1
|
Qiu C, Arora P, Malik I, Laperuta AJ, Pavlovic EM, Ugochukwu S, Naik M, Kaplan CD. Thiolutin has complex effects in vivo but is a direct inhibitor of RNA polymerase II in vitro. Nucleic Acids Res 2024; 52:2546-2564. [PMID: 38214235 PMCID: PMC10954460 DOI: 10.1093/nar/gkad1258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 12/18/2023] [Accepted: 12/29/2023] [Indexed: 01/13/2024] Open
Abstract
Thiolutin is a natural product transcription inhibitor with an unresolved mode of action. Thiolutin and the related dithiolopyrrolone holomycin chelate Zn2+ and previous studies have concluded that RNA Polymerase II (Pol II) inhibition in vivo is indirect. Here, we present chemicogenetic and biochemical approaches to investigate thiolutin's mode of action in Saccharomyces cerevisiae. We identify mutants that alter sensitivity to thiolutin. We provide genetic evidence that thiolutin causes oxidation of thioredoxins in vivo and that thiolutin both induces oxidative stress and interacts functionally with multiple metals including Mn2+ and Cu2+, and not just Zn2+. Finally, we show direct inhibition of RNA polymerase II (Pol II) transcription initiation by thiolutin in vitro in support of classical studies that thiolutin can directly inhibit transcription in vitro. Inhibition requires both Mn2+ and appropriate reduction of thiolutin as excess DTT abrogates its effects. Pause prone, defective elongation can be observed in vitro if inhibition is bypassed. Thiolutin effects on Pol II occupancy in vivo are widespread but major effects are consistent with prior observations for Tor pathway inhibition and stress induction, suggesting that thiolutin use in vivo should be restricted to studies on its modes of action and not as an experimental tool.
Collapse
Affiliation(s)
- Chenxi Qiu
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843, USA
| | - Payal Arora
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843, USA
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Indranil Malik
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843, USA
| | | | | | | | - Mandar Naik
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843, USA
| | - Craig D Kaplan
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA
| |
Collapse
|
2
|
Deschamps A, Thines L, Colinet AS, Stribny J, Morsomme P. The yeast Gdt1 protein mediates the exchange of H + for Ca 2+ and Mn 2+ influencing the Golgi pH. J Biol Chem 2023; 299:104628. [PMID: 36963491 PMCID: PMC10148156 DOI: 10.1016/j.jbc.2023.104628] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Revised: 02/24/2023] [Accepted: 03/16/2023] [Indexed: 03/26/2023] Open
Abstract
The GDT1 family is broadly spread and highly conserved among living organisms. GDT1 members have functions in key processes like glycosylation in humans and yeasts, and photosynthesis in plants. These functions are mediated by their ability to transport ions. While transport of Ca2+ or Mn2+ is well established for several GDT1 members, their transport mechanism is poorly understood. Here, we demonstrate that H+ ions are transported in exchange for Ca2+ and Mn2+ cations by the Golgi-localized yeast Gdt1 protein. We performed direct transport measurement across a biological membrane by expressing Gdt1p in Lactococcus lactis bacterial cells and by recording either the extracellular pH or the intracellular pH during the application of Ca2+, Mn2+ or H+ gradients. Besides, in vivo cytosolic and Golgi pH measurements were performed in Saccharomyces cerevisiae with genetically encoded pH probes targeted to those subcellular compartments. These data point out that the flow of H+ ions carried by Gdt1p could be reversed according to the physiological conditions. Together, our experiments unravel the influence of the relative concentration gradients for Gdt1p-mediated H+ transport and pave the way to decipher the regulatory mechanisms driving the activity of GDT1 orthologs in various biological contexts.
Collapse
Affiliation(s)
- Antoine Deschamps
- UCLouvain, Louvain Institute of Biomolecular Science and Technology (LIBST), Group of Molecular Physiology, Croix du Sud 4-5, B-1348 Louvain-la-Neuve, Belgium
| | - Louise Thines
- UCLouvain, Louvain Institute of Biomolecular Science and Technology (LIBST), Group of Molecular Physiology, Croix du Sud 4-5, B-1348 Louvain-la-Neuve, Belgium
| | - Anne-Sophie Colinet
- UCLouvain, Louvain Institute of Biomolecular Science and Technology (LIBST), Group of Molecular Physiology, Croix du Sud 4-5, B-1348 Louvain-la-Neuve, Belgium
| | - Jiri Stribny
- UCLouvain, Louvain Institute of Biomolecular Science and Technology (LIBST), Group of Molecular Physiology, Croix du Sud 4-5, B-1348 Louvain-la-Neuve, Belgium
| | - Pierre Morsomme
- UCLouvain, Louvain Institute of Biomolecular Science and Technology (LIBST), Group of Molecular Physiology, Croix du Sud 4-5, B-1348 Louvain-la-Neuve, Belgium.
| |
Collapse
|
3
|
Chen Z, Watanabe S, Hashida H, Inoue M, Daigaku Y, Kikkawa M, Inaba K. Cryo-EM structures of human SPCA1a reveal the mechanism of Ca 2+/Mn 2+ transport into the Golgi apparatus. SCIENCE ADVANCES 2023; 9:eadd9742. [PMID: 36867705 PMCID: PMC9984183 DOI: 10.1126/sciadv.add9742] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2022] [Accepted: 01/27/2023] [Indexed: 06/02/2023]
Abstract
Secretory pathway Ca2+/Mn2+ ATPase 1 (SPCA1) actively transports cytosolic Ca2+ and Mn2+ into the Golgi lumen, playing a crucial role in cellular calcium and manganese homeostasis. Detrimental mutations of the ATP2C1 gene encoding SPCA1 cause Hailey-Hailey disease. Here, using nanobody/megabody technologies, we determined cryo-electron microscopy structures of human SPCA1a in the ATP and Ca2+/Mn2+-bound (E1-ATP) state and the metal-free phosphorylated (E2P) state at 3.1- to 3.3-Å resolutions. The structures revealed that Ca2+ and Mn2+ share the same metal ion-binding pocket with similar but notably different coordination geometries in the transmembrane domain, corresponding to the second Ca2+-binding site in sarco/endoplasmic reticulum Ca2+-ATPase (SERCA). In the E1-ATP to E2P transition, SPCA1a undergoes similar domain rearrangements to those of SERCA. Meanwhile, SPCA1a shows larger conformational and positional flexibility of the second and sixth transmembrane helices, possibly explaining its wider metal ion specificity. These structural findings illuminate the unique mechanisms of SPCA1a-mediated Ca2+/Mn2+ transport.
Collapse
Affiliation(s)
- Zhenghao Chen
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai, Miyagi 980-8577, Japan
- Department of Molecular and Chemical Life Sciences, Graduate School of Life Sciences, Tohoku University, Sendai, Miyagi 980-8577, Japan
| | - Satoshi Watanabe
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai, Miyagi 980-8577, Japan
- Department of Molecular and Chemical Life Sciences, Graduate School of Life Sciences, Tohoku University, Sendai, Miyagi 980-8577, Japan
- Department of Chemistry, Graduate School of Science, Tohoku University, Sendai, Miyagi 980-8578, Japan
| | - Hironori Hashida
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai, Miyagi 980-8577, Japan
- Department of Molecular and Chemical Life Sciences, Graduate School of Life Sciences, Tohoku University, Sendai, Miyagi 980-8577, Japan
| | - Michio Inoue
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai, Miyagi 980-8577, Japan
| | - Yasukazu Daigaku
- Cancer Institute, Japanese Foundation for Cancer Research (JFCR), Tokyo 135-8550, Japan
| | - Masahide Kikkawa
- Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Kenji Inaba
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai, Miyagi 980-8577, Japan
- Department of Molecular and Chemical Life Sciences, Graduate School of Life Sciences, Tohoku University, Sendai, Miyagi 980-8577, Japan
- Department of Chemistry, Graduate School of Science, Tohoku University, Sendai, Miyagi 980-8578, Japan
- Core Research for Evolutional Science and Technology (CREST), Japan Agency for Medical Research and Development (AMED), Tokyo, Japan
| |
Collapse
|
4
|
Diessl J, Berndtsson J, Broeskamp F, Habernig L, Kohler V, Vazquez-Calvo C, Nandy A, Peselj C, Drobysheva S, Pelosi L, Vögtle FN, Pierrel F, Ott M, Büttner S. Manganese-driven CoQ deficiency. Nat Commun 2022; 13:6061. [PMID: 36229432 PMCID: PMC9563070 DOI: 10.1038/s41467-022-33641-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Accepted: 09/26/2022] [Indexed: 12/24/2022] Open
Abstract
Overexposure to manganese disrupts cellular energy metabolism across species, but the molecular mechanism underlying manganese toxicity remains enigmatic. Here, we report that excess cellular manganese selectively disrupts coenzyme Q (CoQ) biosynthesis, resulting in failure of mitochondrial bioenergetics. While respiratory chain complexes remain intact, the lack of CoQ as lipophilic electron carrier precludes oxidative phosphorylation and leads to premature cell and organismal death. At a molecular level, manganese overload causes mismetallation and proteolytic degradation of Coq7, a diiron hydroxylase that catalyzes the penultimate step in CoQ biosynthesis. Coq7 overexpression or supplementation with a CoQ headgroup analog that bypasses Coq7 function fully corrects electron transport, thus restoring respiration and viability. We uncover a unique sensitivity of a diiron enzyme to mismetallation and define the molecular mechanism for manganese-induced bioenergetic failure that is conserved across species.
Collapse
Affiliation(s)
- Jutta Diessl
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, 10691, Stockholm, Sweden
| | - Jens Berndtsson
- Department of Biochemistry and Biophysics, Stockholm University, 10691, Stockholm, Sweden
| | - Filomena Broeskamp
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, 10691, Stockholm, Sweden
| | - Lukas Habernig
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, 10691, Stockholm, Sweden
| | - Verena Kohler
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, 10691, Stockholm, Sweden
| | - Carmela Vazquez-Calvo
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, 10691, Stockholm, Sweden
- Department of Biochemistry and Biophysics, Stockholm University, 10691, Stockholm, Sweden
| | - Arpita Nandy
- Institute of Biochemistry and Molecular Biology, ZBMZ, University of Freiburg, 79104, Freiburg, Germany
- Faculty of Biology, University of Freiburg, 79104, Freiburg, Germany
- Spemann Graduate School of Biology and Medicine, University of Freiburg, 79104, Freiburg, Germany
| | - Carlotta Peselj
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, 10691, Stockholm, Sweden
| | - Sofia Drobysheva
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, 10691, Stockholm, Sweden
| | - Ludovic Pelosi
- Univ. Grenoble Alpes, CNRS, UMR 5525, VetAgro Sup, Grenoble INP, TIMC, 38000, Grenoble, France
| | - F-Nora Vögtle
- Institute of Biochemistry and Molecular Biology, ZBMZ, University of Freiburg, 79104, Freiburg, Germany
- CIBSS - Centre for Integrative Biological Signalling Studies, University of Freiburg, 79104, Freiburg, Germany
- Center for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance, 69120, Heidelberg, Germany
- Network Aging Research, Heidelberg University, 69120, Heidelberg, Germany
| | - Fabien Pierrel
- Univ. Grenoble Alpes, CNRS, UMR 5525, VetAgro Sup, Grenoble INP, TIMC, 38000, Grenoble, France
| | - Martin Ott
- Department of Biochemistry and Biophysics, Stockholm University, 10691, Stockholm, Sweden
- Department of Medical Biochemistry and Cell Biology, Institute of Biomedicine, University of Gothenburg, 40530, Gothenburg, Sweden
| | - Sabrina Büttner
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, 10691, Stockholm, Sweden.
| |
Collapse
|
5
|
Gao J, Gao A, Zhou H, Chen L. The role of metal ions in the Golgi apparatus. Cell Biol Int 2022; 46:1309-1319. [PMID: 35830695 DOI: 10.1002/cbin.11848] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2022] [Revised: 05/19/2022] [Accepted: 05/28/2022] [Indexed: 11/09/2022]
Abstract
The Golgi apparatus is a membrane-bound organelle that functions as a central role in the secretory pathway. Since the discovery of the Golgi apparatus, its structure and function have attracted ever-increasing attention from researchers. Recently, it has been demonstrated that metal ions are necessary for the Golgi apparatus to maintain its proper structure and functions. Given that metal ions play an important role in various biological processes, their abnormal homeostasis is related to many diseases. Therefore, in this paper, we reviewed the uptake and release mechanisms of the Golgi apparatus Ca2+ , Cu, and Zn2+ . Furthermore, we describe the diseases associated with Golgi apparatus Ca2+ , Cu, and Zn2+ imbalance.
Collapse
Affiliation(s)
- Jiayin Gao
- Institute of Pharmacy and Pharmacology, Learning Key Laboratory for Pharmacoproteomics, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China
| | - Anbo Gao
- Institute of Pharmacy and Pharmacology, Learning Key Laboratory for Pharmacoproteomics, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China
| | - Hong Zhou
- Department of Radiology of the First Affiliated Hospital of University of South China, Hengyang, China
| | - Linxi Chen
- Institute of Pharmacy and Pharmacology, Learning Key Laboratory for Pharmacoproteomics, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China
| |
Collapse
|
6
|
He J, Rössner N, Hoang MTT, Alejandro S, Peiter E. Transport, functions, and interaction of calcium and manganese in plant organellar compartments. PLANT PHYSIOLOGY 2021; 187:1940-1972. [PMID: 35235665 PMCID: PMC8890496 DOI: 10.1093/plphys/kiab122] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Accepted: 03/02/2021] [Indexed: 05/05/2023]
Abstract
Calcium (Ca2+) and manganese (Mn2+) are essential elements for plants and have similar ionic radii and binding coordination. They are assigned specific functions within organelles, but share many transport mechanisms to cross organellar membranes. Despite their points of interaction, those elements are usually investigated and reviewed separately. This review takes them out of this isolation. It highlights our current mechanistic understanding and points to open questions of their functions, their transport, and their interplay in the endoplasmic reticulum (ER), vesicular compartments (Golgi apparatus, trans-Golgi network, pre-vacuolar compartment), vacuoles, chloroplasts, mitochondria, and peroxisomes. Complex processes demanding these cations, such as Mn2+-dependent glycosylation or systemic Ca2+ signaling, are covered in some detail if they have not been reviewed recently or if recent findings add to current models. The function of Ca2+ as signaling agent released from organelles into the cytosol and within the organelles themselves is a recurrent theme of this review, again keeping the interference by Mn2+ in mind. The involvement of organellar channels [e.g. glutamate receptor-likes (GLR), cyclic nucleotide-gated channels (CNGC), mitochondrial conductivity units (MCU), and two-pore channel1 (TPC1)], transporters (e.g. natural resistance-associated macrophage proteins (NRAMP), Ca2+ exchangers (CAX), metal tolerance proteins (MTP), and bivalent cation transporters (BICAT)], and pumps [autoinhibited Ca2+-ATPases (ACA) and ER Ca2+-ATPases (ECA)] in the import and export of organellar Ca2+ and Mn2+ is scrutinized, whereby current controversial issues are pointed out. Mechanisms in animals and yeast are taken into account where they may provide a blueprint for processes in plants, in particular, with respect to tunable molecular mechanisms of Ca2+ versus Mn2+ selectivity.
Collapse
Affiliation(s)
- Jie He
- Faculty of Natural Sciences III, Plant Nutrition Laboratory, Institute of Agricultural and Nutritional Sciences, Martin Luther University Halle-Wittenberg, D-06099 Halle (Saale), Germany
| | - Nico Rössner
- Faculty of Natural Sciences III, Plant Nutrition Laboratory, Institute of Agricultural and Nutritional Sciences, Martin Luther University Halle-Wittenberg, D-06099 Halle (Saale), Germany
| | - Minh T T Hoang
- Faculty of Natural Sciences III, Plant Nutrition Laboratory, Institute of Agricultural and Nutritional Sciences, Martin Luther University Halle-Wittenberg, D-06099 Halle (Saale), Germany
| | - Santiago Alejandro
- Faculty of Natural Sciences III, Plant Nutrition Laboratory, Institute of Agricultural and Nutritional Sciences, Martin Luther University Halle-Wittenberg, D-06099 Halle (Saale), Germany
| | - Edgar Peiter
- Faculty of Natural Sciences III, Plant Nutrition Laboratory, Institute of Agricultural and Nutritional Sciences, Martin Luther University Halle-Wittenberg, D-06099 Halle (Saale), Germany
- Author for communication:
| |
Collapse
|
7
|
Pujari I, Thomas A, Sankar Babu V. Native and non-native host assessment towards metabolic pathway reconstructions of plant natural products. ACTA ACUST UNITED AC 2021; 30:e00619. [PMID: 33996523 PMCID: PMC8091882 DOI: 10.1016/j.btre.2021.e00619] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 04/05/2021] [Accepted: 04/11/2021] [Indexed: 11/16/2022]
Abstract
Plant metabolic networks are highly complex. Engineering the phytochemical pathways fully in heterologous hosts is challenging. Single plant cells with amplified multiple fission enable homogeneity. Homogeneity and high cell division rate can facilitate stable product scale-up.
Plant-based biopreparations are reasonably priced and are devoid of viral, prion and endotoxin contaminants. However, synthesizing these natural plant products by chemical methods is quite expensive. The structural complexity of plant-derived natural products poses a challenge for chemical synthesis at a commercial scale. Failure of commercial-scale synthesis is the chief reason why metabolic reconstructions in heterologous hosts are inevitable. This review discusses plant metabolite pathway reconstructions experimented in various heterologous hosts, and the inherent challenges involved. Plants as native hosts possess enhanced post-translational modification ability, along with rigorous gene edits, unlike microbes. To achieve a high yield of metabolites in plants, increased cell division rate is one of the requisites. This improved cell division rate will promote cellular homogeneity. Incorporation and maintenance of plant cell synchrony, in turn, can program stable product scale-up.
Collapse
Affiliation(s)
- Ipsita Pujari
- Department of Plant Sciences, Manipal School of Life Sciences, Manipal Academy of Higher Education, Manipal, Karnataka, 576104, India
| | - Abitha Thomas
- Department of Plant Sciences, Manipal School of Life Sciences, Manipal Academy of Higher Education, Manipal, Karnataka, 576104, India
| | - Vidhu Sankar Babu
- Department of Plant Sciences, Manipal School of Life Sciences, Manipal Academy of Higher Education, Manipal, Karnataka, 576104, India
| |
Collapse
|
8
|
Cytotoxicity of Oleandrin Is Mediated by Calcium Influx and by Increased Manganese Uptake in Saccharomyces cerevisiae Cells. Molecules 2020; 25:molecules25184259. [PMID: 32957533 PMCID: PMC7570853 DOI: 10.3390/molecules25184259] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Revised: 09/09/2020] [Accepted: 09/15/2020] [Indexed: 11/22/2022] Open
Abstract
Oleandrin, the main component of Nerium oleander L. extracts, is a cardiotoxic glycoside with multiple pharmacological implications, having potential anti-tumoral and antiviral characteristics. Although it is accepted that the main mechanism of oleandrin action is the inhibition of Na+/K+-ATPases and subsequent increase in cell calcium, many aspects which determine oleandrin cytotoxicity remain elusive. In this study, we used the model Saccharomyces cerevisiae to unravel new elements accounting for oleandrin toxicity. Using cells expressing the Ca2+-sensitive photoprotein aequorin, we found that oleandrin exposure resulted in Ca2+ influx into the cytosol and that failing to pump Ca2+ from the cytosol to the vacuole increased oleandrin toxicity. We also found that oleandrin exposure induced Mn2+ accumulation by yeast cells via the plasma membrane Smf1 and that mutants with defects in Mn2+ homeostasis are oleandrin-hypersensitive. Our data suggest that combining oleandrin with agents which alter Ca2+ or Mn2+ uptake may be a way of controlling oleandrin toxicity.
Collapse
|
9
|
Oyama M, Tamaki H, Yamaguchi Y, Ogita A, Tanaka T, Fujita KI. Deletion of the Golgi Ca2+-ATPase PMR1 gene potentiates antifungal effects of dodecanol that depend on intracellular Ca2+ accumulation in budding yeast. FEMS Yeast Res 2020; 20:5706841. [PMID: 31942998 DOI: 10.1093/femsyr/foaa003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Accepted: 01/14/2020] [Indexed: 12/13/2022] Open
Abstract
One strategy for overcoming infectious diseases caused by drug-resistant fungi involves combining drugs rendered inactive by resistance with agents targeting the drug resistance mechanism. The antifungal activity of n-dodecanol disappears as incubation time passes. In Saccharomyces cerevisiae, anethole, a principal component of anise oil, prolongs the transient antifungal effect of dodecanol by downregulating genes of multidrug efflux pumps, mainly PDR5. However, the detailed mechanisms of dodecanol's antifungal action and the anethole-induced prolonged antifungal action of dodecanol are unknown. Screening of S. cerevisiae strains lacking genes related to Ca2+ homeostasis and signaling identified a pmr1Δ strain lacking Golgi Ca2+-ATPase as more sensitive to dodecanol than the parental strain. Dodecanol and the dodecanol + anethole combination significantly increased intracellular Ca2+ levels in both strains, but the mutant failed to clear intracellular Ca2+ accumulation. Further, dodecanol and the drug combination reduced PMR1 expression and did not lead to specific localization of Pmr1p in the parental strain after 4-h treatment. By contrast with the parental strain, dodecanol did not stimulate PDR5 expression in pmr1Δ. Based on these observations, we propose that the antifungal activity of dodecanol is related to intracellular Ca2+ accumulation, possibly dependent on PMR1 function, with anethole enabling Ca2+ accumulation by restricting dodecanol efflux.
Collapse
Affiliation(s)
- Masahiro Oyama
- Graduate School of Science, Osaka City University, Osaka, Japan
| | - Hiroyuki Tamaki
- Graduate School of Science, Osaka City University, Osaka, Japan
| | | | - Akira Ogita
- Graduate School of Science, Osaka City University, Osaka, Japan.,Research Center for Urban Health and Sports, Osaka City University, Osaka, Japan
| | - Toshio Tanaka
- Graduate School of Science, Osaka City University, Osaka, Japan
| | - Ken-Ichi Fujita
- Graduate School of Science, Osaka City University, Osaka, Japan
| |
Collapse
|
10
|
Chen J, Smaardijk S, Mattelaer CA, Pamula F, Vandecaetsbeek I, Vanoevelen J, Wuytack F, Lescrinier E, Eggermont J, Vangheluwe P. An N-terminal Ca 2+-binding motif regulates the secretory pathway Ca 2+/Mn 2+-transport ATPase SPCA1. J Biol Chem 2019; 294:7878-7891. [PMID: 30923126 DOI: 10.1074/jbc.ra118.006250] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Revised: 03/23/2019] [Indexed: 11/06/2022] Open
Abstract
The Ca2+/Mn2+ transport ATPases 1a and 2 (SPCA1a/2) are closely related to the sarco(endo)plasmic reticulum Ca2+-ATPase (SERCA) and are implicated in breast cancer and Hailey-Hailey skin disease. Here, we purified the human SPCA1a/2 isoforms from a yeast recombinant expression system and compared their biochemical properties after reconstitution. We observed that the purified SPCA1a displays a lower Ca2+ affinity and slightly lower Mn2+ affinity than SPCA2. Remarkably, the turnover rates of SPCA1a in the presence of Mn2+ and SPCA2 incubated with Ca2+ and Mn2+ were comparable, whereas the turnover rate of SPCA1a in Ca2+ was 2-fold higher. Moreover, we noted an unusual biphasic activation curve for the SPCA1a ATPase and autophosphorylation activity, not observed with SPCA2. We also found that the biphasic pattern and low apparent ion affinity of SPCA1a critically depends on ATP concentration. We further show that the specific properties of SPCA1a at least partially depend on an N-terminal EF-hand-like motif, which is present only in the SPCA1a isoform and absent in SPCA2. This motif binds Ca2+, and its mutation lowered the Ca2+ turnover rate relative to that of Mn2+, increased substrate affinity, and reduced the level of biphasic activation of SPCA1a. A biochemical analysis indicated that Ca2+ binding to the N-terminal EF-hand-like motif promotes the activity of SPCA1a by facilitating autophosphorylation. We propose that this regulation may be physiologically relevant in cells with a high Ca2+ load, such as mammary gland cells during lactation, or in cells with a low ATP content, such as keratinocytes.
Collapse
Affiliation(s)
- Jialin Chen
- From the Laboratory of Cellular Transport Systems, Department of Cellular and Molecular Medicine and
| | - Susanne Smaardijk
- From the Laboratory of Cellular Transport Systems, Department of Cellular and Molecular Medicine and
| | - Charles-Alexandre Mattelaer
- Medicinal Chemistry, Department of Pharmaceutical and Pharmacological Sciences, Rega Institute, KU Leuven, Belgium
| | - Filip Pamula
- From the Laboratory of Cellular Transport Systems, Department of Cellular and Molecular Medicine and
| | - Ilse Vandecaetsbeek
- From the Laboratory of Cellular Transport Systems, Department of Cellular and Molecular Medicine and
| | - Jo Vanoevelen
- From the Laboratory of Cellular Transport Systems, Department of Cellular and Molecular Medicine and
| | - Frank Wuytack
- From the Laboratory of Cellular Transport Systems, Department of Cellular and Molecular Medicine and
| | - Eveline Lescrinier
- Medicinal Chemistry, Department of Pharmaceutical and Pharmacological Sciences, Rega Institute, KU Leuven, Belgium
| | - Jan Eggermont
- From the Laboratory of Cellular Transport Systems, Department of Cellular and Molecular Medicine and
| | - Peter Vangheluwe
- From the Laboratory of Cellular Transport Systems, Department of Cellular and Molecular Medicine and
| |
Collapse
|
11
|
Manganese Suppresses the Haploinsufficiency of Heterozygous trpy1Δ/TRPY1 Saccharomyces cerevisiae Cells and Stimulates the TRPY1-Dependent Release of Vacuolar Ca 2+ under H₂O₂ Stress. Cells 2019; 8:cells8020079. [PMID: 30678234 PMCID: PMC6406398 DOI: 10.3390/cells8020079] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Revised: 01/09/2019] [Accepted: 01/18/2019] [Indexed: 11/17/2022] Open
Abstract
Transient potential receptor (TRP) channels are conserved cation channels found in most eukaryotes, known to sense a variety of chemical, thermal or mechanical stimuli. The Saccharomyces cerevisiae TRPY1 is a TRP channel with vacuolar localization involved in the cellular response to hyperosmotic shock and oxidative stress. In this study, we found that S. cerevisiae diploid cells with heterozygous deletion in TRPY1 gene are haploinsufficient when grown in synthetic media deficient in essential metal ions and that this growth defect is alleviated by non-toxic Mn2+ surplus. Using cells expressing the Ca2+-sensitive photoprotein aequorin we found that Mn2+ augmented the Ca2+ flux into the cytosol under oxidative stress, but not under hyperosmotic shock, a trait that was absent in the diploid cells with homozygous deletion of TRPY1 gene. TRPY1 activation under oxidative stress was diminished in cells devoid of Smf1 (the Mn2+-high-affinity plasma membrane transporter) but it was clearly augmented in cells lacking Pmr1 (the endoplasmic reticulum (ER)/Golgi located ATPase responsible for Mn2+ detoxification via excretory pathway). Taken together, these observations lead to the conclusion that increased levels of intracytosolic Mn2+ activate TRPY1 in the response to oxidative stress.
Collapse
|
12
|
Thompson KJ, Hein J, Baez A, Sosa JC, Wessling-Resnick M. Manganese transport and toxicity in polarized WIF-B hepatocytes. Am J Physiol Gastrointest Liver Physiol 2018; 315:G351-G363. [PMID: 29792530 PMCID: PMC6335010 DOI: 10.1152/ajpgi.00103.2018] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Manganese (Mn) toxicity arises from nutritional problems, community and occupational exposures, and genetic risks. Mn blood levels are controlled by hepatobiliary clearance. The goals of this study were to determine the cellular distribution of Mn transporters in polarized hepatocytes, to establish an in vitro assay for hepatocyte Mn efflux, and to examine possible roles the Mn transporters would play in metal import and export. For these experiments, hepatocytoma WIF-B cells were grown for 12-14 days to achieve maximal polarity. Immunoblots showed that Mn transporters ZIP8, ZnT10, ferroportin (Fpn), and ZIP14 were present. Indirect immunofluorescence microscopy localized Fpn and ZIP14 to WIF-B cell basolateral domains whereas ZnT10 and ZIP8 associated with intracellular vesicular compartments. ZIP8-positive structures were distributed uniformly throughout the cytoplasm, but ZnT10-positive vesicles were adjacent to apical bile compartments. WIF-B cells were sensitive to Mn toxicity, showing decreased viability after 16 h exposure to >250 μM MnCl2. However, the hepatocytes were resistant to 4-h exposures of up to 500 μM MnCl2 despite 50-fold increased Mn content. Washout experiments showed time-dependent efflux with 80% Mn released after a 4 h chase period. Hepcidin reduced levels of Fpn in WIF-B cells, clearing Fpn from the cell surface, but Mn efflux was unaffected. The secretory inhibitor, brefeldin A, did block release of Mn from WIF-B cells, suggesting vesicle fusion may be involved in export. These results point to a possible role of ZnT10 to import Mn into vesicles that subsequently fuse with the apical membrane and empty their contents into bile. NEW & NOTEWORTHY Polarized WIF-B hepatocytes express manganese (Mn) transporters ZIP8, ZnT10, ferroportin (Fpn), and ZIP14. Fpn and ZIP14 localize to basolateral domains. ZnT10-positive vesicles were adjacent to apical bile compartments, and ZIP8-positive vesicles were distributed uniformly throughout the cytoplasm. WIF-B hepatocyte Mn export was resistant to hepcidin but inhibited by brefeldin A, pointing to an efflux mechanism involving ZnT10-mediated uptake of Mn into vesicles that subsequently fuse with and empty their contents across the apical bile canalicular membrane.
Collapse
Affiliation(s)
- Khristy J. Thompson
- Department of Genetics and Complex Diseases, Harvard T. H. Chan School of Public Health, Harvard University, Boston, Massachusetts
| | - Jennifer Hein
- Department of Genetics and Complex Diseases, Harvard T. H. Chan School of Public Health, Harvard University, Boston, Massachusetts
| | - Andrew Baez
- Department of Genetics and Complex Diseases, Harvard T. H. Chan School of Public Health, Harvard University, Boston, Massachusetts
| | - Jose Carlo Sosa
- Department of Genetics and Complex Diseases, Harvard T. H. Chan School of Public Health, Harvard University, Boston, Massachusetts
| | - Marianne Wessling-Resnick
- Department of Genetics and Complex Diseases, Harvard T. H. Chan School of Public Health, Harvard University, Boston, Massachusetts
| |
Collapse
|
13
|
Thines L, Deschamps A, Sengottaiyan P, Savel O, Stribny J, Morsomme P. The yeast protein Gdt1p transports Mn 2+ ions and thereby regulates manganese homeostasis in the Golgi. J Biol Chem 2018; 293:8048-8055. [PMID: 29632074 DOI: 10.1074/jbc.ra118.002324] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Revised: 04/05/2018] [Indexed: 11/06/2022] Open
Abstract
The uncharacterized protein family 0016 (UPF0016) is a family of secondary ion transporters implicated in calcium homeostasis and some diseases. More precisely, genetic variants of the human UPF0016 ortholog transmembrane protein 165 (TMEM165) have been linked to congenital disorders of glycosylation (CDG). The Saccharomyces cerevisiae ortholog Gdt1p has been shown to be involved in calcium homeostasis and protein glycosylation. Moreover, plant and bacterial UPF0016 members appear to have putative roles in Mn2+ homeostasis. Here, we produced the yeast UPF0016 member Gdt1p in the bacterial host Lactococcus lactis Using Mn2+-induced quenching of Fura-2-emitted fluorescence, we observed that Gdt1p mediates Mn2+ influx, in addition to its previously reported regulation of Ca2+ influx. The estimated Km values of Gdt1p of 15.6 ± 2.6 μm for Ca2+ and 83.2 ± 9.8 μm for Mn2+ indicated that Gdt1p has a higher affinity for Ca2+ than for Mn2+ In yeast cells, we found that Gdt1p is involved in the resistance to high Mn2+ concentration and controls total Mn2+ stores. Lastly, we demonstrated that GDT1 deletion affects the activity of the yeast Mn2+-dependent Sod2p superoxide dismutase, most likely by modulating cytosolic Mn2+ concentrations. Taken together, we obtained first evidence that Gdt1p from yeast directly transports manganese, which strongly reinforces the suggested link between the UPF0016 family and Mn2+ homeostasis and provides new insights into the molecular causes of human TMEM165-associated CDGs. Our results also shed light on how yeast cells may regulate Golgi intraluminal concentrations of manganese, a key cofactor of many enzymes involved in protein glycosylation.
Collapse
Affiliation(s)
- Louise Thines
- Institut des Sciences de la Vie, Université catholique de Louvain, B-1348 Louvain-la-Neuve, Belgium
| | - Antoine Deschamps
- Institut des Sciences de la Vie, Université catholique de Louvain, B-1348 Louvain-la-Neuve, Belgium
| | - Palanivelu Sengottaiyan
- Institut des Sciences de la Vie, Université catholique de Louvain, B-1348 Louvain-la-Neuve, Belgium
| | - Oksana Savel
- Institut des Sciences de la Vie, Université catholique de Louvain, B-1348 Louvain-la-Neuve, Belgium
| | - Jiri Stribny
- Institut des Sciences de la Vie, Université catholique de Louvain, B-1348 Louvain-la-Neuve, Belgium
| | - Pierre Morsomme
- Institut des Sciences de la Vie, Université catholique de Louvain, B-1348 Louvain-la-Neuve, Belgium.
| |
Collapse
|
14
|
Investigating the function of Gdt1p in yeast Golgi glycosylation. Biochim Biophys Acta Gen Subj 2018; 1862:394-402. [DOI: 10.1016/j.bbagen.2017.11.006] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Revised: 10/06/2017] [Accepted: 11/01/2017] [Indexed: 11/20/2022]
|
15
|
Chen Y, Shen Y, Wang W, Wei D. Mn 2+ modulates the expression of cellulase genes in Trichoderma reesei Rut-C30 via calcium signaling. BIOTECHNOLOGY FOR BIOFUELS 2018; 11:54. [PMID: 29507606 PMCID: PMC5831609 DOI: 10.1186/s13068-018-1055-6] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Accepted: 02/18/2018] [Indexed: 05/11/2023]
Abstract
BACKGROUND The filamentous fungus Trichoderma reesei Rut-C30 is one of the most vital fungi for the production of cellulases, which can be used for biofuel production from lignocellulose. Nevertheless, the mechanism of transmission of external stimuli and signals in modulating cellulase production in T. reesei Rut-C30 remains unclear. Calcium is a known second messenger regulating cellulase gene expression in T. reesei. RESULTS In this study, we found that a biologically relevant extracellular Mn2+ concentration markedly stimulates cellulase production, total protein secretion, and the intracellular Mn2+ concentration of Rut-C30, a cellulase hyper-producing strain of T. reesei. Furthermore, we identified two Mn2+ transport proteins, designated as TPHO84-1 and TPHO84-2, indicating that they are upstream in the signaling pathway that leads to cellulase upregulation. We also found that Mn2+ induced a significant increase in cytosolic Ca2+ concentration, and that this increased cytosolic Ca2+ might be a key step in the Mn2+-mediated regulation of cellulase gene transcription and production. The utilization of LaCl3 to block plasma membrane Ca2+ channels, and deletion of crz1 (calcineurin-responsive zinc finger transcription factor 1) to interrupt calcium signaling, showed that Mn2+ exerts the induction of cellulase genes via calcium channels and calcium signaling. To substantiate this, we identified a Ca2+/Mn2+ P-type ATPase, TPMR1, which could play a pivotal role in Ca2+/Mn2+ homeostasis and Mn2+ induction of cellulase genes in T. reesei Rut-C30. CONCLUSIONS Taken together, our results revealed for the first time that Mn2+ stimulates cellulase production, and demonstrates that Mn2+ upregulates cellulase genes via calcium channels and calcium signaling. Our research also provides a direction to facilitate enhanced cellulase production by T. reesei.
Collapse
Affiliation(s)
- Yumeng Chen
- State Key Lab of Bioreactor Engineering, New World Institute of Biotechnology, East China University of Science and Technology, East China University of Science and Technology, 130 Meilong Road, P.O.B. 311, Shanghai, 200237 China
| | - Yaling Shen
- State Key Lab of Bioreactor Engineering, New World Institute of Biotechnology, East China University of Science and Technology, East China University of Science and Technology, 130 Meilong Road, P.O.B. 311, Shanghai, 200237 China
| | - Wei Wang
- State Key Lab of Bioreactor Engineering, New World Institute of Biotechnology, East China University of Science and Technology, East China University of Science and Technology, 130 Meilong Road, P.O.B. 311, Shanghai, 200237 China
| | - Dongzhi Wei
- State Key Lab of Bioreactor Engineering, New World Institute of Biotechnology, East China University of Science and Technology, East China University of Science and Technology, 130 Meilong Road, P.O.B. 311, Shanghai, 200237 China
| |
Collapse
|
16
|
Tran Nguyen Hoang P, Ko JK, Gong G, Um Y, Lee SM. Genomic and phenotypic characterization of a refactored xylose-utilizing Saccharomyces cerevisiae strain for lignocellulosic biofuel production. BIOTECHNOLOGY FOR BIOFUELS 2018; 11:268. [PMID: 30288173 PMCID: PMC6162923 DOI: 10.1186/s13068-018-1269-7] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Accepted: 09/21/2018] [Indexed: 05/12/2023]
Abstract
BACKGROUND Engineered strains of Saccharomyces cerevisiae have significantly improved the prospects of biorefinery by improving the bioconversion yields in lignocellulosic bioethanol production and expanding the product profiles to include advanced biofuels and chemicals. However, the lignocellulosic biorefinery concept has not been fully applied using engineered strains in which either xylose utilization or advanced biofuel/chemical production pathways have been upgraded separately. Specifically, high-performance xylose-fermenting strains have rarely been employed as advanced biofuel and chemical production platforms and require further engineering to expand their product profiles. RESULTS In this study, we refactored a high-performance xylose-fermenting S. cerevisiae that could potentially serve as a platform strain for advanced biofuels and biochemical production. Through combinatorial CRISPR-Cas9-mediated rational and evolutionary engineering, we obtained a newly refactored isomerase-based xylose-fermenting strain, XUSE, that demonstrated efficient conversion of xylose into ethanol with a high yield of 0.43 g/g. In addition, XUSE exhibited the simultaneous fermentation of glucose and xylose with negligible glucose inhibition, indicating the potential of this isomerase-based xylose-utilizing strain for lignocellulosic biorefinery. The genomic and transcriptomic analysis of XUSE revealed beneficial mutations and changes in gene expression that are responsible for the enhanced xylose fermentation performance of XUSE. CONCLUSIONS In this study, we developed a high-performance xylose-fermenting S. cerevisiae strain, XUSE, with high ethanol yield and negligible glucose inhibition. Understanding the genomic and transcriptomic characteristics of XUSE revealed isomerase-based engineering strategies for improved xylose fermentation in S. cerevisiae. With high xylose fermentation performance and room for further engineering, XUSE could serve as a promising platform strain for lignocellulosic biorefinery.
Collapse
Affiliation(s)
- Phuong Tran Nguyen Hoang
- Clean Energy Research Center, Korea Institute of Science and Technology (KIST), Seoul, 02792 Republic of Korea
- Division of Energy and Environment Technology, University of Science and Technology (UST), Daejeon, 34113 Republic of Korea
| | - Ja Kyong Ko
- Clean Energy Research Center, Korea Institute of Science and Technology (KIST), Seoul, 02792 Republic of Korea
| | - Gyeongtaek Gong
- Clean Energy Research Center, Korea Institute of Science and Technology (KIST), Seoul, 02792 Republic of Korea
| | - Youngsoon Um
- Clean Energy Research Center, Korea Institute of Science and Technology (KIST), Seoul, 02792 Republic of Korea
- Division of Energy and Environment Technology, University of Science and Technology (UST), Daejeon, 34113 Republic of Korea
| | - Sun-Mi Lee
- Clean Energy Research Center, Korea Institute of Science and Technology (KIST), Seoul, 02792 Republic of Korea
- Division of Energy and Environment Technology, University of Science and Technology (UST), Daejeon, 34113 Republic of Korea
- Green School, Korea University, Seoul, 02841 Republic of Korea
| |
Collapse
|
17
|
High-Resolution Phenotypic Landscape of the RNA Polymerase II Trigger Loop. PLoS Genet 2016; 12:e1006321. [PMID: 27898685 PMCID: PMC5127505 DOI: 10.1371/journal.pgen.1006321] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2016] [Accepted: 10/24/2016] [Indexed: 11/30/2022] Open
Abstract
The active sites of multisubunit RNA polymerases have a “trigger loop” (TL) that multitasks in substrate selection, catalysis, and translocation. To dissect the Saccharomyces cerevisiae RNA polymerase II TL at individual-residue resolution, we quantitatively phenotyped nearly all TL single variants en masse. Three mutant classes, revealed by phenotypes linked to transcription defects or various stresses, have distinct distributions among TL residues. We find that mutations disrupting an intra-TL hydrophobic pocket, proposed to provide a mechanism for substrate-triggered TL folding through destabilization of a catalytically inactive TL state, confer phenotypes consistent with pocket disruption and increased catalysis. Furthermore, allele-specific genetic interactions among TL and TL-proximal domain residues support the contribution of the funnel and bridge helices (BH) to TL dynamics. Our structural genetics approach incorporates structural and phenotypic data for high-resolution dissection of transcription mechanisms and their evolution, and is readily applicable to other essential yeast proteins. Proper regulation of Pol II transcription, the first step of gene expression, is essential for life. Extensive evidence has revealed a widely conserved and dynamic polymerase active site component, termed the Trigger Loop (TL), in balancing transcription rate and fidelity while possibly allowing control of transcription elongation. Coupling high-throughput sequencing with our previously established genetic system, we are able to assess the in vivo phenotypes for almost all possible single substitution Pol II TL mutants in the budding yeast Saccharomyces cerevisiae. We show that mutants in the TL nucleotide interacting and linker regions widely confer dominant and severe growth defects. Clustering of TL mutants’ transcription-related and general stress phenotypes reveals three main classes of TL mutants, including previously identified fast and slow elongating mutants. Comprehensive analyses of the distribution of fast and slow elongation mutants in light of existing Pol II crystal structures reveal critical regions contributing to proper TL dynamics and function. Evidence is presented linking a previously observed hydrophobic pocket to NTP substrate-induced TL closing, the mechanism critical for correct substrates selection and transcription fidelity. Finally, we assess the functional interplay between TL and its proximal domains, and their presumptive roles in the function and evolution of the TL. Utilizing the Pol II TL as a case study, we present a structural genetics approach that reveals insights into a complex, multi-functional, and essential domain in yeast.
Collapse
|
18
|
Shawn, the Drosophila Homolog of SLC25A39/40, Is a Mitochondrial Carrier That Promotes Neuronal Survival. J Neurosci 2016; 36:1914-29. [PMID: 26865615 DOI: 10.1523/jneurosci.3432-15.2016] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
UNLABELLED Mitochondria play an important role in the regulation of neurotransmission, and mitochondrial impairment is a key event in neurodegeneration. Cells rely on mitochondrial carrier proteins of the SLC25 family to shuttle ions, cofactors, and metabolites necessary for enzymatic reactions. Mutations in these carriers often result in rare but severe pathologies in the brain, and some of the genes, including SLC25A39 and SLC25A40, reside in susceptibility loci of severe forms of epilepsy. However, the role of most of these carriers has not been investigated in neurons in vivo. We identified shawn, the Drosophila homolog of SLC25A39 and SLC25A40, in a genetic screen to identify genes involved in neuronal function. Shawn localizes to mitochondria, and missense mutations result in an accumulation of reactive oxygen species, mitochondrial dysfunction, and neurodegeneration. Shawn regulates metal homeostasis, and we found in shawn mutants increased levels of manganese, calcium, and mitochondrial free iron. Mitochondrial mutants often cannot maintain synaptic transmission under demanding conditions, but shawn mutants do, and they also do not display endocytic defects. In contrast, shawn mutants harbor a significant increase in neurotransmitter release. Our work provides the first functional annotation of these essential mitochondrial carriers in the nervous system, and the results suggest that metal imbalances and mitochondrial dysfunction may contribute to defects in synaptic transmission and neuronal survival. SIGNIFICANCE STATEMENT We describe for the first time the role of the mitochondrial carrier Shawn/SLC25A39/SLC25A40 in the nervous system. In humans, these genes reside in susceptibility loci for epilepsy, and, in flies, we observe neuronal defects related to mitochondrial dysfunction and metal homeostasis defects. Interestingly, shawn mutants also harbor increased neurotransmitter release and neurodegeneration. Our data suggest a connection between maintaining a correct metal balance and mitochondrial function to regulate neuronal survival and neurotransmitter release.
Collapse
|
19
|
Micaroni M, Giacchetti G, Plebani R, Xiao GG, Federici L. ATP2C1 gene mutations in Hailey-Hailey disease and possible roles of SPCA1 isoforms in membrane trafficking. Cell Death Dis 2016; 7:e2259. [PMID: 27277681 PMCID: PMC5143377 DOI: 10.1038/cddis.2016.147] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2015] [Revised: 04/17/2016] [Accepted: 04/28/2016] [Indexed: 12/12/2022]
Abstract
ATP2C1 gene codes for the secretory pathway Ca(2+)/Mn(2+)-ATPase pump type 1 (SPCA1) localizing at the golgi apparatus. Mutations on the human ATP2C1 gene, causing decreased levels of the SPCA1 expression, have been identified as the cause of the Hailey-Hailey disease, a rare skin disorder. In the last few years, several mutations have been described, and here we summarize how they are distributed along the gene and how missense mutations affect protein expression. SPCA1 is expressed in four different isoforms through alternative splicing of the ATP2C1 gene and none of these isoforms is differentially affected by any of these mutations. However, a better understanding of the tissue specific expression of the isoforms, their localization along the secretory pathway, their specific binding partners and the role of the C-terminal tail making isoforms different from each other, will be future goals of the research in this field.
Collapse
Affiliation(s)
- M Micaroni
- School of Pharmaceutical Science and Technology, Dalian University of Technology, Dalian 116024, China
| | - G Giacchetti
- Aging Research Center (Ce.S.I.), University 'G. D'Annunzio' of Chieti-Pescara, Chieti 66100, Italy.,Department of Neuroscience, Imaging and Clinical Sciences, University 'G. D'Annunzio' of Chieti-Pescara, Chieti 66100, Italy
| | - R Plebani
- Aging Research Center (Ce.S.I.), University 'G. D'Annunzio' of Chieti-Pescara, Chieti 66100, Italy.,Department of Medical Oral and Biotechnological Sciences, School of Medicine and Health Sciences, University 'G. D'Annunzio' of Chieti-Pescara, Chieti 66100, Italy
| | - G G Xiao
- School of Pharmaceutical Science and Technology, Dalian University of Technology, Dalian 116024, China
| | - L Federici
- Aging Research Center (Ce.S.I.), University 'G. D'Annunzio' of Chieti-Pescara, Chieti 66100, Italy.,Department of Medical Oral and Biotechnological Sciences, School of Medicine and Health Sciences, University 'G. D'Annunzio' of Chieti-Pescara, Chieti 66100, Italy
| |
Collapse
|
20
|
Mukherjee I, Barlowe C. Overexpression of Sly41 suppresses COPII vesicle-tethering deficiencies by elevating intracellular calcium levels. Mol Biol Cell 2016; 27:1635-49. [PMID: 27030673 PMCID: PMC4865320 DOI: 10.1091/mbc.e15-10-0704] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Accepted: 03/22/2016] [Indexed: 11/29/2022] Open
Abstract
SLY41 is a multicopy suppressor of mutations in the essential Ypt1 GTPase. Overexpression of Sly41 elevates cytosolic Ca2+ concentration, which stimulates SNARE-dependent fusion of COPII vesicles with Golgi membranes and suppresses deficiencies in Ypt1-dependent vesicle tethering. Thus Ca2+ positively regulates vesicle fusion with Golgi membranes. SLY41 was identified as a multicopy suppressor of loss of Ypt1, a Rab GTPase essential for COPII vesicle tethering at the Golgi complex. SLY41 encodes a polytopic membrane protein with homology to a class of solute transporter proteins, but how overexpression suppresses vesicle-tethering deficiencies is not known. Here we show that Sly41 is efficiently packaged into COPII vesicles and actively cycles between the ER and Golgi compartments. SLY41 displays synthetic negative genetic interactions with PMR1, which encodes the major Golgi-localized Ca2+/Mn2+ transporter and suggests that Sly41 influences cellular Ca2+ and Mn2+ homeostasis. Experiments using the calcium probe aequorin to measure intracellular Ca2+ concentrations in live cells reveal that Sly41 overexpression significantly increases cytosolic calcium levels. Although specific substrates of the Sly41 transporter were not identified, our findings indicate that localized overexpression of Sly41 to the early secretory pathway elevates cytosolic calcium levels to suppress vesicle-tethering mutants. In vitro SNARE cross-linking assays were used to directly monitor the influence of Ca2+ on tethering and fusion of COPII vesicles with Golgi membranes. Strikingly, calcium at suppressive concentrations stimulated SNARE-dependent membrane fusion when vesicle-tethering activity was reduced. These results show that calcium positively regulates the SNARE-dependent fusion stage of ER–Golgi transport.
Collapse
Affiliation(s)
- Indrani Mukherjee
- Department of Biochemistry, Geisel School of Medicine at Dartmouth, Hanover, NH 03755
| | - Charles Barlowe
- Department of Biochemistry, Geisel School of Medicine at Dartmouth, Hanover, NH 03755
| |
Collapse
|
21
|
Zhao Y, Xu H, Zhang Y, Jiang L. Vcx1-D1 (M383I), the Vcx1 mutant with a calcineurin-independent vacuolar Ca(2+)/H(+) exchanger activity, confers calcineurin-independent Mn(2+) tolerance in Saccharomyces cerevisiae. Can J Microbiol 2016; 62:475-84. [PMID: 27100389 DOI: 10.1139/cjm-2015-0595] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The Vcx1-M1 mutant is known to confer calcineurin-dependent Mn(2+) tolerance in budding yeast. Here, we demonstrate that another Vcx1 mutant, Vcx1-D1 with calcineurin-independent vacuolar Ca(2+)/H(+) exchanger activity, confers calcineurin-independent Mn(2+) tolerance. Unlike Vcx1-M1, the Mn(2+) tolerance conferred by Vcx1-D1 is dependent on the presence of Pmr1 or Pmc1. The Pmr1-dependent Mn(2+) tolerance of Vcx1-D1 requires the presence of calcineurin but not the functioning of the Ca(2+)/calcineurin signaling pathway. Similar to the wild-type Vcx1, C-terminally green fluorescent protein tagged Vcx1-D1 and Vcx1-M1 mutants localize to the endoplasmic reticulum instead of its normal vacuolar destination, but they remain functional in Ca(2+) sensitivity and Mn(2+) tolerance.
Collapse
Affiliation(s)
- Yunying Zhao
- a The State Key Laboratory of Food Science and Technology, School of Biotechnology, Jiangnan University, Wuxi 214122, People's Republic of China.,b The National Engineering Laboratory for Cereal Fermentation Technology, School of Biotechnology, Jiangnan University, Wuxi 214122, People's Republic of China
| | - Huihui Xu
- b The National Engineering Laboratory for Cereal Fermentation Technology, School of Biotechnology, Jiangnan University, Wuxi 214122, People's Republic of China
| | - Yan Zhang
- b The National Engineering Laboratory for Cereal Fermentation Technology, School of Biotechnology, Jiangnan University, Wuxi 214122, People's Republic of China
| | - Linghuo Jiang
- a The State Key Laboratory of Food Science and Technology, School of Biotechnology, Jiangnan University, Wuxi 214122, People's Republic of China.,b The National Engineering Laboratory for Cereal Fermentation Technology, School of Biotechnology, Jiangnan University, Wuxi 214122, People's Republic of China
| |
Collapse
|
22
|
Abstract
Calcium is an essential cation for a cell. This cation participates in the regulation of numerous processes in either prokaryotes or eukaryotes, from bacteria to humans. Saccharomyces cerevisiae has served as a model organism to understand calcium homeostasis and calcium-dependent signaling in fungi. In this chapter it will be reviewed known and predicted transport mechanisms that mediate calcium homeostasis in the yeast. How and when calcium enters the cell, how and where it is stored, when is reutilized, and finally secreted to the environment to close the cycle. As a second messenger, maintenance of a controlled free intracellular calcium concentration is important for mediating transcriptional regulation. Many environmental stimuli modify the concentration of cytoplasmic free calcium generating the "calcium signal". This is sensed and transduced through the calmodulin/calcineurin pathway to a transcription factor, named calcineurin-responsive zinc finger, CRZ, also known as "crazy", to mediate transcriptional regulation of a large number of genes of diverse pathways including a negative feedback regulation of the calcium homeostasis system.
Collapse
Affiliation(s)
- Eduardo A Espeso
- Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas, CSIC, Ramiro de Maeztu, 9, 28040, Madrid, Spain.
| |
Collapse
|
23
|
Petrov VV. Role of loop L5-6 connecting transmembrane segments M5 and M6 in biogenesis and functioning of yeast Pma1 H+-ATPase. BIOCHEMISTRY (MOSCOW) 2015; 80:31-44. [PMID: 25754037 DOI: 10.1134/s0006297915010046] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The L5-6 loop is a short extracytoplasmic stretch (714-DNSLDID) connecting transmembrane segments M5 and M6 and forming along with segments M4 and M8 the core through which cations are transported by H+-, Ca2+-, K+,Na+-, H+,K+-, and other P2-ATPases. To study structure-function relationships within this loop of the yeast plasma membrane Pma1 H+-ATPase, alanine- and cysteine-scanning mutagenesis has been employed. Ala and Cys substitutions for the most conserved residue (Leu717) led to complete block in biogenesis preventing the enzyme from reaching secretory vesicles. The Ala replacement at Asp714 led to five-fold decrease in the mutant expression and loss of its activity, while the Cys substitution blocked biogenesis completely. Replacements of other residues did not lead to loss of enzymatic activity. Additional replacements were made for Asp714 and Asp720 (Asp®Asn/Glu). Of the substitutions made at Asp714, only D714N partially restored the mutant enzyme biogenesis and functioning. However, all mutant enzymes with substituted Asp720 were active. The expressed mutants (34-95% of the wild-type level) showed activity high enough (35-108%) to be analyzed in detail. One of the mutants (I719A) had three-fold reduced coupling ratio between ATP hydrolysis and H+ transport; however, the I719C mutation was rather indistinguishable from the wild-type enzyme. Thus, substitutions at two of the seven positions seriously affected biogenesis and/or functioning of the enzyme. Taken together, these results suggest that the M5-M6 loop residues play an important role in protein stability and function, and they are probably responsible for proper arrangement of transmembrane segments M5 and M6 and other domains of the enzyme. This might also be important for the regulation of the enzyme.
Collapse
Affiliation(s)
- V V Petrov
- Skryabin Institute of Biochemistry and Physiology of Microorganisms, Russian Academy of Sciences, Pushchino, Moscow Region, 142290, Russia.
| |
Collapse
|
24
|
García-Rodríguez N, Manzano-López J, Muñoz-Bravo M, Fernández-García E, Muñiz M, Wellinger RE. Manganese redistribution by calcium-stimulated vesicle trafficking bypasses the need for P-type ATPase function. J Biol Chem 2015; 290:9335-47. [PMID: 25713143 DOI: 10.1074/jbc.m114.616334] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Indexed: 12/31/2022] Open
Abstract
Regulation of intracellular ion homeostasis is essential for eukaryotic cell physiology. An example is provided by loss of ATP2C1 function, which leads to skin ulceration, improper keratinocyte adhesion, and cancer formation in Hailey-Hailey patients. The yeast ATP2C1 orthologue PMR1 codes for a Mn(2+)/Ca(2+) transporter that is crucial for cis-Golgi manganese supply. Here, we present evidence that calcium overcomes the lack of Pmr1 through vesicle trafficking-stimulated manganese delivery and requires the endoplasmic reticulum Mn(2+) transporter Spf1 and the late endosome/trans-Golgi Nramp metal transporter Smf2. Smf2 co-localizes with the putative Mn(2+) transporter Atx2, and ATX2 overexpression counteracts the beneficial impact of calcium treatment. Our findings suggest that vesicle trafficking promotes organelle-specific ion interchange and cytoplasmic metal detoxification independent of calcineurin signaling or metal transporter re-localization. Our study identifies an alternative mode for cis-Golgi manganese supply in yeast and provides new perspectives for Hailey-Hailey disease treatment.
Collapse
Affiliation(s)
- Néstor García-Rodríguez
- From the Centro Andaluz de Biología Molecular y Medicina Regenerativa (CABIMER), Universidad de Sevilla, 41092, Sevilla, Spain and
| | - Javier Manzano-López
- the Departamento de Biolgía Celular-Instituto de Biomedicina de Sevilla (IBiS), Universidad de Sevilla, 41012 Sevilla, Spain
| | - Miguel Muñoz-Bravo
- From the Centro Andaluz de Biología Molecular y Medicina Regenerativa (CABIMER), Universidad de Sevilla, 41092, Sevilla, Spain and
| | - Elisabet Fernández-García
- From the Centro Andaluz de Biología Molecular y Medicina Regenerativa (CABIMER), Universidad de Sevilla, 41092, Sevilla, Spain and
| | - Manuel Muñiz
- the Departamento de Biolgía Celular-Instituto de Biomedicina de Sevilla (IBiS), Universidad de Sevilla, 41012 Sevilla, Spain
| | - Ralf Erik Wellinger
- From the Centro Andaluz de Biología Molecular y Medicina Regenerativa (CABIMER), Universidad de Sevilla, 41092, Sevilla, Spain and
| |
Collapse
|
25
|
Fan LL, Dong YC, Fan YF, Zhang J, Chen QH. Production and identification of mannosylerythritol lipid-A homologs from the ustilaginomycetous yeast Pseudozyma aphidis ZJUDM34. Carbohydr Res 2014; 392:1-6. [PMID: 24814655 DOI: 10.1016/j.carres.2014.04.013] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2014] [Revised: 04/17/2014] [Accepted: 04/18/2014] [Indexed: 11/30/2022]
Abstract
Mannosylerythritol lipids (MELs) are mainly produced by strains of the genus Pseudozyma and by Ustilago maydis. These glycolipid biosurfactants exhibit not only excellent surface-active properties but also versatile bioactivities. Mannosylerythritol lipid-A (MEL-A) is worth investigating due to its self-assembling property. In this work, crude MELs were produced by resting Pseudozyma aphidis ZJUDM34 cells using different culture media. MEL-A fractions were isolated and identified using high-performance liquid chromatography combined with mass spectrometry (HPLC-MS) and gas chromatography combined with mass spectrometry (GC-MS). The results showed that MEL-A homologs had long unsaturated fatty acid chains, and the chain lengths range from C8 to C20. Nuclear magnetic resonance (NMR) was employed to confirm the chemical structures of the MEL-A homologs. Fermentation medium without NaNO3 and medium with manganese ions enhanced MEL-A production by Pseudozyma aphidis ZJUDM34.
Collapse
Affiliation(s)
- Lin-Lin Fan
- School of Biosystems Engineering and Food Science, Zhejiang University, Yuhangtang Rd. 866, Hangzhou 310058, PR China
| | - Ya-Chen Dong
- School of Biosystems Engineering and Food Science, Zhejiang University, Yuhangtang Rd. 866, Hangzhou 310058, PR China
| | - Yi-Fei Fan
- School of Biosystems Engineering and Food Science, Zhejiang University, Yuhangtang Rd. 866, Hangzhou 310058, PR China; Fuli Institute of Food Science, Zhejiang University, Hangzhou 310058, PR China
| | - Jun Zhang
- School of Biosystems Engineering and Food Science, Zhejiang University, Yuhangtang Rd. 866, Hangzhou 310058, PR China
| | - Qi-He Chen
- School of Biosystems Engineering and Food Science, Zhejiang University, Yuhangtang Rd. 866, Hangzhou 310058, PR China; Fuli Institute of Food Science, Zhejiang University, Hangzhou 310058, PR China.
| |
Collapse
|
26
|
Voisset C, García-Rodríguez N, Birkmire A, Blondel M, Wellinger RE. Using yeast to model calcium-related diseases: example of the Hailey-Hailey disease. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2014; 1843:2315-21. [PMID: 24583118 DOI: 10.1016/j.bbamcr.2014.02.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2013] [Revised: 01/25/2014] [Accepted: 02/16/2014] [Indexed: 02/05/2023]
Abstract
Cross-complementation studies offer the possibility to overcome limitations imposed by the inherent complexity of multicellular organisms in the study of human diseases, by taking advantage of simpler model organisms like the budding yeast Saccharomyces cerevisiae. This review deals with, (1) the use of S. cerevisiae as a model organism to study human diseases, (2) yeast-based screening systems for the detection of disease modifiers, (3) Hailey-Hailey as an example of a calcium-related disease, and (4) the presentation of a yeast-based model to search for chemical modifiers of Hailey-Hailey disease. The preliminary experimental data presented and discussed here show that it is possible to use yeast as a model system for Hailey-Hailey disease and suggest that in all likelihood, yeast has the potential to reveal candidate drugs for the treatment of this disorder. This article is part of a Special Issue entitled: Calcium signaling in health and disease. Guest Editors: Geert Bultynck, Jacques Haiech, Claus W. Heizmann, Joachim Krebs, and Marc Moreau.
Collapse
Affiliation(s)
- Cécile Voisset
- Institut National de la Santé et de la Recherche Médicale UMR 1078; Université de Bretagne Occidentale, Faculté de Médecine et des Sciences de la Santé; Etablissement Français du Sang (EFS) Bretagne; CHRU Brest, Hôpital Morvan, Laboratoire de Génétique Moléculaire, Brest F-29200, France
| | - Néstor García-Rodríguez
- Andalusian Center of Molecular Biology and Regenerative Medicine (CABIMER), University of Seville, Avd. Americo Vespucio SN, 41092 Sevilla, Spain
| | - April Birkmire
- Andalusian Center of Molecular Biology and Regenerative Medicine (CABIMER), University of Seville, Avd. Americo Vespucio SN, 41092 Sevilla, Spain
| | - Marc Blondel
- Institut National de la Santé et de la Recherche Médicale UMR 1078; Université de Bretagne Occidentale, Faculté de Médecine et des Sciences de la Santé; Etablissement Français du Sang (EFS) Bretagne; CHRU Brest, Hôpital Morvan, Laboratoire de Génétique Moléculaire, Brest F-29200, France.
| | - Ralf Erik Wellinger
- Andalusian Center of Molecular Biology and Regenerative Medicine (CABIMER), University of Seville, Avd. Americo Vespucio SN, 41092 Sevilla, Spain
| |
Collapse
|
27
|
Cohen Y, Megyeri M, Chen OCW, Condomitti G, Riezman I, Loizides-Mangold U, Abdul-Sada A, Rimon N, Riezman H, Platt FM, Futerman AH, Schuldiner M. The yeast p5 type ATPase, spf1, regulates manganese transport into the endoplasmic reticulum. PLoS One 2013; 8:e85519. [PMID: 24392018 PMCID: PMC3877380 DOI: 10.1371/journal.pone.0085519] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2013] [Accepted: 11/27/2013] [Indexed: 12/13/2022] Open
Abstract
The endoplasmic reticulum (ER) is a large, multifunctional and essential organelle. Despite intense research, the function of more than a third of ER proteins remains unknown even in the well-studied model organism Saccharomyces cerevisiae. One such protein is Spf1, which is a highly conserved, ER localized, putative P-type ATPase. Deletion of SPF1 causes a wide variety of phenotypes including severe ER stress suggesting that this protein is essential for the normal function of the ER. The closest homologue of Spf1 is the vacuolar P-type ATPase Ypk9 that influences Mn(2+) homeostasis. However in vitro reconstitution assays with Spf1 have not yielded insight into its transport specificity. Here we took an in vivo approach to detect the direct and indirect effects of deleting SPF1. We found a specific reduction in the luminal concentration of Mn(2+) in ∆spf1 cells and an increase following it's overexpression. In agreement with the observed loss of luminal Mn(2+) we could observe concurrent reduction in many Mn(2+)-related process in the ER lumen. Conversely, cytosolic Mn(2+)-dependent processes were increased. Together, these data support a role for Spf1p in Mn(2+) transport in the cell. We also demonstrate that the human sequence homologue, ATP13A1, is a functionally conserved orthologue. Since ATP13A1 is highly expressed in developing neuronal tissues and in the brain, this should help in the study of Mn(2+)-dependent neurological disorders.
Collapse
Affiliation(s)
- Yifat Cohen
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Márton Megyeri
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
- Department of Biological Chemistry, Weizmann Institute of Science, Rehovot, Israel
| | - Oscar C. W. Chen
- Department of Pharmacology, University of Oxford, Oxford, United Kingdom
| | - Giuseppe Condomitti
- Department of Biological Chemistry, Weizmann Institute of Science, Rehovot, Israel
| | - Isabelle Riezman
- Department of Biochemistry, University of Geneva, Geneva, Switzerland
| | | | - Alaa Abdul-Sada
- School of Life Sciences, University of Sussex, Brighton, United Kingdom
| | - Nitzan Rimon
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Howard Riezman
- Department of Biochemistry, University of Geneva, Geneva, Switzerland
- National Centre of Competence in Research (NCCR) Chemical Biology, University of Geneva, Geneva, Switzerland
| | - Frances M. Platt
- Department of Pharmacology, University of Oxford, Oxford, United Kingdom
| | - Anthony H. Futerman
- Department of Biological Chemistry, Weizmann Institute of Science, Rehovot, Israel
- The Joseph Meyerhoff Professor of Biochemistry at the Weizmann Institute of Science, Weizmann Institute of Science, Rehovot, Israel
| | - Maya Schuldiner
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
- * E-mail:
| |
Collapse
|
28
|
Petrov VV. Point mutations in the extracytosolic loop between transmembrane segments M5 and M6 of the yeast Pma1 H+-ATPase: alanine-scanning mutagenesis. J Biomol Struct Dyn 2013; 33:70-84. [PMID: 24256122 DOI: 10.1080/07391102.2013.849619] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Membrane-spanning segments M4, M5, M6, and M8 of the H(+)-, Ca(2+)-, and K(+), Na(+)-ATPases, which belong to the P2-type pumps are the core through which cations are transported. M5 and M6 loop is a short extracytoplasmic stretch of the seven amino acid residues (714-DNSLDID) connecting two of these segments, M5 and M6, where residues involved in the formation of the proton-binding site(s) are located. In the present study, we have used alanine-scanning mutagenesis to explore the structural and functional relationships within this loop of the yeast plasma membrane Pma1 H(+)-ATPase. Of the 7 Ala mutants made, substitution for the most conserved residue (Leu-717) has led to a severe misfolding and complete block in biogenesis of the mutant enzyme. The replacement of Asp-714 has also caused misfolding leading to significant decrease in the expression of the mutant and loss of activity. The remaining mutants were expressed in secretory vesicles at 21-119% of the wild-type level and were active enough to be analyzed in detail. One of these mutants (I719A) showed five- to threefold decrease in both expression and ATP hydrolyzing and H(+) pumping activities and also threefold reduction in the coupling ratio between ATP hydrolysis and H(+) transport. Thus, Ala substitutions at three positions of the seven seriously affected biogenesis, folding, stability and/or functioning of the enzyme. Taken together, these results lead to suggestion that M5 and M6 loop play an important role in the protein stability and function and is responsible for proper arrangement of transmembrane segments M5 and M6 and probably other domains of the enzyme. Results for additional conserved substitutions (Asn and Glu) at Asp-714 and Asp-720 confirmed this suggestion.
Collapse
Affiliation(s)
- Valery V Petrov
- a Institute of Biochemistry and Physiology of Microorganisms, Russian Academy of Sciences , pr. Nauki 5, Pushchino 142290 , Russia
| |
Collapse
|
29
|
Characterization of two genes encoding metal tolerance proteins from Beta vulgaris subspecies maritima that confers manganese tolerance in yeast. Biometals 2013; 26:795-804. [DOI: 10.1007/s10534-013-9658-7] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2013] [Accepted: 07/08/2013] [Indexed: 10/26/2022]
|
30
|
Wang J, Zhou G, Ying SH, Feng MG. P-type calcium ATPase functions as a core regulator of Beauveria bassiana growth, conidiation and responses to multiple stressful stimuli through cross-talk with signalling networks. Environ Microbiol 2012. [PMID: 23206243 DOI: 10.1111/1462-2920.12044] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
P-type Ca(2+) -ATPase (Pmr1) is a core element in calcium-calcineurin pathway and evidence for its cross-talk with other signalling pathways in filamentous fungi is of scarcity. Here, we characterized the striking functions of a Golgi Ca(2+) -ATPase (Bbpmr1) in Beauveria bassiana (fungal entomopathogen) by multi-phenotypic and transcriptional analyses under normal and stressful conditions. Bbpmr1 inactivation caused severe defects in nutritional uptake, growth, conidiation and germination under normal conditions, drastic reductions in cell tolerances to oxidative, hyperosmotic, cell wall disturbing and fungicidal stresses and toxic metal ions during colony growth and/or conidial germination, and half loss of the fungal biocontrol potential represented by conidial virulence, thermotolerance and UV-B resistance. Accompanied with the multi-phenotypic defects, four important genes associated with asexual development were repressed by ≥ 75% in ΔBbpmr1 versus wild type, and all or most of stress-responsive genes encoding 14 cascaded proteins in MAPK pathways, two Ras GTPases, two protein kinases, Ssk1-type response regulator, TOR signalling protein, and many downstream enzymes and proteins were greatly downregulated in ΔBbpmr1 under the chemical stresses. Conclusively, Bbpmr1 regulates positively fundamental aspects on B. bassiana biology and environmental adaptation through wide cross-talk with cellular signalling networks including MAPK cascades and those upstream or independent of the cascades.
Collapse
Affiliation(s)
- Jie Wang
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, 310058, Zhejiang, China
| | | | | | | |
Collapse
|
31
|
The Ca2+/Mn2+ ion-pump PMR1 links elevation of cytosolic Ca(2+) levels to α-synuclein toxicity in Parkinson's disease models. Cell Death Differ 2012; 20:465-77. [PMID: 23154387 PMCID: PMC3569987 DOI: 10.1038/cdd.2012.142] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Parkinson's disease (PD) is characterized by the progressive loss of dopaminergic neurons, which arises from a yet elusive concurrence between genetic and environmental factors. The protein α-synuclein (αSyn), the principle toxic effector in PD, has been shown to interfere with neuronal Ca(2+) fluxes, arguing for an involvement of deregulated Ca(2+) homeostasis in this neuronal demise. Here, we identify the Golgi-resident Ca(2+)/Mn(2+) ATPase PMR1 (plasma membrane-related Ca(2+)-ATPase 1) as a phylogenetically conserved mediator of αSyn-driven changes in Ca(2+) homeostasis and cytotoxicity. Expression of αSyn in yeast resulted in elevated cytosolic Ca(2+) levels and increased cell death, both of which could be inhibited by deletion of PMR1. Accordingly, absence of PMR1 prevented αSyn-induced loss of dopaminergic neurons in nematodes and flies. In addition, αSyn failed to compromise locomotion and survival of flies when PMR1 was absent. In conclusion, the αSyn-driven rise of cytosolic Ca(2+) levels is pivotal for its cytotoxicity and requires PMR1.
Collapse
|
32
|
Bowman BJ, Abreu S, Johl JK, Bowman EJ. The pmr gene, encoding a Ca2+-ATPase, is required for calcium and manganese homeostasis and normal development of hyphae and conidia in Neurospora crassa. EUKARYOTIC CELL 2012; 11:1362-70. [PMID: 22983986 PMCID: PMC3486030 DOI: 10.1128/ec.00105-12] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2012] [Accepted: 09/06/2012] [Indexed: 12/17/2022]
Abstract
The pmr gene is predicted to encode a Ca(2+)-ATPase in the secretory pathway. We examined two strains of Neurospora crassa that lacked PMR: the Δpmr strain, in which pmr was completely deleted, and pmr(RIP), in which the gene was extensively mutated. Both strains had identical, complex phenotypes. Compared to the wild type, these strains required high concentrations of calcium or manganese for optimal growth and had highly branched, slow-growing hyphae. They conidiated poorly, and the shape and size of the conidia were abnormal. Calcium accumulated in the Δpmr strains to only 20% of the wild-type level. High concentrations of MnCl(2) (1 to 5 mM) in growth medium partially suppressed the morphological defects but did not alter the defect in calcium accumulation. The Δpmr Δnca-2 double mutant (nca-2 encodes a Ca(2+)-ATPase in the plasma membrane) accumulated 8-fold more calcium than the wild type, and the morphology of the hyphae was more similar to that of wild-type hyphae. Previous experiments failed to show a function for nca-1, which encodes a SERCA-type Ca(2+)-ATPase in the endoplasmic reticulum (B. J. Bowman, S. Abreu, E. Margolles-Clark, M. Draskovic, and E. J. Bowman, Eukaryot. Cell 10:654-661, 2011). The pmr(RIP) Δnca-1 double mutant accumulated small amounts of calcium, like the Δpmr strain, but exhibited even more extreme morphological defects. Thus, PMR can apparently replace NCA-1 in the endoplasmic reticulum, but NCA-1 cannot replace PMR. The morphological defects in the Δpmr strain are likely caused, in part, by insufficient concentrations of calcium and manganese in the Golgi compartment; however, PMR is also needed to accumulate normal levels of calcium in the whole cell.
Collapse
Affiliation(s)
- Barry J Bowman
- Department of Molecular, Cell, and Developmental Biology, University of California, Santa Cruz, CA, USA.
| | | | | | | |
Collapse
|
33
|
Sepúlveda MR, Wuytack F, Mata AM. High levels of Mn²⁺ inhibit secretory pathway Ca²⁺/Mn²⁺-ATPase (SPCA) activity and cause Golgi fragmentation in neurons and glia. J Neurochem 2012; 123:824-36. [PMID: 22845487 DOI: 10.1111/j.1471-4159.2012.07888.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2012] [Revised: 06/19/2012] [Accepted: 07/18/2012] [Indexed: 11/28/2022]
Abstract
Excess Mn(2+) in humans causes a neurological disorder known as manganism, which shares symptoms with Parkinson's disease. However, the cellular mechanisms underlying Mn(2+) -neurotoxicity and the involvement of Mn(2+) -transporters in cellular homeostasis and repair are poorly understood and require further investigation. In this work, we have analyzed the effect of Mn(2+) on neurons and glia from mice in primary cultures. Mn(2+) overload compromised survival of both cell types, specifically affecting cellular integrity and Golgi organization, where the secretory pathway Ca(2+) /Mn(2+) -ATPase is localized. This ATP-driven Mn(2+) transporter might take part in Mn(2+) accumulation/detoxification at low loads of Mn(2+) , but its ATPase activity is inhibited at high concentration of Mn(2+) . Glial cells appear to be significantly more resistant to this toxicity than neurons and their presence in cocultures provided some protection to neurons against degeneration induced by Mn(2+) . Interestingly, the Mn(2+) toxicity was partially reversed upon Mn(2+) removal by wash out or by the addition of EDTA as a chelating agent, in particular in glial cells. These studies provide data on Mn(2+) neurotoxicity and may contribute to explore new therapeutic approaches for reducing Mn(2+) poisoning.
Collapse
Affiliation(s)
- M Rosario Sepúlveda
- Departamento de Bioquímica y Biología Molecular y Genética, Facultad de Ciencias, Universidad de Extremadura, Badajoz, Spain
| | | | | |
Collapse
|
34
|
Sepúlveda MR, Dresselaers T, Vangheluwe P, Everaerts W, Himmelreich U, Mata AM, Wuytack F. Evaluation of manganese uptake and toxicity in mouse brain during continuous MnCl2 administration using osmotic pumps. CONTRAST MEDIA & MOLECULAR IMAGING 2012; 7:426-34. [DOI: 10.1002/cmmi.1469] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Affiliation(s)
| | - T. Dresselaers
- Biomedical NMR Unit/ MoSAIC, Department of Imaging and Pathology of Medical Diagnostic Sciences, Faculty of Medicine; Katholieke Universiteit Leuven; Leuven; Belgium
| | - P. Vangheluwe
- Laboratory of Cellular Transport Systems; Department of. Molecular Cell Biology; Faculty of Medicine; Katholieke Universiteit Leuven; Leuven; Belgium
| | - W. Everaerts
- Laboratory of Experimental Urology; Department of Surgery; Faculty of Medicine; Katholieke Universiteit Leuven; Leuven; Belgium
| | - U. Himmelreich
- Biomedical NMR Unit/ MoSAIC, Department of Imaging and Pathology of Medical Diagnostic Sciences, Faculty of Medicine; Katholieke Universiteit Leuven; Leuven; Belgium
| | - A. M. Mata
- Departamento de Bioquímica y Biología Molecular y Genética; Facultad de Ciencias; Universidad de Extremadura; Badajoz; Spain
| | - F. Wuytack
- Laboratory of Cellular Transport Systems; Department of. Molecular Cell Biology; Faculty of Medicine; Katholieke Universiteit Leuven; Leuven; Belgium
| |
Collapse
|
35
|
García-Rodríguez N, Díaz de la Loza MDC, Andreson B, Monje-Casas F, Rothstein R, Wellinger RE. Impaired manganese metabolism causes mitotic misregulation. J Biol Chem 2012; 287:18717-29. [PMID: 22493290 DOI: 10.1074/jbc.m112.358309] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Manganese is an essential trace element, whose intracellular levels need to be carefully regulated. Mn(2+) acts as a cofactor for many enzymes and excess of Mn(2+) is toxic. Alterations in Mn(2+) homeostasis affect metabolic functions and mutations in the human Mn(2+)/Ca(2+) transporter ATP2C1 have been linked to Hailey-Hailey disease. By deletion of the yeast orthologue PMR1 we have studied the impact of Mn(2+) on cell cycle progression and show that an excess of cytosolic Mn(2+) alters S-phase transit, induces transcriptional up-regulation of cell cycle regulators, bypasses the need for S-phase cell cycle checkpoints and predisposes to genomic instability. On the other hand, we find that depletion of the Golgi Mn(2+) pool requires a functional morphology checkpoint to avoid the formation of polyploid cells.
Collapse
Affiliation(s)
- Néstor García-Rodríguez
- Centro Andaluz de Biología Molecular y Medicina Regenerativa (CABIMER), Universidad de Sevilla-CSIC, Sevilla, Spain
| | | | | | | | | | | |
Collapse
|
36
|
Chesi A, Kilaru A, Fang X, Cooper AA, Gitler AD. The role of the Parkinson's disease gene PARK9 in essential cellular pathways and the manganese homeostasis network in yeast. PLoS One 2012; 7:e34178. [PMID: 22457822 PMCID: PMC3311584 DOI: 10.1371/journal.pone.0034178] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2011] [Accepted: 02/27/2012] [Indexed: 02/01/2023] Open
Abstract
YPK9 (Yeast PARK9; also known as YOR291W) is a non-essential yeast gene predicted by sequence to encode a transmembrane P-type transport ATPase. However, its substrate specificity is unknown. Mutations in the human homolog of YPK9, ATP13A2/PARK9, have been linked to genetic forms of early onset parkinsonism. We previously described a strong genetic interaction between Ypk9 and another Parkinson's disease (PD) protein α-synuclein in multiple model systems, and a role for Ypk9 in manganese detoxification in yeast. In humans, environmental exposure to toxic levels of manganese causes a syndrome similar to PD and is thus an environmental risk factor for the disease. How manganese contributes to neurodegeneration is poorly understood. Here we describe multiple genome-wide screens in yeast aimed at defining the cellular function of Ypk9 and the mechanisms by which it protects cells from manganese toxicity. In physiological conditions, we found that Ypk9 genetically interacts with essential genes involved in cellular trafficking and the cell cycle. Deletion of Ypk9 sensitizes yeast cells to exposure to excess manganese. Using a library of non-essential gene deletions, we screened for additional genes involved in tolerance to excess manganese exposure, discovering several novel pathways involved in manganese homeostasis. We defined the dependence of the deletion strain phenotypes in the presence of manganese on Ypk9, and found that Ypk9 deletion modifies the manganese tolerance of only a subset of strains. These results confirm a role for Ypk9 in manganese homeostasis and illuminates cellular pathways and biological processes in which Ypk9 likely functions.
Collapse
Affiliation(s)
- Alessandra Chesi
- Department of Genetics, Stanford University School of Medicine, Stanford University, Stanford, California, United States of America
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Austin Kilaru
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Xiaodong Fang
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Antony A. Cooper
- Garvan Institute of Medical Research, University of New South Wales, Sydney, New South Wales, Australia
| | - Aaron D. Gitler
- Department of Genetics, Stanford University School of Medicine, Stanford University, Stanford, California, United States of America
- * E-mail:
| |
Collapse
|
37
|
Structural evolution and tissue-specific expression of tetrapod-specific second isoform of secretory pathway Ca2+-ATPase. Biochem Biophys Res Commun 2012; 417:1298-303. [DOI: 10.1016/j.bbrc.2011.12.135] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2011] [Accepted: 12/25/2011] [Indexed: 11/19/2022]
|
38
|
Overexpression of the PHO84 gene causes heavy metal accumulation and induces Ire1p-dependent unfolded protein response in Saccharomyces cerevisiae cells. Appl Microbiol Biotechnol 2011; 94:425-35. [DOI: 10.1007/s00253-011-3784-3] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2011] [Revised: 11/15/2011] [Accepted: 11/22/2011] [Indexed: 11/27/2022]
|
39
|
The Role of the Golgi-Resident SPCA Ca2+/Mn2+ Pump in Ionic Homeostasis and Neural Function. Neurochem Res 2011; 37:455-68. [DOI: 10.1007/s11064-011-0644-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2011] [Revised: 10/28/2011] [Accepted: 11/02/2011] [Indexed: 12/23/2022]
|
40
|
Shull GE, Miller ML, Prasad V. Secretory pathway stress responses as possible mechanisms of disease involving Golgi Ca2+ pump dysfunction. Biofactors 2011; 37:150-8. [PMID: 21674634 PMCID: PMC3338190 DOI: 10.1002/biof.141] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2010] [Accepted: 12/15/2010] [Indexed: 01/15/2023]
Abstract
In mammalian tissues, uptake of Ca(2+) and Mn(2+) by Golgi membranes is mediated by the secretory pathway Ca(2+) -ATPases, SPCA1 and SPCA2, encoded by the ATP2C1 and ATP2C2 genes. Loss of one copy of the ATP2C1 gene, which causes SPCA1 haploinsufficiency, leads to squamous cell tumors of keratinized epithelia in mice and to Hailey-Hailey disease, an acantholytic skin disease, in humans. Although the disease phenotypes resulting from SPCA1 haploinsufficiency in mice and humans are quite different, each species-specific phenotype is remarkably similar to those arising as a result of null mutations in one copy of the ATP2A2 gene, encoding SERCA2, the endoplasmic reticulum (ER) Ca(2+) pump. SERCA2 haploinsufficiency, like SPCA1 haploinsufficiency, causes squamous cell tumors in mice and Darier's disease, also an acantholytic skin disease, in humans. The phenotypic similarities between SPCA1 and SERCA2 haploinsufficiency in the two species, and the general functions of the two pumps in consecutive compartments of the secretory pathway, suggest that the underlying disease mechanisms are similar. In this review, we discuss evidence supporting the view that chronic Golgi stress and/or ER stress resulting from Ca(2+) pump haploinsufficiencies leads to activation of cellular stress responses in keratinocytes, with the predominance of proapoptotic pathways (although not necessarily apoptosis itself) leading to acantholytic skin disease in humans and the predominance of prosurvival pathways leading to tumors in mice.
Collapse
Affiliation(s)
- Gary E Shull
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati, College of Medicine, OH, USA.
| | | | | |
Collapse
|
41
|
The marine sponge-derived polyketide endoperoxide plakortide F acid mediates its antifungal activity by interfering with calcium homeostasis. Antimicrob Agents Chemother 2011; 55:1611-21. [PMID: 21300833 DOI: 10.1128/aac.01022-10] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Plakortide F acid (PFA), a marine-derived polyketide endoperoxide, exhibits strong inhibitory activity against the opportunistic fungal pathogens Candida albicans, Cryptococcus neoformans, and Aspergillus fumigatus. In the present study, transcriptional profiling coupled with mutant and biochemical analyses were conducted using the model organism Saccharomyces cerevisiae to investigate the mechanism of action of this compound. PFA elicited a transcriptome response indicative of a Ca(2+) imbalance, affecting the expression of genes known to be responsive to altered cellular calcium levels. Several additional lines of evidence obtained supported a role for Ca(2+) in PFA's activity. First, mutants lacking calcineurin and various Ca(2+) transporters, including pumps (Pmr1 and Pmc1) and channels (Cch1 and Mid1), showed increased sensitivity to PFA. In addition, the calcineurin inhibitors FK506 and cyclosporine strongly enhanced PFA activity in wild-type cells. Furthermore, PFA activated the transcription of a lacZ reporter gene driven by the calcineurin-dependent response element. Finally, elemental analysis indicated a significant increase in intracellular calcium levels in PFA-treated cells. Collectively, our results demonstrate that PFA mediates its antifungal activity by perturbing Ca(2+) homeostasis, thus representing a potentially novel mechanism distinct from that of currently used antifungal agents.
Collapse
|
42
|
Leitch S, Feng M, Muend S, Braiterman LT, Hubbard AL, Rao R. Vesicular distribution of Secretory Pathway Ca²+-ATPase isoform 1 and a role in manganese detoxification in liver-derived polarized cells. Biometals 2011; 24:159-70. [PMID: 20981470 PMCID: PMC3238027 DOI: 10.1007/s10534-010-9384-3] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2010] [Accepted: 10/13/2010] [Indexed: 12/24/2022]
Abstract
Manganese is a trace element that is an essential co-factor in many enzymes critical to diverse biological pathways. However, excess Mn(2+) leads to neurotoxicity, with psychiatric and motor dysfunction resembling parkinsonism. The liver is the main organ for Mn(2+) detoxification by excretion into bile. Although many pathways of cellular Mn(2+) uptake have been established, efflux mechanisms remain essentially undefined. In this study, we evaluated a potential role in Mn(2+) detoxification by the Secretory Pathway Ca(2+), Mn(2+)-ATPase in rat liver and a liver-derived cell model WIF-B that polarizes to distinct bile canalicular and sinusoidal domains in culture. Of two known isoforms, only secretory pathway Ca(2+)-ATPase isoform 1 (SPCA1) was expressed in liver and WIF-B cells. As previously observed in non-polarized cells, SPCA1 showed overlapping distribution with TGN38, consistent with Golgi/TGN localization. However, a prominent novel localization of SPCA1 to an endosomal population close to, but not on the basolateral membrane was also observed. This was confirmed by fractionation of rat liver homogenates which revealed dual distribution of SPCA1 to the Golgi/TGN and a fraction that included the early endosomal marker, EEA1. We suggest that this novel pool of endosomes may serve to sequester Mn(2+) as it enters from the sinusoidal/basolateral domains. Isoform-specific partial knockdown of SPCA1 delayed cell growth and formation of canalicular domain by about 30% and diminished viability upon exposure to Mn(2+). Conversely, overexpression of SPCA1 in HEK 293T cells conferred tolerance to Mn(2+) toxicity. Taken together, our findings suggest a role for SPCA1 in Mn(2+) detoxification in liver.
Collapse
Affiliation(s)
- Sharon Leitch
- Department of Physiology, Johns Hopkins University School of Medicine, 725 N. Wolfe Street, Baltimore, MD 21205, USA
| | - Mingye Feng
- Department of Physiology, Johns Hopkins University School of Medicine, 725 N. Wolfe Street, Baltimore, MD 21205, USA
| | - Sabina Muend
- Department of Physiology, Johns Hopkins University School of Medicine, 725 N. Wolfe Street, Baltimore, MD 21205, USA
| | | | - Ann L. Hubbard
- Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Rajini Rao
- Department of Physiology, Johns Hopkins University School of Medicine, 725 N. Wolfe Street, Baltimore, MD 21205, USA
| |
Collapse
|
43
|
Abstract
RNA viruses are the champions of evolution due to high frequency mutations and genetic recombination occurring during virus replication. These genetic events are due to the error-prone nature of viral RNA-dependent RNA polymerases (RdRp). Recently emerging models on viral RNA recombination, however, also include key roles for host and environmental factors. Accordingly, genome-wide screens and global proteomics approaches with Tomato bushy stunt virus (TBSV) and yeast (Saccharomyces cerevisiae) as a model host have identified 38 host proteins affecting viral RNA recombination. Follow-up studies have identified key host proteins and cellular pathways involved in TBSV RNA recombination. In addition, environmental factors, such as salt stress, have been shown to affect TBSV recombination via influencing key host or viral factors involved in the recombination process. These advances will help build more accurate models on viral recombination, evolution, and adaptation.
Collapse
|
44
|
Identification of a gain-of-function mutation in a Golgi P-type ATPase that enhances Mn2+ efflux and protects against toxicity. Proc Natl Acad Sci U S A 2010; 108:858-63. [PMID: 21187401 DOI: 10.1073/pnas.1013642108] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
P-type ATPases transport a wide array of ions, regulate diverse cellular processes, and are implicated in a number of human diseases. However, mechanisms that increase ion transport by these ubiquitous proteins are not known. SPCA1 is a P-type pump that transports Mn(2+) from the cytosol into the Golgi. We developed an intra-Golgi Mn(2+) sensor and used it to screen for mutations introduced in SPCA1, on the basis of its predicted structure, which could increase its Mn(2+) pumping activity. Remarkably, a point mutation (Q747A) predicted to increase the size of its ion permeation cavity enhanced the sensor response and a compensatory mutation restoring the cavity to its original size abolished this effect. In vivo and in vitro Mn(2+) transport assays confirmed the hyperactivity of SPCA1-Q747A. Furthermore, increasing Golgi Mn(2+) transport by expression of SPCA1-Q747A increased cell viability upon Mn(2+) exposure, supporting the therapeutic potential of increased Mn(2+) uptake by the Golgi in the management of Mn(2+)-induced neurotoxicity.
Collapse
|
45
|
Miranda M, Pardo JP, Petrov VV. Structure-function relationships in membrane segment 6 of the yeast plasma membrane Pma1 H(+)-ATPase. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2010; 1808:1781-9. [PMID: 21156155 DOI: 10.1016/j.bbamem.2010.11.034] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2010] [Revised: 11/24/2010] [Accepted: 11/30/2010] [Indexed: 11/30/2022]
Abstract
The crystal structures of the Ca(2+)- and H(+)-ATPases shed light into the membrane embedded domains involved in binding and ion translocation. Consistent with site-directed mutagenesis, these structures provided additional evidence that membrane-spanning segments M4, M5, M6 and M8 are the core through which cations are pumped. In the present study, we have used alanine/serine scanning mutagenesis to study the structure-function relationships within M6 (Leu-721-Pro-742) of the yeast plasma membrane ATPase. Of the 22 mutants expressed and analyzed in secretory vesicles, alanine substitutions at two well conserved residues (Asp-730 and Asp-739) led to a complete block in biogenesis; in the mammalian P-ATPases, residues corresponding to Asp-730 are part of the cation-binding domain. Two other mutants (V723A and I736A) displayed a dramatic 20-fold increase in the IC(50) for inorganic orthovanadate compared to the wild-type control, accompanied by a significant reduction in the K(m) for Mg-ATP, and an alkaline shift in the pH optimum for ATP hydrolysis. This behavior is apparently due to a shift in equilibrium from the E(2) conformation of the ATPase towards the E(1) conformation. By contrast, the most striking mutants lying toward the extracellular side in a helical structure (L721A, I722A, F724A, I725A, I727A and F728A) were expressed in secretory vesicles but had a severe reduction of ATPase activity. Moreover, all of these mutants but one (F728A) were unable to support yeast growth when the wild-type chromosomal PMA1 gene was replaced by the mutant allele. Surprisingly, in contrast to M8 where mutations S800A and E803Q (Guerra et al., Biochim. Biophys. Acta 1768: 2383-2392, 2007) led to a dramatic increase in the apparent stoichiometry of H(+) transport, three substitutions (A726S, A732S and T733A) in M6 showed a reduction in the apparent coupling ratio. Taken together, these results suggest that M6 residues play an important role in protein stability and function, and probably are responsible for cation binding and stoichiometry of ion transport as suggested by homology modeling.
Collapse
Affiliation(s)
- Manuel Miranda
- Department of Biological Sciences, University of Texas, El Paso, TX 79968, USA.
| | | | | |
Collapse
|
46
|
Nagy PD, Pogany J. Global genomics and proteomics approaches to identify host factors as targets to induce resistance against Tomato bushy stunt virus. Adv Virus Res 2010; 76:123-77. [PMID: 20965073 PMCID: PMC7173251 DOI: 10.1016/s0065-3527(10)76004-8] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The success of RNA viruses as pathogens of plants, animals, and humans depends on their ability to reprogram the host cell metabolism to support the viral infection cycle and to suppress host defense mechanisms. Plus-strand (+)RNA viruses have limited coding potential necessitating that they co-opt an unknown number of host factors to facilitate their replication in host cells. Global genomics and proteomics approaches performed with Tomato bushy stunt virus (TBSV) and yeast (Saccharomyces cerevisiae) as a model host have led to the identification of 250 host factors affecting TBSV RNA replication and recombination or bound to the viral replicase, replication proteins, or the viral RNA. The roles of a dozen host factors involved in various steps of the replication process have been validated in yeast as well as a plant host. Altogether, the large number of host factors identified and the great variety of cellular functions performed by these factors indicate the existence of a truly complex interaction between TBSV and the host cell. This review summarizes the advantages of using a simple plant virus and yeast as a model host to advance our understanding of virus–host interactions at the molecular and cellular levels. The knowledge of host factors gained can potentially be used to inhibit virus replication via gene silencing, expression of dominant negative mutants, or design of specific chemical inhibitors leading to novel specific or broad-range resistance and antiviral tools against (+)RNA plant viruses.
Collapse
Affiliation(s)
- Peter D Nagy
- Department of Plant Pathology, University of Kentucky, Lexington, KY 40546, USA.
| | | |
Collapse
|
47
|
Jaag HM, Pogany J, Nagy PD. A host Ca2+/Mn2+ ion pump is a factor in the emergence of viral RNA recombinants. Cell Host Microbe 2010; 7:74-81. [PMID: 20114029 DOI: 10.1016/j.chom.2009.12.009] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2009] [Revised: 10/16/2009] [Accepted: 12/21/2009] [Indexed: 10/19/2022]
Abstract
Viruses change rapidly due to genetic mutations, and viral RNA recombination in RNA viruses can lead to the emergence of drug-resistant or highly virulent strains. Here, we report that host Pmr1p, an ion pump that controls Ca2+/Mn2+ influx into the Golgi from the cytosol, affects the frequency of viral RNA recombination and the efficiency of replication. Inactivation of PMR1 leads to an approximately 160-fold increase in RNA recombination of Tomato bushy stunt virus (TBSV) in yeast, a model host. Expression of separation-of-function mutants of Pmr1p reveals that the ability of Pmr1p to control the Mn2+ concentration in the cytosol is a key factor in viral RNA recombination. Indeed, a high Mn2+ concentration in a cell-free TBSV replication system increases the recombination frequency, and knockdown of Ca2+/Mn2+ exporters in plants increases virus replication and RNA recombination. Thus, a conserved host protein could affect the adaptive evolution of RNA viruses.
Collapse
Affiliation(s)
- Hannah M Jaag
- Department of Plant Pathology, University of Kentucky, Plant Science Building, Lexington, KY 40546, USA
| | | | | |
Collapse
|
48
|
Abstract
Ca2+-ATPases (pumps) are key actors in the regulation of Ca2+ in eukaryotic cells and are thus essential to the correct functioning of the cell machinery. They have high affinity for Ca2+ and can efficiently regulate it down to very low concentration levels. Two of the pumps have been known for decades (the SERCA and PMCA pumps); one (the SPCA pump) has only become known recently. Each pump is the product of a multigene family, the number of isoforms being further increased by alternative splicing of the primary transcripts. The three pumps share the basic features of the catalytic mechanism but differ in a number of properties related to tissue distribution, regulation, and role in the cellular homeostasis of Ca2+. The molecular understanding of the function of the pumps has received great impetus from the solution of the three-dimensional structure of one of them, the SERCA pump. These spectacular advances in the structure and molecular mechanism of the pumps have been accompanied by the emergence and rapid expansion of the topic of pump malfunction, which has paralleled the rapid expansion of knowledge in the topic of Ca2+-signaling dysfunction. Most of the pump defects described so far are genetic: when they are very severe, they produce gross and global disturbances of Ca2+ homeostasis that are incompatible with cell life. However, pump defects may also be of a type that produce subtler, often tissue-specific disturbances that affect individual components of the Ca2+-controlling and/or processing machinery. They do not bring cells to immediate death but seriously compromise their normal functioning.
Collapse
|
49
|
Affiliation(s)
- Amit R. Reddi
- Environmental Health Sciences, Bloomberg School of Public Health, Johns Hopkins University, 615 North Wolfe Street, Baltimore, Maryland 21205
| | - Laran T. Jensen
- Environmental Health Sciences, Bloomberg School of Public Health, Johns Hopkins University, 615 North Wolfe Street, Baltimore, Maryland 21205
| | - Valeria C. Culotta
- To whom correspondence should be addressed. . Phone: (410) 955-4712. Fax: (410) 955-0116
| |
Collapse
|
50
|
Removing heavy metals from synthetic effluents using “kamikaze” Saccharomyces cerevisiae cells. Appl Microbiol Biotechnol 2009; 85:763-71. [DOI: 10.1007/s00253-009-2266-3] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2009] [Revised: 09/12/2009] [Accepted: 09/15/2009] [Indexed: 12/01/2022]
|