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Hou Y, Yang S, Zhao Z, Huang Y, Zhang Y, Ruan W, Duan X. Long Noncoding RNA lnc-TCEA1-3 Affects Osteoclastic Function by Regulating ATP6V1H. Crit Rev Eukaryot Gene Expr 2024; 34:15-26. [PMID: 37824389 DOI: 10.1615/critreveukaryotgeneexpr.2023048669] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2023]
Abstract
H subunit of V-ATPase (ATP6V1H) is specifically expressed in osteoclasts and its deficiency lead to osteoporosis. Our group previously found four intronic SNPs of ATP6V1H related to reduced bone mineral density, but the mechanisms was not clear. In this study, we found that the above four SNPs were located at lncRNA lnc-TCEA1-3 by using bioinformatics analysis. We further detected the function of lnc-TCEA1-3 on regulating ATP6V1H and osteoclast function using Atp6v1h knockout mice, lentivirus transfection and qPCR analysis. Over expression of lnc-TCEA1-3 up regulated the expression of ATP6V1H in HEK293 cells, HOS cells and primarily cultured osteoclasts, and increased the number of primarily cultured osteoclasts. In addition, over expression of lnc-TCEA1-3 exerted distinct effect on two transcripts of ATP6V1H in HEK293, HOS and osteoclasts. This study will facilitate the in-depth analysis of the effects of ATP6V1H on bone diseases, and discover new therapeutic strategies.
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Affiliation(s)
- Yuzhuan Hou
- State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases & Shaanxi Key Laboratory of Stomatology, Department of Oral Biology, School of Stomatology, The Fourth Military Medical University, Xi'an 710032, China; College of Stomatology, Ningxia Medical University, Yinchuan 750004, China
| | - Shaoqing Yang
- State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases & Shaanxi Key Laboratory of Stomatology, Department of Oral Biology, School of Stomatology, The Fourth Military Medical University, Xi'an 710032, China
| | - Zanyan Zhao
- State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases & Shaanxi Key Laboratory of Stomatology, Department of Oral Biology, School of Stomatology, The Fourth Military Medical University, Xi'an 710032, China
| | - Yongqing Huang
- College of Stomatology, Ningxia Medical University, Yinchuan 750004, China
| | - Yanli Zhang
- State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases & Shaanxi Key Laboratory of Stomatology, Department of Oral Biology, School of Stomatology, The Fourth Military Medical University, Xi'an 710032, China
| | - Wenyan Ruan
- State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases & Shaanxi Key Laboratory of Stomatology, Department of Oral Biology, School of Stomatology, The Fourth Military Medical University, Xi'an 710032, China; College of Stomatology, Ningxia Medical University, Yinchuan 750004, China
| | - Xiaohong Duan
- State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases & Shaanxi Key Laboratory of Stomatology, Department of Oral Biology, School of Stomatology, The Fourth Military Medical University, Xi'an 710032, China
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Di Pompo G, Kusuzaki K, Ponzetti M, Leone VF, Baldini N, Avnet S. Radiodynamic Therapy with Acridine Orange Is an Effective Treatment for Bone Metastases. Biomedicines 2022; 10:biomedicines10081904. [PMID: 36009451 PMCID: PMC9405350 DOI: 10.3390/biomedicines10081904] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 07/29/2022] [Accepted: 08/03/2022] [Indexed: 11/29/2022] Open
Abstract
Current multimodal treatment of bone metastases is partially effective and often associated with side effects, and novel therapeutic options are needed. Acridine orange is a photosensitizing molecule that accumulates in acidic compartments. After photo- or radiodynamic activation (AO-PDT or AO-RDT), acridine orange can induce lysosomal-mediated cell death, and we explored AO-RDT as an acid-targeted anticancer therapy for bone metastases. We used osteotropic carcinoma cells and human osteoclasts to assess the extracellular acidification and invasiveness of cancer cells, acridine orange uptake and lysosomal pH/stability, and the AO-RDT cytotoxicity in vitro. We then used a xenograft model of bone metastasis to compare AO-RDT to another antiacid therapeutic strategy (omeprazole). Carcinoma cells showed extracellular acidification activity and tumor-derived acidosis enhanced cancer invasiveness. Furthermore, cancer cells accumulated acridine orange more than osteoclasts and were more sensitive to lysosomal death. In vivo, omeprazole did not reduce osteolysis, whereas AO-RDT promoted cancer cell necrosis and inhibited tumor-induced bone resorption, without affecting osteoclasts. In conclusion, AO-RDT was selectively toxic only for carcinoma cells and effective to impair both tumor expansion in bone and tumor-associated osteolysis. We therefore suggest the use of AO-RDT, in combination with the standard antiresorptive therapies, to reduce disease burden in bone metastasis.
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Affiliation(s)
- Gemma Di Pompo
- Biomedical Science and Technologies and Nanobiotechnology Laboratory, IRCCS Istituto Ortopedico Rizzoli, 40136 Bologna, Italy
| | - Katsuyuki Kusuzaki
- Department of Musculoskeletal Oncology, Takai Hospital, Tenri 632-0372, Japan
| | - Marco Ponzetti
- Department of Biotechnological and Applied Clinical Sciences, University of L’Aquila, 67100 L’Aquila, Italy
| | | | - Nicola Baldini
- Biomedical Science and Technologies and Nanobiotechnology Laboratory, IRCCS Istituto Ortopedico Rizzoli, 40136 Bologna, Italy
- Department of Biomedical and Neuromotor Sciences, University of Bologna, 40126 Bologna, Italy
| | - Sofia Avnet
- Department of Biomedical and Neuromotor Sciences, University of Bologna, 40126 Bologna, Italy
- Correspondence:
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Marshansky V. Discovery and Study of Transmembrane Rotary Ion-Translocating Nano-Motors: F-ATPase/Synthase of Mitochondria/Bacteria and V-ATPase of Eukaryotic Cells. BIOCHEMISTRY. BIOKHIMIIA 2022; 87:702-719. [PMID: 36171652 DOI: 10.1134/s000629792208003x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Revised: 07/08/2022] [Accepted: 07/08/2022] [Indexed: 06/16/2023]
Abstract
This review discusses the history of discovery and study of the operation of the two rotary ion-translocating ATPase nano-motors: (i) F-ATPase/synthase (holocomplex F1FO) of mitochondria/bacteria and (ii) eukaryotic V-ATPase (holocomplex V1VO). Vacuolar adenosine triphosphatase (V-ATPase) is a transmembrane multisubunit complex found in all eukaryotes from yeast to humans. It is structurally and functionally similar to the F-ATPase/synthase of mitochondria/bacteria and the A-ATPase/synthase of archaebacteria, which indicates a common evolutionary origin of the rotary ion-translocating nano-motors built into cell membranes and invented by Nature billions of years ago. Previously we have published several reviews on this topic with appropriate citations of our original research. This review is focused on the historical analysis of the discovery and study of transmembrane rotary ion-translocating ATPase nano-motors functioning in bacteria, eukaryotic cells and mitochondria of animals.
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Grochowska KM, Andres‐Alonso M, Karpova A, Kreutz MR. The needs of a synapse—How local organelles serve synaptic proteostasis. EMBO J 2022; 41:e110057. [PMID: 35285533 PMCID: PMC8982616 DOI: 10.15252/embj.2021110057] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 12/24/2021] [Accepted: 02/10/2022] [Indexed: 12/12/2022] Open
Abstract
Synaptic function crucially relies on the constant supply and removal of neuronal membranes. The morphological complexity of neurons poses a significant challenge for neuronal protein transport since the machineries for protein synthesis and degradation are mainly localized in the cell soma. In response to this unique challenge, local micro‐secretory systems have evolved that are adapted to the requirements of neuronal membrane protein proteostasis. However, our knowledge of how neuronal proteins are synthesized, trafficked to membranes, and eventually replaced and degraded remains scarce. Here, we review recent insights into membrane trafficking at synaptic sites and into the contribution of local organelles and micro‐secretory pathways to synaptic function. We describe the role of endoplasmic reticulum specializations in neurons, Golgi‐related organelles, and protein complexes like retromer in the synthesis and trafficking of synaptic transmembrane proteins. We discuss the contribution of autophagy and of proteasome‐mediated and endo‐lysosomal degradation to presynaptic proteostasis and synaptic function, as well as nondegradative roles of autophagosomes and lysosomes in signaling and synapse remodeling. We conclude that the complexity of neuronal cyto‐architecture necessitates long‐distance protein transport that combines degradation with signaling functions.
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Affiliation(s)
- Katarzyna M Grochowska
- Leibniz Group “Dendritic Organelles and Synaptic Function” Center for Molecular Neurobiology ZMNH University Medical Center Hamburg‐Eppendorf Hamburg Germany
- Research Group Neuroplasticity Leibniz Institute for Neurobiology Magdeburg Germany
| | - Maria Andres‐Alonso
- Leibniz Group “Dendritic Organelles and Synaptic Function” Center for Molecular Neurobiology ZMNH University Medical Center Hamburg‐Eppendorf Hamburg Germany
- Research Group Neuroplasticity Leibniz Institute for Neurobiology Magdeburg Germany
| | - Anna Karpova
- Research Group Neuroplasticity Leibniz Institute for Neurobiology Magdeburg Germany
- Center for Behavioral Brain Sciences Otto von Guericke University Magdeburg Germany
| | - Michael R Kreutz
- Leibniz Group “Dendritic Organelles and Synaptic Function” Center for Molecular Neurobiology ZMNH University Medical Center Hamburg‐Eppendorf Hamburg Germany
- Research Group Neuroplasticity Leibniz Institute for Neurobiology Magdeburg Germany
- Center for Behavioral Brain Sciences Otto von Guericke University Magdeburg Germany
- German Center for Neurodegenerative Diseases (DZNE) Magdeburg Germany
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Karanth DS, Martin ML, Holliday LS. Plasma Membrane Receptors Involved in the Binding and Response of Osteoclasts to Noncellular Components of the Bone. Int J Mol Sci 2021; 22:ijms221810097. [PMID: 34576260 PMCID: PMC8466431 DOI: 10.3390/ijms221810097] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 09/13/2021] [Accepted: 09/16/2021] [Indexed: 12/21/2022] Open
Abstract
Osteoclasts differentiate from hematopoietic cells and resorb the bone in response to various signals, some of which are received directly from noncellular elements of the bone. In vitro, adherence to the bone triggers the reduction of cell–cell fusion events between osteoclasts and the activation of osteoclasts to form unusual dynamic cytoskeletal and membrane structures that are required for degrading the bone. Integrins on the surface of osteoclasts are known to receive regulatory signals from the bone matrix. Regulation of the availability of these signals is accomplished by enzymatic alterations of the bone matrix by protease activity and phosphorylation/dephosphorylation events. Other membrane receptors are present in osteoclasts and may interact with as yet unidentified signals in the bone. Bone mineral has been shown to have regulatory effects on osteoclasts, and osteoclast activity is also directly modulated by mechanical stress. As understanding of how osteoclasts and other bone cells interact with the bone has emerged, increasingly sophisticated efforts have been made to create bone biomimetics that reproduce both the structural properties of the bone and the bone’s ability to regulate osteoclasts and other bone cells. A more complete understanding of the interactions between osteoclasts and the bone may lead to new strategies for the treatment of bone diseases and the production of bone biomimetics to repair defects.
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Affiliation(s)
- Divakar S. Karanth
- Department of Orthodontics, College of Dentistry, University of Florida, Gainesville, FL 32610, USA; (D.S.K.); (M.L.M.)
| | - Macey L. Martin
- Department of Orthodontics, College of Dentistry, University of Florida, Gainesville, FL 32610, USA; (D.S.K.); (M.L.M.)
| | - Lexie S. Holliday
- Department of Orthodontics, College of Dentistry, University of Florida, Gainesville, FL 32610, USA; (D.S.K.); (M.L.M.)
- Department of Anatomy & Cell Biology, College of Medicine, University of Florida, Gainesville, FL 32610, USA
- Correspondence:
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Shi Y, Han X, Pan S, Wu Y, Jiang Y, Lin J, Chen Y, Jin H. Gold Nanomaterials and Bone/Cartilage Tissue Engineering: Biomedical Applications and Molecular Mechanisms. Front Chem 2021; 9:724188. [PMID: 34307305 PMCID: PMC8299113 DOI: 10.3389/fchem.2021.724188] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2021] [Accepted: 06/28/2021] [Indexed: 01/26/2023] Open
Abstract
Recently, as our population increasingly ages with more pressure on bone and cartilage diseases, bone/cartilage tissue engineering (TE) have emerged as a potential alternative therapeutic technique accompanied by the rapid development of materials science and engineering. The key part to fulfill the goal of reconstructing impaired or damaged tissues lies in the rational design and synthesis of therapeutic agents in TE. Gold nanomaterials, especially gold nanoparticles (AuNPs), have shown the fascinating feasibility to treat a wide variety of diseases due to their excellent characteristics such as easy synthesis, controllable size, specific surface plasmon resonance and superior biocompatibility. Therefore, the comprehensive applications of gold nanomaterials in bone and cartilage TE have attracted enormous attention. This review will focus on the biomedical applications and molecular mechanism of gold nanomaterials in bone and cartilage TE. In addition, the types and cellular uptake process of gold nanomaterials are highlighted. Finally, the current challenges and future directions are indicated.
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Affiliation(s)
- Yifeng Shi
- Department of Orthopaedics, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China.,College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou, China.,The Second School of Medicine, Wenzhou Medical University, Wenzhou, China
| | - Xuyao Han
- The Second School of Medicine, Wenzhou Medical University, Wenzhou, China
| | - Shuang Pan
- College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou, China
| | - Yuhao Wu
- The Second School of Medicine, Wenzhou Medical University, Wenzhou, China
| | - Yuhan Jiang
- The Second School of Medicine, Wenzhou Medical University, Wenzhou, China
| | - Jinghao Lin
- The Second School of Medicine, Wenzhou Medical University, Wenzhou, China
| | - Yihuang Chen
- College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou, China
| | - Haiming Jin
- Department of Orthopaedics, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China.,The Second School of Medicine, Wenzhou Medical University, Wenzhou, China
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Chu A, Zirngibl RA, Manolson MF. The V-ATPase a3 Subunit: Structure, Function and Therapeutic Potential of an Essential Biomolecule in Osteoclastic Bone Resorption. Int J Mol Sci 2021; 22:ijms22136934. [PMID: 34203247 PMCID: PMC8269383 DOI: 10.3390/ijms22136934] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 06/18/2021] [Accepted: 06/21/2021] [Indexed: 12/29/2022] Open
Abstract
This review focuses on one of the 16 proteins composing the V-ATPase complex responsible for resorbing bone: the a3 subunit. The rationale for focusing on this biomolecule is that mutations in this one protein account for over 50% of osteopetrosis cases, highlighting its critical role in bone physiology. Despite its essential role in bone remodeling and its involvement in bone diseases, little is known about the way in which this subunit is targeted and regulated within osteoclasts. To this end, this review is broadened to include the three other mammalian paralogues (a1, a2 and a4) and the two yeast orthologs (Vph1p and Stv1p). By examining the literature on all of the paralogues/orthologs of the V-ATPase a subunit, we hope to provide insight into the molecular mechanisms and future research directions specific to a3. This review starts with an overview on bone, highlighting the role of V-ATPases in osteoclastic bone resorption. We then cover V-ATPases in other location/functions, highlighting the roles which the four mammalian a subunit paralogues might play in differential targeting and/or regulation. We review the ways in which the energy of ATP hydrolysis is converted into proton translocation, and go in depth into the diverse role of the a subunit, not only in proton translocation but also in lipid binding, cell signaling and human diseases. Finally, the therapeutic implication of targeting a3 specifically for bone diseases and cancer is discussed, with concluding remarks on future directions.
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Duan X, Yang S, Zhang L, Yang T. V-ATPases and osteoclasts: ambiguous future of V-ATPases inhibitors in osteoporosis. Theranostics 2018; 8:5379-5399. [PMID: 30555553 PMCID: PMC6276090 DOI: 10.7150/thno.28391] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Accepted: 10/10/2018] [Indexed: 12/11/2022] Open
Abstract
Vacuolar ATPases (V-ATPases) play a critical role in regulating extracellular acidification of osteoclasts and bone resorption. The deficiencies of subunit a3 and d2 of V-ATPases result in increased bone density in humans and mice. One of the traditional drug design strategies in treating osteoporosis is the use of subunit a3 inhibitor. Recent findings connect subunits H and G1 with decreased bone density. Given the controversial effects of ATPase subunits on bone density, there is a critical need to review the subunits of V-ATPase in osteoclasts and their functions in regulating osteoclasts and bone remodeling. In this review, we comprehensively address the following areas: information about all V-ATPase subunits and their isoforms; summary of V-ATPase subunits associated with human genetic diseases; V-ATPase subunits and osteopetrosis/osteoporosis; screening of all V-ATPase subunits variants in GEFOS data and in-house data; spectrum of V-ATPase subunits during osteoclastogenesis; direct and indirect roles of subunits of V-ATPases in osteoclasts; V-ATPase-associated signaling pathways in osteoclasts; interactions among V-ATPase subunits in osteoclasts; osteoclast-specific V-ATPase inhibitors; perspective of future inhibitors or activators targeting V-ATPase subunits in the treatment of osteoporosis.
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Affiliation(s)
- Xiaohong Duan
- State Key Laboratory of Military Stomatology, National Clinical Research Center for Oral Diseases, Department of Oral Biology, Clinic of Oral Rare and Genetic Diseases, School of Stomatology, the Fourth Military Medical University, 145 West Changle Road, Xi'an 710032, P. R. China
| | - Shaoqing Yang
- State Key Laboratory of Military Stomatology, National Clinical Research Center for Oral Diseases, Department of Oral Biology, Clinic of Oral Rare and Genetic Diseases, School of Stomatology, the Fourth Military Medical University, 145 West Changle Road, Xi'an 710032, P. R. China
| | - Lei Zhang
- Center for Genetic Epidemiology and Genomics, School of Public Health, Medical College of Soochow University, 199 Renai Road, Suzhou, Jiangsu, P. R. China
| | - Tielin Yang
- Key Laboratory of Biomedical Information Engineering of Ministry of Education, and Institute of Molecular Genetics, School of Life Science and Technology, Xi'an Jiaotong University, 28 West Xianning Road, Xi'an 710049, People's Republic of China
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Zhang K, Jia C, Yu Q, Xiao C, Dong Y, Zhang M, Zhang D, Zhao Q, Zhang B, Li M. Contribution of VMA5 to vacuolar function, stress response, ion homeostasis and autophagy in Candida albicans. Future Microbiol 2017; 12:1147-1166. [PMID: 28879785 DOI: 10.2217/fmb-2017-0029] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
AIM V-ATPase is a conservative multi-subunit enzyme in eukaryotes and modulates several cellular responses. This study aimed to illustrate the roles of Vma5 in vacuolar function, oxidative stress response, calcium homeostasis, autophagy and virulence. MATERIALS & METHODS The vma5Δ/Δ mutant was obtained using PCR-mediated homologous recombination. The functions of Vma5 were investigated by a series of biochemical and systemic infection methods. RESULTS Disruption of VMA5 led to growth inhibition, vacuolar dysfunction, disturbance of calcium homeostasis and inhibition of calcium-related oxidative stress response. Furthermore, its deletion caused defects in autophagy completion and hyphal development, and resulted in attenuated Candida albicans virulence. CONCLUSION Our findings provide new insights into V-ATPase functions in C. albicans, and reveal a potential candidate for development of antifungal drugs.
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Affiliation(s)
- Kai Zhang
- Department of Microbiology, Key Laboratory of Molecular Microbiology & Technology, College of Life Sciences, Nankai University, Ministry of Education, Tianjin 300071, China
| | - Chang Jia
- Department of Microbiology, Key Laboratory of Molecular Microbiology & Technology, College of Life Sciences, Nankai University, Ministry of Education, Tianjin 300071, China
| | - Qilin Yu
- Department of Microbiology, Key Laboratory of Molecular Microbiology & Technology, College of Life Sciences, Nankai University, Ministry of Education, Tianjin 300071, China
| | - Chenpeng Xiao
- Department of Microbiology, Key Laboratory of Molecular Microbiology & Technology, College of Life Sciences, Nankai University, Ministry of Education, Tianjin 300071, China
| | - Yijie Dong
- Department of Microbiology, Key Laboratory of Molecular Microbiology & Technology, College of Life Sciences, Nankai University, Ministry of Education, Tianjin 300071, China.,The State Key Laboratory for Biology of Plant Disease & Insect Pests, Institute of Plant protection, Chinese Academy of Agricultural Sciences, Beijing 100871, China
| | - Meng Zhang
- Department of Microbiology, Key Laboratory of Molecular Microbiology & Technology, College of Life Sciences, Nankai University, Ministry of Education, Tianjin 300071, China
| | - Dan Zhang
- Department of Microbiology, Key Laboratory of Molecular Microbiology & Technology, College of Life Sciences, Nankai University, Ministry of Education, Tianjin 300071, China
| | - Qiang Zhao
- Department of Zoology & Developmental Biology, College of Life Sciences, Nankai University, Tianjin, 300071, China
| | - Biao Zhang
- College of Language & Culture, Tianjin University of Traditional Chinese Medicine, Tianjin 300193, China
| | - Mingchun Li
- Department of Microbiology, Key Laboratory of Molecular Microbiology & Technology, College of Life Sciences, Nankai University, Ministry of Education, Tianjin 300071, China
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ten Harkel B, Schoenmaker T, Picavet DI, Davison NL, de Vries TJ, Everts V. The Foreign Body Giant Cell Cannot Resorb Bone, But Dissolves Hydroxyapatite Like Osteoclasts. PLoS One 2015; 10:e0139564. [PMID: 26426806 PMCID: PMC4591016 DOI: 10.1371/journal.pone.0139564] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Accepted: 09/15/2015] [Indexed: 12/22/2022] Open
Abstract
Foreign body multinucleated giant cells (FBGCs) and osteoclasts share several characteristics, like a common myeloid precursor cell, multinuclearity, expression of tartrate-resistant acid phosphatase (TRAcP) and dendritic cell-specific transmembrane protein (DC-STAMP). However, there is an important difference: osteoclasts form and reside in the vicinity of bone, while FBGCs form only under pathological conditions or at the surface of foreign materials, like medical implants. Despite similarities, an important distinction between these cell types is that osteoclasts can resorb bone, but it is unknown whether FBGCs are capable of such an activity. To investigate this, we differentiated FBGCs and osteoclasts in vitro from their common CD14+ monocyte precursor cells, using different sets of cytokines. Both cell types were cultured on bovine bone slices and analyzed for typical osteoclast features, such as bone resorption, presence of actin rings, formation of a ruffled border, and characteristic gene expression over time. Additionally, both cell types were cultured on a biomimetic hydroxyapatite coating to discriminate between bone resorption and mineral dissolution independent of organic matrix proteolysis. Both cell types differentiated into multinucleated cells on bone, but FBGCs were larger and had a higher number of nuclei compared to osteoclasts. FBGCs were not able to resorb bone, yet they were able to dissolve the mineral fraction of bone at the surface. Remarkably, FBGCs also expressed actin rings, podosome belts and sealing zones--cytoskeletal organization that is considered to be osteoclast-specific. However, they did not form a ruffled border. At the gene expression level, FBGCs and osteoclasts expressed similar levels of mRNAs that are associated with the dissolution of mineral (e.g., anion exchange protein 2 (AE2), carbonic anhydrase 2 (CAII), chloride channel 7 (CIC7), and vacuolar-type H+-ATPase (v-ATPase)), in contrast the matrix degrading enzyme cathepsin K, which was hardly expressed by FBGCs. Functionally, the latter cells were able to dissolve a biomimetic hydroxyapatite coating in vitro, which was blocked by inhibiting v-ATPase enzyme activity. These results show that FBGCs have the capacity to dissolve the mineral phase of bone, similar to osteoclasts. However, they are not able to digest the matrix fraction of bone, likely due to the lack of a ruffled border and cathepsin K.
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Affiliation(s)
- Bas ten Harkel
- Department of Oral Cell Biology, Academic Centre for Dentistry Amsterdam (ACTA), MOVE Research Institute, University of Amsterdam and VU University Amsterdam, Amsterdam, The Netherlands
- * E-mail:
| | - Ton Schoenmaker
- Department of Periodontology, Academic Centre for Dentistry Amsterdam (ACTA), MOVE Research Institute, University of Amsterdam and VU University Amsterdam, Amsterdam, The Netherlands
| | - Daisy I. Picavet
- Department of Cell Biology and Histology, Center for Advanced Microscopy, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Noel L. Davison
- MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente, Enschede, The Netherlands
- Xpand Biotechnology BV, Bilthoven, The Netherlands
| | - Teun J. de Vries
- Department of Periodontology, Academic Centre for Dentistry Amsterdam (ACTA), MOVE Research Institute, University of Amsterdam and VU University Amsterdam, Amsterdam, The Netherlands
| | - Vincent Everts
- Department of Oral Cell Biology, Academic Centre for Dentistry Amsterdam (ACTA), MOVE Research Institute, University of Amsterdam and VU University Amsterdam, Amsterdam, The Netherlands
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Kawamura N, Sun-Wada GH, Wada Y. Loss of G2 subunit of vacuolar-type proton transporting ATPase leads to G1 subunit upregulation in the brain. Sci Rep 2015; 5:14027. [PMID: 26353914 PMCID: PMC4564858 DOI: 10.1038/srep14027] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2015] [Accepted: 08/13/2015] [Indexed: 12/21/2022] Open
Abstract
Vacuolar-type ATPase (V-ATPase) is a primary proton pump with versatile functions in various tissues. In nerve cells, V-ATPase is required for accumulation of neurotransmitters into secretory vesicles and subsequent release at the synapse. Neurons express a specific isoform (G2) of the G subunit of V-ATPase constituting the catalytic sector of the enzyme complex. Using gene targeting, we generated a mouse lacking functional G2 (G2 null), which showed no apparent disorders in architecture and behavior. In the G2-null mouse brain, a G1 subunit isoform, which is ubiquitously expressed in neuronal and non-neuronal tissues, accumulated more abundantly than in wild-type animals. This G1 upregulation was not accompanied by an increase in mRNA. These results indicate that loss of function of neuron-specific G2 isoform was compensated by an increase in levels of the G1 isoform without apparent upregulation of the G1 mRNA.
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Affiliation(s)
- Nobuyuki Kawamura
- Faculty of Pharmaceutical Sciences, Doshisha Women's College of Liberal Arts, Kohdo, Kyotanabe, Kyoto 610-0395, Japan
| | - Ge-Hong Sun-Wada
- Faculty of Pharmaceutical Sciences, Doshisha Women's College of Liberal Arts, Kohdo, Kyotanabe, Kyoto 610-0395, Japan
| | - Yoh Wada
- Division of Biological Sciences, Institute of Scientific and Industrial Research, Osaka University, Mihogaoka 8-1, Ibaraki, Osaka 567-0047, Japan
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12
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Komatsu S, Kamal AHM, Hossain Z. Wheat proteomics: proteome modulation and abiotic stress acclimation. FRONTIERS IN PLANT SCIENCE 2014; 5:684. [PMID: 25538718 PMCID: PMC4259124 DOI: 10.3389/fpls.2014.00684] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2014] [Accepted: 11/18/2014] [Indexed: 05/21/2023]
Abstract
Cellular mechanisms of stress sensing and signaling represent the initial plant responses to adverse conditions. The development of high-throughput "Omics" techniques has initiated a new era of the study of plant molecular strategies for adapting to environmental changes. However, the elucidation of stress adaptation mechanisms in plants requires the accurate isolation and characterization of stress-responsive proteins. Because the functional part of the genome, namely the proteins and their post-translational modifications, are critical for plant stress responses, proteomic studies provide comprehensive information about the fine-tuning of cellular pathways that primarily involved in stress mitigation. This review summarizes the major proteomic findings related to alterations in the wheat proteomic profile in response to abiotic stresses. Moreover, the strengths and weaknesses of different sample preparation techniques, including subcellular protein extraction protocols, are discussed in detail. The continued development of proteomic approaches in combination with rapidly evolving bioinformatics tools and interactive databases will facilitate understanding of the plant mechanisms underlying stress tolerance.
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Affiliation(s)
- Setsuko Komatsu
- National Institute of Crop Science, National Agriculture and Food Research OrganizationTsukuba, Japan
| | - Abu H. M. Kamal
- National Institute of Crop Science, National Agriculture and Food Research OrganizationTsukuba, Japan
| | - Zahed Hossain
- Plant Stress Biology Lab, Department of Botany, West Bengal State UniversityKolkata, India
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13
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Chan CY, Parra KJ. Yeast phosphofructokinase-1 subunit Pfk2p is necessary for pH homeostasis and glucose-dependent vacuolar ATPase reassembly. J Biol Chem 2014; 289:19448-57. [PMID: 24860096 DOI: 10.1074/jbc.m114.569855] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
V-ATPases are conserved ATP-driven proton pumps that acidify organelles. Yeast V-ATPase assembly and activity are glucose-dependent. Glucose depletion causes V-ATPase disassembly and its inactivation. Glucose readdition triggers reassembly and resumes proton transport and organelle acidification. We investigated the roles of the yeast phosphofructokinase-1 subunits Pfk1p and Pfk2p for V-ATPase function. The pfk1Δ and pfk2Δ mutants grew on glucose and assembled wild-type levels of V-ATPase pumps at the membrane. Both phosphofructokinase-1 subunits co-immunoprecipitated with V-ATPase in wild-type cells; upon deletion of one subunit, the other subunit retained binding to V-ATPase. The pfk2Δ cells exhibited a partial vma growth phenotype. In vitro ATP hydrolysis and proton transport were reduced by 35% in pfk2Δ membrane fractions; they were normal in pfk1Δ. In vivo, the pfk1Δ and pfk2Δ vacuoles were alkalinized and the cytosol acidified, suggestive of impaired V-ATPase proton transport. Overall the pH alterations were more dramatic in pfk2Δ than pfk1Δ at steady state and after readdition of glucose to glucose-deprived cells. Glucose-dependent reassembly was 50% reduced in pfk2Δ, and the vacuolar lumen was not acidified after reassembly. RAVE-assisted glucose-dependent reassembly and/or glucose signals were disturbed in pfk2Δ. Binding of disassembled V-ATPase (V1 domain) to its assembly factor RAVE (subunit Rav1p) was 5-fold enhanced, indicating that Pfk2p is necessary for V-ATPase regulation by glucose. Because Pfk1p and Pfk2p are necessary for V-ATPase proton transport at the vacuole in vivo, a role for glycolysis at regulating V-ATPase proton transport is discussed.
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Affiliation(s)
- Chun-Yuan Chan
- From the Department of Biochemistry and Molecular Biology of the School of Medicine, University of New Mexico Health Sciences Center, Albuquerque, New Mexico 87131
| | - Karlett J Parra
- From the Department of Biochemistry and Molecular Biology of the School of Medicine, University of New Mexico Health Sciences Center, Albuquerque, New Mexico 87131
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14
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Hayek SR, Lee SA, Parra KJ. Advances in targeting the vacuolar proton-translocating ATPase (V-ATPase) for anti-fungal therapy. Front Pharmacol 2014; 5:4. [PMID: 24478704 PMCID: PMC3902353 DOI: 10.3389/fphar.2014.00004] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2013] [Accepted: 01/06/2014] [Indexed: 11/13/2022] Open
Abstract
Vacuolar proton-translocating ATPase (V-ATPase) is a membrane-bound, multi-subunit enzyme that uses the energy of ATP hydrolysis to pump protons across membranes. V-ATPase activity is critical for pH homeostasis and organelle acidification as well as for generation of the membrane potential that drives secondary transporters and cellular metabolism. V-ATPase is highly conserved across species and is best characterized in the model fungus Saccharomyces cerevisiae. However, recent studies in mammals have identified significant alterations from fungi, particularly in the isoform composition of the 14 subunits and in the regulation of complex disassembly. These differences could be exploited for selectivity between fungi and humans and highlight the potential for V-ATPase as an anti-fungal drug target. Candida albicans is a major human fungal pathogen and causes fatality in 35% of systemic infections, even with anti-fungal treatment. The pathogenicity of C. albicans correlates with environmental, vacuolar, and cytoplasmic pH regulation, and V-ATPase appears to play a fundamental role in each of these processes. Genetic loss of V-ATPase in pathogenic fungi leads to defective virulence, and a comprehensive picture of the mechanisms involved is emerging. Recent studies have explored the practical utility of V-ATPase as an anti-fungal drug target in C. albicans, including pharmacological inhibition, azole therapy, and targeting of downstream pathways. This overview will discuss these studies as well as hypothetical ways to target V-ATPase and novel high-throughput methods for use in future drug discovery screens.
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Affiliation(s)
- Summer R Hayek
- Department of Biochemistry and Molecular Biology, School of Medicine, University of New Mexico Health Sciences Center Albuquerque, NM, USA
| | - Samuel A Lee
- Department of Internal Medicine, School of Medicine, University of New Mexico Health Sciences Center Albuquerque, NM, USA ; Section of Infectious Diseases, New Mexico Veterans Healthcare System Albuquerque, NM, USA
| | - Karlett J Parra
- Department of Biochemistry and Molecular Biology, School of Medicine, University of New Mexico Health Sciences Center Albuquerque, NM, USA
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15
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Pérez-Sayáns M, Suárez-Peñaranda JM, Barros-Angueira F, Diz PG, Gándara-Rey JM, García-García A. An update in the structure, function, and regulation of V-ATPases: the role of the C subunit. BRAZ J BIOL 2012; 72:189-98. [PMID: 22437401 DOI: 10.1590/s1519-69842012000100023] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2011] [Accepted: 02/23/2011] [Indexed: 11/22/2022] Open
Abstract
Vacuolar ATPases (V-ATPases) are present in specialized proton secretory cells in which they pump protons across the membranes of various intracellular organelles and across the plasma membrane. The proton transport mechanism is electrogenic and establishes an acidic pH and a positive transmembrane potential in these intracellular and extracellular compartments. V-ATPases have been found to be practically identical in terms of the composition of their subunits in all eukaryotic cells. They have two distinct structures: a peripheral catalytic sector (V1) and a hydrophobic membrane sector (V0) responsible for driving protons. V-ATPase activity is regulated by three different mechanisms, which control pump density, association/dissociation of the V1 and V0 domains, and secretory activity. The C subunit is a 40-kDa protein located in the V1 domain of V-ATPase. The protein is encoded by the ATP6V1C gene and is located at position 22 of the long arm of chromosome 8 (8q22.3). The C subunit has very important functions in terms of controlling the regulation of the reversible dissociation of V-ATPases.
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Affiliation(s)
- M Pérez-Sayáns
- Faculty of Medicine and Dentistry, Santiago de Compostela, Spain
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16
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Qin A, Cheng TS, Pavlos NJ, Lin Z, Dai KR, Zheng MH. V-ATPases in osteoclasts: structure, function and potential inhibitors of bone resorption. Int J Biochem Cell Biol 2012; 44:1422-35. [PMID: 22652318 DOI: 10.1016/j.biocel.2012.05.014] [Citation(s) in RCA: 102] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2012] [Revised: 05/18/2012] [Accepted: 05/18/2012] [Indexed: 01/06/2023]
Abstract
The vacuolar-type H(+)-ATPase (V-ATPase) proton pump is a macromolecular complex composed of at least 14 subunits organized into two functional domains, V(1) and V(0). The complex is located on the ruffled border plasma membrane of bone-resorbing osteoclasts, mediating extracellular acidification for bone demineralization during bone resorption. Genetic studies from mice to man implicate a critical role for V-ATPase subunits in osteoclast-related diseases including osteopetrosis and osteoporosis. Thus, the V-ATPase complex is a potential molecular target for the development of novel anti-resorptive agents useful for the treatment of osteolytic diseases. Here, we review the current structure and function of V-ATPase subunits, emphasizing their exquisite roles in osteoclastic function. In addition, we compare several distinct classes of V-ATPase inhibitors with specific inhibitory effects on osteoclasts. Understanding the structure-function relationship of the osteoclast V-ATPase may lead to the development of osteoclast-specific V-ATPase inhibitors that may serve as alternative therapies for the treatment of osteolytic diseases.
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Affiliation(s)
- A Qin
- Centre for Orthopaedic Research, School of Surgery, The University of Western Australia, Crawley, Australia.
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17
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Traina G, Bigini P, Federighi G, Sitia L, Paroni G, Fiordaliso F, Salio M, Bendotti C, Brunelli M. Lipofuscin accumulation and gene expression in different tissues of mnd mice. Mol Neurobiol 2012; 45:247-57. [PMID: 22399241 DOI: 10.1007/s12035-012-8248-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2011] [Accepted: 02/15/2012] [Indexed: 12/12/2022]
Abstract
Neuronal ceroid lipofuscinoses (NCLs) are a group of lysosomal storage diseases characterized by neurological impairment and blindness. NCLs are almost always due to single mutations in different genes (CLN1-CLN8). Ubiquitous accumulation of undigested material and of a hydrophobic inner mitochondrial membrane protein, the subunit c of mitochondrial ATP synthase, has been described. Although protein mutation(s) in the endoplasmic reticulum-lysosomes axis can modify the trafficking and the recycling of different molecules, one of the upstream targets in these diseases may be represented by the balance of gene expression. To understand if and how neurons modify the levels of important genes during the first phases of the disease, it is important to characterize the mechanisms of neurodegeneration. Due to the impossibility of performing this analysis in humans, alternative models of investigation are required. In this study, a mouse model of human NCL8, the mnd mouse has been employed. The mnd mice recapitulate many clinical and histopathological features described in NCL8 patients. In this study, we found an altered expression of different genes in both central and peripheral organs associated with lipopigment accumulation. This is a preliminary approach, which could also be of interest in providing new diagnostic tools for NCLs.
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Affiliation(s)
- Giovanna Traina
- Department of Economics and Food Sciences, University of Perugia, Via San Costanzo, 06126 Perugia, Italy.
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18
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Oshima Y, Kinouchi K, Ichihara A, Sakoda M, Kurauchi-Mito A, Bokuda K, Narita T, Kurosawa H, Sun-Wada GH, Wada Y, Yamada T, Takemoto M, Saleem MA, Quaggin SE, Itoh H. Prorenin receptor is essential for normal podocyte structure and function. J Am Soc Nephrol 2011; 22:2203-12. [PMID: 22052048 DOI: 10.1681/asn.2011020202] [Citation(s) in RCA: 148] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
The prorenin receptor is an accessory subunit of the vacuolar H(+)-ATPase, suggesting that it has fundamental functions beyond activation of the local renin-angiotensin system. Podocytes express the prorenin receptor, but its function in these cells is unknown. Here, podocyte-specific, conditional, prorenin receptor-knockout mice died of kidney failure and severe proteinuria within 4 weeks of birth. The podocytes of these mice exhibited foot process effacement with reduced and altered localization of the slit-diaphragm proteins nephrin and podocin. Furthermore, the podocytes contained numerous autophagic vacuoles, confirmed by enhanced accumulation of microtubule-associated protein 1 light chain 3-positive intracellular vesicles. Ablation of the prorenin receptor selectively suppressed expression of the V(0) c-subunit of the vacuolar H(+)-ATPase in podocytes, resulting in deacidification of intracellular vesicles. In conclusion, the prorenin receptor is important for the maintenance of normal podocyte structure and function.
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Affiliation(s)
- Yoichi Oshima
- Department of Endocrinology & Anti-Aging Medicine and Internal Medicine, Keio University School of Medicine, 35 Shinanomachi Shinjuku-ku, Tokyo, 160-8582, Japan
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19
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Sun-Wada GH, Tabata H, Kuhara M, Kitahara I, Takashima Y, Wada Y. Generation of chicken monoclonal antibodies against the a1, a2, and a3 subunit isoforms of vacuolar-type proton ATPase. Hybridoma (Larchmt) 2011; 30:199-203. [PMID: 21529295 DOI: 10.1089/hyb.2010.0087] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The vacuolar-type proton pump ATPase (V-ATPase) plays several pivotal roles in the acidification of diverse intracellular compartments and the extracellular environment. The a subunit isoforms a1, a2, and a3, constituting the membrane-embedded section, are expressed in various tissues, and they are involved in the regulation of subcellular localization and activity of the holocomplex. Therefore, the characterization of their properties is indispensable for dissection of the physiological roles of the V-ATPase in highly differentiated cells. In this study, we report the production and characterization of chicken monoclonal antibodies (MAbs) against these mouse a1, a2 and a3 subunit isoforms. These MAbs are shown to be suitable for both immunoblotting and immunofluorescence analysis. The MAbs obtained in this study are useful in understanding the pathological basis of V-ATPase dysfunction.
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Affiliation(s)
- Ge-Hong Sun-Wada
- Department of Biochemistry, Faculty of Pharmaceutical Sciences, Doshisha Women's College, Kyotanabe, Japan.
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20
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Nishisho T, Hata K, Nakanishi M, Morita Y, Sun-Wada GH, Wada Y, Yasui N, Yoneda T. The a3 isoform vacuolar type H⁺-ATPase promotes distant metastasis in the mouse B16 melanoma cells. Mol Cancer Res 2011; 9:845-55. [PMID: 21669964 DOI: 10.1158/1541-7786.mcr-10-0449] [Citation(s) in RCA: 103] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Accumulating evidence indicates that the acidic microenvironments critically influence malignant behaviors of cancer including invasiveness, metastasis, and chemoresistance. Because the vacuolar-type H(+)-ATPase (V-ATPase) has been shown to cause extracellular acidification by pumping protons, we studied the role of V-ATPase in distant metastasis. Real-time PCR analysis revealed that the high-metastatic B16-F10 melanoma cells strongly expressed the a3 isoform V-ATPase compared to the low-metastatic B16 parental cells. Consistent with this, B16-F10 cells created acidic environments in lung metastases by acridine orange staining and strong a3 V-ATPase expression in bone metastases by immunohistochemistry. Immunocytochemical analysis showed B16-F10 cells expressed a3 V-ATPase not only in cytoplasm but also plasma membrane, whereas B16 parental cells exhibited its expression only in cytoplasm. Of note, knockdown of a3 V-ATPase suppressed invasiveness and migration with reduced MMP-2 and MMP-9 expression in B16-F10 cells and significantly decreased lung and bone metastases, despite that tumor growth was not altered. Importantly, administration of a specific V-ATPase a3 inhibitor FR167356 reduced bone metastasis of B16-F10 cells. These results suggest that a3 V-ATPase promotes distant metastasis of B16-F10 cells by creating acidic environments via proton secretion. Our results also suggest that inhibition of the development of cancer-associated acidic environments by suppressing a3 V-ATPase could be a novel therapeutic approach for the treatment of cancer metastasis.
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Affiliation(s)
- Toshihiko Nishisho
- Department of Molecular and Cellular Biochemistry, Osaka University Graduate School of Dentistry, Osaka, Japan
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21
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Kinouchi K, Ichihara A, Sano M, Sun-Wada GH, Wada Y, Kurauchi-Mito A, Bokuda K, Narita T, Oshima Y, Sakoda M, Tamai Y, Sato H, Fukuda K, Itoh H. The (pro)renin receptor/ATP6AP2 is essential for vacuolar H+-ATPase assembly in murine cardiomyocytes. Circ Res 2010; 107:30-4. [PMID: 20570919 DOI: 10.1161/circresaha.110.224667] [Citation(s) in RCA: 242] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
RATIONALE The (pro)renin receptor [(P)RR], encoded in ATP6AP2, plays a key role in the activation of local renin-angiotensin system (RAS). A truncated form of (P)RR, termed M8.9, was also found to be associated with the vacuolar H(+)-ATPase (V-ATPase), implicating a non-RAS-related function of ATP6AP2. OBJECTIVE We investigated the role of (P)RR/ATP6AP2 in murine cardiomyocytes. METHODS AND RESULTS Cardiomyocyte-specific ablation of Atp6ap2 resulted in lethal heart failure; the cardiomyocytes contained RAB7- and lysosomal-associated membrane protein 2 (LAMP2)-positive multivesicular vacuoles, especially in the perinuclear regions. The myofibrils and mitochondria remained at the cell periphery. Cardiomyocyte death was accompanied by numerous autophagic vacuoles that contained undigested cellular constituents, as a result of impaired autophagic degradation. Notably, ablation of Atp6ap2 selectively suppressed expression of the V(O) subunits of V-ATPase, resulting in deacidification of the intracellular vesicles. Furthermore, the inhibition of intracellular acidification by treatment with bafilomycin A1 or chloroquine reproduced the phenotype observed for the (P)RR/ATP6AP2-deficient cardiomyocytes. CONCLUSIONS Genetic ablation of Atp6ap2 created a loss-of-function model for V-ATPase. The gene product of ATP6AP2 is considered to act as in 2 ways: (1) as (P)RR, exerting a RAS-related function; and (2) as the V-ATPase-associated protein, exerting a non-RAS-related function that is essential for cell survival.
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Affiliation(s)
- Kenichiro Kinouchi
- Department of Endocrinology, Metabolism, and Nephrology, Keio University School of Medicine, Tokyo, Japan
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22
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Assembly of subunit d (Vma6p) and G (Vma10p) and the NMR solution structure of subunit G (G(1-59)) of the Saccharomyces cerevisiae V(1)V(O) ATPase. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2009; 1787:242-51. [PMID: 19344662 DOI: 10.1016/j.bbabio.2009.01.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2008] [Revised: 01/12/2009] [Accepted: 01/13/2009] [Indexed: 11/21/2022]
Abstract
Understanding the structural traits of subunit G is essential, as it is needed for V(1)V(O) assembly and function. Here solution NMR of the recombinant N- (G(1-59)) and C-terminal segment (G(61-114)) of subunit G, has been performed in the absence and presence of subunit d of the yeast V-ATPase. The data show that G does bind to subunit d via its N-terminal part, G(1-59) only. The residues of G(1-59) involved in d binding are Gly7 to Lys34. The structure of G(1-59) has been solved, revealing an alpha-helix between residues 10 and 56, whereby the first nine- and the last three residues of G(1-59) are flexible. The surface charge distribution of G(1-59) reveals an amphiphilic character at the N-terminus due to positive and negative charge distribution at one side and a hydrophobic surface on the opposite side of the structure. The C-terminus exhibits a strip of negative residues. The data imply that G(1-59)-d assembly is accomplished by hydrophobic interactions and salt-bridges of the polar residues. Based on the recently determined NMR structure of segment E(18-38) of subunit E of yeast V-ATPase and the presently solved structure of G(1-59), both proteins have been docked and binding epitopes have been analyzed.
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Ge C, Ding Y, Wang Z, Wan D, Wang Y, Shang Q, Luo S. Responses of wheat seedlings to cadmium, mercury and trichlorobenzene stresses. J Environ Sci (China) 2009; 21:806-813. [PMID: 19803087 DOI: 10.1016/s1001-0742(08)62345-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The molecular response of wheat (Triticum aestivum L., cv. Yangmai 13) seedlings to heavy metal (Cd, Hg) and 1,2,4-trichlorobenzene (TCB) stresses were examined by two-dimensional gel electrophoresis, image analysis, and peptide mass fingerprinting. The results showed inhibitions of root and shoot growth by Cd, Hg, and TCB. These stresses led to water deficit and lipid phosphorylation in the seedling which also promoted protein phophorylation in the leaves. Hg stress inhibited protein synthesis while Cd and TCB stresses induced or up-regulated more proteins in the leaves. Most of these induced proteins played important roles in the biochemical reactions involved in tolerance of wheat to Cd and TCB stresses. The primary functions of Cd- and TCB-induced proteins included methionine metabolism, Rubisco modification, protein phosphorylation regulation, protein configuration protection, H+ transmembrane transportation and also the synthesis of ethylene, defense substances and cell wall compounds.
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Affiliation(s)
- Cailin Ge
- Jiangsu Provencial Key Laboratory of Crop Genetics and Physiology, Yangzhou University, Yangzhou 225009, China.
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24
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Flannery AR, Stevens TH. Functional characterization of the N-terminal domain of subunit H (Vma13p) of the yeast vacuolar ATPase. J Biol Chem 2008; 283:29099-108. [PMID: 18708638 DOI: 10.1074/jbc.m803280200] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
The yeast Saccharomyces cerevisiae vacuolar H(+)-ATPase (V-ATPase) is a multisubunit complex responsible for acidifying intracellular organelles and is highly regulated. One of the regulatory subunits, subunit H, is encoded by the VMA13 gene in yeast and is composed of two domains, the N-terminal domain (amino acids (aa) 1-352) and the C-terminal domain (aa 353-478). The N-terminal domain is required for the activation of the complex, whereas the C-terminal domain is required for coupling ATP hydrolysis to proton translocation (Liu, M., Tarsio, M., Charsky, C. M., and Kane, P. M. (2005) J. Biol. Chem. 280, 36978-36985). Experiments with epitope-tagged copies of Vma13p revealed that there is only one copy of Vma13p/subunit H per V-ATPase complex. Analysis of the N-terminal domain shows that the first 179 amino acids are not required for the activation and full function of the V-ATPase complex and that the minimal region of Vma13p/subunit H capable of activating the V-ATPase is aa 180-353 of the N-terminal domain. Subunit H is expressed as two splice variants in mammals, and deletion of 18 amino acids in yeast Vma13p corresponding to the mammalian subunit H beta isoform results in reduced V-ATPase activity and significantly lower coupling of ATPase hydrolysis to proton translocation. Intriguingly, the yeast Vma13p mimicking the mammalian subunit H beta isoform is functionally equivalent to Vma13p lacking the entire C-terminal domain. These results suggest that the mammalian V-ATPase complexes with subunit H splice variant SFD-alpha or SFD-beta are likely to have different activities and may perform distinct cellular functions.
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Affiliation(s)
- Andrew R Flannery
- Section of Microbial Pathogenesis, Yale University School of Medicine, New Haven, Connecticut 06536-0812, USA
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25
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Hayashi K, Sun-Wada GH, Wada Y, Nakanishi-Matsui M, Futai M. Defective assembly of a hybrid vacuolar H(+)-ATPase containing the mouse testis-specific E1 isoform and yeast subunits. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2008; 1777:1370-7. [PMID: 18662668 DOI: 10.1016/j.bbabio.2008.06.011] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2008] [Revised: 06/26/2008] [Accepted: 06/30/2008] [Indexed: 01/10/2023]
Abstract
Mammalian vacuolar-type proton pumping ATPases (V-ATPases) are diverse multi-subunit proton pumps. They are formed from membrane V(o) and catalytic V(1) sectors, whose subunits have cell-specific or ubiquitous isoforms. Biochemical study of a unique V-ATPase is difficult because ones with different isoforms are present in the same cell. However, the properties of mouse isoforms can be studied using hybrid V-ATPases formed from the isoforms and other yeast subunits. As shown previously, mouse subunit E isoform E1 (testis-specific) or E2 (ubiquitous) can form active V-ATPases with other subunits of yeast, but E1/yeast hybrid V-ATPase is defective in proton transport at 37 degrees C (Sun-Wada, G.-H., Imai-Senga, Y., Yamamoto, A., Murata, Y., Hirata, T., Wada, Y., and Futai, M., 2002, J. Biol. Chem. 277, 18098-18105). In this study, we have analyzed the properties of E1/yeast hybrid V-ATPase to understand the role of the E subunit. The proton transport by the defective hybrid ATPase was reversibly recovered when incubation temperature of vacuoles or cells was shifted to 30 degrees C. Corresponding to the reversible defect of the hybrid V-ATPase, the V(o) subunit a epitope was exposed to the corresponding antibody at 37 degrees C, but became inaccessible at 30 degrees C. However, the V(1) sector was still associated with V(o) at 37 degrees C, as shown immunochemically. The control yeast V-ATPase was active at 37 degrees C, and its epitope was not accessible to the antibody. Glucose depletion, known to dissociate V(1) from V(o) in yeast, had only a slight effect on the hybrid at acidic pH. The domain between Lys26 and Val83 of E1, which contains eight residues not conserved between E1 and E2, was responsible for the unique properties of the hybrid. These results suggest that subunit E, especially its amino-terminal domain, plays a pertinent role in the assembly of V-ATPase subunits in vacuolar membranes.
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Affiliation(s)
- Kazuhiro Hayashi
- Department of Biochemistry, Faculty of Pharmaceutical Sciences, Iwate Medical University, Iwate, Japan
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26
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Kóta Z, Páli T, Dixon N, Kee TP, Harrison MA, Findlay JBC, Finbow ME, Marsh D. Incorporation of Transmembrane Peptides from the Vacuolar H+-ATPase in Phospholipid Membranes: Spin-Label Electron Paramagnetic Resonance and Polarized Infrared Spectroscopy. Biochemistry 2008; 47:3937-49. [DOI: 10.1021/bi7025112] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Zoltán Kóta
- Max-Planck-Institut für biophysikalische Chemie, Abt. Spektroskopie, 37070 Göttingen, Germany, Institute of Biophysics, Biological Research Centre, 6701 Szeged, Hungary, School of Chemistry and School of Biochemistry and Molecular Biology, University of Leeds, Leeds LS2 9JT, U.K., and Department of Biological and Biomedical Sciences, Glasgow Caledonian University, Glasgow G4 0BA, U.K
| | - Tibor Páli
- Max-Planck-Institut für biophysikalische Chemie, Abt. Spektroskopie, 37070 Göttingen, Germany, Institute of Biophysics, Biological Research Centre, 6701 Szeged, Hungary, School of Chemistry and School of Biochemistry and Molecular Biology, University of Leeds, Leeds LS2 9JT, U.K., and Department of Biological and Biomedical Sciences, Glasgow Caledonian University, Glasgow G4 0BA, U.K
| | - Neil Dixon
- Max-Planck-Institut für biophysikalische Chemie, Abt. Spektroskopie, 37070 Göttingen, Germany, Institute of Biophysics, Biological Research Centre, 6701 Szeged, Hungary, School of Chemistry and School of Biochemistry and Molecular Biology, University of Leeds, Leeds LS2 9JT, U.K., and Department of Biological and Biomedical Sciences, Glasgow Caledonian University, Glasgow G4 0BA, U.K
| | - Terry P. Kee
- Max-Planck-Institut für biophysikalische Chemie, Abt. Spektroskopie, 37070 Göttingen, Germany, Institute of Biophysics, Biological Research Centre, 6701 Szeged, Hungary, School of Chemistry and School of Biochemistry and Molecular Biology, University of Leeds, Leeds LS2 9JT, U.K., and Department of Biological and Biomedical Sciences, Glasgow Caledonian University, Glasgow G4 0BA, U.K
| | - Michael A. Harrison
- Max-Planck-Institut für biophysikalische Chemie, Abt. Spektroskopie, 37070 Göttingen, Germany, Institute of Biophysics, Biological Research Centre, 6701 Szeged, Hungary, School of Chemistry and School of Biochemistry and Molecular Biology, University of Leeds, Leeds LS2 9JT, U.K., and Department of Biological and Biomedical Sciences, Glasgow Caledonian University, Glasgow G4 0BA, U.K
| | - John B. C. Findlay
- Max-Planck-Institut für biophysikalische Chemie, Abt. Spektroskopie, 37070 Göttingen, Germany, Institute of Biophysics, Biological Research Centre, 6701 Szeged, Hungary, School of Chemistry and School of Biochemistry and Molecular Biology, University of Leeds, Leeds LS2 9JT, U.K., and Department of Biological and Biomedical Sciences, Glasgow Caledonian University, Glasgow G4 0BA, U.K
| | - Malcolm E. Finbow
- Max-Planck-Institut für biophysikalische Chemie, Abt. Spektroskopie, 37070 Göttingen, Germany, Institute of Biophysics, Biological Research Centre, 6701 Szeged, Hungary, School of Chemistry and School of Biochemistry and Molecular Biology, University of Leeds, Leeds LS2 9JT, U.K., and Department of Biological and Biomedical Sciences, Glasgow Caledonian University, Glasgow G4 0BA, U.K
| | - Derek Marsh
- Max-Planck-Institut für biophysikalische Chemie, Abt. Spektroskopie, 37070 Göttingen, Germany, Institute of Biophysics, Biological Research Centre, 6701 Szeged, Hungary, School of Chemistry and School of Biochemistry and Molecular Biology, University of Leeds, Leeds LS2 9JT, U.K., and Department of Biological and Biomedical Sciences, Glasgow Caledonian University, Glasgow G4 0BA, U.K
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27
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Dixon N, Páli T, Kee TP, Ball S, Harrison MA, Findlay JBC, Nyman J, Väänänen K, Finbow ME, Marsh D. Interaction of spin-labeled inhibitors of the vacuolar H+-ATPase with the transmembrane Vo-sector. Biophys J 2007; 94:506-14. [PMID: 17872954 PMCID: PMC2157245 DOI: 10.1529/biophysj.107.111781] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The osteoclast variant of the vacuolar H(+)-ATPase (V-ATPase) is a potential therapeutic target for combating the excessive bone resorption that is involved in osteoporosis. The most potent in a series of synthetic inhibitors based on 5-(5,6-dichloro-2-indolyl)-2-methoxy-2,4-pentadienamide (INDOL0) has demonstrated specificity for the osteoclast enzyme, over other V-ATPases. Interaction of two nitroxide spin-labeled derivatives (INDOL6 and INDOL5) with the V-ATPase is studied here by using the transport-active 16-kDa proteolipid analog of subunit c from the hepatopancreas of Nephrops norvegicus, in conjunction with electron paramagnetic resonance (EPR) spectroscopy. Analogous experiments are also performed with vacuolar membranes from Saccharomyces cerevisiae, in which subunit c of the V-ATPase is replaced functionally by the Nephrops 16-kDa proteolipid. The INDOL5 derivative is designed to optimize detection of interaction with the V-ATPase by EPR. In membranous preparations of the Nephrops 16-kDa proteolipid, the EPR spectra of INDOL5 contain a motionally restricted component that arises from direct association of the indolyl inhibitor with the transmembrane domain of the proteolipid subunit c. A similar, but considerably smaller, motionally restricted population is detected in the EPR spectra of the INDOL6 derivative in vacuolar membranes, in addition to the larger population from INDOL6 in the fluid bilayer regions of the membrane. The potent classical V-ATPase inhibitor concanamycin A at high concentrations induces motional restriction of INDOL5, which masks the spectral effects of displacement at lower concentrations of concanamycin A. The INDOL6 derivative, which is closest to the parent INDOL0 inhibitor, displays limited subtype specificity for the osteoclast V-ATPase, with an IC(50) in the 10-nanomolar range.
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Affiliation(s)
- Neil Dixon
- Max-Planck-Institut für biophysikalische Chemie, Abt. Spektroskopie, Göttingen, Germany; University of Leeds, School of Chemistry and School of Biochemistry and Molecular Biology, Leeds, United Kingdom; University of Turku, Institute of Biomedicine, Department of Anatomy, Turku, Finland; and Department of Biological and Biomedical Sciences, Glasgow Caledonian University, Glasgow, United Kingdom
| | - Tibor Páli
- Max-Planck-Institut für biophysikalische Chemie, Abt. Spektroskopie, Göttingen, Germany; University of Leeds, School of Chemistry and School of Biochemistry and Molecular Biology, Leeds, United Kingdom; University of Turku, Institute of Biomedicine, Department of Anatomy, Turku, Finland; and Department of Biological and Biomedical Sciences, Glasgow Caledonian University, Glasgow, United Kingdom
| | - Terence P. Kee
- Max-Planck-Institut für biophysikalische Chemie, Abt. Spektroskopie, Göttingen, Germany; University of Leeds, School of Chemistry and School of Biochemistry and Molecular Biology, Leeds, United Kingdom; University of Turku, Institute of Biomedicine, Department of Anatomy, Turku, Finland; and Department of Biological and Biomedical Sciences, Glasgow Caledonian University, Glasgow, United Kingdom
| | - Stephen Ball
- Max-Planck-Institut für biophysikalische Chemie, Abt. Spektroskopie, Göttingen, Germany; University of Leeds, School of Chemistry and School of Biochemistry and Molecular Biology, Leeds, United Kingdom; University of Turku, Institute of Biomedicine, Department of Anatomy, Turku, Finland; and Department of Biological and Biomedical Sciences, Glasgow Caledonian University, Glasgow, United Kingdom
| | - Michael A. Harrison
- Max-Planck-Institut für biophysikalische Chemie, Abt. Spektroskopie, Göttingen, Germany; University of Leeds, School of Chemistry and School of Biochemistry and Molecular Biology, Leeds, United Kingdom; University of Turku, Institute of Biomedicine, Department of Anatomy, Turku, Finland; and Department of Biological and Biomedical Sciences, Glasgow Caledonian University, Glasgow, United Kingdom
| | - John B. C. Findlay
- Max-Planck-Institut für biophysikalische Chemie, Abt. Spektroskopie, Göttingen, Germany; University of Leeds, School of Chemistry and School of Biochemistry and Molecular Biology, Leeds, United Kingdom; University of Turku, Institute of Biomedicine, Department of Anatomy, Turku, Finland; and Department of Biological and Biomedical Sciences, Glasgow Caledonian University, Glasgow, United Kingdom
| | - Jonas Nyman
- Max-Planck-Institut für biophysikalische Chemie, Abt. Spektroskopie, Göttingen, Germany; University of Leeds, School of Chemistry and School of Biochemistry and Molecular Biology, Leeds, United Kingdom; University of Turku, Institute of Biomedicine, Department of Anatomy, Turku, Finland; and Department of Biological and Biomedical Sciences, Glasgow Caledonian University, Glasgow, United Kingdom
| | - Kalervo Väänänen
- Max-Planck-Institut für biophysikalische Chemie, Abt. Spektroskopie, Göttingen, Germany; University of Leeds, School of Chemistry and School of Biochemistry and Molecular Biology, Leeds, United Kingdom; University of Turku, Institute of Biomedicine, Department of Anatomy, Turku, Finland; and Department of Biological and Biomedical Sciences, Glasgow Caledonian University, Glasgow, United Kingdom
| | - Malcolm E. Finbow
- Max-Planck-Institut für biophysikalische Chemie, Abt. Spektroskopie, Göttingen, Germany; University of Leeds, School of Chemistry and School of Biochemistry and Molecular Biology, Leeds, United Kingdom; University of Turku, Institute of Biomedicine, Department of Anatomy, Turku, Finland; and Department of Biological and Biomedical Sciences, Glasgow Caledonian University, Glasgow, United Kingdom
| | - Derek Marsh
- Max-Planck-Institut für biophysikalische Chemie, Abt. Spektroskopie, Göttingen, Germany; University of Leeds, School of Chemistry and School of Biochemistry and Molecular Biology, Leeds, United Kingdom; University of Turku, Institute of Biomedicine, Department of Anatomy, Turku, Finland; and Department of Biological and Biomedical Sciences, Glasgow Caledonian University, Glasgow, United Kingdom
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28
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Sun-Wada GH, Tabata H, Kawamura N, Futai M, Wada Y. Differential expression of a subunit isoforms of the vacuolar-type proton pump ATPase in mouse endocrine tissues. Cell Tissue Res 2007; 329:239-48. [PMID: 17497178 DOI: 10.1007/s00441-007-0421-7] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2007] [Accepted: 03/31/2007] [Indexed: 11/26/2022]
Abstract
Vacuolar-type proton ATPase (V-ATPase) is a multi-subunit enzyme that couples ATP hydrolysis to the translocation of protons across membranes. Mammalian cells express four isoforms of the a subunit of V-ATPase. Previously, we have shown that V-ATPase with the a3 isoform is highly expressed in pancreatic islets and is located in the membranes of insulin-containing granules in the beta cells. The a3 isoform functions in the regulation of hormone secretion. In this study, we have examined the distribution of a subunit isoforms in endocrine tissues, including the adrenal, parathyroid, thyroid, and pituitary glands, with isoform-specific antibodies. We have found that the a3 isoform is strongly expressed in all these endocrine tissues. Our results suggest that functions of the a3 isoform are commonly involved in the process of exocytosis in regulated secretion.
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Affiliation(s)
- Ge-Hong Sun-Wada
- Department of Biochemistry, Faculty of Pharmaceutical Sciences, Doshisha Women's College, Kyotanabe, 610-0395, Japan.
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29
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Watanabe Y, Inanami O, Horiuchi M, Hiraoka W, Shimoyama Y, Inagaki F, Kuwabara M. Identification of pH-sensitive regions in the mouse prion by the cysteine-scanning spin-labeling ESR technique. Biochem Biophys Res Commun 2006; 350:549-56. [PMID: 17022940 DOI: 10.1016/j.bbrc.2006.09.082] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2006] [Accepted: 09/18/2006] [Indexed: 12/01/2022]
Abstract
We analyzed the pH-induced mobility changes in moPrP(C) alpha-helix and beta-sheets by cysteine-scanning site-directed spin labeling (SDSL) with ESR. Nine amino acid residues of alpha-helix1 (H1, codon 143-151), four amino acid residues of beta-sheet1 (S1, codon 127-130), and four amino acid residues of beta-sheet2 (S2, codon 160-163) were substituted for by cysteine residues. These recombinant mouse PrP(C) (moPrP(C)) mutants were reacted with a methane thiosulfonate sulfhydryl-specific spin labeling reagent (MTSSL). The 1/deltaH of the central (14N hyperfine) component (M(I) = 0) in the ESR spectrum of spin-labeled moPrP(C) was measured as a mobility parameter of nitroxide residues (R1). The mobilities of E145R1 and Y149R1 at pH 7.4, which was identified as a tertiary contact site by a previous NMR study of moPrP, were lower than those of D143R1, R147R1, and R150R1 reported on the helix surface. Thus, the mobility in the H1 region in the neutral solution was observed with the periodicity associated with a helical structure. On the other hand, the values in the S2 region, known to be located in the buried side, were lower than those in the S1 region located in the surface side. These results indicated that the mobility parameter of the nitroxide label was well correlated with the 3D structure of moPrP. Furthermore, the present study clearly demonstrated three pH-sensitive sites in moPrP, i.e., (1) the N-terminal tertiary contact site of H1, (2) the C-terminal end of H1, and (3) the S2 region. In particular, among these pH-sensitive sites, the N-terminal tertiary contact region of H1 was found to be the most pH-sensitive one and was easily converted to a flexible structure by a slight decrease of pH in the solution. These data provided molecular evidence to explain the cellular mechanism for conversion from PrP(C) to PrP(Sc) in acidic organelles such as the endosome.
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Affiliation(s)
- Yasuko Watanabe
- Laboratory of Radiation Biology, Department of Environmental Veterinary Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Kita 18-Jo Nishi 9-chome, Sapporo 060-0818, Japan
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30
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Sun-Wada GH, Toyomura T, Murata Y, Yamamoto A, Futai M, Wada Y. The a3 isoform of V-ATPase regulates insulin secretion from pancreatic beta-cells. J Cell Sci 2006; 119:4531-40. [PMID: 17046993 DOI: 10.1242/jcs.03234] [Citation(s) in RCA: 164] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Vacuolar-type H(+)-ATPase (V-ATPase) is a multi-subunit enzyme that has important roles in the acidification of a variety of intracellular compartments and some extracellular milieus. Four isoforms for the membrane-intrinsic subunit (subunit a) of the V-ATPase have been identified in mammals, and they confer distinct cellular localizations and activities on the proton pump. We found that V-ATPase with the a3 isoform is highly expressed in pancreatic islets, and is localized to membranes of insulin-containing secretory granules in beta-cells. oc/oc mice, which have a null mutation at the a3 locus, exhibited a reduced level of insulin in the blood, even with high glucose administration. However, islet lysates contained mature insulin, and the ratio of the amount of insulin to proinsulin in oc/oc islets was similar to that of wild-type islets, indicating that processing of insulin was normal even in the absence of the a3 function. The insulin contents of oc/oc islets were reduced slightly, but this was not significant enough to explain the reduced levels of the blood insulin. The secretion of insulin from isolated islets in response to glucose or depolarizing stimulation was impaired. These results suggest that the a3 isoform of V-ATPase has a regulatory function in the exocytosis of insulin secretion.
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Affiliation(s)
- Ge-Hong Sun-Wada
- Department of Biochemistry, Faculty of Pharmaceutical Sciences, Doshisha Women's College, Kyotanabe 610-0395, Japan.
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31
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Nakanishi-Matsui M, Futai M. Stochastic proton pumping ATPases: from single molecules to diverse physiological roles. IUBMB Life 2006; 58:318-22. [PMID: 16754325 DOI: 10.1080/15216540600702255] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
We discuss the most recent reports on two proton pumps, F-ATPase (ATP synthase) and V-ATPase (endomembrane proton pump). They are formed from similar extrinsic (F1 or V1) and intrinsic (Fo or Vo) membrane sectors, and couple chemistry and proton transport through subunit rotation for apparently different physiological roles. Emphasis is placed on the stochastic rotational catalysis of F-ATPase and isoforms of V-ATPase.
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Affiliation(s)
- Mayumi Nakanishi-Matsui
- Futai Special Laboratory, Microbial Chemistry Research Center, Microbial Chemistry Research Foundation, CREST, Japan Science, and Technology Agency, Kamiosaki, Shinagawa-ku, Tokyo, Japan
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32
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Compton MA, Graham LA, Stevens TH. Vma9p (subunit e) is an integral membrane V0 subunit of the yeast V-ATPase. J Biol Chem 2006; 281:15312-9. [PMID: 16569636 DOI: 10.1074/jbc.m600890200] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The Saccharomyces cerevisiae vacuolar proton-translocating ATPase (V-ATPase) is composed of 14 subunits distributed between a peripheral V1 subcomplex and an integral membrane V0 subcomplex. Genome-wide screens have led to the identification of the newest yeast V-ATPase subunit, Vma9p. Vma9p (subunit e) is a small hydrophobic protein that is conserved from fungi to animals. We demonstrate that disruption of yeast VMA9 results in the failure of V1 and V0 V-ATPase subunits to assemble onto the vacuole and in decreased levels of the subunit a isoforms Vph1p and Stv1p. We also show that Vma9p is an integral membrane protein, synthesized and inserted into the endoplasmic reticulum (ER), which then localizes to the limiting membrane of the vacuole. All V0 subunits and V-ATPase assembly factors are required for Vma9p to efficiently exit the ER. In the ER, Vma9p and the V0 subunits interact with the V-ATPase assembly factor Vma21p. Interestingly, the association of Vma9p with the V0-Vma21p assembly complex is disrupted with the loss of any single V0 subunit. Similarly, Vma9p is required for V0 subunits Vph1p and Vma6p to associate with the V0-Vma21p complex. In contrast, the proteolipids associate with Vma21p even in the absence of Vma9p. These results demonstrate that Vma9p is an integral membrane subunit of the yeast V-ATPase V0 subcomplex and suggest a model for the arrangement of polypeptides within the V0 subcomplex.
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Affiliation(s)
- Mark A Compton
- Institute of Molecular Biology, University of Oregon, Eugene, Oregon 97403-1229, USA
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33
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Wang Y, Inoue T, Forgac M. Subunit a of the yeast V-ATPase participates in binding of bafilomycin. J Biol Chem 2005; 280:40481-8. [PMID: 16216877 DOI: 10.1074/jbc.m509106200] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Bafilomycin and concanamycin are potent and highly specific inhibitors of the vacuolar (H(+))-ATPases (V-ATPases), typically inhibiting at nanomolar concentrations. Previous studies have shown that subunit c of the integral V(0) domain participates in bafilomycin binding, and that this site resembles the oligomycin binding site of the F-ATPase (Bowman, B. J., and Bowman, E. J. (2002) J. Biol. Chem. 277, 3965-3972). Because mutations in F-ATPase subunit a also confer resistance to oligomycin, we investigated whether the a subunit of the V-ATPase might participate in binding bafilomycin. Twenty-eight subunit a mutations were constructed just N-terminal to the critical Arg(735) residue in transmembrane 7 required for proton transport, a region similar to that shown to participate in oligomycin binding by the F-ATPase. The mutants appeared to assemble normally and all but two showed normal growth at pH 7.5, whereas all but three had at least 25% of wild-type levels of proton transport and ATPase activity. Of the functional mutants, three displayed K(i) values for bafilomycin significantly different from wild-type (0.22 +/- 0.03 nm). These included E721K (K(i) 0.38 +/- 0.03 nm), L724A (0.40 +/- 0.02 nm), and N725F (0.54 +/- 0.06 nm). Only the N725F mutation displayed a K(i) for concanamycin (0.84 +/- 0.04 nm) that was slightly higher than wild-type (0.60 +/- 0.07 nm). These results suggest that subunit a of V-ATPase participates along with subunit c in binding bafilomycin.
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Affiliation(s)
- Yanru Wang
- Department of Physiology, Tufts University School of Medicine, Boston, Massachusetts 02111, USA
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Park M, Lee D, Lee GJ, Hwang I. AtRMR1 functions as a cargo receptor for protein trafficking to the protein storage vacuole. ACTA ACUST UNITED AC 2005; 170:757-67. [PMID: 16115960 PMCID: PMC2171354 DOI: 10.1083/jcb.200504112] [Citation(s) in RCA: 92] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Organellar proteins are sorted by cargo receptors on the way to their final destination. However, receptors for proteins that are destined for the protein storage vacuole (PSV) are largely unknown. In this study, we investigated the biological role that Arabidopsis thaliana receptor homology region transmembrane domain ring H2 motif protein (AtRMR) 1 plays in protein trafficking to the PSV. AtRMR1 mainly colocalized to the prevacuolar compartment of the PSV, but a minor portion also localized to the Golgi complex. The coexpression of AtRMR1 mutants that were localized to the Golgi complex strongly inhibited the trafficking of phaseolin to the PSV and caused accumulation of phaseolin in the Golgi complex or its secretion. Coimmunoprecipitation and in vitro binding assays revealed that the lumenal domain of AtRMR1 interacts with the COOH-terminal sorting signal of phaseolin at acidic pH. Furthermore, phaseolin colocalized with AtRMR1 on its way to the PSV. Based on these results, we propose that AtRMR1 functions as the sorting receptor of phaseolin for its trafficking to the PSV.
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Affiliation(s)
- Misoon Park
- Division of Molecular and Life Sciences, Center for Plant Intracellular Trafficking, Pohang University of Science and Technology, Pohang 790-784, Korea
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35
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Inoue T, Forgac M. Cysteine-mediated cross-linking indicates that subunit C of the V-ATPase is in close proximity to subunits E and G of the V1 domain and subunit a of the V0 domain. J Biol Chem 2005; 280:27896-903. [PMID: 15951435 DOI: 10.1074/jbc.m504890200] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The vacuolar (H+)-ATPases (V-ATPases) are multisubunit complexes responsible for ATP-dependent proton transport across both intracellular and plasma membranes. The V-ATPases are composed of a peripheral domain (V1) that hydrolyzes ATP and an integral domain (V0) that conducts protons. Dissociation of V1 and V0 is an important mechanism of controlling V-ATPase activity in vivo. The crystal structure of subunit C of the V-ATPase reveals two globular domains connected by a flexible linker (Drory, O., Frolow, F., and Nelson, N. (2004) EMBO Rep. 5, 1-5). Subunit C is unique in being released from both V1 and V0 upon in vivo dissociation. To localize subunit C within the V-ATPase complex, unique cysteine residues were introduced into 25 structurally defined sites within the yeast C subunit and used as sites of attachment of the photoactivated sulfhydryl reagent 4-(N-maleimido)benzophenone (MBP). Analysis of photocross-linked products by Western blot reveals that subunit E (part of V1) is in close proximity to both the head domain (residues 166-263) and foot domain (residues 1-151 and 287-392) of subunit C. By contrast, subunit G (also part of V1) shows cross-linking to only the head domain whereas subunit a (part of V0) shows cross-linking to only the foot domain. The localization of subunit C to the interface of the V1 and V0 domains is consistent with a role for this subunit in controlling assembly of the V-ATPase complex.
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Affiliation(s)
- Takao Inoue
- Department of Physiology, Tufts University School of Medicine, Boston, Massachusetts 02111, USA
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36
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Sun-Wada GH, Wada Y, Futai M. Diverse and essential roles of mammalian vacuolar-type proton pump ATPase: toward the physiological understanding of inside acidic compartments. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2004; 1658:106-14. [PMID: 15282181 DOI: 10.1016/j.bbabio.2004.04.013] [Citation(s) in RCA: 98] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2004] [Revised: 04/19/2004] [Accepted: 04/20/2004] [Indexed: 11/19/2022]
Abstract
The vacuolar-type H(+)-ATPases (V-ATPase) are a family of multi-subunit ATP-dependent proton pumps involved in a wide variety of physiological processes. They are present in endomembrane organelles such as vacuoles, lysosomes, endosomes, the Golgi apparatus, chromaffin granules and coated vesicles, and acidify the luminal pH of these intracellular compartments. They also pump protons across the plasma membranes of specialized cells including osteoclasts and epithelial cells in kidneys and male genital tracts. Here, we briefly summarize our recent studies on the diverse and essential roles of mammalian V-ATPase.
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Affiliation(s)
- Ge-Hong Sun-Wada
- Division of Biological Sciences and Nanoscience, Institute of Scientific and Industrial Research, Osaka University, Mihogaoka 8-1, Ibaraki, Osaka 567-0047, Japan
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37
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Chaban YL, Coskun U, Keegstra W, Oostergetel GT, Boekema EJ, Grüber G. Structural Characterization of an ATPase Active F1-/V1 -ATPase (α3β3EG) Hybrid Complex. J Biol Chem 2004; 279:47866-70. [PMID: 15355991 DOI: 10.1074/jbc.m408460200] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Co-reconstitution of subunits E and G of the yeast V-ATPase and the alpha and beta subunits of the F(1)-ATPase from the thermophilic Bacillus PS3 (TF(1)) resulted in an alpha(3)beta(3)EG hybrid complex showing 53% of the ATPase activity of TF(1). The alpha(3)beta(3)EG oligomer was characterized by electron microscopy. By processing 40,000 single particle projections, averaged two-dimensional projections at 1.2-2.4-nm resolution were obtained showing the hybrid complex in various positions. Difference mapping of top and side views of this complex with projections of the atomic model of the alpha(3)beta(3) subcomplex from TF(1) (Shirakihara, Y., Leslie, A. G., Abrahams, J. P., Walker, J. E., Ueda, T., Sekimoto, Y., Kambara, M., Saika, K., Kagawa, Y., and Yoshida, M. (1997) Structure 5, 825-836) demonstrates that a seventh mass is located inside the shaft of the alpha(3)beta(3) barrel and extends out from the hexamer. Furthermore, difference mapping of the alpha(3)beta(3)EG oligomer with projections of the A(3)B(3)E and A(3)B(3)EC subcomplexes of the V(1) from Caloramator fervidus (Chaban, Y., Ubbink-Kok, T., Keegstra, W., Lolkema, J. S., and Boekema, E. J. (2002) EMBO Rep. 3, 982-987) shows that the mass inside the shaft is made up of subunit E, whereby subunit G was assigned to belong at least in part to the density of the protruding stalk. The formation of an active alpha(3)beta(3)EG hybrid complex indicates that the coupling subunit gamma inside the alpha(3)beta(3) oligomer of F(1) can be effectively replaced by subunit E of the V-ATPase. Our results have also demonstrated that the E and gamma subunits are structurally similar, despite the fact that their genes do not show significant homology.
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Affiliation(s)
- Yuriy L Chaban
- Department of Biophysical Chemistry, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen Nijenborgh 4, 9747 AG Groningen, The Netherlands
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Bowman EJ, Graham LA, Stevens TH, Bowman BJ. The Bafilomycin/Concanamycin Binding Site in Subunit c of the V-ATPases from Neurospora crassa and Saccharomyces cerevisiae. J Biol Chem 2004; 279:33131-8. [PMID: 15180988 DOI: 10.1074/jbc.m404638200] [Citation(s) in RCA: 114] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The vacuolar H+-ATPase is inhibited with high specificity and potency by bafilomycin and concanamycin, macrolide antibiotics with similar structures. We previously reported that mutation at three residues in subunit c of the vacuolar ATPase from Neurospora crassa conferred strong resistance to bafilomycin but little or no resistance to concanamycin (Bowman, B. J., and Bowman, E. J. (2002) J. Biol. Chem. 277, 3965-3972). We have identified additional mutated sites in subunit c that confer resistance to bafilomycin. Furthermore, by subjecting a resistant mutant to a second round of mutation we isolated strains with increased resistance to both bafilomycin and concanamycin. In all of these strains the second mutation is also in subunit c, suggesting it forms at least part of the concanamycin binding site. Site-directed mutagenesis of the gene encoding subunit c in Saccharomyces cerevisiae showed that single mutations in each of the residues identified in one of the double mutants of N. crassa conferred resistance to both bafilomycin and concanamycin. Mutations at the corresponding sites in the VMA11 and VMA16 genes of S. cerevisiae, which encode the c' and c" subunits, did not confer resistance to the drugs. In all, nine residues of subunit c have been implicated in drug binding. The positions of these residues support a model in which the drug binding site is a pocket formed by helices 1, 2, and 4. We hypothesize that the drugs inhibit by preventing the rotation of the c subunits.
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Affiliation(s)
- Emma Jean Bowman
- Department of Molecular, Cell, and Developmental Biology, University of California, Santa Cruz, California 95064, USA
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Futai M, Sun-Wada GH, Wada Y. Proton pumping ATPases and diverse inside-acidic compartments. YAKUGAKU ZASSHI 2004; 124:243-60. [PMID: 15118237 DOI: 10.1248/yakushi.124.243] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Proton-translocating ATPases are essential cellular energy converters that transduce the chemical energy of ATP hydrolysis into transmembrane proton electrochemical potential differences. The structures, catalytic mechanism, and cellular functions of three major classes of ATPases including the F-type, V-type, and P-type ATPase are discussed in this review. Physiological roles of the acidic organelles and compartments contained are also discussed.
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Affiliation(s)
- Masamitsu Futai
- Division of Biological Sciences, Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihogaoka, Ibaraki City, Osaka 567-0047, Japan.
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Sun-Wada GH, Wada Y, Futai M. Lysosome and lysosome-related organelles responsible for specialized functions in higher organisms, with special emphasis on vacuolar-type proton ATPase. Cell Struct Funct 2003; 28:455-63. [PMID: 14745137 DOI: 10.1247/csf.28.455] [Citation(s) in RCA: 95] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Mammals contain various cells differentiated in both morphology and function, which play vital roles in tissue-specific functions. Late endosome/lysosome and lysosomal-related organelles are involved in these specialized functions including antigen presentation, bone remodeling and hormone regulation. To fulfill these diverse roles, lysosomes are present at different levels in different tissues and cell types; however, their morphology within these different tissues varies and the regulation of their activities differs with lysosomal compartments in some cells also functioning as secretory compartments. The luminal acidification of these organelles is closely correlated with their functions. This review will discuss the functions of lysosomes and lysosomal-related organelles, with particular emphasis on the major proton pump, the vacuolar-type proton ATPase (V-ATPase), which is responsible for luminal acidification.
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Affiliation(s)
- Ge-Hong Sun-Wada
- Division of Biological Sciences and Nanoscience, Japan Science and Technology Cooperation, Institute of Scientific and Industrial Research, Osaka University, Mihogaoka 8-1, Ibaraki, Osaka 567-0047, Japan.
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