1
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Xuan Z, Wang K, Duan F, Lu L. Non-carrier immobilization of yeast cells by genipin crosslinking for the synthesis of prebiotic galactooligosaccharides from plant-derived galactose. Int J Biol Macromol 2024:133991. [PMID: 39089904 DOI: 10.1016/j.ijbiomac.2024.133991] [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: 04/09/2024] [Revised: 06/23/2024] [Accepted: 07/16/2024] [Indexed: 08/04/2024]
Abstract
Galactooligosaccharides (GOS), as mimics of human milk oligosaccharides, are important prebiotics for modulating the ecological balance of intestinal microbiota. A novel carrier-free cell immobilization method was established using genipin to cross-link Kluyveromyces lactis CGMCC 2.1494, which produced β-galactosidase, an enzyme essential for GOS synthesis. The resulting immobilized cells were characterized as stable by thermogravimetric analysis and confirmed to be crosslinked through scanning electron microscopy analysis (SEM) and Fourier transform infrared spectroscopy (FTIR). The Km and Vmax values of β-galactosidase in immobilized cells towards o-nitrophenyl β-D-galactoside were determined to be 3.446 mM and 2210 μmol min-1 g-1, respectively. The enzyme in the immobilized showed higher thermal and organic solvent tolerance compared to that in free cells. The immobilized cells were subsequently employed for GOS synthesis using plant-derived galactose as the substrate. The synthetic reaction conditions were optimized through both single-factor experiments and response surface methodology, resulting in a high yield of 49.1 %. Moreover, the immobilized cells showed good reusability and could be reused for at least 20 batches of GOS synthesis, with the enzyme activity remaining above 70 % at 35 °C.
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Affiliation(s)
- Zehui Xuan
- School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Ke Wang
- School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Feiyu Duan
- School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Lili Lu
- School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China.
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2
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Fees J, Christ JJ, Willbold S, Blank LM. Biotechnological production of polyphosphate from industrial wash water. Biotechnol Bioeng 2023; 120:456-464. [PMID: 36314689 DOI: 10.1002/bit.28274] [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: 06/15/2022] [Revised: 10/10/2022] [Accepted: 10/23/2022] [Indexed: 01/13/2023]
Abstract
Phosphate is mined from phosphate rock, which is a limited resource on a human time scale. For a sustainable phosphate supply, strategies for efficient use and recycling of phosphate must be developed. A German chemical company produces annually wash water containing phosphate and other inorganic substances (e.g., sodium, potassium, sulfate, and chloride) at a ton scale. Chemical precipitation is mostly used for phosphate removal. In this study, a biotechnological process utilizing Saccharomyces cerevisiae to upcycle phosphate-containing wastewater into pure sodium polyphosphate in powder form was developed. The process comprises fermentation and downstream processing (polyphosphate yields: 25% and 36%, respectively). The polyphosphate quality was independent of the wash water composition. Polyphosphate with a purity of 23% molar ratio Na to Na, K, and Mg of > 90%, and with an average chain length of 12.5 phosphate subunits was produced. The upcycled polyphosphate can be reused compared to phosphate fertilizer in many different applications. Overall, the here developed process can contribute to truly slowing down phosphate mining and finally enable a sustainable utilization of phosphate. Thereby, the benefit of the process is the cascade use of phosphate, reducing the need for phosphate rock before the phosphate ends up in the soil and ultimately in the sea.
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Affiliation(s)
- Jana Fees
- Institute of Applied Microbiology - iAMB, Aachen Biology and Biotechnology - ABBt, RWTH Aachen University, Aachen, Germany
| | - Jonas J Christ
- Institute of Applied Microbiology - iAMB, Aachen Biology and Biotechnology - ABBt, RWTH Aachen University, Aachen, Germany
| | - Sabine Willbold
- Central Institute for Engineering, Electronics and Analytics, Analytics (ZEA-3), Wilhelm-Johnen-Straße, Forschungszentrum Jülich, Jülich, Germany
| | - Lars M Blank
- Institute of Applied Microbiology - iAMB, Aachen Biology and Biotechnology - ABBt, RWTH Aachen University, Aachen, Germany
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3
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Yan J, Ye X, Song Y, Ren T, Wang C, Li X, Cong R, Lu Z, Lu J. Sufficient potassium improves inorganic phosphate-limited photosynthesis in Brassica napus by enhancing metabolic phosphorus fractions and Rubisco activity. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2023; 113:416-429. [PMID: 36479950 DOI: 10.1111/tpj.16057] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Revised: 11/22/2022] [Accepted: 12/03/2022] [Indexed: 06/17/2023]
Abstract
Crop photosynthesis (A) and productivity are often limited by a combination of nutrient stresses, such that changes in the availability of one nutrient may affect the availability of another nutrient, in turn influencing A. In this study, we examined the synergistic effects of phosphorus (P) and potassium (K) on leaf A in a nutrient amendment experiment, in which P and K were added individually or in combination to Brassica napus grown under P and K co-limitation. The data revealed that the addition of P gradually removed the dominant limiting factor (i.e. the limited availability of P) and improved leaf A. Strikingly, the addition of K synergistically improved the overall uptake of P, mainly by boosting plant growth, and compensated for the physiological demand for P by prioritizing investment in metabolic pools of P (P-containing metabolites and inorganic phosphate, Pi). The enlarged pool of metabolically active P was partially associated with the upregulation of Pi regeneration through release from triose phosphates rather than replacement of P-containing lipids. This process mitigated P restrictions on A by maintaining the ATP/NADPH and NADPH/NADP+ ratios and increasing the content and activity of Rubisco. Our findings demonstrate that sufficient K increased Pi-limited A by enhancing metabolic P fractions and Rubisco activity. Thus, ionic synergism may be exploited to mitigate nutrient-limiting factors to improve crop productivity.
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Affiliation(s)
- Jinyao Yan
- Microelement Research Center, Huazhong Agricultural University, Wuhan, 430070, China
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture and Rural Affairs, Wuhan, 430070, China
| | - Xiaolei Ye
- Microelement Research Center, Huazhong Agricultural University, Wuhan, 430070, China
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture and Rural Affairs, Wuhan, 430070, China
| | - Yi Song
- Microelement Research Center, Huazhong Agricultural University, Wuhan, 430070, China
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture and Rural Affairs, Wuhan, 430070, China
| | - Tao Ren
- Microelement Research Center, Huazhong Agricultural University, Wuhan, 430070, China
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture and Rural Affairs, Wuhan, 430070, China
| | - Chongming Wang
- Microelement Research Center, Huazhong Agricultural University, Wuhan, 430070, China
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture and Rural Affairs, Wuhan, 430070, China
| | - Xiaokun Li
- Microelement Research Center, Huazhong Agricultural University, Wuhan, 430070, China
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture and Rural Affairs, Wuhan, 430070, China
| | - Rihuan Cong
- Microelement Research Center, Huazhong Agricultural University, Wuhan, 430070, China
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture and Rural Affairs, Wuhan, 430070, China
| | - Zhifeng Lu
- Microelement Research Center, Huazhong Agricultural University, Wuhan, 430070, China
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture and Rural Affairs, Wuhan, 430070, China
| | - Jianwei Lu
- Microelement Research Center, Huazhong Agricultural University, Wuhan, 430070, China
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture and Rural Affairs, Wuhan, 430070, China
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4
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Ribeiro-Filho N, Linforth R, Bora N, Powell CD, Fisk ID. The role of inorganic-phosphate, potassium and magnesium in yeast-flavour formation. Food Res Int 2022; 162:112044. [DOI: 10.1016/j.foodres.2022.112044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 10/04/2022] [Accepted: 10/10/2022] [Indexed: 11/16/2022]
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5
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Abstract
Most cells live in environments that are permissive for proliferation only a small fraction of the time. Entering quiescence enables cells to survive long periods of nondivision and reenter the cell cycle when signaled to do so. Here, we describe what is known about the molecular basis for quiescence in Saccharomyces cerevisiae, with emphasis on the progress made in the last decade. Quiescence is triggered by depletion of an essential nutrient. It begins well before nutrient exhaustion, and there is extensive crosstalk between signaling pathways to ensure that all proliferation-specific activities are stopped when any one essential nutrient is limiting. Every aspect of gene expression is modified to redirect and conserve resources. Chromatin structure and composition change on a global scale, from histone modifications to three-dimensional chromatin structure. Thousands of proteins and RNAs aggregate, forming unique structures with unique fates, and the cytoplasm transitions to a glass-like state.
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Affiliation(s)
- Linda L Breeden
- Basic Sciences Division, Fred Hutchinson Cancer Center, Seattle, Washington, USA; ,
| | - Toshio Tsukiyama
- Basic Sciences Division, Fred Hutchinson Cancer Center, Seattle, Washington, USA; ,
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6
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The NPR/Hal family of protein kinases in yeasts: biological role, phylogeny and regulation under environmental challenges. Comput Struct Biotechnol J 2022; 20:5698-5712. [PMID: 36320937 PMCID: PMC9596735 DOI: 10.1016/j.csbj.2022.10.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Revised: 09/30/2022] [Accepted: 10/02/2022] [Indexed: 11/30/2022] Open
Abstract
Protein phosphorylation is the most common and versatile post-translational modification occurring in eukaryotes. In yeast, protein phosphorylation is fundamental for maintaining cell growth and adapting to sudden changes in environmental conditions by regulating cellular processes and activating signal transduction pathways. Protein kinases catalyze the reversible addition of phosphate groups to target proteins, thereby regulating their activity. In Saccharomyces cerevisiae, kinases are classified into six major groups based on structural and functional similarities. The NPR/Hal family of kinases comprises nine fungal-specific kinases that, due to lack of similarity with the remaining kinases, were classified to the “Other” group. These kinases are primarily implicated in regulating fundamental cellular processes such as maintaining ion homeostasis and controlling nutrient transporters’ concentration at the plasma membrane. Despite their biological relevance, these kinases remain poorly characterized and explored. This review provides an overview of the information available regarding each of the kinases from the NPR/Hal family, including their known biological functions, mechanisms of regulation, and integration in signaling pathways in S. cerevisiae. Information gathered for non-Saccharomyces species of biotechnological or clinical relevance is also included.
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7
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Ribeiro‐Filho N, Ayed C, Akepach P. The buffering capacity of single amino acids in brewing wort. Int J Food Sci Technol 2022. [DOI: 10.1111/ijfs.15924] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- Normando Ribeiro‐Filho
- DSER/Centre for Agrarian Science Campus II Federal University of Paraiba Areia Paraiba Brazil
| | - Charfedinne Ayed
- Division of Food, Nutrition and Dietetics, School of Biosciences University of Nottingham Loughborough Leicestershire UK
| | - Patchaniya Akepach
- Department of Thai and International Culinary Art, International School of Tourism Suratthani Rajabhat University Tambon Bo Put, Amphoe Ko Samui Chang Wat Surat Thani 84320 Thailand
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8
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The Toxic Effects of Ppz1 Overexpression Involve Nha1-Mediated Deregulation of K + and H + Homeostasis. J Fungi (Basel) 2021; 7:jof7121010. [PMID: 34946993 PMCID: PMC8704375 DOI: 10.3390/jof7121010] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Revised: 11/18/2021] [Accepted: 11/23/2021] [Indexed: 11/17/2022] Open
Abstract
The alteration of the fine-tuned balance of phospho/dephosphorylation reactions in the cell often results in functional disturbance. In the yeast Saccharomyces cerevisiae, the overexpression of Ser/Thr phosphatase Ppz1 drastically blocks cell proliferation, with a profound change in the transcriptomic and phosphoproteomic profiles. While the deleterious effect on growth likely derives from the alteration of multiple targets, the precise mechanisms are still obscure. Ppz1 is a negative effector of potassium influx. However, we show that the toxic effect of Ppz1 overexpression is unrelated to the Trk1/2 high-affinity potassium importers. Cells overexpressing Ppz1 exhibit decreased K+ content, increased cytosolic acidification, and fail to properly acidify the medium. These effects, as well as the growth defect, are counteracted by the deletion of NHA1 gene, which encodes a plasma membrane Na+, K+/H+ antiporter. The beneficial effect of a lack of Nha1 on the growth vanishes as the pH of the medium approaches neutrality, is not eliminated by the expression of two non-functional Nha1 variants (D145N or D177N), and is exacerbated by a hyperactive Nha1 version (S481A). All our results show that high levels of Ppz1 overactivate Nha1, leading to an excessive entry of H+ and efflux of K+, which is detrimental for growth.
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9
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Lacerda-Abreu MA, Russo-Abrahão T, Rocco-Machado N, Cosentino-Gomes D, Dick CF, Carvalho-Kelly LF, Cunha Nascimento MT, Rocha-Vieira TC, Meyer-Fernandes JR. Hydrogen Peroxide Generation as an Underlying Response to High Extracellular Inorganic Phosphate (Pi) in Breast Cancer Cells. Int J Mol Sci 2021; 22:ijms221810096. [PMID: 34576256 PMCID: PMC8468810 DOI: 10.3390/ijms221810096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Revised: 09/15/2021] [Accepted: 09/16/2021] [Indexed: 11/16/2022] Open
Abstract
According to the growth rate hypothesis (GRH), tumour cells have high inorganic phosphate (Pi) demands due to accelerated proliferation. Compared to healthy individuals, cancer patients present with a nearly 2.5-fold higher Pi serum concentration. In this work, we show that an increasing concentration of Pi had the opposite effect on Pi-transporters only in MDA-MB-231 when compared to other breast cell lines: MCF-7 or MCF10-A (non-tumoural breast cell line). Here, we show for the first time that high extracellular Pi concentration mediates ROS production in TNBC (MDA-MB-231). After a short-time exposure (1 h), Pi hyperpolarizes the mitochondrial membrane, increases mitochondrial ROS generation, impairs oxygen (O2) consumption and increases PKC activity. However, after 24 h Pi-exposure, the source of H2O2 seems to shift from mitochondria to an NADPH oxidase enzyme (NOX), through activation of PKC by H2O2. Exogenous-added H2O2 modulated Pi-transporters the same way as extracellular high Pi, which could be reversed by the addition of the antioxidant N-acetylcysteine (NAC). NAC was also able to abolish Pi-induced Epithelial-mesenchymal transition (EMT), migration and adhesion of MDA-MB-231. We believe that Pi transporters support part of the energy required for the metastatic processes stimulated by Pi and trigger Pi-induced H2O2 production as a signalling response to promote cell migration and adhesion.
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Affiliation(s)
- Marco Antonio Lacerda-Abreu
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-901, RJ, Brazil; (M.A.L.-A.); (T.R.-A.); (N.R.-M.); (D.C.-G.); (C.F.D.); (L.F.C.-K.); (M.T.C.N.); (T.C.R.-V.)
- Instituto Nacional de Ciência e Tecnologia em Biologia Estrutural e Bioimagem, Rio de Janeiro 21941-590, RJ, Brazil
| | - Thais Russo-Abrahão
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-901, RJ, Brazil; (M.A.L.-A.); (T.R.-A.); (N.R.-M.); (D.C.-G.); (C.F.D.); (L.F.C.-K.); (M.T.C.N.); (T.C.R.-V.)
- Instituto Nacional de Ciência e Tecnologia em Biologia Estrutural e Bioimagem, Rio de Janeiro 21941-590, RJ, Brazil
| | - Nathália Rocco-Machado
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-901, RJ, Brazil; (M.A.L.-A.); (T.R.-A.); (N.R.-M.); (D.C.-G.); (C.F.D.); (L.F.C.-K.); (M.T.C.N.); (T.C.R.-V.)
- Instituto Nacional de Ciência e Tecnologia em Biologia Estrutural e Bioimagem, Rio de Janeiro 21941-590, RJ, Brazil
- National Heart, Lung, and Blood Institute, NIH, Bethesda, Rockville, MD 20814, USA
| | - Daniela Cosentino-Gomes
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-901, RJ, Brazil; (M.A.L.-A.); (T.R.-A.); (N.R.-M.); (D.C.-G.); (C.F.D.); (L.F.C.-K.); (M.T.C.N.); (T.C.R.-V.)
- Instituto Nacional de Ciência e Tecnologia em Biologia Estrutural e Bioimagem, Rio de Janeiro 21941-590, RJ, Brazil
- Departamento de Bioquímica, Universidade Federal Rural do Rio de Janeiro, Seropédica 23890-000, RJ, Brazil
| | - Claudia Fernanda Dick
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-901, RJ, Brazil; (M.A.L.-A.); (T.R.-A.); (N.R.-M.); (D.C.-G.); (C.F.D.); (L.F.C.-K.); (M.T.C.N.); (T.C.R.-V.)
- Instituto Nacional de Ciência e Tecnologia em Biologia Estrutural e Bioimagem, Rio de Janeiro 21941-590, RJ, Brazil
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-901, RJ, Brazil
| | - Luiz Fernando Carvalho-Kelly
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-901, RJ, Brazil; (M.A.L.-A.); (T.R.-A.); (N.R.-M.); (D.C.-G.); (C.F.D.); (L.F.C.-K.); (M.T.C.N.); (T.C.R.-V.)
- Instituto Nacional de Ciência e Tecnologia em Biologia Estrutural e Bioimagem, Rio de Janeiro 21941-590, RJ, Brazil
| | - Michelle Tanny Cunha Nascimento
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-901, RJ, Brazil; (M.A.L.-A.); (T.R.-A.); (N.R.-M.); (D.C.-G.); (C.F.D.); (L.F.C.-K.); (M.T.C.N.); (T.C.R.-V.)
- Instituto Nacional de Ciência e Tecnologia em Biologia Estrutural e Bioimagem, Rio de Janeiro 21941-590, RJ, Brazil
| | - Thaís Cristino Rocha-Vieira
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-901, RJ, Brazil; (M.A.L.-A.); (T.R.-A.); (N.R.-M.); (D.C.-G.); (C.F.D.); (L.F.C.-K.); (M.T.C.N.); (T.C.R.-V.)
- Instituto Nacional de Ciência e Tecnologia em Biologia Estrutural e Bioimagem, Rio de Janeiro 21941-590, RJ, Brazil
| | - José Roberto Meyer-Fernandes
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-901, RJ, Brazil; (M.A.L.-A.); (T.R.-A.); (N.R.-M.); (D.C.-G.); (C.F.D.); (L.F.C.-K.); (M.T.C.N.); (T.C.R.-V.)
- Instituto Nacional de Ciência e Tecnologia em Biologia Estrutural e Bioimagem, Rio de Janeiro 21941-590, RJ, Brazil
- Correspondence: ; Tel.: +55-21-3938-6781; Fax: +55-21-2270-8647
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10
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Ribeiro-Filho N, Linforth R, Powell CD, Fisk ID. Influence of essential inorganic elements on flavour formation during yeast fermentation. Food Chem 2021; 361:130025. [PMID: 34029908 DOI: 10.1016/j.foodchem.2021.130025] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 04/13/2021] [Accepted: 05/07/2021] [Indexed: 11/25/2022]
Abstract
The relative concentration of available inorganic elements is critical for yeast growth and metabolism and has potential to be a tool leading to directed yeast flavour formation during fermentation. This study investigates the influence of essential inorganic elements during alcoholic fermentation of brewers wort, fermented using three independent yeast strains, Saccharomyces pastorianus W34/70, and Saccharomyces cerevisiae strains M2 and NCYC2592 under a range of conditions replicated for each yeast strain. 10 treatments were applied: 1 control and 9 inorganic supplementations: standard brewers wort, ammonia-nitrogen, inorganic phosphate, potassium, magnesium, copper, zinc, iron, manganese and a composite mixture, Twenty-five chemical markers were evaluated by HPLC (ethanol, glycerol), and GC-MS (aroma). There was a significant change in volatile aroma compounds during fermentation, which was more prominent when supplemented with ammonia nitrogen, inorganic phosphate, potassium or magnesium (P < 0.05). Heavy metal ions mostly had a negative effect on the flavour formation.
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Affiliation(s)
- Normando Ribeiro-Filho
- DSER/Centre of Agrarian Science Campus II, Federal University of Paraiba, Areia, Paraiba, Brazil; Division of Food, Nutrition and Dietetics, School of Biosciences, University of Nottingham, Loughborough, Leicestershire, UK
| | - Robert Linforth
- Division of Food, Nutrition and Dietetics, School of Biosciences, University of Nottingham, Loughborough, Leicestershire, UK
| | - Chris D Powell
- Division of Food, Nutrition and Dietetics, School of Biosciences, University of Nottingham, Loughborough, Leicestershire, UK
| | - Ian D Fisk
- Division of Food, Nutrition and Dietetics, School of Biosciences, University of Nottingham, Loughborough, Leicestershire, UK; The University of Adelaide, North Terrace, Adelaide, South Australia, Australia
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11
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Calafí C, López-Malo M, Albacar M, Casamayor A, Ariño J. The N-Terminal Region of Yeast Protein Phosphatase Ppz1 Is a Determinant for Its Toxicity. Int J Mol Sci 2020; 21:ijms21207733. [PMID: 33086699 PMCID: PMC7590015 DOI: 10.3390/ijms21207733] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Revised: 10/13/2020] [Accepted: 10/17/2020] [Indexed: 12/01/2022] Open
Abstract
The Ppz enzymes are Ser/Thr protein phosphatases present only in fungi that are characterized by a highly conserved C-terminal catalytic region, related to PP1c phosphatases, and a more divergent N-terminal extension. In Saccharomyces cerevisiae, Ppz phosphatases are encoded by two paralog genes, PPZ1 and PPZ2. Ppz1 is the most toxic protein when overexpressed in budding yeast, halting cell proliferation, and this effect requires its phosphatase activity. We show here that, in spite of their conserved catalytic domain, Ppz2 was not toxic when tested under the same conditions as Ppz1, albeit Ppz2 levels were somewhat lower. Remarkably, a hybrid protein composed of the N-terminal extension of Ppz1 and the catalytic domain of Ppz2 was as toxic as Ppz1, even if its expression level was comparable to that of Ppz2. Similar amounts of yeast PP1c (Glc7) produced an intermediate effect on growth. Mutation of the Ppz1 myristoylable Gly2 to Ala avoided the localization of the phosphatase at the cell periphery but only slightly attenuated its toxicity. Therefore, the N-terminal extension of Ppz1 plays a key role in defining Ppz1 toxicity. This region is predicted to be intrinsically disordered and contains several putative folding-upon-binding regions which are absent in Ppz2 and might be relevant for toxicity.
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12
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Austin S, Mayer A. Phosphate Homeostasis - A Vital Metabolic Equilibrium Maintained Through the INPHORS Signaling Pathway. Front Microbiol 2020; 11:1367. [PMID: 32765429 PMCID: PMC7381174 DOI: 10.3389/fmicb.2020.01367] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Accepted: 05/27/2020] [Indexed: 12/12/2022] Open
Abstract
Cells face major changes in demand for and supply of inorganic phosphate (Pi). Pi is often a limiting nutrient in the environment, particularly for plants and microorganisms. At the same time, the need for phosphate varies, establishing conflicts of goals. Cells experience strong peaks of Pi demand, e.g., during the S-phase, when DNA, a highly abundant and phosphate-rich compound, is duplicated. While cells must satisfy these Pi demands, they must safeguard themselves against an excess of Pi in the cytosol. This is necessary because Pi is a product of all nucleotide-hydrolyzing reactions. An accumulation of Pi shifts the equilibria of these reactions and reduces the free energy that they can provide to drive endergonic metabolic reactions. Thus, while Pi starvation may simply retard growth and division, an elevated cytosolic Pi concentration is potentially dangerous for cells because it might stall metabolism. Accordingly, the consequences of perturbed cellular Pi homeostasis are severe. In eukaryotes, they range from lethality in microorganisms such as yeast (Sethuraman et al., 2001; Hürlimann, 2009), severe growth retardation and dwarfism in plants (Puga et al., 2014; Liu et al., 2015; Wild et al., 2016) to neurodegeneration or renal Fanconi syndrome in humans (Legati et al., 2015; Ansermet et al., 2017). Intracellular Pi homeostasis is thus not only a fundamental topic of cell biology but also of growing interest for medicine and agriculture.
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Affiliation(s)
- Sisley Austin
- Département de Biochimie, Université de Lausanne, Lausanne, Switzerland
| | - Andreas Mayer
- Département de Biochimie, Université de Lausanne, Lausanne, Switzerland
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13
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Christ JJ, Smith SA, Willbold S, Morrissey JH, Blank LM. Biotechnological synthesis of water-soluble food-grade polyphosphate with Saccharomyces cerevisiae. Biotechnol Bioeng 2020; 117:2089-2099. [PMID: 32190899 DOI: 10.1002/bit.27337] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 03/11/2020] [Accepted: 03/17/2020] [Indexed: 12/21/2022]
Abstract
Inorganic polyphosphate (polyP) is the polymer of phosphate. Water-soluble polyPs with average chain lengths of 2-40 P-subunits are widely used as food additives and are currently synthesized chemically. An environmentally friendly highly scalable process to biosynthesize water-soluble food-grade polyP in powder form (termed bio-polyP) is presented in this study. After incubation in a phosphate-free medium, generally regarded as safe wild-type baker's yeast (Saccharomyces cerevisiae) took up phosphate and intracellularly polymerized it into 26.5% polyP (as KPO3 , in cell dry weight). The cells were lyzed by freeze-thawing and gentle heat treatment (10 min, 70°C). Protein and nucleic acid were removed from the soluble cell components by precipitation with 50 mM HCl. Two chain length fractions (42 and 11P-subunits average polyP chain length, purity on a par with chemically produced polyP) were obtained by fractional polyP precipitation (Fraction 1 was precipitated with 100 mM NaCl and 0.15 vol ethanol, and Fraction 2 with 1 final vol ethanol), drying, and milling. The physicochemical properties of bio-polyP were analyzed with an enzyme assay, 31 P nuclear magnetic resonance spectroscopy, and polyacrylamide gel electrophoresis, among others. An envisaged application of the process is phosphate recycling from waste streams into high-value bio-polyP.
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Affiliation(s)
- Jonas Johannes Christ
- Institute of Applied Microbiology-iAMB, Aachen Biology and Biotechnology-ABBt, RWTH Aachen University, Aachen, Germany
| | - Stephanie A Smith
- Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, Michigan
| | - Sabine Willbold
- Central Institute for Engineering, Electronics and Analytics, Analytics (ZEA-3), Forschungszentrum Jülich, Jülich, Germany
| | - James H Morrissey
- Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, Michigan
| | - Lars Mathias Blank
- Institute of Applied Microbiology-iAMB, Aachen Biology and Biotechnology-ABBt, RWTH Aachen University, Aachen, Germany
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14
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Fisher KJ, Kryazhimskiy S, Lang GI. Detecting genetic interactions using parallel evolution in experimental populations. Philos Trans R Soc Lond B Biol Sci 2019; 374:20180237. [PMID: 31154981 DOI: 10.1098/rstb.2018.0237] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Eukaryotic genomes contain thousands of genes organized into complex and interconnected genetic interaction networks. Most of our understanding of how genetic variation affects these networks comes from quantitative-trait loci mapping and from the systematic analysis of double-deletion (or knockdown) mutants, primarily in the yeast Saccharomyces cerevisiae. Evolve and re-sequence experiments are an alternative approach for identifying novel functional variants and genetic interactions, particularly between non-loss-of-function mutations. These experiments leverage natural selection to obtain genotypes with functionally important variants and positive genetic interactions. However, no systematic methods for detecting genetic interactions in these data are yet available. Here, we introduce a computational method based on the idea that variants in genes that interact will co-occur in evolved genotypes more often than expected by chance. We apply this method to a previously published yeast experimental evolution dataset. We find that genetic targets of selection are distributed non-uniformly among evolved genotypes, indicating that genetic interactions had a significant effect on evolutionary trajectories. We identify individual gene pairs with a statistically significant genetic interaction score. The strongest interaction is between genes TRK1 and PHO84, genes that have not been reported to interact in previous systematic studies. Our work demonstrates that leveraging parallelism in experimental evolution is useful for identifying genetic interactions that have escaped detection by other methods. This article is part of the theme issue 'Convergent evolution in the genomics era: new insights and directions'.
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Affiliation(s)
- Kaitlin J Fisher
- 1 Department of Biological Sciences, Lehigh University , Bethlehem, PA 18015 , USA
| | - Sergey Kryazhimskiy
- 2 Division of Biological Sciences, University of California San Diego , La Jolla, CA 92093 , USA
| | - Gregory I Lang
- 1 Department of Biological Sciences, Lehigh University , Bethlehem, PA 18015 , USA
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15
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High External K + Concentrations Impair Pi Nutrition, Induce the Phosphate Starvation Response, and Reduce Arsenic Toxicity in Arabidopsis Plants. Int J Mol Sci 2019; 20:ijms20092237. [PMID: 31067662 PMCID: PMC6539835 DOI: 10.3390/ijms20092237] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Revised: 04/30/2019] [Accepted: 05/03/2019] [Indexed: 01/30/2023] Open
Abstract
Potassium (K+) and phosphorous (Pi) are two of the most important nutrients required by plants and there is an interest in studying how they are acquired. Most studies have focused on the characterization of the mechanisms involved in K+ and Pi uptake and their distribution within the plants, as well as the regulatory mechanisms involved. Evidence is emerging which points to interactions in the nutrition of different nutrients and to the existence of crosstalk in the signaling cascades regulating their acquisition. However, the interaction between K+ and Pi has been scarcely studied. Here we show that high concentrations of K+ in the external solution inhibit Pi uptake and impair Pi nutrition in Arabidopsis plants, resulting in the induction of phosphate starvation response (PSR) and the upregulation of genes encoding root phosphate uptake systems. The high K+-induced PSR depends on the PHR1 and PHL1 transcription factors that are key pieces of Pi signaling in Arabidopsis. Importantly, high K+ reduces arsenic accumulation in plants and its toxic effects. The results presented may help to design strategies to reduce Pi deficiency as well as the accumulation of arsenic in crops.
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16
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Ariño J, Ramos J, Sychrova H. Monovalent cation transporters at the plasma membrane in yeasts. Yeast 2018; 36:177-193. [PMID: 30193006 DOI: 10.1002/yea.3355] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Revised: 08/24/2018] [Accepted: 08/29/2018] [Indexed: 01/08/2023] Open
Abstract
Maintenance of proper intracellular concentrations of monovalent cations, mainly sodium and potassium, is a requirement for survival of any cell. In the budding yeast Saccharomyces cerevisiae, monovalent cation homeostasis is determined by the active extrusion of protons through the Pma1 H+ -ATPase (reviewed in another chapter of this issue), the influx and efflux of these cations through the plasma membrane transporters (reviewed in this chapter), and the sequestration of toxic cations into the vacuoles. Here, we will describe the structure, function, and regulation of the plasma membrane transporters Trk1, Trk2, Tok1, Nha1, and Ena1, which play a key role in maintaining physiological intracellular concentrations of Na+ , K+ , and H+ , both under normal growth conditions and in response to stress.
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Affiliation(s)
- Joaquín Ariño
- Institut de Biotecnologia i Biomedicina and Departament de Bioquimica i Biologia Molecular, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Spain
| | - José Ramos
- Departamento de Microbiología, Universidad de Córdoba, Córdoba, Spain
| | - Hana Sychrova
- Department of Membrane Transport, Institute of Physiology Czech Academy of Sciences, Prague, Czech Republic
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17
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Teunissen JHM, Crooijmans ME, Teunisse PPP, van Heusden GPH. Lack of 14-3-3 proteins in Saccharomyces cerevisiae results in cell-to-cell heterogeneity in the expression of Pho4-regulated genes SPL2 and PHO84. BMC Genomics 2017; 18:701. [PMID: 28877665 PMCID: PMC5588707 DOI: 10.1186/s12864-017-4105-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Accepted: 08/31/2017] [Indexed: 01/16/2023] Open
Abstract
Background Ion homeostasis is an essential property of living organisms. The yeast Saccharomyces cerevisiae is an ideal model organism to investigate ion homeostasis at all levels. In this yeast genes involved in high-affinity phosphate uptake (PHO genes) are strongly induced during both phosphate and potassium starvation, indicating a link between phosphate and potassium homeostasis. However, the signal transduction processes involved are not completely understood. As 14-3-3 proteins are key regulators of signal transduction processes, we investigated the effect of deletion of the 14-3-3 genes BMH1 or BMH2 on gene expression during potassium starvation and focused especially on the expression of genes involved in phosphate uptake. Results Genome-wide analysis of the effect of disruption of either BMH1 or BMH2 revealed that the mRNA levels of the PHO genes PHO84 and SPL2 are greatly reduced in the mutant strains compared to the levels in wild type strains. This was especially apparent at standard potassium and phosphate concentrations. Furthermore the promoter of these genes is less active after deletion of BMH1. Microscopic and flow cytometric analysis of cells with GFP-tagged SPL2 showed that disruption of BMH1 resulted in two populations of genetically identical cells, cells expressing the protein and the majority of cells with no detectible expression. Heterogeneity was also observed for the expression of GFP under control of the PHO84 promoter. Upon deletion of PHO80 encoding a regulator of the transcription factor Pho4, the effect of the BMH1 deletion on SPL2 and PHO84 promoter was lost, suggesting that the BMH1 deletion mainly influences processes upstream of the Pho4 transcription factor. Conclusion Our data indicate that that yeast cells can be in either of two states, expressing or not expressing genes required for high-affinity phosphate uptake and that 14-3-3 proteins are involved in the process(es) that establish the activation state of the PHO regulon. Electronic supplementary material The online version of this article (10.1186/s12864-017-4105-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Janneke H M Teunissen
- Institute of Biology, Leiden University, Sylviusweg 72, NL-2333BE, Leiden, the Netherlands
| | - Marjolein E Crooijmans
- Institute of Biology, Leiden University, Sylviusweg 72, NL-2333BE, Leiden, the Netherlands
| | - Pepijn P P Teunisse
- Institute of Biology, Leiden University, Sylviusweg 72, NL-2333BE, Leiden, the Netherlands
| | - G Paul H van Heusden
- Institute of Biology, Leiden University, Sylviusweg 72, NL-2333BE, Leiden, the Netherlands.
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18
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Molero C, Casado C, Ariño J. The inhibitory mechanism of Hal3 on the yeast Ppz1 phosphatase: A mutagenesis analysis. Sci Rep 2017; 7:8819. [PMID: 28821821 PMCID: PMC5562863 DOI: 10.1038/s41598-017-09360-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Accepted: 07/24/2017] [Indexed: 11/20/2022] Open
Abstract
The Ser/Thr protein phosphatase (PPase) Ppz1 is an enzyme related to the ubiquitous type-1 PPases (PP1c) but found only in fungi. It is regulated by an inhibitory subunit, Hal3, which binds to its catalytic domain. Overexpression of Ppz1 is highly toxic for yeast cells, so its de-regulation has been proposed as a target for novel antifungal therapies. While modulation of PP1c by its many regulatory subunits has been extensively characterized, the manner by which Hal3 controls Ppz1 remains unknown. We have used error-prone PCR mutagenesis to construct a library of Ppz1 variants and developed a functional assay to identify mutations affecting the binding or/and the inhibitory capacity of Hal3. We have characterized diverse Ppz1 mutated versions in vivo and in vitro and found that, although they were clearly refractory to Hal3 inhibition, none of them exhibited significant reduction in Hal3 binding. Mapping the mutations strengthened the notion that Hal3 does not interact with Ppz1 through its RVxF-like motif (found in most PP1c regulators). In contrast, the most relevant mutations mapped to a conserved α-helix region used by mammalian Inhibitor-2 to regulate PP1c. Therefore, modulation of PP1c and Ppz1 by their subunits likely differs, but could share some structural features.
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Affiliation(s)
- Cristina Molero
- Departament de Bioquímica i Biologia Molecular and Institut de Biotecnologia i Biomedicina, Universitat Autònoma de Barcelona, Bellaterra, 08193, Barcelona, Spain
| | - Carlos Casado
- Departament de Bioquímica i Biologia Molecular and Institut de Biotecnologia i Biomedicina, Universitat Autònoma de Barcelona, Bellaterra, 08193, Barcelona, Spain.,Evolva Biotech A/S, Copenhagen, Denmark
| | - Joaquín Ariño
- Departament de Bioquímica i Biologia Molecular and Institut de Biotecnologia i Biomedicina, Universitat Autònoma de Barcelona, Bellaterra, 08193, Barcelona, Spain.
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19
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Ródenas R, García-Legaz MF, López-Gómez E, Martínez V, Rubio F, Ángeles Botella M. NO 3- , PO 43- and SO 42- deprivation reduced LKT1-mediated low-affinity K + uptake and SKOR-mediated K + translocation in tomato and Arabidopsis plants. PHYSIOLOGIA PLANTARUM 2017; 160:410-424. [PMID: 28244226 DOI: 10.1111/ppl.12558] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Revised: 02/02/2017] [Accepted: 02/09/2017] [Indexed: 05/27/2023]
Abstract
Regulation of essential macronutrients acquisition by plants in response to their availability is a key process for plant adaptation to changing environments. Here we show in tomato and Arabidopsis plants that when they are subjected to NO3- , PO43- and SO42- deprivation, low-affinity K+ uptake and K+ translocation to the shoot are reduced. In parallel, these nutritional deficiencies produce reductions in the messenger levels of the genes encoding the main systems for low-affinity K+ uptake and K+ translocation, i.e. AKT1 and SKOR in Arabidopsis and LKT1 and the tomato homolog of SKOR, SlSKOR in tomato, respectively. The results suggest that the shortage of one nutrient produces a general downregulation of the acquisition of other nutrients. In the case of K+ nutrient, one of the mechanisms for such a response resides in the transcriptional repression of the genes encoding the systems for K+ uptake and translocation.
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Affiliation(s)
- Reyes Ródenas
- Departamento de Nutrición Vegetal, CEBAS-CSIC, Murcia, 30100, Spain
| | | | - Elvira López-Gómez
- Departamento de Agroquímica y Medioambiente, Universidad Miguel Hernández, Alicante, 03312, Spain
| | - Vicente Martínez
- Departamento de Nutrición Vegetal, CEBAS-CSIC, Murcia, 30100, Spain
| | - Francisco Rubio
- Departamento de Nutrición Vegetal, CEBAS-CSIC, Murcia, 30100, Spain
| | - M Ángeles Botella
- Departamento de Biología Aplicada, Universidad Miguel Hernández, Alicante, 03312, Spain
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20
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Bru S, Jiménez J, Canadell D, Ariño J, Clotet J. Improvement of biochemical methods of polyP quantification. MICROBIAL CELL 2016; 4:6-15. [PMID: 28357384 PMCID: PMC5354550 DOI: 10.15698/mic2017.01.551] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Polyphosphate (polyP) is an abundant and physiologically important biomolecule
for virtually any living cell. Therefore, determination of changes in cellular
content of polyP is crucial for its functional characterization. Determination
of cellular polyP has been performed by many different methods, and the lack of
a standardized procedure is possibly responsible for the large dispersion of
results found in the relevant literature. For a relatively simple organism, such
as the yeast Saccharomyces cerevisiae, this variation can be up
to 12-fold. polyP extraction and determination of free phosphate released by
enzymatic degradation of the polymer is a method quite common and relatively
straightforward for polyP determination. By using the yeast S.
cerevisiae as model, we have experimentally evaluated the different
steps in this procedure in order to identify critical issues that might explain
the disparate reported results. As the main output of this evaluation we propose
a straightforward and robust procedure that can be used as gold standard
protocol for cellular polyP purification and determination from unicellular
organisms, thus providing consistency to measurements and facilitating
inter-laboratory comparisons and biological interpretation of the results.
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Affiliation(s)
- Samuel Bru
- Department of Basic Sciences, Faculty of Medicine and Health Sciences. Universitat Internacional de Catalunya. Barcelona, Spain
| | - Javier Jiménez
- Department of Basic Sciences, Faculty of Medicine and Health Sciences. Universitat Internacional de Catalunya. Barcelona, Spain
| | - David Canadell
- Departament de Bioquímica i Biologia Molecular and Institut de Biotecnologia i Biomedicina, Universitat Autònoma de Barcelona. Cerdanyola del Vallès, Spain
| | - Joaquín Ariño
- Departament de Bioquímica i Biologia Molecular and Institut de Biotecnologia i Biomedicina, Universitat Autònoma de Barcelona. Cerdanyola del Vallès, Spain
| | - Josep Clotet
- Department of Basic Sciences, Faculty of Medicine and Health Sciences. Universitat Internacional de Catalunya. Barcelona, Spain
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21
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The yeast Aft2 transcription factor determines selenite toxicity by controlling the low affinity phosphate transport system. Sci Rep 2016; 6:32836. [PMID: 27618952 PMCID: PMC5020356 DOI: 10.1038/srep32836] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Accepted: 08/16/2016] [Indexed: 01/13/2023] Open
Abstract
The yeast Saccharomyces cerevisiae is employed as a model to study the cellular mechanisms of toxicity and defense against selenite, the most frequent environmental selenium form. We show that yeast cells lacking Aft2, a transcription factor that together with Aft1 regulates iron homeostasis, are highly sensitive to selenite but, in contrast to aft1 mutants, this is not rescued by iron supplementation. The absence of Aft2 strongly potentiates the transcriptional responses to selenite, particularly for DNA damage- and oxidative stress-responsive genes, and results in intracellular hyperaccumulation of selenium. Overexpression of PHO4, the transcriptional activator of the PHO regulon under low phosphate conditions, partially reverses sensitivity and hyperaccumulation of selenite in a way that requires the presence of Spl2, a Pho4-controlled protein responsible for post-transcriptional downregulation of the low-affinity phosphate transporters Pho87 and Pho90. SPL2 expression is strongly downregulated in aft2 cells, especially upon selenite treatment. Selenite hypersensitivity of aft2 cells is fully rescued by deletion of PHO90, suggesting a major role for Pho90 in selenite uptake. We propose that the absence of Aft2 leads to enhanced Pho90 function, involving both Spl2-dependent and independent events and resulting in selenite hyperaccumulation and toxicity.
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22
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A Thermodynamic Model of Monovalent Cation Homeostasis in the Yeast Saccharomyces cerevisiae. PLoS Comput Biol 2016; 12:e1004703. [PMID: 26815455 PMCID: PMC4729481 DOI: 10.1371/journal.pcbi.1004703] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Accepted: 12/13/2015] [Indexed: 11/20/2022] Open
Abstract
Cationic and heavy metal toxicity is involved in a substantial number of diseases in mammals and crop plants. Therefore, the understanding of tightly regulated transporter activities, as well as conceiving the interplay of regulatory mechanisms, is of substantial interest. A generalized thermodynamic description is developed for the complex interplay of the plasma membrane ion transporters, membrane potential and the consumption of energy for maintaining and restoring specific intracellular cation concentrations. This concept is applied to the homeostasis of cation concentrations in the yeast cells of S. cerevisiae. The thermodynamic approach allows to model passive ion fluxes driven by the electrochemical potential differences, but also primary or secondary active transport processes driven by the inter- play of different ions (symport, antiport) or by ATP consumption (ATPases). The model-confronted with experimental data-reproduces the experimentally observed potassium and proton fluxes induced by the external stimuli KCl and glucose. The estimated phenomenological constants combine kinetic parameters and transport coefficients. These are in good agreement with the biological understanding of the transporters thus providing a better understanding of the control exerted by the coupled fluxes. The model predicts the flux of additional ion species, like e.g. chloride, as a potential candidate for counterbalancing positive charges. Furthermore, the effect of a second KCl stimulus is simulated, predicting a reduced cellular response for cells that were first exposed to a high KCl stimulus compared to cells pretreated with a mild KCl stimulus. By describing the generalized forces that are responsible for a given flow, the model provides information and suggestions for new experiments. Furthermore, it can be extended to other systems such as e.g. Candida albicans, or selected plant cells.
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23
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Yenush L. Potassium and Sodium Transport in Yeast. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 892:187-228. [DOI: 10.1007/978-3-319-25304-6_8] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Interactions Between Monovalent Cations and Nutrient Homeostasis. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 892:271-289. [PMID: 26721278 DOI: 10.1007/978-3-319-25304-6_11] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Maintenance of appropriate fluxes of monovalent cation is a requirement for growth and survival. In the budding yeast Saccharomyces cerevisiae an electrochemical gradient of H(+) is fundamental for the uptake of diverse cations, such as K(+), and of many other nutrients. In spite of early work suggesting that alterations in monovalent cation fluxes impact on the uptake and utilization of nutrients, such as phosphate anions, only recently this important aspect of the yeast physiology has been addressed and characterized in some detail. This chapter provides a historical background and summarizes the latest findings.
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25
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Mathematical Modelling of Cation Transport and Regulation in Yeast. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 892:291-305. [DOI: 10.1007/978-3-319-25304-6_12] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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26
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Serra-Cardona A, Canadell D, Ariño J. Coordinate responses to alkaline pH stress in budding yeast. MICROBIAL CELL 2015; 2:182-196. [PMID: 28357292 PMCID: PMC5349140 DOI: 10.15698/mic2015.06.205] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Alkalinization of the medium represents a stress condition for the budding yeast Saccharomyces cerevisiae to which this organism responds with profound remodeling of gene expression. This is the result of the modulation of a substantial number of signaling pathways whose participation in the alkaline response has been elucidated within the last ten years. These regulatory inputs involve not only the conserved Rim101/PacC pathway, but also the calcium-activated phosphatase calcineurin, the Wsc1-Pkc1-Slt2 MAP kinase, the Snf1 and PKA kinases and oxidative stress-response pathways. The uptake of many nutrients is perturbed by alkalinization of the environment and, consequently, an impact on phosphate, iron/copper and glucose homeostatic mechanisms can also be observed. The analysis of available data highlights cases in which diverse signaling pathways are integrated in the gene promoter to shape the appropriate response pattern. Thus, the expression of different genes sharing the same signaling network can be coordinated, allowing functional coupling of their gene products.
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Affiliation(s)
- Albert Serra-Cardona
- Departament de Bioquímica i Biologia Molecular & Institut de Biotecnologia i Biomedicina, Universitat Autònoma de Barcelona, Bellaterra 08193, Barcelona, Spain
| | - David Canadell
- Departament de Bioquímica i Biologia Molecular & Institut de Biotecnologia i Biomedicina, Universitat Autònoma de Barcelona, Bellaterra 08193, Barcelona, Spain
| | - Joaquín Ariño
- Departament de Bioquímica i Biologia Molecular & Institut de Biotecnologia i Biomedicina, Universitat Autònoma de Barcelona, Bellaterra 08193, Barcelona, Spain
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