestry University), Harbin, 150040, China.
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Jung HY, Kim W, Hahn KR, Kwon HJ, Nam SM, Chung JY, Yoon YS, Kim DW, Yoo DY, Hwang IK. Effects of Pyridoxine Deficiency on Hippocampal Function and Its Possible Association with V-Type Proton ATPase Subunit B2 and Heat Shock Cognate Protein 70. Cells 2020; 9:cells9051067. [PMID: 32344819 PMCID: PMC7290376 DOI: 10.3390/cells9051067] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 04/20/2020] [Accepted: 04/21/2020] [Indexed: 02/06/2023] Open
Abstract
Pyridoxine, one of the vitamin B6 vitamers, plays a crucial role in amino acid metabolism and synthesis of monoamines as a cofactor. In the present study, we observed the effects of pyridoxine deficiency on novel object recognition memory. In addition, we examined the levels of 5-hydroxytryptamine (5-HT), 5-hydroxyindoleacetic acid (5-HIAA), 3,4-dihydroxyphenethylamine (DA), 3,4-dihydroxyphenylacetic acid, and homovanillic acid and the number of proliferating cells and neuroblasts in the hippocampus. We also examined the effects of pyridoxine deficiency on protein profiles applying a proteomic study. Five-week-old mice fed pyridoxine-deficient diets for 8 weeks and showed a significant decrease in the serum and brain (cerebral cortex, hippocampus, and thalamus) levels of pyridoxal 5′-phosphate, a catalytically active form of vitamin-B6, and decline in 5-HT and DA levels in the hippocampus compared to controls fed a normal chow. In addition, pyridoxine deficiency significantly decreased Ki67-positive proliferating cells and differentiated neuroblasts in the dentate gyrus compared to controls. A proteomic study demonstrated that a total of 41 spots were increased or decreased more than two-fold. Among the detected proteins, V-type proton ATPase subunit B2 (ATP6V1B2) and heat shock cognate protein 70 (HSC70) showed coverage and matching peptide scores. Validation by Western blot analysis showed that ATP6V1B2 and HSC70 levels were significantly decreased and increased, respectively, in pyridoxine-deficient mice compared to controls. These results suggest that pyridoxine is an important element of novel object recognition memory, monoamine levels, and hippocampal neurogenesis. Pyridoxine deficiency causes cognitive impairments and reduction in 5-HT and DA levels, which may be associated with a reduction of ATP6V1B2 and elevation of HSC70 levels in the hippocampus.
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Affiliation(s)
- Hyo Young Jung
- Department of Anatomy and Cell Biology, College of Veterinary Medicine, and Research Institute for Veterinary Science, Seoul National University, Seoul 08826, Korea; (H.Y.J.); (K.R.H.); (Y.S.Y.)
| | - Woosuk Kim
- Department of Biomedical Sciences, and Research Institute for Bioscience and Biotechnology, Hallym University, Chuncheon 24252, Korea;
| | - Kyu Ri Hahn
- Department of Anatomy and Cell Biology, College of Veterinary Medicine, and Research Institute for Veterinary Science, Seoul National University, Seoul 08826, Korea; (H.Y.J.); (K.R.H.); (Y.S.Y.)
| | - Hyun Jung Kwon
- Department of Biochemistry and Molecular Biology, Research Institute of Oral Sciences, College of Dentistry, Gangneung-Wonju National University, Gangneung 25457, Korea; (H.J.K.); (D.W.K.)
| | - Sung Min Nam
- Department of Anatomy, College of Veterinary Medicine, Konkuk University, Seoul 05030, Korea;
| | - Jin Young Chung
- Department of Veterinary Internal Medicine and Geriatrics, College of Veterinary Medicine, Kangwon National University, Chuncheon 24341, Korea;
| | - Yeo Sung Yoon
- Department of Anatomy and Cell Biology, College of Veterinary Medicine, and Research Institute for Veterinary Science, Seoul National University, Seoul 08826, Korea; (H.Y.J.); (K.R.H.); (Y.S.Y.)
| | - Dae Won Kim
- Department of Biochemistry and Molecular Biology, Research Institute of Oral Sciences, College of Dentistry, Gangneung-Wonju National University, Gangneung 25457, Korea; (H.J.K.); (D.W.K.)
| | - Dae Young Yoo
- Department of Anatomy, College of Medicine, Soonchunhyang University, Cheonan 31151, Korea
- Correspondence: (D.Y.Y.); (I.K.H.)
| | - In Koo Hwang
- Department of Anatomy and Cell Biology, College of Veterinary Medicine, and Research Institute for Veterinary Science, Seoul National University, Seoul 08826, Korea; (H.Y.J.); (K.R.H.); (Y.S.Y.)
- Correspondence: (D.Y.Y.); (I.K.H.)
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Suda C, Yatabe J, Yatabe M, Yarita M, Ichihara A. Soluble (pro)renin receptor increased by hypoxia maintains oxidative metabolism in trophoblasts. J Mol Endocrinol 2020; 64:145-154. [PMID: 31958319 DOI: 10.1530/jme-19-0050] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Accepted: 01/17/2020] [Indexed: 11/08/2022]
Abstract
Elevated soluble (pro)renin receptor (s(P)RR) concentration in maternal blood is associated with gestational hypertension and preeclampsia. Placenta has abundant expression of (P)RR, and the binding of (P)RR with pyruvate dehydrogenase E1 beta subunit (PDHB) is reported to maintain oxidative metabolism. Thus, we hypothesized that placental hypoxia may increase (P)RR, and the increased (P)RR may preserve PDHB expression. Expression and functional analyses were performed using human placental trophoblast cells, mainly JAR cells. (P)RR co-immunoprecipitated and showed co-immunofluorescence with PDHB mainly in the mitochondria. Hypoxia treatment significantly increased intracellular s(P)RR protein expression, but secreted s(P)RR in the culture medium was decreased by hypoxia. Hypoxia treatment did not alter PDHB expression or activity in the basal condition, but when (P)RR was knocked down by siRNA, PDHB protein and activity were reduced by hypoxia. Acetyl-CoA, the product of PDH activity, was significantly reduced by hypoxia treatment with (P)RR siRNA. S(P)RR is generated from full-length PRR when cleaved by specific proteases. Protease inhibitor experiments suggested furin and site 1 protease as the enzymes generating s(P)RR in JAR cells, and only when treated by site 1 protease inhibitor, PF429242, PDHB protein showed a significant trend to decrease with hypoxia. In JAR cells, hypoxia increased intracellular s(P)RR, and (P)RR preserved the expression and function of PDHB during hypoxia. (P)RR may help maintain oxidative metabolism and efficient energy production during placental ischemia in hypertensive disorders of pregnancy.
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Affiliation(s)
- Chikahito Suda
- Department of Medicine II, Endocrinology and Hypertension, Tokyo Women's Medical University, Tokyo, Japan
| | - Junichi Yatabe
- Department of Medicine II, Endocrinology and Hypertension, Tokyo Women's Medical University, Tokyo, Japan
| | - Midori Yatabe
- Department of Medicine II, Endocrinology and Hypertension, Tokyo Women's Medical University, Tokyo, Japan
| | - Miki Yarita
- Department of Medicine II, Endocrinology and Hypertension, Tokyo Women's Medical University, Tokyo, Japan
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Atsuhiro Ichihara
- Department of Medicine II, Endocrinology and Hypertension, Tokyo Women's Medical University, Tokyo, Japan
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Son SW, Chau GC, Kim ST, Um SH. Vacuolar H +-ATPase Subunit V0C Regulates Aerobic Glycolysis of Esophageal Cancer Cells via PKM2 Signaling. Cells 2019; 8:E1137. [PMID: 31554233 PMCID: PMC6830105 DOI: 10.3390/cells8101137] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Revised: 09/16/2019] [Accepted: 09/20/2019] [Indexed: 12/16/2022] Open
Abstract
The vacuolar H+-adenosine triphosphatase (ATPase) subunit V0C (ATP6V0C), a proton-conducting, pore-forming subunit of vacuolar ATPase, maintains pH homeostasis and induces organelle acidification. The intracellular and extracellular pH of cancer cells affects their growth; however, the role of ATP6V0C in highly invasive esophageal cancer cells (ECCs) remains unclear. In this study, we examined the role of ATP6V0C in glucose metabolism in ECCs. The ATP6V0C depletion attenuated ECC proliferation, invasion, and suppressed glucose metabolism, as indicated by reduced glucose uptake and decreased lactate and adenosine triphosphate (ATP) production in cells. Consistent with this, expression of glycolytic enzyme and the extracellular acidification rate (ECAR) were also decreased by ATP6V0C knockdown. Mechanistically, ATP6V0C interacted with pyruvate kinase isoform M2 (PKM2), a key regulator of glycolysis in ECCs. The ATP6V0C depletion reduced PKM2 phosphorylation at tyrosine residue 105 (Tyr105), leading to inhibition of nuclear translocation of PKM2. In addition, ATP6V0C was recruited at hypoxia response element (HRE) sites in the lactate dehydrogenase A (LDHA) gene for glycolysis. Thus, our data suggest that ATP6V0C enhances aerobic glycolysis and motility in ECCs.
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Affiliation(s)
- Sung Wook Son
- Department of Molecular Cell Biology, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine, Suwon, Gyeonggi-do 16419, Korea.
- Department of Health Sciences and Technology, Samsung Advanced Institute for Health Sciences and Technology, Samsung Medical Center, Sungkyunkwan University, Seoul 06351, Korea.
| | - Gia Cac Chau
- Department of Molecular Cell Biology, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine, Suwon, Gyeonggi-do 16419, Korea.
- Department of Health Sciences and Technology, Samsung Advanced Institute for Health Sciences and Technology, Samsung Medical Center, Sungkyunkwan University, Seoul 06351, Korea.
| | - Seong-Tae Kim
- Department of Molecular Cell Biology, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine, Suwon, Gyeonggi-do 16419, Korea.
| | - Sung Hee Um
- Department of Molecular Cell Biology, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine, Suwon, Gyeonggi-do 16419, Korea.
- Department of Health Sciences and Technology, Samsung Advanced Institute for Health Sciences and Technology, Samsung Medical Center, Sungkyunkwan University, Seoul 06351, Korea.
- Biomedical Institute Convergence at Sungkyunkwan University, Suwon, Gyeonggi-do 16419, Korea.
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Faraco M, Li Y, Li S, Spelt C, Di Sansebastiano GP, Reale L, Ferranti F, Verweij W, Koes R, Quattrocchio FM. A Tonoplast P 3B-ATPase Mediates Fusion of Two Types of Vacuoles in Petal Cells. Cell Rep 2018. [PMID: 28636930 DOI: 10.1016/j.celrep.2017.05.076] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
It is known that plant cells can contain multiple distinct vacuoles; however, the abundance of multivacuolar cells and the mechanisms underlying vacuolar differentiation and communication among different types of vacuoles remain unknown. PH1 and PH5 are tonoplast P-ATPases that form a heteromeric pump that hyper-acidifies the central vacuole (CV) of epidermal cells in petunia petals. Here, we show that the sorting of this pump and other vacuolar proteins to the CV involves transit through small vacuoles: vacuolinos. Vacuolino formation is controlled by transcription factors regulating pigment synthesis and transcription of PH1 and PH5. Trafficking of proteins from vacuolinos to the central vacuole is impaired by misexpression of vacuolar SNAREs as well as mutants for the PH1 component of the PH1-PH5 pump. The finding that PH1-PH5 and these SNAREs interact strongly suggests that structural tonoplast proteins can act as tethering factors in the recognition of different vacuolar types.
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Affiliation(s)
- Marianna Faraco
- Plant Development and (Epi)Genetics, Swammerdam Institute for Life Science, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, the Netherlands; Section of Genetics, Department of Molecular Cell Biology, VU University, de Boelelaan 1087, 1081 HV Amsterdam, the Netherlands; Department of Biotechnology and Environmental Sciences, University of Salento, via Monteroni, Centro Ecotekne, 73100 Lecce, Italy
| | - Yanbang Li
- Plant Development and (Epi)Genetics, Swammerdam Institute for Life Science, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, the Netherlands; Section of Genetics, Department of Molecular Cell Biology, VU University, de Boelelaan 1087, 1081 HV Amsterdam, the Netherlands
| | - Shuangjiang Li
- Plant Development and (Epi)Genetics, Swammerdam Institute for Life Science, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, the Netherlands; Section of Genetics, Department of Molecular Cell Biology, VU University, de Boelelaan 1087, 1081 HV Amsterdam, the Netherlands
| | - Cornelis Spelt
- Plant Development and (Epi)Genetics, Swammerdam Institute for Life Science, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, the Netherlands; Section of Genetics, Department of Molecular Cell Biology, VU University, de Boelelaan 1087, 1081 HV Amsterdam, the Netherlands
| | - Gian Pietro Di Sansebastiano
- Department of Biotechnology and Environmental Sciences, University of Salento, via Monteroni, Centro Ecotekne, 73100 Lecce, Italy
| | - Lara Reale
- Department of Agricultural, Food, and Environmental Sciences, University of Perugia, Borgo XX Giugno 74, 06121 Perugia, Italy
| | - Francesco Ferranti
- Department of Agricultural, Food, and Environmental Sciences, University of Perugia, Borgo XX Giugno 74, 06121 Perugia, Italy
| | - Walter Verweij
- Section of Genetics, Department of Molecular Cell Biology, VU University, de Boelelaan 1087, 1081 HV Amsterdam, the Netherlands
| | - Ronald Koes
- Plant Development and (Epi)Genetics, Swammerdam Institute for Life Science, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, the Netherlands; Section of Genetics, Department of Molecular Cell Biology, VU University, de Boelelaan 1087, 1081 HV Amsterdam, the Netherlands.
| | - Francesca M Quattrocchio
- Plant Development and (Epi)Genetics, Swammerdam Institute for Life Science, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, the Netherlands; Section of Genetics, Department of Molecular Cell Biology, VU University, de Boelelaan 1087, 1081 HV Amsterdam, the Netherlands.
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Yang X, Gong P, Li K, Huang F, Cheng F, Pan G. A single cytosine deletion in the OsPLS1 gene encoding vacuolar-type H+-ATPase subunit A1 leads to premature leaf senescence and seed dormancy in rice. J Exp Bot 2016; 67:2761-76. [PMID: 26994476 PMCID: PMC4861022 DOI: 10.1093/jxb/erw109] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Leaf senescence is a programmed developmental process orchestrated by many factors, but its molecular regulation is not yet fully understood. In this study, a novel Oryza sativa premature leaf senescence mutant (ospls1) was examined. Despite normal development in early seedlings, the ospls1 mutant leaves displayed lesion-mimics and early senescence, and a high transpiration rate after tillering. The mutant also showed seed dormancy attributable to physical (defect of micropyle structure) and physiological (abscisic acid sensitivity) factors. Using a map-based cloning approach, we determined that a cytosine deletion in the OsPLS1 gene encoding vacuolar H(+)-ATPase subunit A1 (VHA-A1) underlies the phenotypic abnormalities in the ospls1 mutant. The OsPSL1/VHA-A1 transcript levels progressively declined with the age-dependent leaf senescence in both the ospls1 mutant and its wild type. The significant decrease in both OsPSL1/VHA-A1 gene expression and VHA enzyme activity in the ospls1 mutant strongly suggests a negative regulatory role for the normal OsPLS1/VHA-A1 gene in the onset of rice leaf senescence. The ospls1 mutant featured higher salicylic acid (SA) levels and reactive oxygen species (ROS) accumulation, and activation of signal transduction by up-regulation of WRKY genes in leaves. Consistent with this, the ospls1 mutant exhibited hypersensitivity to exogenous SA and/or H2O2 Collectively, these results indicated that the OsPSL1/VAH-A1 mutation played a causal role in premature leaf senescence through a combination of ROS and SA signals. To conclude, OsPLS1 is implicated in leaf senescence and seed dormancy in rice.
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Affiliation(s)
- Xi Yang
- Department of Agronomy, Zijingang Campus, Zhejiang University, Hangzhou 310058, PR China
| | - Pan Gong
- Department of Agronomy, Zijingang Campus, Zhejiang University, Hangzhou 310058, PR China
| | - Kunyu Li
- Department of Agronomy, Zijingang Campus, Zhejiang University, Hangzhou 310058, PR China
| | - Fudeng Huang
- Institute of Crop and Nuclear Technology Utilization, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, PR China
| | - Fangmin Cheng
- Department of Agronomy, Zijingang Campus, Zhejiang University, Hangzhou 310058, PR China
| | - Gang Pan
- Department of Agronomy, Zijingang Campus, Zhejiang University, Hangzhou 310058, PR China
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Li Z, Zhen Z, Guo K, Harvey P, Li J, Yang H. MAPK-mediated enhanced expression of vacuolar H(+)-ATPase confers the improved adaption to NaCl stress in a halotolerate peppermint (Mentha piperita L.). Protoplasma 2016; 253:553-69. [PMID: 25999237 DOI: 10.1007/s00709-015-0834-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2015] [Accepted: 05/12/2015] [Indexed: 05/24/2023]
Abstract
Vacuolar H(+)-ATPase (V-H(+)-ATPase) has been proved to be of importance in maintenance of ion homeostasis inside plant cells under NaCl stress. In this study, the expression levels and salt-tolerate function of V-H(+)-ATPase genes were investigated in the roots and leaves of a halotolerate peppermint (Mentha × piperita L.) Keyuan-1 treated with different concentrations of NaCl. Results showed that the expressions of V-H(+)-ATPase in the transcriptional, protein and activity levels were significantly enhanced in the halotolerate peppermint Keyuan-1 compared to the wild-type (WT) peppermint under 50, 100, and 150 mM NaCl treatment. Moreover, inhibition experiments exhibited that V-H(+)-ATPase activity played vital roles in the salt tolerance of peppermint Keyuan-1 to 150 mM NaCl stress through increasing the vacuolar H(+) pumping activity and Na(+) compartmentalization capacity. Furthermore, results of Western blots showed that the activity of a mitogen-activated protein kinase (MAPK) was significantly increased under different concentrations of NaCl in the halotolerate peppermint Keyuan-1, which was much higher than that of WT peppermint. Further experiments with inhibitors suggested that this MAPK protein was responsible for the enhanced expression of V-H(+)-ATPase in the halotolerate peppermint Keyuan-1. In response to NaCl stress, increase of cytoplasmic calcium concentration ([Ca(2+)]cyt) occurred upstream of MAPK activation in the halotolerate peppermint Keyuan-1. In all, these findings demonstrated that increased V-H(+)-ATPase activity was positively correlated with the enhanced salt tolerance in the halotolerate peppermint Keyuan-1, providing the theoretic basis for the further development and utilization of peppermint in saline areas.
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Affiliation(s)
- Zhe Li
- Biotechnology Center, Shandong Academy of Sciences, Jinan, 250014, China.
| | - Zhen Zhen
- Institute of Botany, Chinese Academy of Science, Beijing, 100093, China
| | - Kai Guo
- Biotechnology Center, Shandong Academy of Sciences, Jinan, 250014, China
| | - Paul Harvey
- Biotechnology Center, Shandong Academy of Sciences, Jinan, 250014, China
- Division of Ecosystem Science, Commonwealth Scientific and Industrial Research Organization, Clayton South, VIC, 3169, Australia
| | - Jishun Li
- Biotechnology Center, Shandong Academy of Sciences, Jinan, 250014, China
| | - Hetong Yang
- Biotechnology Center, Shandong Academy of Sciences, Jinan, 250014, China
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Guo YM, Liu Y, Chen LM. [Bicarbonate reabsorption in proximal renal tubule: molecular mechanisms and metabolic acidosis]. Sheng Li Xue Bao 2014; 66:398-414. [PMID: 25131781] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
HCO3(-) reabsorption in the renal tubules plays a critically important role in maintaining the global acid-base balance. Loss of HCO3(-) causes metabolic acidosis. Proximal renal tubule is the major site for HCO3(-) reabsorption, accounting for more than 80% of total HCO3(-) reabsorption along the nephron. Over the past more than half centuries, tremendous progresses have been made on understanding the molecular mechanisms underlying the HCO3(-) reabsorption in proximal tubules. The transepithelial movement of HCO3(-) involves the coordinated operation of machineries on both the apical and the basolateral membranes of the epithelial cells. On the apical domain, Na(+)-H(+) exchanger NHE3 and the vacuolar H(+)-ATPase are two major pathways mediating the apical uptake of HCO3(-)-related species. Taken together, NHE3 and H(+)-ATPase are responsible for about 80% of HCO3(-) reabsorption in the proximal tubule. The remaining 20% is likely mediated by pathways yet to be characterized. On the basolateral membrane, NBCe1 represents the only major known pathway mediating the extrusion of HCO3(-) coupled with Na(+) into the interstitial space. In the present article, we provide a historical view about the studies on the mechanisms of HCO3(-) reabsorption since 1940s. Moreover, we summarize the latest progresses emerging over the past decade in the physiological as well as pathological roles of acid-base transporters underlying the HCO3(-) reabsorption in proximal tubules.
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Affiliation(s)
- Yi-Min Guo
- Department of Biophysics and Molecular Physiology, Key Laboratory of Molecular Biophysics of Ministry of Education, Huazhong University of Science & Technology School of Life Science & Technology, Wuhan 430074, China.
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11
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Sennoune SR, Arutunyan A, del Rosario C, Castro-Marin R, Hussain F, Martinez-Zaguilan R. V-ATPase regulates communication between microvascular endothelial cells and metastatic cells. Cell Mol Biol (Noisy-le-grand) 2014; 60:19-25. [PMID: 24606724] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2014] [Accepted: 02/17/2014] [Indexed: 06/03/2023]
Abstract
To metastasize distant organs, tumor cells and endothelial cells lining the blood vessels must crosstalk. The nature of this communication that allows metastatic cells to intravasate and travel through the circulation and to extravasate to colonize different organs is poorly understood. In this study, we evaluated one of the first steps in this process—the proximity and physical interaction of endothelial and metastatic cells. To do this, we developed a cell separator chamber that allows endothelial and metastatic cells to grow side by side. We have shown in our previous studies that V-ATPases at the cell surface (pmV-ATPase) are involved in angiogenesis and metastasis. Therefore, we hypothesized that the physical proximity/interaction between endothelial and metastatic cells expressing pmV-ATPase will increase its activity in both cell types, and such activity in turn will increase pmV-ATPase expression on the membranes of both cell types. To determine pmV-ATPase activity we measured the proton fluxes (JH+) across the cell membrane. Our data indicated that interaction between endothelial and metastatic cells elicited a significant increase of JH+ via pmV-ATPase in both cell types. Bafilomycin, a V-ATPase inhibitor, significantly decrease JH+. In contrast, JH+ of the non-metastatic cells were not affected by the endothelial cells and vice-versa. Altogether, our data reveal that one of the early consequences of endothelial and metastatic cell interaction is an increase in pmV-ATPase that helps to acidify the extracellular medium and favors protease activity. These data emphasize the significance of the acidic tumor microenvironment enhancing a metastatic and invasive phenotype.
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Affiliation(s)
- S R Sennoune
- Texas Tech University Health Sciences Center Department of Cell Physiology & Molecular Biophysics Lubbock USA
| | - A Arutunyan
- George Washington University Medical Center Department of Pharmacology & Physiology Washington USA
| | - C del Rosario
- Texas Tech University Health Sciences Center Department of Cell Physiology & Molecular Biophysics Lubbock USA
| | - R Castro-Marin
- Texas Tech University Health Sciences Center Department of Cell Physiology & Molecular Biophysics Lubbock USA
| | - F Hussain
- Texas Tech University Health Sciences Center Department of Cell Physiology & Molecular Biophysics Lubbock USA
| | - R Martinez-Zaguilan
- Texas Tech University Health Sciences Center Department of Cell Physiology & Molecular Biophysics Lubbock USA Raul.MartinezZaguilan@ttuhsc.edu
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12
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Feng S, Cai M, Liu P, Wei L, Wang J, Qi J, Deng L. Atp6v1c1 may regulate filament actin arrangement in breast cancer cells. PLoS One 2014; 9:e84833. [PMID: 24454753 PMCID: PMC3893128 DOI: 10.1371/journal.pone.0084833] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2013] [Accepted: 11/19/2013] [Indexed: 01/26/2023] Open
Abstract
Previous studies have shown that the rate of breast cancer metastasis correlates with the expression of vacuolar H+-ATPases (V-ATPases). However, how V-ATPase is involved in breast cancer metastasis remains unknown. Our previous study showed that Atp6v1c1-depleted osteoclasts did not form organized actin rings and that Atp6v1c1 co-localizes with F-actin. In this study, we found that the normal arrangement of filamentous actin is disrupted in Atp6v1c1-depleted 4T1 mouse breast cancer cells and in the ATP6V1C1-depleted human breast cancer cell lines MDA-MB-231 and MDA-MB-435s. We further found that Atp6v1c1 co-localizes with F-actin in 4T1 cells. The results of our study suggest that high expression of Atp6v1c1 affects the actin structure of cancer cells such that it facilitates breast cancer metastasis. The findings also indicate that Atp6v1c1 could be a novel target for breast cancer metastasis therapy.
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Affiliation(s)
- Shengmei Feng
- Shanghai Institute of Traumatology and Orthopaedics, Shanghai Key Laboratory for Prevention and Treatment of Bone and Joint Diseases with Integrated Chinese-Western Medicine, Ruijin Hospital, Jiao Tong University School of Medicine, Shanghai, China
- * E-mail: (SMF); (LFD)
| | - Ming Cai
- Department of Orthopaedics, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, China
| | - Pengcheng Liu
- Department of Orthopaedics, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, China
| | - Li Wei
- Shanghai Institute of Traumatology and Orthopaedics, Shanghai Key Laboratory for Prevention and Treatment of Bone and Joint Diseases with Integrated Chinese-Western Medicine, Ruijin Hospital, Jiao Tong University School of Medicine, Shanghai, China
| | - Jinshen Wang
- Shanghai Institute of Traumatology and Orthopaedics, Shanghai Key Laboratory for Prevention and Treatment of Bone and Joint Diseases with Integrated Chinese-Western Medicine, Ruijin Hospital, Jiao Tong University School of Medicine, Shanghai, China
| | - Jin Qi
- Shanghai Institute of Traumatology and Orthopaedics, Shanghai Key Laboratory for Prevention and Treatment of Bone and Joint Diseases with Integrated Chinese-Western Medicine, Ruijin Hospital, Jiao Tong University School of Medicine, Shanghai, China
| | - Lianfu Deng
- Shanghai Institute of Traumatology and Orthopaedics, Shanghai Key Laboratory for Prevention and Treatment of Bone and Joint Diseases with Integrated Chinese-Western Medicine, Ruijin Hospital, Jiao Tong University School of Medicine, Shanghai, China
- * E-mail: (SMF); (LFD)
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13
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Abstract
Vacuolar ATPases (v-ATPases) hydrolyze adenosine triphospate (ATP) to pump protons across cell membranes. Mutations in v-ATPase subunits are implicated in three human disorders: distal renal tubular acidosis, osteopetrosis, and cutis laxa type II. In the eye, the role of v-ATPases is only emerging. Mutations in v-ATPase subunits are not linked to human blindness, but altered proton pump function may underlie ocular pathologies. For example, inhibition of v-ATPase by A2E may accentuate age-related macular degeneration (AMD). In animal models, v-ATPase mutations perturb the retinal pigment epithelium (RPE) and photoreceptor outer segment (OS) phagocytosis, an event linked to retinal degeneration. As the RPE plays essential roles in eye development and vision, the study of v-ATPase-induced RPE dysfunction may improve our understanding of RPE diseases.
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Affiliation(s)
- Lisa Shine
- School of Biomolecular and Biomedical Science, Conway Institute, University College Dublin, Belfield, Dublin 4, Ireland,
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Martinière A, Bassil E, Jublanc E, Alcon C, Reguera M, Sentenac H, Blumwald E, Paris N. In vivo intracellular pH measurements in tobacco and Arabidopsis reveal an unexpected pH gradient in the endomembrane system. Plant Cell 2013; 25:4028-43. [PMID: 24104564 PMCID: PMC3877828 DOI: 10.1105/tpc.113.116897] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Revised: 07/30/2013] [Accepted: 09/18/2013] [Indexed: 05/18/2023]
Abstract
The pH homeostasis of endomembranes is essential for cellular functions. In order to provide direct pH measurements in the endomembrane system lumen, we targeted genetically encoded ratiometric pH sensors to the cytosol, the endoplasmic reticulum, and the trans-Golgi, or the compartments labeled by the vacuolar sorting receptor (VSR), which includes the trans-Golgi network and prevacuoles. Using noninvasive live-cell imaging to measure pH, we show that a gradual acidification from the endoplasmic reticulum to the lytic vacuole exists, in both tobacco (Nicotiana tabacum) epidermal (ΔpH -1.5) and Arabidopsis thaliana root cells (ΔpH -2.1). The average pH in VSR compartments was intermediate between that of the trans-Golgi and the vacuole. Combining pH measurements with in vivo colocalization experiments, we found that the trans-Golgi network had an acidic pH of 6.1, while the prevacuole and late prevacuole were both more alkaline, with pH of 6.6 and 7.1, respectively. We also showed that endosomal pH, and subsequently vacuolar trafficking of soluble proteins, requires both vacuolar-type H(+) ATPase-dependent acidification as well as proton efflux mediated at least by the activity of endosomal sodium/proton NHX-type antiporters.
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Affiliation(s)
- Alexandre Martinière
- Biochemistry and Plant Molecular Biology Lab, Unité Mixte de Recherche 5004, 34060 Montpellier, France
| | - Elias Bassil
- Department of Plant Sciences, University of California, Davis, California 95616
| | - Elodie Jublanc
- Institut National de la Recherche Agronomique, Unité Mixte de Recherche 866, Dynamique Musculaire et Métabolisme, 34060 Montpellier, France
| | - Carine Alcon
- Biochemistry and Plant Molecular Biology Lab, Unité Mixte de Recherche 5004, 34060 Montpellier, France
| | - Maria Reguera
- Department of Plant Sciences, University of California, Davis, California 95616
| | - Hervé Sentenac
- Biochemistry and Plant Molecular Biology Lab, Unité Mixte de Recherche 5004, 34060 Montpellier, France
| | - Eduardo Blumwald
- Department of Plant Sciences, University of California, Davis, California 95616
| | - Nadine Paris
- Biochemistry and Plant Molecular Biology Lab, Unité Mixte de Recherche 5004, 34060 Montpellier, France
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15
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Lü P, Xia H, Gao L, Pan Y, Wang Y, Cheng X, Lü H, Lin F, Chen L, Yao Q, Liu X, Tang Q, Chen K. V-ATPase Is Involved in Silkworm Defense Response against Bombyx mori Nucleopolyhedrovirus. PLoS One 2013; 8:e64962. [PMID: 23823190 PMCID: PMC3688796 DOI: 10.1371/journal.pone.0064962] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2012] [Accepted: 04/23/2013] [Indexed: 11/29/2022] Open
Abstract
Silkworms are usually susceptible to the infection of Bombyx mori (B. mori) nucleopolyhedrovirus (BmNPV), which can cause significant economic loss. However, some silkworm strains are identified to be highly resistant to BmNPV. To explore the silkworm genes involved in this resistance in the present study, we performed comparative real-time PCR, ATPase assay, over-expression and sub-cellular localization experiments. We found that when inoculated with BmNPV both the expression and activity of V-ATPase were significantly up-regulated in the midgut column cells (not the goblet cells) of BmNPV-resistant strains (NB and BC8), the main sites for the first step of BmNPV invasion, but not in those of a BmNPV-susceptible strain 306. Furthermore, this up-regulation mainly took place during the first 24 hours post inoculation (hpi), the essential period required for establishment of virus infection, and then was down-regulated to normal levels. Amazingly, transient over-expression of V-ATPase c subunit in BmNPV-infected silkworm cells could significantly inhibit BmNPV proliferation. To our knowledge this is the first report demonstrating clearly that V-ATPase is indeed involved in the defense response against BmNPV. Our data further suggests that prompt and potent regulation of V-ATPase may be essential for execution of this response, which may enable fast acidification of endosomes and/or lysosomes to render them competent for degradation of invading viruses.
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Affiliation(s)
- Peng Lü
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang, Jiangsu, PR China
- Institute of Life Sciences, Jiangsu University, Zhenjiang, Jiangsu, PR China
| | - Hengchuan Xia
- Institute of Life Sciences, Jiangsu University, Zhenjiang, Jiangsu, PR China
| | - Lu Gao
- School of Medical Science and Laboratory Medicine, Jiangsu University, Zhenjiang, Jiangsu, PR China
| | - Ye Pan
- The Laboratory Animal Research Center, Jiangsu University, Zhenjiang, Jiangsu, PR China
| | - Yong Wang
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang, Jiangsu, PR China
| | - Xin Cheng
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang, Jiangsu, PR China
- Nanchang Key Laboratory of Applied Fermentation Technology, Jiangxi Agricultural University, Nanchang, PR China
| | - Honggang Lü
- Institute of Life Sciences, Jiangsu University, Zhenjiang, Jiangsu, PR China
| | - Feng Lin
- Zhejiang Institute of Freshwater Fisheries, Huzhou, Zhejiang, PR China
| | - Liang Chen
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang, Jiangsu, PR China
| | - Qin Yao
- Institute of Life Sciences, Jiangsu University, Zhenjiang, Jiangsu, PR China
| | - Xiaoyong Liu
- Institute of Life Sciences, Jiangsu University, Zhenjiang, Jiangsu, PR China
| | - Qi Tang
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang, Jiangsu, PR China
| | - Keping Chen
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang, Jiangsu, PR China
- Institute of Life Sciences, Jiangsu University, Zhenjiang, Jiangsu, PR China
- * E-mail:
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16
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Dong QL, Wang CR, Liu DD, Hu DG, Fang MJ, You CX, Yao YX, Hao YJ. MdVHA-A encodes an apple subunit A of vacuolar H(+)-ATPase and enhances drought tolerance in transgenic tobacco seedlings. J Plant Physiol 2013; 170:601-9. [PMID: 23399407 DOI: 10.1016/j.jplph.2012.12.014] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2012] [Revised: 11/29/2012] [Accepted: 12/04/2012] [Indexed: 05/04/2023]
Abstract
Vacuole H(+)-ATPases (VHAs) are plant proton pumps, which play a crucial role in plant growth and stress tolerance. In the present study, we demonstrated that the apple vacuolar H(+)-ATPase subunit A (MdVHA-A) is highly conserved with subunit A of VHA (VHA-A) proteins from other plant species. MdVHA-A was expressed in vegetative and reproductive organs. In apple in vitro shoot cultures, expression was induced by polyethylene glycol (PEG)-mediated osmotic stress. We further verified that over-expression of MdVHA-A conferred transgenic tobacco seedlings with enhanced vacuole H+-ATPase (VHA) activity and improved drought tolerance. The enhanced PEG-mimic drought response of transgenic tobacco seedlings was related to an extended lateral root system (dependent on auxin translocation) and more efficient osmotic adjustment. Our results indicate that MdVHA-A is a candidate gene for improving drought tolerance in plants.
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Affiliation(s)
- Qing-Long Dong
- State Key Laboratory of Crop Biology, National Research Center for Apple Engineering and Technology, College of Horticulture Science and Engineering, Shandong Agricultural University, Tai'an, Shandong 271018, China; Shandong Institute of Pomology, Tai'an, Shandong 271000, China
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17
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Abstract
Vacuolar (H(+) )-ATPase (V-ATPase) functions as an electrogenic pump, transporting protons from the cytoplasm to the extracellular fluid to generate cell-negative membrane voltage. The V-ATPase subunit H, encoded by Vhasfd, is required for V-ATPase activity. In this study, the gene encoding V-ATPase subunit H from Locusta migratoria manilensis was cloned, and designated as Lm-Vhasfd. The complete cDNA sequence is 2018 bp, with an open reading frame encoding 515 amino acid residues. Semi-quantitative reverse transcription PCR (RT-PCR) showed that Lm-Vhasfd transcription is high in the haemolymph, midgut, trunk and leg, but relatively low in the fat body and head tissues. Injection with a specific double-strand RNA (dsRNA) led to a significant decrease in Lm-Vhasfd mRNA, V-ATPase enzyme activity and ATP concentration. Bioassays showed that silencing Lm-Vhasfd led to the death of individuals and various moulting defects. The accumulative mortality of the RNA interference (RNAi) mutant 11 days post-injection was 96.7%, which was conspicuously higher than that seen in wild type locusts. These RNAi phenotypes demonstrate that Lm-Vhasfd is essential for the growth and moulting of L. migratoria manilensis.
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Affiliation(s)
- C Li
- Genetic Engineering Research Center, School of Bioengineering, Chongqing Engineering Research Center for Fungal Insecticide, The Key Laboratory of Gene Function and Expression Regulation, Chongqing University, Chongqing, China
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18
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Hasegawa T, Konno M, Baba T, Sugeno N, Kikuchi A, Kobayashi M, Miura E, Tanaka N, Tamai K, Furukawa K, Arai H, Mori F, Wakabayashi K, Aoki M, Itoyama Y, Takeda A. The AAA-ATPase VPS4 regulates extracellular secretion and lysosomal targeting of α-synuclein. PLoS One 2011; 6:e29460. [PMID: 22216284 PMCID: PMC3245276 DOI: 10.1371/journal.pone.0029460] [Citation(s) in RCA: 115] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2011] [Accepted: 11/29/2011] [Indexed: 11/18/2022] Open
Abstract
Many neurodegenerative diseases share a common pathological feature: the deposition of amyloid-like fibrils composed of misfolded proteins. Emerging evidence suggests that these proteins may spread from cell-to-cell and encourage the propagation of neurodegeneration in a prion-like manner. Here, we demonstrated that α-synuclein (αSYN), a principal culprit for Lewy pathology in Parkinson's disease (PD), was present in endosomal compartments and detectably secreted into the extracellular milieu. Unlike prion protein, extracellular αSYN was mainly recovered in the supernatant fraction rather than in exosome-containing pellets from the neuronal culture medium and cerebrospinal fluid. Surprisingly, impaired biogenesis of multivesicular body (MVB), an organelle from which exosomes are derived, by dominant-negative mutant vacuolar protein sorting 4 (VPS4) not only interfered with lysosomal targeting of αSYN but facilitated αSYN secretion. The hypersecretion of αSYN in VPS4-defective cells was efficiently restored by the functional disruption of recycling endosome regulator Rab11a. Furthermore, both brainstem and cortical Lewy bodies in PD were found to be immunoreactive for VPS4. Thus, VPS4, a master regulator of MVB sorting, may serve as a determinant of lysosomal targeting or extracellular secretion of αSYN and thereby contribute to the intercellular propagation of Lewy pathology in PD.
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Affiliation(s)
- Takafumi Hasegawa
- Division of Neurology, Department of Neuroscience & Sensory Organs, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan.
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19
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Henriksen K, Flores C, Thomsen JS, Brüel AM, Thudium CS, Neutzsky-Wulff AV, Langenbach GEJ, Sims N, Askmyr M, Martin TJ, Everts V, Karsdal MA, Richter J. Dissociation of bone resorption and bone formation in adult mice with a non-functional V-ATPase in osteoclasts leads to increased bone strength. PLoS One 2011; 6:e27482. [PMID: 22087326 PMCID: PMC3210177 DOI: 10.1371/journal.pone.0027482] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2011] [Accepted: 10/17/2011] [Indexed: 01/23/2023] Open
Abstract
Osteopetrosis caused by defective acid secretion by the osteoclast, is characterized by defective bone resorption, increased osteoclast numbers, while bone formation is normal or increased. In contrast the bones are of poor quality, despite this uncoupling of formation from resorption.To shed light on the effect of uncoupling in adult mice with respect to bone strength, we transplanted irradiated three-month old normal mice with hematopoietic stem cells from control or oc/oc mice, which have defective acid secretion, and followed them for 12 to 28 weeks.Engraftment levels were assessed by flow cytometry of peripheral blood. Serum samples were collected every six weeks for measurement of bone turnover markers. At termination bones were collected for µCT and mechanical testing. An engraftment level of 98% was obtained. From week 6 until termination bone resorption was significantly reduced, while the osteoclast number was increased when comparing oc/oc to controls. Bone formation was elevated at week 6, normalized at week 12, and reduced onwards. µCT and mechanical analyses of femurs and vertebrae showed increased bone volume and bone strength of cortical and trabecular bone.In conclusion, these data show that attenuation of acid secretion in adult mice leads to uncoupling and improves bone strength.
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Qin A, Cheng TS, Lin Z, Pavlos NJ, Jiang Q, Xu J, Dai KR, Zheng MH. Versatile roles of V-ATPases accessory subunit Ac45 in osteoclast formation and function. PLoS One 2011; 6:e27155. [PMID: 22087256 PMCID: PMC3210823 DOI: 10.1371/journal.pone.0027155] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2011] [Accepted: 10/11/2011] [Indexed: 11/25/2022] Open
Abstract
Vacuolar-type H(+)-ATPases (V-ATPases) are macromolecular proton pumps that acidify intracellular cargos and deliver protons across the plasma membrane of a variety of specialized cells, including bone-resorbing osteoclasts. Extracellular acidification is crucial for osteoclastic bone resorption, a process that initiates the dissolution of mineralized bone matrix. While the importance of V-ATPases in osteoclastic resorptive function is well-defined, whether V-ATPases facilitate additional aspects of osteoclast function and/or formation remains largely obscure. Here we report that the V-ATPase accessory subunit Ac45 participates in both osteoclast formation and function. Using a siRNA-based approach, we show that targeted suppression of Ac45 impairs intracellular acidification and endocytosis, both are prerequisite for osteoclastic bone resorptive function in vitro. Interestingly, we find that knockdown of Ac45 also attenuates osteoclastogenesis owing to a reduced fusion capacity of osteoclastic precursor cells. Finally, in an effort to gain more detailed insights into the functional role of Ac45 in osteoclasts, we attempted to generate osteoclast-specific Ac45 conditional knockout mice using a Cathepsin K-Cre-LoxP system. Surprisingly, however, insertion of the neomycin cassette in the Ac45-Flox(Neo) mice resulted in marked disturbances in CNS development and ensuing embryonic lethality thus precluding functional assessment of Ac45 in osteoclasts and peripheral bone tissues. Based on these unexpected findings we propose that, in addition to its canonical function in V-ATPase-mediated acidification, Ac45 plays versatile roles during osteoclast formation and function.
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Affiliation(s)
- An Qin
- Shanghai Key Laboratory of Orthopaedic Implant, Department of Orthopaedics, Shanghai Jiao Tong University School of Medicine, Ninth People's Hospital, Shanghai, The People's Republic of China
- Centre for Orthopaedic Research, School of Surgery, The University of Western Australia, Perth, Australia
| | - Tak S. Cheng
- Centre for Orthopaedic Research, School of Surgery, The University of Western Australia, Perth, Australia
| | - Zhen Lin
- Centre for Orthopaedic Research, School of Surgery, The University of Western Australia, Perth, Australia
- Division of Orthopaedic, Department of Surgery, Guangdong Academy of Medical Sciences, Guangdong General Hospital, Guangdong, The People's Republic of China
| | - Nathan J. Pavlos
- Centre for Orthopaedic Research, School of Surgery, The University of Western Australia, Perth, Australia
| | - Qing Jiang
- Australian-China Joint Centre for Bone and Joint Research, Model Animal Research Centre of Nanjing University, Nanjing, The People's Republic of China
- The Center of Diagnosis and Treatment for Joint Disease, Drum Tower Hospital Affiliated to Medical School of Nanjing University, Nanjing, The People's Republic of China
| | - Jiake Xu
- School of Pathology and Laboratory Medicine, The University of Western Australia, Perth, Australia
| | - Ke R. Dai
- Shanghai Key Laboratory of Orthopaedic Implant, Department of Orthopaedics, Shanghai Jiao Tong University School of Medicine, Ninth People's Hospital, Shanghai, The People's Republic of China
- Orthopaedic Cellular and Molecular Biology Laboratory, Institute of Health Sciences, School of Medicine, Chinese Academy of Sciences, Shanghai Jiao Tong University, Shanghai, The People's Republic of China
| | - Ming H. Zheng
- Centre for Orthopaedic Research, School of Surgery, The University of Western Australia, Perth, Australia
- Australian-China Joint Centre for Bone and Joint Research, Model Animal Research Centre of Nanjing University, Nanjing, The People's Republic of China
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21
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Kinouchi K, Ichihara A, Ito H. [(Pro)renin receptor /ATP6AP2 and cell death]. Nihon Jinzo Gakkai Shi 2011; 53:996-999. [PMID: 22073862] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
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22
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Seki G, Horita S, Suzuki M, Yamada H. [Renal tubular acidosis]. Nihon Jinzo Gakkai Shi 2011; 53:173-176. [PMID: 21516702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
MESH Headings
- Acidosis, Renal Tubular/genetics
- Amino Acid Transport Systems, Neutral/genetics
- Amino Acid Transport Systems, Neutral/physiology
- Anion Exchange Protein 1, Erythrocyte/genetics
- Anion Exchange Protein 1, Erythrocyte/physiology
- Fanconi Syndrome/etiology
- Genes, Recessive
- Humans
- Lysosomes/metabolism
- Mutation
- Sodium-Bicarbonate Symporters/genetics
- Sodium-Bicarbonate Symporters/physiology
- Sodium-Phosphate Cotransporter Proteins, Type IIa/genetics
- Sodium-Phosphate Cotransporter Proteins, Type IIa/physiology
- Sodium-Phosphate Cotransporter Proteins, Type IIc/genetics
- Sodium-Phosphate Cotransporter Proteins, Type IIc/physiology
- Vacuolar Proton-Translocating ATPases/genetics
- Vacuolar Proton-Translocating ATPases/physiology
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23
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Carraro-Lacroix LR, Malnic G. Acid-base transport by the renal distal nephron. J Nephrol 2010; 23 Suppl 16:S19-S27. [PMID: 21170879] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/01/2010] [Indexed: 05/30/2023]
Abstract
The functional versatility of the distal nephron is mainly due to the large cytological heterogeneity of the segment. Part of Na+ uptake by distal tubules is dependent on Na+/H+ exchanger 2 (NHE2), implicating a role of distal convoluted cells also in acid-base homeostasis. In addition, intercalated (IC) cells expressed in distal convoluted tubules, connecting tubules and collecting ducts are involved in the final regulation of acid-base excretion. IC cells regulate acid-base handling by 2 main transport proteins, a V-type H+-ATPase and a Cl/HCO3- exchanger, localized at different membrane domains. Type A IC cells are characterized by a luminal H+-ATPase in series with a basolateral Cl/HCO3- exchanger, the anion exchanger AE1. Type B IC cells mediate HCO3- secretion through the apical Cl-/HCO3- exchanger pendrin in series with a H+-ATPase at the basolateral membrane. Alternatively, H+/K+-ATPases have also been found in several distal tubule cells, particularly in type A and B IC cells. All of these mechanisms are finely regulated, and mutations of 1 or more proteins ultimately lead to expressive disorders of acid-base balance.
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Affiliation(s)
- Luciene R Carraro-Lacroix
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
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Ichihara A, Ito H. [Prorenin/renin and the (pro) renin receptor in the kidney]. Nihon Jinzo Gakkai Shi 2010; 52:106-109. [PMID: 20415229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
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Slabý A, Zák A. [Renin, prorenin, and the direct renin inhibitor aliskiren]. Cas Lek Cesk 2010; 149:55-60. [PMID: 20662466] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The renin-angiotensin system plays an important role in various physiological and pathophysiological regulatory mechanisms. Within the past few years, the classical concept of a linear enzymatic cascade has experienced substantial changes. A parallel counterregulatory axis has been identified which involves the angiotensin converting enzyme homologue ACE2, angiotensin (1-7), and receptors Mas. The research in prorenin and its non-proteolytic activation has greatly advanced after the discovery of cellular receptors (P)RR; binding of renin or prorenin to these receptors not only facilitates angiotensin generation, but at the same time activates specific signal transduction pathways. The long-term search for clinically useful direct renin inhibitors has recently succeeded with the new antihypertensive drug aliskiren. While beneficial effects of aliskiren on some markers of cardiovascular and renal diseases have been proved in large clinical studies, important questions remain to be solved.
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Affiliation(s)
- Adolf Slabý
- Univerzita Karlova v Praze, 1. lékarská fakulta, IV. Interní klinika VFN.
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Murata T. [Towards structure-based design of novel inhibitors for V-ATPase]. Tanpakushitsu Kakusan Koso 2009; 54:1654-1659. [PMID: 21089603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
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Morissette G, Ammoury A, Rusu D, Marguery MC, Lodge R, Poubelle PE, Marceau F. Intracellular sequestration of amiodarone: role of vacuolar ATPase and macroautophagic transition of the resulting vacuolar cytopathology. Br J Pharmacol 2009; 157:1531-40. [PMID: 19594752 PMCID: PMC2765325 DOI: 10.1111/j.1476-5381.2009.00320.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2009] [Accepted: 03/31/2009] [Indexed: 01/20/2023] Open
Abstract
BACKGROUND AND PURPOSE Tissue deposits of the anti-arrhythmic drug amiodarone are a major source of side effects (skin discoloration, etc.). We addressed the mechanism of the concentration of amiodarone in cells, and characterized the resulting vacuolar cytopathology and its evolution towards macroautophagy. EXPERIMENTAL APPROACH Sequestration of amiodarone in human cells (macrophages, smooth muscle cells, HEK 293a cells) was evaluated using its violet fluorescence and cytopathology using GFP-conjugated subcellular markers. Autophagic signalling was probed by immunoblotting for the effector protein LC3. A patient biopsy of amiodarone-induced blue-gray skin discoloration was investigated for the presence of macroautophagy (immunofluorescence for LC3). KEY RESULTS Most of the amiodarone (1-20 microM, 4-24 h) captured by cultured cells (macrophages were most avid) was present in enlarged vacuoles. The specific vacuolar ATPase (V-ATPase) inhibitors, bafilomycin A1 or FR167356, prevented vacuolization and drug uptake. Vacuoles in HEK 293a cells were positive for markers of late endosomes and lysosomes (GFP-Rab7, -CD63) and for an effector of macroautophagy, GFP-LC3. The vacuoles accumulated endogenous LC3 and filled with lipids (Nile red staining) following longer amiodarone treatments (> or =24 h). The electrophoretic mobility of both GFP-LC3 and endogenous LC3 changed, showing activation in response to amiodarone. Paraffin tissue sections of the pigmented skin exhibited granular LC3 accumulation in superficial dermis macrophages. CONCLUSION AND IMPLICATIONS Vacuolar sequestration of amiodarone occurs at concentrations close to therapeutic levels, is mediated by V-ATPase and evolves towards persistent macroautophagy and phospholipidosis. This cytopathology is not cell type specific, but tissue macrophages appear to be particularly susceptible.
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Affiliation(s)
- G Morissette
- Centre de Recherche en Rhumatologie et Immunologie, Centre Hospitalier Universitaire de Québec, Québec QC, Canada
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Watanabe T, Sakurai A, Kawaoka Y. [Identification of host factors involved in influenza virus replication]. Tanpakushitsu Kakusan Koso 2009; 54:920-925. [PMID: 21089518] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
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Abstract
Background Growth and division of Saccharomyces cerevisiae is dependent on the action of SNARE proteins that are required for membrane fusion. SNAREs are regulated, through a poorly understood mechanism, to ensure membrane fusion at the correct time and place within a cell. Although fusion of secretory vesicles with the plasma membrane is important for yeast cell growth, the relationship between exocytic SNAREs and cell physiology has not been established. Methodology/Principal Findings Using genetic analysis, we identified several influences on the function of exocytic SNAREs. Genetic disruption of the V-ATPase, but not vacuolar proteolysis, can suppress two different temperature-sensitive mutations in SEC9. Suppression is unlikely due to increased SNARE complex formation because increasing SNARE complex formation, through overexpression of SRO7, does not result in suppression. We also observed suppression of sec9 mutations by growth on alkaline media or on a non-fermentable carbon source, conditions associated with a reduced growth rate of wild-type cells and decreased SNARE complex formation. Conclusions/Significance Three main conclusions arise from our results. First, there is a genetic interaction between SEC9 and the V-ATPase, although it is unlikely that this interaction has functional significance with respect to membrane fusion or SNAREs. Second, Sro7p acts to promote SNARE complex formation. Finally, Sec9p function and SNARE complex formation are tightly coupled to the physiological state of the cell.
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Affiliation(s)
- Daniel C. Williams
- Department of Cell Biology, Yale University School of Medicine, New Haven, Connecticut, United States of America
| | - Peter J. Novick
- Department of Cell Biology, Yale University School of Medicine, New Haven, Connecticut, United States of America
- * E-mail:
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Yamamoto A. [Electron microscope as "Dokodemo door" in bioscience]. Tanpakushitsu Kakusan Koso 2008; 53:2231-2237. [PMID: 21038614] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
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Jefferies KC, Cipriano DJ, Forgac M. Function, structure and regulation of the vacuolar (H+)-ATPases. Arch Biochem Biophys 2008; 476:33-42. [PMID: 18406336 PMCID: PMC2543942 DOI: 10.1016/j.abb.2008.03.025] [Citation(s) in RCA: 179] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2008] [Revised: 03/05/2008] [Accepted: 03/07/2008] [Indexed: 02/07/2023]
Abstract
The vacuolar ATPases (or V-ATPases) are ATP-driven proton pumps that function to both acidify intracellular compartments and to transport protons across the plasma membrane. Intracellular V-ATPases function in such normal cellular processes as receptor-mediated endocytosis, intracellular membrane traffic, prohormone processing, protein degradation and neurotransmitter uptake, as well as in disease processes, including infection by influenza and other viruses and killing of cells by anthrax and diphtheria toxin. Plasma membrane V-ATPases are important in such physiological processes as urinary acidification, bone resorption and sperm maturation as well as in human diseases, including osteopetrosis, renal tubular acidosis and tumor metastasis. V-ATPases are large multi-subunit complexes composed of a peripheral domain (V(1)) responsible for hydrolysis of ATP and an integral domain (V(0)) that carries out proton transport. Proton transport is coupled to ATP hydrolysis by a rotary mechanism. V-ATPase activity is regulated in vivo using a number of mechanisms, including reversible dissociation of the V(1) and V(0) domains, changes in coupling efficiency of proton transport and ATP hydrolysis and changes in pump density through reversible fusion of V-ATPase containing vesicles. V-ATPases are emerging as potential drug targets in treating a number of human diseases including osteoporosis and cancer.
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Affiliation(s)
| | | | - Michael Forgac
- Department of Physiology, Tufts University School of Medicine, 136 Harrison Ave., Boston, MA 02111
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Fang J, Rohloff P, Miranda K, Docampo R. Ablation of a small transmembrane protein of Trypanosoma brucei (TbVTC1) involved in the synthesis of polyphosphate alters acidocalcisome biogenesis and function, and leads to a cytokinesis defect. Biochem J 2008; 407:161-70. [PMID: 17635107 PMCID: PMC2049025 DOI: 10.1042/bj20070612] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Inorganic poly P (polyphosphate) is an abundant component of acidocalcisomes of Trypanosoma brucei. In the present study we report the presence of a protein homologous with the yeast Vtc1p (vacuolar transporter chaperone 1) in T. brucei that is essential for poly P synthesis, acidocalcisome biogenesis and cytokinesis. Localization studies in a cell line expressing a TbVTC1 fused to GFP (green fluorescent protein) revealed its co-localization with the V-H+-PPase (vacuolar H+-pyrophosphatase), a marker for acidocalcisomes. Western blot analysis of acidocalcisome fractions and immunogold electron microscopy using polyclonal antibodies against a fragment of TbVTC1 confirmed the acidocalcisome localization. Ablation of TbVTC1 expression by RNA interference caused an abnormal morphology of acidocalcisomes, indicating that their biogenesis was disturbed, with a decreased pyrophosphate-driven H+ uptake and Ca2+ content, a significant decrease in the amount of poly P and a deficient response to hyposmotic stress. Ablation of TbVTC1 expression for longer periods produced marked gross morphological alterations compatible with a defect in cytokinesis, followed by cell death. Overexpression of the TbVTC1 gene caused mild alterations in growth rate, but had no perceptible effect on acidocalcisome morphology. We propose that the PP(i)-driven H+ pumping deficiency induced by ablation of TbVTC1 leads to alterations in the protonmotive force of acidocalcisomes, which results in deficient fusion or budding of the organelles, decreased H+ and Ca2+ content, and decreased synthesis of poly P. A decrease in the poly P content would lead to osmotic sensitivity and defects in cytokinesis.
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Affiliation(s)
- Jianmin Fang
- Center for Tropical and Emerging Global Disease and Department of Cellular Biology, University of Georgia, Athens, GA 30602, U.S.A
| | - Peter Rohloff
- Center for Tropical and Emerging Global Disease and Department of Cellular Biology, University of Georgia, Athens, GA 30602, U.S.A
| | - Kildare Miranda
- Center for Tropical and Emerging Global Disease and Department of Cellular Biology, University of Georgia, Athens, GA 30602, U.S.A
| | - Roberto Docampo
- Center for Tropical and Emerging Global Disease and Department of Cellular Biology, University of Georgia, Athens, GA 30602, U.S.A
- To whom correspondence should be addressed (email )
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Choi YO, Park JH, Song YS, Lee W, Moriyama Y, Choe H, Leem CH, Jang YJ. Involvement of vesicular H+-ATPase in insulin-stimulated glucose transport in 3T3-F442A adipocytes. Endocr J 2007; 54:733-43. [PMID: 17827791 DOI: 10.1507/endocrj.k07-090] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
In secretory cells, osmotic swelling of secretory granules is proposed to be an intermediate step in exocytic fusion of the granules with the plasma membrane. For osmotic swelling of the granule, a H (+) gradient generated by vacuolar-type H (+) -ATPase (V-ATPase) may be a driving force for accumulation of K (+) via its exchange with H (+) , concurrent with accumulation of Cl (-) and H(2)O. Here, we investigated whether a similar chemiosmotic mechanism is involved in the insulin-stimulated recruitment of GLUT4 to the plasma membrane in 3T3-F442A adipocytes. Incubating cells in a hypo-osmotic medium significantly increased 2-deoxy glucose (2-DG) uptake and the plasma membrane GLUT4 content (possibly via induction of osmotic swelling of GLUT4-containing vesicles (G4V)) and also potentiated the insulin-stimulated 2-DG uptake. Promotion of the G4V membrane ionic permeability using nigericin, an electroneutral K (+) /H (+) exchange ionophore, increased 2-DG uptake and the plasma membrane GLUT4 content. However, co-treatment with nigericin and insulin did not show an additive effect. Bafilomycin A(1), a diagnostically specific inhibitor of V-ATPase, inhibited insulin- and nigericin-stimulated 2-DG uptake. Immunoadsorption plus immunoblotting demonstrated that GLUT4 and V-ATPase co-localize in the same intracellular membranes. Together, these results indicate that V-ATPases in the G4V membrane may play an important role in the insulin-stimulated exocytic fusion of G4V with the plasma membrane via its participation in osmotic swelling of the vesicle.
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Affiliation(s)
- Young Ok Choi
- Department of Physiology, University of Ulsan College of Medicine, Seoul, Korea
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Cagnac O, Leterrier M, Yeager M, Blumwald E. Identification and Characterization of Vnx1p, a Novel Type of Vacuolar Monovalent Cation/H+ Antiporter of Saccharomyces cerevisiae. J Biol Chem 2007; 282:24284-93. [PMID: 17588950 DOI: 10.1074/jbc.m703116200] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We identified and characterized Vnx1p, a novel vacuolar monovalent cation/H+ antiporter encoded by the open reading frame YNL321w from Saccharomyces cerevisiae. Despite the homology of Vnx1p with other members of the CAX (calcium exchanger) family of transporters, Vnx1p is unable to mediate Ca2+ transport but is a low affinity Na+/H+ and K+/H+ anti-porter with a Km of 22.4 and 82.2 mm for Na+ and K+, respectively. Sequence analyses of Vnx1p revealed the absence of key amino acids shown to be essential for Ca2+/H+ exchange. vnx1Delta cells displayed growth inhibition when grown in the presence of hygromycin B or NaCl. Vnx1p activity was found in the vacuoles and shown to be dependent on the electrochemical potential gradient of H+ generated by the action of the V-type H+-ATPase. The presence of Vnx1p at the vacuolar membrane was further confirmed with cells expressing a VNX1::GFP chimeric gene. Similar to Nhx1p, the prevacuolar compartment-bound Na+/H+ antiporter, the vacuole-bound Vnx1p appears to play roles in the regulation of ion homeostasis and cellular pH.
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Affiliation(s)
- Olivier Cagnac
- Department of Plant Sciences, University of California, Davis, California 95616, USA
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Sun AQ, Ponamgi VM, Boyer JL, Suchy FJ. Membrane trafficking of the human organic anion-transporting polypeptide C (hOATPC). Pharm Res 2007; 25:463-74. [PMID: 17641954 DOI: 10.1007/s11095-007-9399-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2007] [Accepted: 05/03/2007] [Indexed: 12/19/2022]
Abstract
INTRODUCTION The human organic anion transporting polypeptide C (OATPC) is one of the major transport proteins involved in the enterohepatic circulation of bile salts and plays an important role in vectorial transport of organic anions and drugs across hepatocytes. MATERIALS AND METHODS In this study, the effects of biological reagents on the membrane localization of OATPC were investigated by confocal microscopy and estrone-3-sulfate transport. RESULTS Our results demonstrated that the functional membrane expression of fluorescent chimera OATPC-GFP was achieved in non-polarized (COS7 and HEK293) and polarized (MDCK) cells. Both brefeldin A (a Golgi complex disruptor) and bafilomycin A1 (an inhibitor of vacuolar H+-ATPase) treatment significantly decreased the polarized membrane trafficking and markedly reduced the uptake of estrone-3-sulfate ( approximately 40-90%) in OATPC-GFP transfected cells, suggesting that membrane sorting of hOATPC-GFP was mediated by Golgi complex and vacuolar H+-ATPase-related vesicle transport pathways. Treatment with 8-Br-cAMP (a cAMP analog) stimulated OATPC-GFP membrane localization and enhanced estrone-3-sulfate uptake by approximately 20%. The protein kinase A (PKA) inhibitors (H89 and KT5720), but not a PKG inhibitor, blocked the polarized membrane expression of OATPC-GFP and reduced estrone-3-sulfate transport activity. The simultaneous treatment of cells with PKA activator/inhibitor and bafilomycin A1 demonstrated that bafilomycin A1 did not change the effects of 8-Br-cAMP and H89 on the membrane localization of OATPC-GFP compared with the use of 8-Br-cAMP and H89 alone. DISCUSSION These data suggest that a cAMP-PKA sensitive membrane sorting pathway for OATPC-GFP is independent of the vacuolar H+-ATPase associated (bafilomycin A1 sensitive) vesicle mediated membrane sorting pathway. In contrast, with combined treatment with brefeldin A, neither the PKA-activator (8-Br-cAMP) nor the inhibitor (H89) further altered the plasma membrane expression and transport activity of OATPC-GFP compared with brefeldin A treatment alone. These data suggest that the cAMP-PKA regulation of OATPC membrane expression involves the Golgi complex. When the Golgi apparatus was disrupted by brefeldin A treatment, the effects of cAMP-PKA on the Golgi-to-basolateral surface sorting process of OATPC was also diminished. In summary, the plasma membrane localization of human OATPC is mediated by Golgi complex and vacuolar H+-ATPase vesicle mediated membrane sorting pathways. cAMP-PKA regulates sorting process through the Golgi complex but not the vacuolar H+-ATPase associated vesicular pathway.
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Affiliation(s)
- An-Qiang Sun
- Department of Pediatrics, Mount Sinai School of Medicine, PO Box 1664, One Gustave L. Levy Place, New York, NY 10029-6574, USA.
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Nakanishi-Matsui M, Fujii-Taira I, Futai M. [Proton pumping ATPases: from single molecule analysis to diverse biological functions]. Seikagaku 2007; 79:512-9. [PMID: 17663154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Affiliation(s)
- Mayumi Nakanishi-Matsui
- Faculty of Pharmaceutical Sciences, Iwate Medical University, 2-1-1 Nishi-tokuta, Yahaba, Iwate 028-3694, Japan
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Imamura H, Yokoyama K. [Two rotary molecular motors, V-ATPase and F0F1]. Seikagaku 2007; 79:425-37. [PMID: 17571591] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Affiliation(s)
- Hiromi Imamura
- Institute of Scientific and Industrial Research, Osaka University, Ibaraki, Japan
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Noji H. [Nanoscience in rotary molecular motor proteins]. Tanpakushitsu Kakusan Koso 2007; 52:297-300. [PMID: 17419447] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
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Murata T, Yamato I, Kakinuma Y, Yokoyama K. [Unveiled multifunctionality of V-ATPase and the molecular mechanism revealed by X-ray crystal structures]. Tanpakushitsu Kakusan Koso 2007; 52:335-41. [PMID: 17419453] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
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Affiliation(s)
- Ira Mellman
- Department of Cell Biology, Ludwig Institute for Cancer Research, Yale University School of Medicine, 333 Cedar Street, PO Box 208002, New Haven, Connecticut 06520-8002, USA.
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Rizzo JM, Tarsio M, Martínez-Muñoz GA, Kane PM. Diploids heterozygous for a vma13Delta mutation in Saccharomyces cerevisiae highlight the importance of V-ATPase subunit balance in supporting vacuolar acidification and silencing cytosolic V1-ATPase activity. J Biol Chem 2007; 282:8521-32. [PMID: 17234635 DOI: 10.1074/jbc.m607092200] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The V-ATPase H subunit (encoded by the VMA13 gene) activates ATP-driven proton pumping in intact V-ATPase complexes and inhibits MgATPase activity in cytosolic V1 sectors (Parra, K. J., Keenan, K. L., and Kane, P. M. (2000) J. Biol. Chem. 275, 21761-21767). Yeast diploids heterozygous for a vma13Delta mutation show the pH- and calcium-dependent conditional lethality characteristic of mutants lacking V-ATPase activity, although they still contain one wild-type copy of VMA13. Vacuolar vesicles from this strain have approximately 50% of the ATPase activity of those from a wild-type diploid but do not support formation of a proton gradient. Compound heterozygotes with a second heterozygous deletion in another V1 subunit gene exhibit improved growth, vacuolar acidification, and ATP-driven proton transport in vacuolar vesicles. In contrast, compound heterozygotes with a second deletion in a Vo subunit grow even more poorly than the vma13Delta heterozygote, have very little vacuolar acidification, and have very low levels of V-ATPase subunits in isolated vacuoles. In addition, cytosolic V1 sectors from this strain and from the strain containing only the heterozygous vma13Delta mutation have elevated MgATPase activity. The results suggest that balancing levels of subunit H with those of other V-ATPase subunits is critical, both for allowing organelle acidification and for preventing unproductive hydrolysis of cytosolic ATP.
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Affiliation(s)
- Jason M Rizzo
- Department of Biochemistry and Molecular Biology, State University of New York Upstate Medical University, Syracuse, New York 13210, USA
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Abstract
Yeast mutants lacking vacuolar proton-translocating ATPase (V-ATPase) subunits (vma mutants) were sensitive to several different oxidants in a recent genomic screen (Thorpe, G. W., Fong, C. S., Alic, N., Higgins, V. J., and Dawes, I. W. (2004) Proc. Natl. Acad. Sci. U. S. A. 101, 6564-6569). We confirmed that mutants lacking a V(1) subunit (vma2Delta), V(o) subunit, or either of the two V(o) a subunit isoforms are acutely sensitive to H(2)O(2) and more sensitive to menadione and diamide than wild-type cells. The vma2Delta mutant contains elevated levels of reactive oxygen species and high levels of oxidative protein damage even in the absence of an applied oxidant, suggesting an endogenous source of oxidative stress. vma2Delta mutants lacking mitochondrial DNA showed neither improved growth nor decreased sensitivity to peroxide, excluding respiration as the major source of the endogenous reactive oxygen species in the mutant. Double mutants lacking both VMA2 and components of the major cytosolic defense systems exhibited synthetic sensitivity to H(2)O(2). Microarray analysis comparing wild-type and vma2Delta mutant cells grown at pH 5, permissive conditions for the vma2Delta mutant, indicated high level up-regulation of several iron uptake and metabolism genes that are part of the Aft1/Aft2 regulon. TSA2, which encodes an isoform of the cytosolic thioredoxin peroxidase, was strongly induced, but other oxidative stress defense systems were not induced. The results indicate that V-ATPase activity helps to protect cells from endogenous oxidative stress.
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Affiliation(s)
- Elena Milgrom
- Department of Biochemistry, SUNY Upstate Medical University, Syracuse, New York 13210, USA
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Bulwin GC, Heinemann T, Bugge V, Winter M, Lohan A, Schlawinsky M, Schulze A, Wälter S, Sabat R, Schülein R, Wiesner B, Veh RW, Löhler J, Blumberg RS, Volk HD, Utku N. TIRC7 inhibits T cell proliferation by modulation of CTLA-4 expression. J Immunol 2007; 177:6833-41. [PMID: 17082597 DOI: 10.4049/jimmunol.177.10.6833] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Ab targeting of TIRC7 has been shown previously to inhibit T cell proliferation and Th1 lymphocyte-associated cytokine production. In this study, we demonstrate that Ab targeting of TIRC7 induces early cell surface expression of CTLA-4. The majority of stimulated CD4+ and CD8+ human T cells coexpress CTLA-4 and TIRC7. Similar to CTLA-4, TIRC7 rapidly accumulates at the site of Ag adhesion upon T cell activation. TIRC7 seems to colocalize with CTLA-4 in human T cells, and both molecules are associated with clathrin-coated vesicles, indicating they share intracellular transport systems. Moreover, Ab targeting of TIRC7 results in an early activation of CTLA-4 transcription. The inhibition of cell proliferation mediated by TIRC7 is dependent on CTLA-4 expression because the TIRC7-mediated inhibitory effects on cell proliferation and cytokine expression are abolished by Ab blockade of CTLA-4. Splenocytes obtained from CTLA-4-deficient mice are not responsive to TIRC7 Ab targeting. Thus, TIRC7 acts as an upstream regulatory molecule of CTLA-4 expression.
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Affiliation(s)
- Grit-Carsta Bulwin
- Institut für Medizinische Immunologie, Campus Charité Mitte, Humboldt-Universität zu Berlin, Berlin, Germany
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Hiruma H, Katakura T, Takenami T, Igawa S, Kanoh M, Fujimura T, Kawakami T. Vesicle disruption, plasma membrane bleb formation, and acute cell death caused by illumination with blue light in acridine orange-loaded malignant melanoma cells. Journal of Photochemistry and Photobiology B: Biology 2007; 86:1-8. [PMID: 16982198 DOI: 10.1016/j.jphotobiol.2006.08.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2006] [Revised: 08/03/2006] [Accepted: 08/04/2006] [Indexed: 11/17/2022]
Abstract
Acridine orange (AO), a weakly basic fluorescent dye, is permeable to plasma and vesicle membranes and preferentially remains in intracellular acidic regions. Using fluorescence microscopy, we observed dynamic changes in AO-loaded cultured malignant melanoma cells during illumination with blue light. Immediately after the start of the illumination, the successive disruption of vesicles was observed as a flash of fluorescence, and shortly after that, blebs were formed on the plasma membrane. These cells died within 5 min. Vesicle disruption was completely inhibited when cells were treated with the vacuolar H(+)-ATPase inhibitor bafilomycin A1 followed by loading with AO, but not when bafilomycin A1 was treated after AO loading. Thus, the filling of AO in the vesicle, which is driven by vacuolar H(+)-ATPase, is initially required for vesicle disruption. In contrast, bafilomycin A1 did not prevent plasma membrane blebbing, indicating that the blebs are formed independently of the vesicle disruption. Acute cell death was inhibited by treatment with bafilomycin A1 before but not after AO loading. Thus, AO- and blue light-induced acute cell death is associated with vesicle disruption rather than bleb formation. Both the vesicle disruption and the formation of plasma membrane blebs were inhibited by removal of oxygen from the cell environment and by singlet oxygen scavengers, sodium azide, ascorbic acid, and L-histidine, but not inhibited by the hydroxyl radical scavenger dimethyl thiourea. Acute cell death was also prevented by singlet oxygen scavengers but not by dimethyl thiourea. Thus, these phenomena are likely caused at least in part by the generation of singlet oxygen. The photosensitive features of plasma and vesicle membranes observed in the present study may be based on the use of the photodynamic effect, such as cancer therapy.
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Affiliation(s)
- Hiromi Hiruma
- Department of Physiology, Kitasato University School of Medicine, Kitasato 1-15-1, Sagamihara 228-8555, Japan.
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Abstract
Calcium transport and calcium signalling mechanisms in bone cells have, in many cases, been discovered by study of diseases with disordered bone metabolism. Calcium matrix deposition is driven primarily by phosphate production, and disorders in bone deposition include abnormalities in membrane phosphate transport such as in chondrocalcinosis, and defects in phosphate-producing enzymes such as in hypophosphatasia. Matrix removal is driven by acidification, which dissolves the mineral. Disorders in calcium removal from bone matrix by osteoclasts cause osteopetrosis. On the other hand, although bone is central to management of extracellular calcium, bone is not a major calcium sensing organ, although calcium sensing proteins are expressed in both osteoblasts and osteoclasts. Intracellular calcium signals are involved in secondary control including cellular motility and survival, but the relationship of these findings to specific diseases is not clear. Intracellular calcium signals may regulate the balance of cell survival versus proliferation or anabolic functional response as part of signalling cascades that integrate the response to primary signals via cell stretch, estrogen, tyrosine kinase, and tumor necrosis factor receptors.
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Affiliation(s)
- H C Blair
- Department of Pathology, University of Pittsburgh, PA 15261, USA
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Lee SH, Rho J, Jeong D, Sul JY, Kim T, Kim N, Kang JS, Miyamoto T, Suda T, Lee SK, Pignolo RJ, Koczon-Jaremko B, Lorenzo J, Choi Y. v-ATPase V0 subunit d2-deficient mice exhibit impaired osteoclast fusion and increased bone formation. Nat Med 2006; 12:1403-9. [PMID: 17128270 DOI: 10.1038/nm1514] [Citation(s) in RCA: 428] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2006] [Accepted: 10/31/2006] [Indexed: 12/22/2022]
Abstract
Matrix-producing osteoblasts and bone-resorbing osteoclasts maintain bone homeostasis. Osteoclasts are multinucleated, giant cells of hematopoietic origin formed by the fusion of mononuclear pre-osteoclasts derived from myeloid cells. Fusion-mediated giant cell formation is critical for osteoclast maturation; without it, bone resorption is inefficient. To understand how osteoclasts differ from other myeloid lineage cells, we previously compared global mRNA expression patterns in these cells and identified genes of unknown function predominantly expressed in osteoclasts, one of which is the d2 isoform of vacuolar (H(+)) ATPase (v-ATPase) V(0) domain (Atp6v0d2). Here we show that inactivation of Atp6v0d2 in mice results in markedly increased bone mass due to defective osteoclasts and enhanced bone formation. Atp6v0d2 deficiency did not affect differentiation or the v-ATPase activity of osteoclasts. Rather, Atp6v0d2 was required for efficient pre-osteoclast fusion. Increased bone formation was probably due to osteoblast-extrinsic factors, as Atp6v02 was not expressed in osteoblasts and their differentiation ex vivo was not altered in the absence of Atp6v02. Our results identify Atp6v0d2 as a regulator of osteoclast fusion and bone formation, and provide genetic data showing that it is possible to simultaneously inhibit osteoclast maturation and stimulate bone formation by therapeutically targeting the function of a single gene.
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Affiliation(s)
- Seoung-Hoon Lee
- Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104, USA
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