1
|
Ding JL, Feng MG, Ying SH. Two ferrous iron transporter-like proteins independently participate in asexual development under iron limitation and virulence in Beauveria bassiana. Fungal Genet Biol 2024; 173:103908. [PMID: 38857848 DOI: 10.1016/j.fgb.2024.103908] [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: 05/16/2024] [Revised: 06/02/2024] [Accepted: 06/07/2024] [Indexed: 06/12/2024]
Abstract
Reductive assimilation pathway involves ferric reductase and ferrous iron transporter, which is integral for fungal iron acquisition. A family of ferric reductase-like proteins has been functionally characterized in the filamentous entomopathogenic fungus Beauveria bassiana. In this investigation, two ferrous iron transporter-like proteins (Ftr) were functionally annotated in B. bassiana. BbFtr1 and BbFtr2 displayed high similarity in structure and were associated with the plasma and nuclear membrane. Their losses had no negatively influence on fungal growth on various nutrients and development under the iron-replete condition. Single mutants of BbFTR1 and BbFTR2 displayed the iron-availability dependent developmental defects, and double mutant exhibited the significantly impaired developmental potential under the iron-limited conditions. In insect bioassay, the double mutant also showed the weaker virulence than either of two single disruption mutants. These results suggested that two ferrous iron transporter-like proteins function independently in fungal physiologies under the iron-deficient condition. Intriguingly, a bZIP transcription factor BbHapX was required for expression of BbFTR1 and BbFTR2 under iron-depleted conditions. This study enhances our understanding of the iron uptake system in the filamentous entomopathogenic fungi.
Collapse
Affiliation(s)
- Jin-Li Ding
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou 310058, China
| | - Ming-Guang Feng
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou 310058, China
| | - Sheng-Hua Ying
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou 310058, China.
| |
Collapse
|
2
|
Abuzeineh A, Vert G, Zelazny E. Birth, life and death of the Arabidopsis IRT1 iron transporter: the role of close friends and foes. PLANTA 2022; 256:112. [PMID: 36367624 DOI: 10.1007/s00425-022-04018-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Accepted: 10/22/2022] [Indexed: 06/16/2023]
Abstract
IRT1 intracellular dynamics and function are finely controlled through protein-protein interactions. In plants, iron uptake from the soil is tightly regulated to allow optimal growth and development. Iron acquisition in Arabidopsis root epidermal cells requires the IRT1 transporter, which also mediates the entry of non-iron metals. In this mini-review, we describe how protein-protein interactions regulate IRT1 intracellular dynamics and IRT1-mediated metal uptake to maintain iron homeostasis. Recent interactomic data provided interesting clues on IRT1 secretion and the putative involvement of COPI- and COPII-mediated pathways. Once delivered to the plasma membrane, IRT1 can interact with other components of the iron uptake machinery to form an iron acquisition complex that likely optimizes iron entrance in root epidermal cells. Then, IRT1 may be internalized from the plasma membrane. In the past decade, IRT1 endocytosis emerged as an essential mechanism to control IRT1 subcellular localization and thus to tune iron uptake. Interestingly, IRT1 endocytosis and degradation are regulated by its non-iron metal substrates in an ubiquitin-dependent manner, which requires a set of interacting-proteins including kinases, E3 ubiquitin ligases and ESCRT complex subunits. This mechanism is essential to avoid non-iron metal overload in Arabidopsis when the iron is scarce.
Collapse
Affiliation(s)
- Anas Abuzeineh
- Institute for Plant Sciences of Montpellier (IPSiM), CNRS, University of Montpellier, INRAE, Montpellier SupAgro, 34060, Montpellier, France
| | - Grégory Vert
- Plant Science Research Laboratory (LRSV), UMR5546, CNRS/Toulouse, INP/University of Toulouse 3, 31320, Auzeville Tolosane, France
| | - Enric Zelazny
- Institute for Plant Sciences of Montpellier (IPSiM), CNRS, University of Montpellier, INRAE, Montpellier SupAgro, 34060, Montpellier, France.
| |
Collapse
|
3
|
Steunou AS, Vigouroux A, Aumont‐Nicaise M, Plancqueel S, Boussac A, Ouchane S, Moréra S. New insights into the mechanism of iron transport through the bacterial Ftr system present in pathogens. FEBS J 2022; 289:6286-6307. [DOI: 10.1111/febs.16476] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Revised: 04/11/2022] [Accepted: 05/06/2022] [Indexed: 11/29/2022]
Affiliation(s)
- Anne Soisig Steunou
- Université Paris‐Saclay, CEA CNRS Institute for Integrative Biology of the Cell (I2BC) Gif‐sur‐Yvette France
| | - Armelle Vigouroux
- Université Paris‐Saclay, CEA CNRS Institute for Integrative Biology of the Cell (I2BC) Gif‐sur‐Yvette France
| | - Magali Aumont‐Nicaise
- Université Paris‐Saclay, CEA CNRS Institute for Integrative Biology of the Cell (I2BC) Gif‐sur‐Yvette France
| | - Stéphane Plancqueel
- Université Paris‐Saclay, CEA CNRS Institute for Integrative Biology of the Cell (I2BC) Gif‐sur‐Yvette France
| | - Alain Boussac
- Université Paris‐Saclay, CEA CNRS Institute for Integrative Biology of the Cell (I2BC) Gif‐sur‐Yvette France
| | - Soufian Ouchane
- Université Paris‐Saclay, CEA CNRS Institute for Integrative Biology of the Cell (I2BC) Gif‐sur‐Yvette France
| | - Solange Moréra
- Université Paris‐Saclay, CEA CNRS Institute for Integrative Biology of the Cell (I2BC) Gif‐sur‐Yvette France
| |
Collapse
|
4
|
Gluck-Thaler E, Ralston T, Konkel Z, Ocampos CG, Ganeshan VD, Dorrance AE, Niblack TL, Wood CW, Slot JC, Lopez-Nicora HD, Vogan AA. Giant Starship Elements Mobilize Accessory Genes in Fungal Genomes. Mol Biol Evol 2022; 39:msac109. [PMID: 35588244 PMCID: PMC9156397 DOI: 10.1093/molbev/msac109] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Accessory genes are variably present among members of a species and are a reservoir of adaptive functions. In bacteria, differences in gene distributions among individuals largely result from mobile elements that acquire and disperse accessory genes as cargo. In contrast, the impact of cargo-carrying elements on eukaryotic evolution remains largely unknown. Here, we show that variation in genome content within multiple fungal species is facilitated by Starships, a newly discovered group of massive mobile elements that are 110 kb long on average, share conserved components, and carry diverse arrays of accessory genes. We identified hundreds of Starship-like regions across every major class of filamentous Ascomycetes, including 28 distinct Starships that range from 27 to 393 kb and last shared a common ancestor ca. 400 Ma. Using new long-read assemblies of the plant pathogen Macrophomina phaseolina, we characterize four additional Starships whose activities contribute to standing variation in genome structure and content. One of these elements, Voyager, inserts into 5S rDNA and contains a candidate virulence factor whose increasing copy number has contrasting associations with pathogenic and saprophytic growth, suggesting Voyager's activity underlies an ecological trade-off. We propose that Starships are eukaryotic analogs of bacterial integrative and conjugative elements based on parallels between their conserved components and may therefore represent the first dedicated agents of active gene transfer in eukaryotes. Our results suggest that Starships have shaped the content and structure of fungal genomes for millions of years and reveal a new concerted route for evolution throughout an entire eukaryotic phylum.
Collapse
Affiliation(s)
- Emile Gluck-Thaler
- Department of Biology, University of Pennsylvania, Philadelphia, PA, USA
- Department of Plant Pathology, The Ohio State University, Columbus, OH, USA
| | - Timothy Ralston
- Department of Plant Pathology, The Ohio State University, Columbus, OH, USA
| | - Zachary Konkel
- Department of Plant Pathology, The Ohio State University, Columbus, OH, USA
| | | | - Veena Devi Ganeshan
- Arabidopsis Biological Resource Center, The Ohio State University, Columbus, OH, USA
| | - Anne E. Dorrance
- Department of Plant Pathology, The Ohio State University, Wooster, OH, USA
| | - Terry L. Niblack
- Department of Plant Pathology, The Ohio State University, Columbus, OH, USA
| | - Corlett W. Wood
- Department of Biology, University of Pennsylvania, Philadelphia, PA, USA
| | - Jason C. Slot
- Department of Plant Pathology, The Ohio State University, Columbus, OH, USA
| | - Horacio D. Lopez-Nicora
- Department of Plant Pathology, The Ohio State University, Columbus, OH, USA
- Departamento de Producción Agrícola, Universidad San Carlos, Asunción, Paraguay
| | - Aaron A. Vogan
- Systematic Biology, Department of Organismal Biology, University of Uppsala, Uppsala, Sweden
| |
Collapse
|
5
|
Ramírez-Zavala B, Krüger I, Dunker C, Jacobsen ID, Morschhäuser J. The protein kinase Ire1 has a Hac1-independent essential role in iron uptake and virulence of Candida albicans. PLoS Pathog 2022; 18:e1010283. [PMID: 35108336 PMCID: PMC8846550 DOI: 10.1371/journal.ppat.1010283] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Revised: 02/14/2022] [Accepted: 01/19/2022] [Indexed: 11/25/2022] Open
Abstract
Protein kinases play central roles in virtually all signaling pathways that enable organisms to adapt to their environment. Microbial pathogens must cope with severely restricted iron availability in mammalian hosts to invade and establish themselves within infected tissues. To uncover protein kinase signaling pathways that are involved in the adaptation of the pathogenic yeast Candida albicans to iron limitation, we generated a comprehensive protein kinase deletion mutant library of a wild-type strain. Screening of this library revealed that the protein kinase Ire1, which has a conserved role in the response of eukaryotic cells to endoplasmic reticulum stress, is essential for growth of C. albicans under iron-limiting conditions. Ire1 was not necessary for the activity of the transcription factor Sef1, which regulates the response of the fungus to iron limitation, and Sef1 target genes that are induced by iron depletion were normally upregulated in ire1Δ mutants. Instead, Ire1 was required for proper localization of the high-affinity iron permease Ftr1 to the cell membrane. Intriguingly, iron limitation did not cause increased endoplasmic reticulum stress, and the transcription factor Hac1, which is activated by Ire1-mediated removal of the non-canonical intron in the HAC1 mRNA, was dispensable for Ftr1 localization to the cell membrane and growth under iron-limiting conditions. Nevertheless, expression of a pre-spliced HAC1 copy in ire1Δ mutants restored Ftr1 localization and rescued the growth defects of the mutants. Both ire1Δ and hac1Δ mutants were avirulent in a mouse model of systemic candidiasis, indicating that an appropriate response to endoplasmic reticulum stress is important for the virulence of C. albicans. However, the specific requirement of Ire1 for the functionality of the high-affinity iron permease Ftr1, a well-established virulence factor, even in the absence of endoplasmic reticulum stress uncovers a novel Hac1-independent essential role of Ire1 in iron acquisition and virulence of C. albicans.
Collapse
Affiliation(s)
| | - Ines Krüger
- Institute for Molecular Infection Biology, University of Würzburg, Würzburg, Germany
| | - Christine Dunker
- Research Group Microbial Immunology, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knoell Institute, Jena, Germany
| | - Ilse D. Jacobsen
- Research Group Microbial Immunology, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knoell Institute, Jena, Germany
- Institute of Microbiology, Friedrich Schiller University Jena, Jena, Germany
| | - Joachim Morschhäuser
- Institute for Molecular Infection Biology, University of Würzburg, Würzburg, Germany
| |
Collapse
|
6
|
Banerjee S, Chanakira MN, Hall J, Kerkan A, Dasgupta S, Martin DW. A review on bacterial redox dependent iron transporters and their evolutionary relationship. J Inorg Biochem 2022; 229:111721. [PMID: 35033753 DOI: 10.1016/j.jinorgbio.2022.111721] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2021] [Revised: 01/04/2022] [Accepted: 01/06/2022] [Indexed: 02/05/2023]
Abstract
Iron is an essential yet toxic micronutrient and its transport across biological membranes is tightly regulated in all living organisms. One such iron transporter, the Ftr-type permeases, is found in both eukaryotic and prokaryotic cells. These Ftr-type transporters are required for iron transport, predicted to form α-helical transmembrane structures, and conserve two ArgGluxxGlu (x = any amino acid) motifs. In the yeast Ftr transporter (Ftr1p), a ferroxidase (Fet3p) is required for iron transport in an oxidation coupled transport step. None of the bacterial Ftr-type transporters (EfeU and FetM from E. coli; cFtr from Campylobacter jejuni; FtrC from Brucella, Bordetella, and Burkholderia spp.) contain a ferroxidase protein. Bioinformatics report predicted periplasmic EfeO and FtrB (from the EfeUOB and FtrABCD systems) as novel cupredoxins. The Cu2+ binding and the ferrous oxidation properties of these proteins are uncharacterized and the other two bacterial Ftr-systems are expressed without any ferroxidase/cupredoxin, leading to controversy about the mode of function of these transporters. Here, we review published data on Ftr-type transporters to gain insight into their functional diversity. Based on original bioinformatics data presented here evolutionary relations between these systems are presented.
Collapse
Affiliation(s)
- Sambuddha Banerjee
- Department of Chemistry, East Carolina University, Greenville, NC 27858, USA.
| | - Mina N Chanakira
- Department of Chemistry, East Carolina University, Greenville, NC 27858, USA
| | - Jonathan Hall
- Department of Chemistry, East Carolina University, Greenville, NC 27858, USA
| | - Alexa Kerkan
- Department of Chemistry, East Carolina University, Greenville, NC 27858, USA
| | - Saumya Dasgupta
- Department of Chemistry, Amity Institute of Applied Sciences, Amity University Kolkata, WB 700135, India
| | - Daniel W Martin
- Department of Microbiology and Immunology, Brody School of Medicine, East Carolina University, Greenville, NC 27834, USA
| |
Collapse
|
7
|
Martín-Barranco A, Thomine S, Vert G, Zelazny E. A quick journey into the diversity of iron uptake strategies in photosynthetic organisms. PLANT SIGNALING & BEHAVIOR 2021; 16:1975088. [PMID: 34514930 PMCID: PMC8525953 DOI: 10.1080/15592324.2021.1975088] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Revised: 08/25/2021] [Accepted: 08/26/2021] [Indexed: 06/02/2023]
Abstract
Iron (Fe) is involved in multiple processes that contribute to the maintenance of the cellular homeostasis of all living beings. In photosynthetic organisms, Fe is notably required for photosynthesis. Although iron is generally abundant in the environment, it is frequently poorly bioavailable. This review focuses on the molecular strategies that photosynthetic organisms have evolved to optimize iron acquisition, using Arabidopsis thaliana, rice (Oryza sativa), and some unicellular algae as models. Non-graminaceous plants, including Arabidopsis, take up iron from the soil by an acidification-reduction-transport process (strategy I) requiring specific proteins that were recently shown to associate in a dedicated complex. On the other hand, graminaceous plants, such as rice, use the so-called strategy II to acquire iron, which relies on the uptake of Fe3+ chelated by phytosiderophores that are secreted by the plant into the rhizosphere. However, apart these main strategies, accessory mechanisms contribute to robust iron uptake in both Arabidopsis and rice. Unicellular algae combine reductive and non-reductive mechanisms for iron uptake and present important specificities compared to land plants. Since the majority of the molecular actors required for iron acquisition in algae are not conserved in land plants, questions arise about the evolution of the Fe uptake processes upon land colonization.
Collapse
Affiliation(s)
- Amanda Martín-Barranco
- Institute for Integrative Biology of the Cell (I2BC), UMR9198 CNRS/CEA/Univ. Paris Sud, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Sébastien Thomine
- Institute for Integrative Biology of the Cell (I2BC), UMR9198 CNRS/CEA/Univ. Paris Sud, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Grégory Vert
- Plant Science Research Laboratory (LRSV), UMR5546 CNRS/University of Toulouse 3, Auzeville Tolosane, France
| | - Enric Zelazny
- Biochemistry and Plant Molecular Physiology (BPMP), CNRS, INRAE, Montpellier SupAgro, Université Montpellier, Montpellier, France
| |
Collapse
|
8
|
Hemkemeyer M, Schwalb SA, Heinze S, Joergensen RG, Wichern F. Functions of elements in soil microorganisms. Microbiol Res 2021; 252:126832. [PMID: 34508963 DOI: 10.1016/j.micres.2021.126832] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 07/23/2021] [Accepted: 07/26/2021] [Indexed: 12/15/2022]
Abstract
The soil microbial community fulfils various functions, such as nutrient cycling and carbon (C) sequestration, therefore contributing to maintenance of soil fertility and mitigation of global warming. In this context, a major focus of research has been on C, nitrogen (N) and phosphorus (P) cycling. However, from aquatic and other environments, it is well known that other elements beyond C, N, and P are essential for microbial functioning. Nonetheless, for soil microorganisms this knowledge has not yet been synthesised. To gain a better mechanistic understanding of microbial processes in soil systems, we aimed at summarising the current knowledge on the function of a range of essential or beneficial elements, which may affect the efficiency of microbial processes in soil. This knowledge is discussed in the context of microbial driven nutrient and C cycling. Our findings may support future investigations and data evaluation, where other elements than C, N, and P affect microbial processes.
Collapse
Affiliation(s)
- Michael Hemkemeyer
- Department of Soil Science and Plant Nutrition, Institute of Biogenic Resources in Sustainable Food Systems - From Farm to Function, Rhine-Waal University of Applied Sciences, Marie-Curie-Str. 1, 47533 Kleve, Germany.
| | - Sanja A Schwalb
- Department of Soil Science and Plant Nutrition, Institute of Biogenic Resources in Sustainable Food Systems - From Farm to Function, Rhine-Waal University of Applied Sciences, Marie-Curie-Str. 1, 47533 Kleve, Germany
| | - Stefanie Heinze
- Department of Soil Science & Soil Ecology, Ruhr-University Bochum, Universitätsstr. 150, 44801 Bochum, Germany
| | - Rainer Georg Joergensen
- Department of Soil Biology and Plant Nutrition, University of Kassel, Nordbahnhofstr. 1a, 37213 Witzenhausen, Germany
| | - Florian Wichern
- Department of Soil Science and Plant Nutrition, Institute of Biogenic Resources in Sustainable Food Systems - From Farm to Function, Rhine-Waal University of Applied Sciences, Marie-Curie-Str. 1, 47533 Kleve, Germany
| |
Collapse
|
9
|
Dietz JV, Fox JL, Khalimonchuk O. Down the Iron Path: Mitochondrial Iron Homeostasis and Beyond. Cells 2021; 10:cells10092198. [PMID: 34571846 PMCID: PMC8468894 DOI: 10.3390/cells10092198] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Revised: 08/22/2021] [Accepted: 08/23/2021] [Indexed: 12/20/2022] Open
Abstract
Cellular iron homeostasis and mitochondrial iron homeostasis are interdependent. Mitochondria must import iron to form iron–sulfur clusters and heme, and to incorporate these cofactors along with iron ions into mitochondrial proteins that support essential functions, including cellular respiration. In turn, mitochondria supply the cell with heme and enable the biogenesis of cytosolic and nuclear proteins containing iron–sulfur clusters. Impairment in cellular or mitochondrial iron homeostasis is deleterious and can result in numerous human diseases. Due to its reactivity, iron is stored and trafficked through the body, intracellularly, and within mitochondria via carefully orchestrated processes. Here, we focus on describing the processes of and components involved in mitochondrial iron trafficking and storage, as well as mitochondrial iron–sulfur cluster biogenesis and heme biosynthesis. Recent findings and the most pressing topics for future research are highlighted.
Collapse
Affiliation(s)
- Jonathan V. Dietz
- Department of Biochemistry, University of Nebraska, Lincoln, NE 68588, USA;
| | - Jennifer L. Fox
- Department of Chemistry and Biochemistry, College of Charleston, Charleston, SC 29424, USA;
| | - Oleh Khalimonchuk
- Department of Biochemistry, University of Nebraska, Lincoln, NE 68588, USA;
- Nebraska Redox Biology Center, University of Nebraska, Lincoln, NE 68588, USA
- Fred and Pamela Buffett Cancer Center, Omaha, NE 68198, USA
- Correspondence:
| |
Collapse
|
10
|
Domnauer M, Zheng F, Li L, Zhang Y, Chang CE, Unruh JR, Conkright-Fincham J, McCroskey S, Florens L, Zhang Y, Seidel C, Fong B, Schilling B, Sharma R, Ramanathan A, Si K, Zhou C. Proteome plasticity in response to persistent environmental change. Mol Cell 2021; 81:3294-3309.e12. [PMID: 34293321 DOI: 10.1016/j.molcel.2021.06.028] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 04/28/2021] [Accepted: 06/22/2021] [Indexed: 01/17/2023]
Abstract
Temperature is a variable component of the environment, and all organisms must deal with or adapt to temperature change. Acute temperature change activates cellular stress responses, resulting in refolding or removal of damaged proteins. However, how organisms adapt to long-term temperature change remains largely unexplored. Here we report that budding yeast responds to long-term high temperature challenge by switching from chaperone induction to reduction of temperature-sensitive proteins and re-localizing a portion of its proteome. Surprisingly, we also find that many proteins adopt an alternative conformation. Using Fet3p as an example, we find that the temperature-dependent conformational difference is accompanied by distinct thermostability, subcellular localization, and, importantly, cellular functions. We postulate that, in addition to the known mechanisms of adaptation, conformational plasticity allows some polypeptides to acquire new biophysical properties and functions when environmental change endures.
Collapse
Affiliation(s)
- Matthew Domnauer
- Buck Institute for Research on Aging, 8001 Redwood Blvd., Novato, CA 94945, USA; USC Leonard Davis School of Gerontology, University of Southern California, 3715 McClintock Ave., Los Angeles, CA 90191, USA
| | - Fan Zheng
- Buck Institute for Research on Aging, 8001 Redwood Blvd., Novato, CA 94945, USA
| | - Liying Li
- UCSF, 1550 Fourth St, RH490 San Francisco, CA 94158, USA
| | - Yanxiao Zhang
- Ludwig Institute for Cancer Research, 9500 Gilman Dr., La Jolla, CA 92093, USA
| | - Catherine E Chang
- Buck Institute for Research on Aging, 8001 Redwood Blvd., Novato, CA 94945, USA
| | - Jay R Unruh
- Stowers Institute for Medical Research, 1000 East 50th Street, Kansas City, MO 64110, USA
| | | | - Scott McCroskey
- Stowers Institute for Medical Research, 1000 East 50th Street, Kansas City, MO 64110, USA
| | - Laurence Florens
- Stowers Institute for Medical Research, 1000 East 50th Street, Kansas City, MO 64110, USA
| | - Ying Zhang
- Stowers Institute for Medical Research, 1000 East 50th Street, Kansas City, MO 64110, USA
| | - Christopher Seidel
- Stowers Institute for Medical Research, 1000 East 50th Street, Kansas City, MO 64110, USA
| | - Benjamin Fong
- Buck Institute for Research on Aging, 8001 Redwood Blvd., Novato, CA 94945, USA
| | - Birgit Schilling
- Buck Institute for Research on Aging, 8001 Redwood Blvd., Novato, CA 94945, USA; USC Leonard Davis School of Gerontology, University of Southern California, 3715 McClintock Ave., Los Angeles, CA 90191, USA
| | - Rishi Sharma
- Buck Institute for Research on Aging, 8001 Redwood Blvd., Novato, CA 94945, USA
| | - Arvind Ramanathan
- Buck Institute for Research on Aging, 8001 Redwood Blvd., Novato, CA 94945, USA; Institute for Stem Cell Science and Regenerative Medicine GKVK, Bengaluru, Karnataka 560065, India
| | - Kausik Si
- Stowers Institute for Medical Research, 1000 East 50th Street, Kansas City, MO 64110, USA; Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, KS 66160, USA.
| | - Chuankai Zhou
- Buck Institute for Research on Aging, 8001 Redwood Blvd., Novato, CA 94945, USA; USC Leonard Davis School of Gerontology, University of Southern California, 3715 McClintock Ave., Los Angeles, CA 90191, USA.
| |
Collapse
|
11
|
Pan C, Zhu Y, Yu M, Zhao Y, Zhang C, Zhang X, Yao Y. Control Analysis of Protein-Protein Interaction Network Reveals Potential Regulatory Targets for MYCN. Front Oncol 2021; 11:633579. [PMID: 33968733 PMCID: PMC8096904 DOI: 10.3389/fonc.2021.633579] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Accepted: 03/04/2021] [Indexed: 12/05/2022] Open
Abstract
BACKGROUND MYCN is an oncogenic transcription factor of the MYC family and plays an important role in the formation of tissues and organs during development before birth. Due to the difficulty in drugging MYCN directly, revealing the molecules in MYCN regulatory networks will help to identify effective therapeutic targets. METHODS We utilized network controllability theory, a recent developed powerful tool, to identify the potential drug target around MYCN based on Protein-Protein interaction network of MYCN. First, we constructed a Protein-Protein interaction network of MYCN based on public databases. Second, network control analysis was applied on network to identify driver genes and indispensable genes of the MYCN regulatory network. Finally, we developed a novel integrated approach to identify potential drug targets for regulating the function of the MYCN regulatory network. RESULTS We constructed an MYCN regulatory network that has 79 genes and 129 interactions. Based on network controllability theory, we analyzed driver genes which capable to fully control the network. We found 10 indispensable genes whose alternation will significantly change the regulatory pathways of the MYCN network. We evaluated the stability and correlation analysis of these genes and found EGFR may be the potential drug target which closely associated with MYCN. CONCLUSION Together, our findings indicate that EGFR plays an important role in the regulatory network and pathways of MYCN and therefore may represent an attractive therapeutic target for cancer treatment.
Collapse
Affiliation(s)
- Chunyu Pan
- Northeastern University, Shenyang, China
- Joint Laboratory of Artificial Intelligence and Precision Medicine of China Medical University and Northeastern University, Shenyang, China
- Early Intervention Unit, Department of Psychiatry, Affiliated Nanjing Brain Hospital, Nanjing Medical University, Nanjing, China
| | - Yuyan Zhu
- Joint Laboratory of Artificial Intelligence and Precision Medicine of China Medical University and Northeastern University, Shenyang, China
- Department of Urology, The First Hospital of China Medical University, Shenyang, China
| | - Meng Yu
- Department of Reproductive Biology and Transgenic Animal, China Medical University, Shenyang, China
| | - Yongkang Zhao
- National Institute of Health and Medical Big Data, China Medical University, Shenyang, China
| | | | - Xizhe Zhang
- Joint Laboratory of Artificial Intelligence and Precision Medicine of China Medical University and Northeastern University, Shenyang, China
- Early Intervention Unit, Department of Psychiatry, Affiliated Nanjing Brain Hospital, Nanjing Medical University, Nanjing, China
- School of Biomedical Engineering and Informatics, Nanjing Medical University, Nanjing, China
| | - Yang Yao
- Department of Physiology, Shenyang Medical College, Shenyang, China
| |
Collapse
|
12
|
Cation Transporters of Candida albicans-New Targets to Fight Candidiasis? Biomolecules 2021; 11:biom11040584. [PMID: 33923411 PMCID: PMC8073359 DOI: 10.3390/biom11040584] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Accepted: 04/14/2021] [Indexed: 02/07/2023] Open
Abstract
Candidiasis is the wide-spread fungal infection caused by numerous strains of yeast, with the prevalence of Candida albicans. The current treatment of candidiasis is becoming rather ineffective and costly owing to the emergence of resistant strains; hence, the exploration of new possible drug targets is necessary. The most promising route is the development of novel antibiotics targeting this pathogen. In this review, we summarize such candidates found in C. albicans and those involved in the transport of (metal) cations, as the latter are essential for numerous processes within the cell; hence, disruption of their fluxes can be fatal for C. albicans.
Collapse
|
13
|
Endocytosis of nutrient transporters in fungi: The ART of connecting signaling and trafficking. Comput Struct Biotechnol J 2021; 19:1713-1737. [PMID: 33897977 PMCID: PMC8050425 DOI: 10.1016/j.csbj.2021.03.013] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2020] [Revised: 03/14/2021] [Accepted: 03/14/2021] [Indexed: 12/11/2022] Open
Abstract
Plasma membrane transporters play pivotal roles in the import of nutrients, including sugars, amino acids, nucleobases, carboxylic acids, and metal ions, that surround fungal cells. The selective removal of these transporters by endocytosis is one of the most important regulatory mechanisms that ensures a rapid adaptation of cells to the changing environment (e.g., nutrient fluctuations or different stresses). At the heart of this mechanism lies a network of proteins that includes the arrestin‐related trafficking adaptors (ARTs) which link the ubiquitin ligase Rsp5 to nutrient transporters and endocytic factors. Transporter conformational changes, as well as dynamic interactions between its cytosolic termini/loops and with lipids of the plasma membrane, are also critical during the endocytic process. Here, we review the current knowledge and recent findings on the molecular mechanisms involved in nutrient transporter endocytosis, both in the budding yeast Saccharomyces cerevisiae and in some species of the filamentous fungus Aspergillus. We elaborate on the physiological importance of tightly regulated endocytosis for cellular fitness under dynamic conditions found in nature and highlight how further understanding and engineering of this process is essential to maximize titer, rate and yield (TRY)-values of engineered cell factories in industrial biotechnological processes.
Collapse
Key Words
- AAs, amino acids
- ACT, amino Acid/Choline Transporter
- AP, adaptor protein
- APC, amino acid-polyamine-organocation
- Arg, arginine
- Arrestins
- Arts, arrestin‐related trafficking adaptors
- Asp, aspartic acid
- Aspergilli
- Biotechnology
- C, carbon
- C-terminus, carboxyl-terminus
- Cell factories
- Conformational changes
- Cu, copper
- DUBs, deubiquitinating enzymes
- EMCs, eisosome membrane compartments
- ER, endoplasmic reticulum
- ESCRT, endosomal sorting complex required for transport
- Endocytic signals
- Endocytosis
- Fe, iron
- Fungi
- GAAC, general amino acid control
- Glu, glutamic acid
- H+, proton
- IF, inward-facing
- LAT, L-type Amino acid Transporter
- LID, loop Interaction Domain
- Lys, lysine
- MCCs, membrane compartments containing the arginine permease Can1
- MCCs/eisosomes
- MCPs, membrane compartments of Pma1
- MFS, major facilitator superfamily
- MVB, multi vesicular bodies
- Met, methionine
- Metabolism
- Mn, manganese
- N, nitrogen
- N-terminus, amino-terminus
- NAT, nucleobase Ascorbate Transporter
- NCS1, nucleobase/Cation Symporter 1
- NCS2, nucleobase cation symporter family 2
- NH4+, ammonium
- Nutrient transporters
- OF, outward-facing
- PEST, proline (P), glutamic acid (E), serine (S), and threonine (T)
- PM, plasma membrane
- PVE, prevacuolar endosome
- Saccharomyces cerevisiae
- Signaling pathways
- Structure-function
- TGN, trans-Golgi network
- TMSs, transmembrane segments
- TORC1, target of rapamycin complex 1
- TRY, titer, rate and yield
- Trp, tryptophan
- Tyr, tyrosine
- Ub, ubiquitin
- Ubiquitylation
- VPS, vacuolar protein sorting
- W/V, weight per volume
- YAT, yeast Amino acid Transporter
- Zn, Zinc
- fAATs, fungal AA transporters
Collapse
|
14
|
Conservation and Loss of a Putative Iron Utilization Gene Cluster among Genotypes of Aspergillus flavus. Microorganisms 2021; 9:microorganisms9010137. [PMID: 33435439 PMCID: PMC7827000 DOI: 10.3390/microorganisms9010137] [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: 12/21/2020] [Revised: 01/04/2021] [Accepted: 01/07/2021] [Indexed: 11/20/2022] Open
Abstract
Iron is an essential component for growth and development. Despite relative abundance in the environment, bioavailability of iron is limited due to oxidation by atmospheric oxygen into insoluble ferric iron. Filamentous fungi have developed diverse pathways to uptake and use iron. In the current study, a putative iron utilization gene cluster (IUC) in Aspergillus flavus was identified and characterized. Gene analyses indicate A. flavus may use reductive as well as siderophore-mediated iron uptake and utilization pathways. The ferroxidation and iron permeation process, in which iron transport depends on the coupling of these two activities, mediates the reductive pathway. The IUC identified in this work includes six genes and is located in a highly polymorphic region of the genome. Diversity among A. flavus genotypes is manifested in the structure of the IUC, which ranged from complete deletion to a region disabled by multiple indels. Molecular profiling of A. flavus populations suggests lineage-specific loss of IUC. The observed variation among A. flavus genotypes in iron utilization and the lineage-specific loss of the iron utilization genes in several A. flavus clonal lineages provide insight on evolution of iron acquisition and utilization within Aspergillus section Flavi. The potential divergence in capacity to acquire iron should be taken into account when selecting A. flavus active ingredients for biocontrol in niches where climate change may alter iron availability.
Collapse
|
15
|
Stanford FA, Voigt K. Iron Assimilation during Emerging Infections Caused by Opportunistic Fungi with emphasis on Mucorales and the Development of Antifungal Resistance. Genes (Basel) 2020; 11:genes11111296. [PMID: 33143139 PMCID: PMC7693903 DOI: 10.3390/genes11111296] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 10/23/2020] [Accepted: 10/28/2020] [Indexed: 02/06/2023] Open
Abstract
Iron is a key transition metal required by most microorganisms and is prominently utilised in the transfer of electrons during metabolic reactions. The acquisition of iron is essential and becomes a crucial pathogenic event for opportunistic fungi. Iron is not readily available in the natural environment as it exists in its insoluble ferric form, i.e., in oxides and hydroxides. During infection, the host iron is bound to proteins such as transferrin, ferritin, and haemoglobin. As such, access to iron is one of the major hurdles that fungal pathogens must overcome in an immunocompromised host. Thus, these opportunistic fungi utilise three major iron acquisition systems to overcome this limiting factor for growth and proliferation. To date, numerous iron acquisition pathways have been fully characterised, with key components of these systems having major roles in virulence. Most recently, proteins involved in these pathways have been linked to the development of antifungal resistance. Here, we provide a detailed review of our current knowledge of iron acquisition in opportunistic fungi, and the role iron may have on the development of resistance to antifungals with emphasis on species of the fungal basal lineage order Mucorales, the causative agents of mucormycosis.
Collapse
Affiliation(s)
- Felicia Adelina Stanford
- Jena Microbial Resource Collection, Leibniz Institute for Natural Product Research, and Infection Biology–Hans Knöll Institute, Jena, Adolf-Reichwein-Straße 23, 07745 Jena, Germany;
- Institute of Microbiology, Faculty of Biological Sciences, Friedrich-Schiller University Jena, Neugasse 25, 07743 Jena, Germany
| | - Kerstin Voigt
- Jena Microbial Resource Collection, Leibniz Institute for Natural Product Research, and Infection Biology–Hans Knöll Institute, Jena, Adolf-Reichwein-Straße 23, 07745 Jena, Germany;
- Institute of Microbiology, Faculty of Biological Sciences, Friedrich-Schiller University Jena, Neugasse 25, 07743 Jena, Germany
- Leibniz Institute for Natural Product Research and Infection Biology–Hans Knöll Institute, Jena Microbial Resource Collection Adolf-Reichwein-Straße 23, 07745 Jena, Germany
- Correspondence: ; Tel.: +49-3641-532-1395; Fax: +49-3641-532-2395
| |
Collapse
|
16
|
Ai H, Cao Y, Jain A, Wang X, Hu Z, Zhao G, Hu S, Shen X, Yan Y, Liu X, Sun Y, Lan X, Xu G, Sun S. The ferroxidase LPR5 functions in the maintenance of phosphate homeostasis and is required for normal growth and development of rice. JOURNAL OF EXPERIMENTAL BOTANY 2020; 71:4828-4842. [PMID: 32618334 PMCID: PMC7475252 DOI: 10.1093/jxb/eraa211] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/01/2020] [Accepted: 07/02/2020] [Indexed: 05/27/2023]
Abstract
Members of the Low Phosphate Root (LPR) family have been identified in rice (Oryza sativa) and expression analyses have been conducted. Here, we investigated the functions of one of the five members in rice, LPR5. qRT-PCR and promoter-GUS reporter analyses indicated that under Pi-sufficient conditions OsLPR5 was highly expressed in the roots, and specific expression occurred in the leaf collars and nodes, and its expression was increased under Pi-deficient conditions. In vitro analysis of the purified OsLPR5 protein showed that it exhibited ferroxidase activity. Overexpression of OsLPR5 triggered higher ferroxidase activity, and elevated concentrations of Fe(III) in the xylem sap and of total Fe in the roots and shoots. Transient expression of OsLPR5 in Nicotiana benthamiana provided evidence of its subcellular localization to the cell wall and endoplasmic reticulum. Knockout mutation in OsLPR5 by means of CRISPR-Cas9 resulted in adverse effects on Pi translocation, on the relative expression of Cis-NATOsPHO1;2, and on several morphological traits, including root development and yield potential. Our results indicate that ferroxidase-dependent OsLPR5 has both a broad-spectrum influence on growth and development in rice as well as affecting a subset of physiological and molecular traits that govern Pi homeostasis.
Collapse
Affiliation(s)
- Hao Ai
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, Key Laboratory of Plant Nutrition and Fertilization in Low-Middle Reaches of the Yangtze River, Ministry of Agriculture, Nanjing Agricultural University, China
| | - Yue Cao
- School of Environmental Science and Engineering, Guangdong Provincial Key Lab for Environmental Pollution Control and Remediation Technology,Sun Yat-sen University, Guangzhou, China
| | - Ajay Jain
- Amity Institute of Biotechnology, Amity University Rajasthan, Jaipur, India
| | - Xiaowen Wang
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, Key Laboratory of Plant Nutrition and Fertilization in Low-Middle Reaches of the Yangtze River, Ministry of Agriculture, Nanjing Agricultural University, China
- Landscape Architecture Department, College of Horticulture, Nanjing Agricultural University, China
| | - Zhi Hu
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, Key Laboratory of Plant Nutrition and Fertilization in Low-Middle Reaches of the Yangtze River, Ministry of Agriculture, Nanjing Agricultural University, China
| | - Gengmao Zhao
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, Key Laboratory of Plant Nutrition and Fertilization in Low-Middle Reaches of the Yangtze River, Ministry of Agriculture, Nanjing Agricultural University, China
| | - Siwen Hu
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, Key Laboratory of Plant Nutrition and Fertilization in Low-Middle Reaches of the Yangtze River, Ministry of Agriculture, Nanjing Agricultural University, China
| | - Xing Shen
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, Key Laboratory of Plant Nutrition and Fertilization in Low-Middle Reaches of the Yangtze River, Ministry of Agriculture, Nanjing Agricultural University, China
| | - Yan Yan
- Institute for Plant Genomics and Biotechnology, Texas A&M University, College Station, TX, USA
| | - Xiuli Liu
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, Key Laboratory of Plant Nutrition and Fertilization in Low-Middle Reaches of the Yangtze River, Ministry of Agriculture, Nanjing Agricultural University, China
| | - Yafei Sun
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, Key Laboratory of Plant Nutrition and Fertilization in Low-Middle Reaches of the Yangtze River, Ministry of Agriculture, Nanjing Agricultural University, China
- Institute of Eco-Environment and Plant Protection, Shanghai Academy of Agricultural Sciences, Shanghai, China
| | - Xiaoxia Lan
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, Key Laboratory of Plant Nutrition and Fertilization in Low-Middle Reaches of the Yangtze River, Ministry of Agriculture, Nanjing Agricultural University, China
| | - Guohua Xu
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, Key Laboratory of Plant Nutrition and Fertilization in Low-Middle Reaches of the Yangtze River, Ministry of Agriculture, Nanjing Agricultural University, China
| | - Shubin Sun
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, Key Laboratory of Plant Nutrition and Fertilization in Low-Middle Reaches of the Yangtze River, Ministry of Agriculture, Nanjing Agricultural University, China
| |
Collapse
|
17
|
Defects in the Ferroxidase That Participates in the Reductive Iron Assimilation System Results in Hypervirulence in Botrytis Cinerea. mBio 2020; 11:mBio.01379-20. [PMID: 32753496 PMCID: PMC7407086 DOI: 10.1128/mbio.01379-20] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
The plant-pathogenic fungus B. cinerea causes enormous economic losses, estimated at anywhere between $10 billion and $100 billion worldwide, under both pre- and postharvest conditions. Here, we present the characterization of a loss-of-function mutant in a component involved in iron acquisition that displays hypervirulence. While in different microbial systems iron uptake mechanisms appear to be critical to achieve full pathogenic potential, we found that the absence of the ferroxidase that is part of the reductive iron assimilation system leads to hypervirulence in this fungus. This is an unusual and rather underrepresented phenotype, which can be modulated by iron levels in the plant and provides an unexpected link between iron acquisition, reactive oxygen species (ROS) production, and pathogenesis in the Botrytis-plant interaction. The plant pathogen Botrytis cinerea is responsible for gray-mold disease, which infects a wide variety of species. The outcome of this host-pathogen interaction, a result of the interplay between plant defense and fungal virulence pathways, can be modulated by various environmental factors. Among these, iron availability and acquisition play a crucial role in diverse biological functions. How B. cinerea obtains iron, an essential micronutrient, during infection is unknown. We set out to determine the role of the reductive iron assimilation (RIA) system during B. cinerea infection. This system comprises the BcFET1 ferroxidase, which belongs to the multicopper oxidase (MCO) family of proteins, and the BcFTR1 membrane-bound iron permease. Gene knockout and complementation studies revealed that, compared to the wild type, the bcfet1 mutant displays delayed conidiation, iron-dependent sclerotium production, and significantly reduced whole-cell iron content. Remarkably, this mutant exhibited a hypervirulence phenotype, whereas the bcftr1 mutant presents normal virulence and unaffected whole-cell iron levels and developmental programs. Interestingly, while in iron-starved plants wild-type B. cinerea produced slightly reduced necrotic lesions, the hypervirulence phenotype of the bcfet1 mutant is no longer observed in iron-deprived plants. This suggests that B. cinerea bcfet1 knockout mutants require plant-derived iron to achieve larger necrotic lesions, whereas in planta analyses of reactive oxygen species (ROS) revealed increased ROS levels only for infections caused by the bcfet1 mutant. These results suggest that increased ROS production, under an iron sufficiency environment, at least partly underlie the observed infection phenotype in this mutant.
Collapse
|
18
|
Skruzny M, Pohl E, Abella M. FRET Microscopy in Yeast. BIOSENSORS 2019; 9:E122. [PMID: 31614546 PMCID: PMC6956097 DOI: 10.3390/bios9040122] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/30/2019] [Revised: 09/19/2019] [Accepted: 09/30/2019] [Indexed: 02/06/2023]
Abstract
Förster resonance energy transfer (FRET) microscopy is a powerful fluorescence microscopy method to study the nanoscale organization of multiprotein assemblies in vivo. Moreover, many biochemical and biophysical processes can be followed by employing sophisticated FRET biosensors directly in living cells. Here, we summarize existing FRET experiments and biosensors applied in yeasts Saccharomyces cerevisiae and Schizosaccharomyces pombe, two important models of fundamental biomedical research and efficient platforms for analyses of bioactive molecules. We aim to provide a practical guide on suitable FRET techniques, fluorescent proteins, and experimental setups available for successful FRET experiments in yeasts.
Collapse
Affiliation(s)
- Michal Skruzny
- Department of Systems and Synthetic Microbiology, Max Planck Institute for Terrestrial Microbiology, 35043 Marburg, Germany.
- LOEWE Center for Synthetic Microbiology (SYNMIKRO), 35043 Marburg, Germany.
| | - Emma Pohl
- Department of Systems and Synthetic Microbiology, Max Planck Institute for Terrestrial Microbiology, 35043 Marburg, Germany
- LOEWE Center for Synthetic Microbiology (SYNMIKRO), 35043 Marburg, Germany
| | - Marc Abella
- Department of Systems and Synthetic Microbiology, Max Planck Institute for Terrestrial Microbiology, 35043 Marburg, Germany
- LOEWE Center for Synthetic Microbiology (SYNMIKRO), 35043 Marburg, Germany
| |
Collapse
|
19
|
Devaux F, Thiébaut A. The regulation of iron homeostasis in the fungal human pathogen Candida glabrata. MICROBIOLOGY-SGM 2019; 165:1041-1060. [PMID: 31050635 DOI: 10.1099/mic.0.000807] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Iron is an essential element to most microorganisms, yet an excess of iron is toxic. Hence, living cells have to maintain a tight balance between iron uptake and iron consumption and storage. The control of intracellular iron concentrations is particularly challenging for pathogens because mammalian organisms have evolved sophisticated high-affinity systems to sequester iron from microbes and because iron availability fluctuates among the different host niches. In this review, we present the current understanding of iron homeostasis and its regulation in the fungal pathogen Candida glabrata. This yeast is an emerging pathogen which has become the second leading cause of candidemia, a life-threatening invasive mycosis. C. glabrata is relatively poorly studied compared to the closely related model yeast Saccharomyces cerevisiae or to the pathogenic yeast Candida albicans. Still, several research groups have started to identify the actors of C. glabrata iron homeostasis and its transcriptional and post-transcriptional regulation. These studies have revealed interesting particularities of C. glabrata and have shed new light on the evolution of fungal iron homeostasis.
Collapse
Affiliation(s)
- Frédéric Devaux
- Sorbonne Université, CNRS, Institut de Biologie Paris-Seine, Laboratory of Computational and Quantitative Biology, F-75005, Paris, France
| | - Antonin Thiébaut
- Sorbonne Université, CNRS, Institut de Biologie Paris-Seine, Laboratory of Computational and Quantitative Biology, F-75005, Paris, France
| |
Collapse
|
20
|
Dlouhy AC, Bailey DK, Steimle BL, Parker HV, Kosman DJ. Fluorescence resonance energy transfer links membrane ferroportin, hephaestin but not ferroportin, amyloid precursor protein complex with iron efflux. J Biol Chem 2019; 294:4202-4214. [PMID: 30647129 DOI: 10.1074/jbc.ra118.005142] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Revised: 01/08/2019] [Indexed: 11/06/2022] Open
Abstract
Iron efflux from mammalian cells is supported by the synergistic actions of the ferrous iron efflux transporter, ferroportin (Fpn) and a multicopper ferroxidase, that is, hephaestin (Heph), ceruloplasmin (Cp) or both. The two proteins stabilize Fpn in the plasma membrane and catalyze extracellular Fe3+ release. The membrane stabilization of Fpn is also stimulated by its interaction with a 22-amino acid synthetic peptide based on a short sequence in the extracellular E2 domain of the amyloid precursor protein (APP). However, whether APP family members interact with Fpn in vivo is unclear. Here, using cyan fluorescent protein (CFP)-tagged Fpn in conjunction with yellow fluorescent protein (YFP) fusions of Heph and APP family members APP, APLP1, and APLP2 in HEK293T cells we used fluorescence and surface biotinylation to quantify Fpn membrane occupancy and also measured 59Fe efflux. We demonstrate that Fpn and Heph co-localize, and FRET analysis indicated that the two proteins form an iron-efflux complex. In contrast, none of the full-length, cellular APP proteins exhibited Fpn co-localization or FRET. Moreover, iron supplementation increased surface expression of the iron-efflux complex, and copper depletion knocked down Heph activity and decreased Fpn membrane localization. Whereas cellular APP species had no effects on Fpn and Heph localization, addition of soluble E2 elements derived from APP and APLP2, but not APLP1, increased Fpn membrane occupancy. We conclude that a ferroportin-targeting sequence, (K/R)EWEE, present in APP and APLP2, but not APLP1, helps modulate Fpn-dependent iron efflux in the presence of an active multicopper ferroxidase.
Collapse
Affiliation(s)
- Adrienne C Dlouhy
- From the Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, New York 14203
| | - Danielle K Bailey
- From the Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, New York 14203
| | - Brittany L Steimle
- From the Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, New York 14203
| | - Haley V Parker
- From the Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, New York 14203
| | - Daniel J Kosman
- From the Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, New York 14203
| |
Collapse
|
21
|
Kosman DJ. The teleos of metallo-reduction and metallo-oxidation in eukaryotic iron and copper trafficking. Metallomics 2018; 10:370-377. [PMID: 29484341 DOI: 10.1039/c8mt00015h] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Eukaryotic cells, whether free-living or organismal, rely on metallo-reductases to process environmental ferric iron and cupric copper prior to uptake. In addition, some free-living eukaryotes (e.g. fungi and algae) couple ferri-reduction to ferro-oxidation, a process catalyzed by a small cohort of multi-copper oxidases; in these organisms, the ferric iron product is a ligand for cell iron uptake via a ferric iron permease. In addition to their support of iron uptake in lower eukaryotes, ferroxidases support ferrous iron efflux in Chordata; in this process the release of the ferrous iron from the efflux transporter is catalyzed by its ferroxidation. Last, ferroxidases also catalyze the oxidation of cuprous copper and, as metallo-oxidases, mirror the dual activity of the metallo-reductases. This Perspective examines the teleos of the yin-yang of this redox cycling of iron and copper in their metabolism.
Collapse
Affiliation(s)
- Daniel J Kosman
- Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, The University at Buffalo, Farber Hall Room 140, 3435 Main St., Buffalo, NY 14214-3000, USA.
| |
Collapse
|
22
|
Vizoso-Vázquez Á, Lamas-Maceiras M, González-Siso MI, Cerdán ME. Ixr1 Regulates Ribosomal Gene Transcription and Yeast Response to Cisplatin. Sci Rep 2018; 8:3090. [PMID: 29449612 PMCID: PMC5814428 DOI: 10.1038/s41598-018-21439-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Accepted: 01/30/2018] [Indexed: 11/22/2022] Open
Abstract
Ixr1 is a Saccharomyces cerevisiae HMGB protein that regulates the hypoxic regulon and also controls the expression of other genes involved in the oxidative stress response or re-adaptation of catabolic and anabolic fluxes when oxygen is limiting. Ixr1 also binds with high affinity to cisplatin-DNA adducts and modulates DNA repair. The influence of Ixr1 on transcription in the absence or presence of cisplatin has been analyzed in this work. Ixr1 regulates other transcriptional factors that respond to nutrient availability or extracellular and intracellular stress stimuli, some controlled by the TOR pathway and PKA signaling. Ixr1 controls transcription of ribosomal RNAs and genes encoding ribosomal proteins or involved in ribosome assembly. qPCR, ChIP, and 18S and 25S rRNAs measurement have confirmed this function. Ixr1 binds directly to several promoters of genes related to rRNA transcription and ribosome biogenesis. Cisplatin treatment mimics the effect of IXR1 deletion on rRNA and ribosomal gene transcription, and prevents Ixr1 binding to specific promoters related to these processes.
Collapse
Affiliation(s)
- Ángel Vizoso-Vázquez
- Universidade da Coruña, Grupo EXPRELA, Centro de Investigacións Científicas Avanzadas (CICA), Facultade de Ciencias, 15071 A, Coruña, Spain
| | - Mónica Lamas-Maceiras
- Universidade da Coruña, Grupo EXPRELA, Centro de Investigacións Científicas Avanzadas (CICA), Facultade de Ciencias, 15071 A, Coruña, Spain
| | - M Isabel González-Siso
- Universidade da Coruña, Grupo EXPRELA, Centro de Investigacións Científicas Avanzadas (CICA), Facultade de Ciencias, 15071 A, Coruña, Spain
| | - M Esperanza Cerdán
- Universidade da Coruña, Grupo EXPRELA, Centro de Investigacións Científicas Avanzadas (CICA), Facultade de Ciencias, 15071 A, Coruña, Spain.
| |
Collapse
|
23
|
Mamouei Z, Zeng G, Wang YM, Wang Y. Candida albicanspossess a highly versatile and dynamic high-affinity iron transport system important for its commensal-pathogenic lifestyle. Mol Microbiol 2017; 106:986-998. [DOI: 10.1111/mmi.13864] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/11/2017] [Indexed: 02/02/2023]
Affiliation(s)
- Zeinab Mamouei
- Multi-Modal Molecular (M3) Biology; Institute of Molecular and Cell Biology, Agency for Science, Technology, and Research; Singapore
| | - Guisheng Zeng
- Multi-Modal Molecular (M3) Biology; Institute of Molecular and Cell Biology, Agency for Science, Technology, and Research; Singapore
| | - Yan-Ming Wang
- Multi-Modal Molecular (M3) Biology; Institute of Molecular and Cell Biology, Agency for Science, Technology, and Research; Singapore
| | - Yue Wang
- Multi-Modal Molecular (M3) Biology; Institute of Molecular and Cell Biology, Agency for Science, Technology, and Research; Singapore
- Department of Biochemistry, Yong Loo Lin School of Medicine; National University of Singapore; Singapore
| |
Collapse
|
24
|
Sharma V, Purushotham R, Kaur R. The Phosphoinositide 3-Kinase Regulates Retrograde Trafficking of the Iron Permease CgFtr1 and Iron Homeostasis in Candida glabrata. J Biol Chem 2016; 291:24715-24734. [PMID: 27729452 DOI: 10.1074/jbc.m116.751529] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Revised: 09/22/2016] [Indexed: 01/13/2023] Open
Abstract
The phosphoinositide 3-kinase (PI3K), which phosphorylates phosphatidylinositol and produces PI3P, has been implicated in protein trafficking, intracellular survival, and virulence in the pathogenic yeast Candida glabrata Here, we demonstrate PI3-kinase (CgVps34) to be essential for maintenance of cellular iron homeostasis. We examine how CgVps34 regulates the fundamental process of iron acquisition, and underscore its function in vesicular trafficking as a central determinant. RNA sequencing analysis revealed iron homeostasis genes to be differentially expressed upon CgVps34 disruption. Consistently, the Cgvps34Δ mutant displayed growth attenuation in low- and high-iron media, increased intracellular iron content, elevated mitochondrial aconitase activity, impaired biofilm formation, and extenuated mouse organ colonization potential. Furthermore, we demonstrate for the first time that C. glabrata cells respond to iron limitation by expressing the iron permease CgFtr1 primarily on the cell membrane, and to iron excess via internalization of the plasma membrane-localized CgFtr1 to the vacuole. Our data show that CgVps34 is essential for the latter process. We also report that macrophage-internalized C. glabrata cells express CgFtr1 on the cell membrane indicative of an iron-restricted macrophage internal milieu, and Cgvps34Δ cells display better survival in iron-enriched medium-cultured macrophages. Overall, our data reveal the centrality of PI3K signaling in iron metabolism and host colonization.
Collapse
Affiliation(s)
- Vandana Sharma
- From the Centre for DNA Fingerprinting and Diagnostics, Survey Nos. 728, 729, 730 and 734, Opposite Uppal Water Tank, Beside BSNL T E Building, Uppal, Hyderabad 500039, Ranga Reddy District, India and; the Graduate Studies, Manipal University, Manipal, India
| | - Rajaram Purushotham
- From the Centre for DNA Fingerprinting and Diagnostics, Survey Nos. 728, 729, 730 and 734, Opposite Uppal Water Tank, Beside BSNL T E Building, Uppal, Hyderabad 500039, Ranga Reddy District, India and
| | - Rupinder Kaur
- From the Centre for DNA Fingerprinting and Diagnostics, Survey Nos. 728, 729, 730 and 734, Opposite Uppal Water Tank, Beside BSNL T E Building, Uppal, Hyderabad 500039, Ranga Reddy District, India and.
| |
Collapse
|
25
|
Xu N, Qiu GW, Lou WJ, Li ZK, Jiang HB, Price NM, Qiu BS. Identification of an iron permease, cFTR1, in cyanobacteria involved in the iron reduction/re-oxidation uptake pathway. Environ Microbiol 2016; 18:5005-5017. [DOI: 10.1111/1462-2920.13464] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Revised: 07/19/2016] [Accepted: 07/23/2016] [Indexed: 11/30/2022]
Affiliation(s)
- Ning Xu
- School of Life Sciences and Hubei Key Laboratory of Genetic Regulation and Integrative Biology; Central China Normal University; Wuhan Hubei 430079 People's Republic of China
| | - Guo-Wei Qiu
- School of Life Sciences and Hubei Key Laboratory of Genetic Regulation and Integrative Biology; Central China Normal University; Wuhan Hubei 430079 People's Republic of China
| | - Wen-Jing Lou
- School of Life Sciences and Hubei Key Laboratory of Genetic Regulation and Integrative Biology; Central China Normal University; Wuhan Hubei 430079 People's Republic of China
| | - Zheng-Ke Li
- School of Life Sciences and Hubei Key Laboratory of Genetic Regulation and Integrative Biology; Central China Normal University; Wuhan Hubei 430079 People's Republic of China
| | - Hai-Bo Jiang
- School of Life Sciences and Hubei Key Laboratory of Genetic Regulation and Integrative Biology; Central China Normal University; Wuhan Hubei 430079 People's Republic of China
| | - Neil M. Price
- Department of Biology; McGill University; 1205 Docteur Penfield Montreal Québec H3A 1B1 Canada
| | - Bao-Sheng Qiu
- School of Life Sciences and Hubei Key Laboratory of Genetic Regulation and Integrative Biology; Central China Normal University; Wuhan Hubei 430079 People's Republic of China
| |
Collapse
|
26
|
Bacterial Metabolism in the Host Environment: Pathogen Growth and Nutrient Assimilation in the Mammalian Upper Respiratory Tract. Microbiol Spectr 2016; 3. [PMID: 26185081 DOI: 10.1128/microbiolspec.mbp-0007-2014] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Pathogens evolve in specific host niches and microenvironments that provide the physical and nutritional requirements conducive to their growth. In addition to using the host as a source of food, bacterial pathogens must avoid the immune response to their presence. The mammalian upper respiratory tract is a site that is exposed to the external environment, and is readily colonized by bacteria that live as resident flora or as pathogens. These bacteria can remain localized, descend to the lower respiratory tract, or traverse the epithelium to disseminate throughout the body. By virtue of their successful colonization of the respiratory epithelium, these bacteria obtain the nutrients needed for growth, either directly from host resources or from other microbes. This chapter describes the upper respiratory tract environment, including its tissue and mucosal structure, prokaryotic biota, and biochemical composition that would support microbial life. Neisseria meningitidis and the Bordetella species are discussed as examples of bacteria that have no known external reservoirs but have evolved to obligately colonize the mammalian upper respiratory tract.
Collapse
|
27
|
Tfp1 is required for ion homeostasis, fluconazole resistance and N-Acetylglucosamine utilization in Candida albicans. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2015; 1853:2731-44. [PMID: 26255859 DOI: 10.1016/j.bbamcr.2015.08.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2015] [Revised: 07/31/2015] [Accepted: 08/05/2015] [Indexed: 11/23/2022]
Abstract
The vacuolar-type H+-ATPase (V-ATPase) is crucial for the maintenance of ion homeostasis. Dysregulation of ion homeostasis affects various aspects of cellular processes. However, the importance of V-ATPase in Candida albicans is not totally clear. In this study, we demonstrated the essential roles of V-ATPase through Tfp1, a putative V-ATPase subunit. Deletion of TFP1 led to generation of an iron starvation signal and reduced total iron content, which was associated with mislocalization of Fet34p that was finally due to disorders in copper homeostasis. Furthermore, the tfp1∆/∆ mutant exhibited weaker growth and lower aconitase activity on nonfermentable carbon sources, and iron or copper addition partially rescued the growth defect. In addition, the tfp1∆/∆ mutant also showed elevated cytosolic calcium levels in normal or low calcium medium that were relevant to calcium release from vacuole. Kinetics of cytosolic calcium response to an alkaline pulse and VCX1 (VCX1 encodes a putative vacuolar Ca2+/H+ exchanger) overexpression assays indicated that the cytosolic calcium status was in relation to Vcx1 activity. Spot assay and concentration-kill curve demonstrated that the tfp1∆/∆ mutant was hypersensitive to fluconazole, which was attributed to reduced ergosterol biosynthesis and CDR1 efflux pump activity, and iron/calcium dysregulation. Interestingly, carbon source utilization tests found the tfp1∆/∆ mutant was defective for growth on N-Acetylglucosamine (GlcNAc) plate, which was associated with ATP depletion due to the decreased ability to catabolize GlcNAc. Taken together, our study gives new insights into functions of Tfp1, and provides the potential to better exploit V-ATPase as an antifungal target.
Collapse
|
28
|
Fukushima T, Allred BE, Raymond KN. Direct evidence of iron uptake by the Gram-positive siderophore-shuttle mechanism without iron reduction. ACS Chem Biol 2014; 9:2092-100. [PMID: 25007174 PMCID: PMC4168784 DOI: 10.1021/cb500319n] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2014] [Accepted: 07/09/2014] [Indexed: 11/29/2022]
Abstract
Iron is an essential element for all organisms, and microorganisms produce small molecule iron-chelators, siderophores, to efficiently acquire Fe(III). Gram-positive bacteria possess lipoprotein siderophore-binding proteins (SBPs) on the membrane. Some of the SBPs bind both apo-siderophores (iron-free) and Fe-siderophore (iron-chelated) and only import Fe-siderophores. When the SBP initially binds an apo-siderophore, the SBP uses the Gram-positive siderophore-shuttle mechanism (the SBPs exchange Fe(III) from a Fe-siderophore to the apo-siderophore bound to the protein) and/or displacement mechanism (the apo-siderophore bound to the SBP is released and a Fe-siderophore is then bound to the protein) to import the Fe-siderophore. Previously, we reported that the Bacillus cereus SBP, YxeB, exchanges Fe(III) from a ferrioxamine B (FO) to a desferrioxamine B (DFO) bound to YxeB using the siderophore-shuttle mechanism although the iron exchange was indirectly elucidated. Synthetic Cr-DFO (inert metal FO analog) and Ga-DFO (nonreducible FO analog) are bound to YxeB and imported via YxeB and the corresponding permeases and ATPase. YxeB exchanges Fe(III) from FO and Ga(III) from Ga-DFO to DFO bound to the protein, indicating that the metal-exchange occurs without metal reduction. YxeB also binds DFO derivatives including acetylated DFO (apo-siderophore) and acetylated FO (AcFO, Fe-siderophore). The iron from AcFO is transferred to DFO when bound to YxeB, giving direct evidence of iron exchange. Moreover, YxeB also uses the displacement mechanism when ferrichrome (Fch) is added to the DFO:YxeB complex. Uptake by the displacement mechanism is a minor pathway compared to the shuttle mechanism.
Collapse
Affiliation(s)
| | | | - Kenneth N. Raymond
- Department of Chemistry, University of
California, Berkeley, California 94720-1460, United States
| |
Collapse
|
29
|
Condon BJ, Oide S, Gibson DM, Krasnoff SB, Turgeon BG. Reductive iron assimilation and intracellular siderophores assist extracellular siderophore-driven iron homeostasis and virulence. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2014; 27:793-808. [PMID: 24762221 DOI: 10.1094/mpmi-11-13-0328-r] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Iron is an essential nutrient and prudent iron acquisition and management are key traits of a successful pathogen. Fungi use nonribosomally synthesized secreted iron chelators (siderophores) or reductive iron assimilation (RIA) mechanisms to acquire iron in a high affinity manner. Previous studies with the maize pathogen Cochliobolus heterostrophus identified two genes, NPS2 and NPS6, encoding different nonribosomal peptide synthetases responsible for biosynthesis of intra- and extracellular siderophores, respectively. Deletion of NPS6 results in loss of extracellular siderophore biosynthesis, attenuated virulence, hypersensitivity to oxidative and iron-depletion stress, and reduced asexual sporulation, while nps2 mutants are phenotypically wild type in all of these traits but defective in sexual spore development when NPS2 is missing from both mating partners. Here, it is reported that nps2nps6 mutants have more severe phenotypes than both nps2 and nps6 single mutants. In contrast, mutants lacking the FTR1 or FET3 genes encoding the permease and ferroxidase components, respectively, of the alternate RIA system, are like wild type in all of the above phenotypes. However, without supplemental iron, combinatorial nps6ftr1 and nps2nps6ftr1 mutants are less virulent, are reduced in growth, and are less able to combat oxidative stress and to sporulate asexually, compared with nps6 mutants alone. These findings demonstrate that, while the role of RIA in metabolism and virulence is overshadowed by that of extracellular siderophores as a high-affinity iron acquisition mechanism in C. heterostrophus, it functions as a critical backup for the fungus.
Collapse
|
30
|
Solomon EI, Heppner DE, Johnston EM, Ginsbach JW, Cirera J, Qayyum M, Kieber-Emmons MT, Kjaergaard CH, Hadt RG, Tian L. Copper active sites in biology. Chem Rev 2014; 114:3659-853. [PMID: 24588098 PMCID: PMC4040215 DOI: 10.1021/cr400327t] [Citation(s) in RCA: 1126] [Impact Index Per Article: 112.6] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
| | - David E. Heppner
- Department of Chemistry, Stanford University, Stanford, CA, 94305
| | | | - Jake W. Ginsbach
- Department of Chemistry, Stanford University, Stanford, CA, 94305
| | - Jordi Cirera
- Department of Chemistry, Stanford University, Stanford, CA, 94305
| | - Munzarin Qayyum
- Department of Chemistry, Stanford University, Stanford, CA, 94305
| | | | | | - Ryan G. Hadt
- Department of Chemistry, Stanford University, Stanford, CA, 94305
| | - Li Tian
- Department of Chemistry, Stanford University, Stanford, CA, 94305
| |
Collapse
|
31
|
Park J, McCormick SP, Chakrabarti M, Lindahl PA. The lack of synchronization between iron uptake and cell growth leads to iron overload in Saccharomyces cerevisiae during post-exponential growth modes. Biochemistry 2013; 52:9413-25. [PMID: 24344915 DOI: 10.1021/bi4010304] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Fermenting cells growing exponentially on rich (YPAD) medium underwent a transition to a slow-growing state as glucose levels declined and their metabolism shifted to respiration. During exponential growth, Fe import and cell-growth rates were matched, affording an approximately invariant cellular Fe concentration. During the transition period, the high-affinity Fe import rate declined slower than the cell-growth rate declined, causing Fe to accumulate, initially as Fe(III) oxyhydroxide nanoparticles but eventually as mitochondrial and vacuolar Fe. Once the cells had reached slow-growth mode, Fe import and cell-growth rates were again matched, and the cellular Fe concentration was again approximately invariant. Fermenting cells grown on minimal medium (MM) grew more slowly during the exponential phase and underwent a transition to a true stationary state as glucose levels declined. The Fe concentration of MM cells that just entered the stationary state was similar to that of YPAD cells, but MM cells continued to accumulate Fe in the stationary state. Fe initially accumulated as nanoparticles and high-spin Fe(II) species, but vacuolar Fe(III) also eventually accumulated. Surprisingly, Fe-packed 5-day-old MM cells suffered no more reactive oxygen species (ROS) damage than younger cells, suggesting that the Fe concentration alone does not accurately predict the extent of ROS damage. The mode and rate of growth at the time of harvesting dramatically affected cellular Fe content. A mathematical model of Fe metabolism in a growing cell was developed. The model included the import of Fe via a regulated high-affinity pathway and an unregulated low-affinity pathway. The import of Fe from the cytosol to vacuoles and mitochondria and nanoparticle formation were also included. The model captured essential trafficking behavior, demonstrating that cells regulate Fe import in accordance with their overall growth rate and that they misregulate Fe import when nanoparticles accumulate. The lack of regulation of Fe in yeast is perhaps unique compared to the tight regulation of other cellular metabolites. This phenomenon likely derives from the unique chemistry associated with Fe nanoparticle formation.
Collapse
Affiliation(s)
- Jinkyu Park
- Department of Chemistry, Texas A&M University , College Station, Texas 77843-3255, United States
| | | | | | | |
Collapse
|
32
|
König S, Browne S, Doleschal B, Schernthaner M, Poteser M, Mächler H, Wittchow E, Braune M, Muik M, Romanin C, Groschner K. Inhibition of Orai1-mediated Ca(2+) entry is a key mechanism of the antiproliferative action of sirolimus in human arterial smooth muscle. Am J Physiol Heart Circ Physiol 2013; 305:H1646-57. [PMID: 24056904 DOI: 10.1152/ajpheart.00365.2013] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Sirolimus (rapamycin) is used in drug-eluting stent strategies and proved clearly superior in this application compared with other immunomodulators such as pimecrolimus. The molecular basis of this action of sirolimus in the vascular system is still incompletely understood. Measurements of cell proliferation in human coronary artery smooth muscle cells (hCASM) demonstrated a higher antiproliferative activity of sirolimus compared with pimecrolimus. Although sirolimus lacks inhibitory effects on calcineurin, nuclear factor of activated T-cell activation in hCASM was suppressed to a similar extent by both drugs at 10 μM. Sirolimus, but not pimecrolimus, inhibited agonist-induced and store-operated Ca(2+) entry as well as cAMP response element binding protein (CREB) phosphorylation in human arterial smooth muscle, suggesting the existence of an as-yet unrecognized inhibitory effect of sirolimus on Ca(2+) signaling and Ca(2+)-dependent gene transcription. Electrophysiological experiments revealed that only sirolimus but not pimecrolimus significantly blocked the classical stromal interaction molecule/Orai-mediated, store-operated Ca(2+) current reconstituted in human embryonic kidney cells (HEK293). A link between Orai function and proliferation was confirmed by dominant-negative knockout of Orai in hCASM. Analysis of the effects of sirolimus on cell proliferation and CREB activation in an in vitro model of arterial intervention using human aorta corroborated the ability of sirolimus to suppress stent implantation-induced CREB activation in human arteries. We suggest inhibition of store-operated Ca(2+) entry based on Orai channels and the resulting suppression of Ca(2+) transcription coupling as a key mechanism underlying the antiproliferative activity of sirolimus in human arteries. This mechanism of action is specific for sirolimus and not a general feature of drugs interacting with FK506-binding proteins.
Collapse
Affiliation(s)
- Sarah König
- Institute of Biophysics, Medical University of Graz, Graz, Austria
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
33
|
Yeast protective response to arsenate involves the repression of the high affinity iron uptake system. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2013; 1833:997-1005. [PMID: 23295455 DOI: 10.1016/j.bbamcr.2012.12.018] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2012] [Revised: 12/19/2012] [Accepted: 12/23/2012] [Indexed: 11/20/2022]
Abstract
Arsenic is a double-edge sword. On the one hand it is powerful carcinogen and on the other it is used therapeutically to treat acute promyelocytic leukemia. Here we report that arsenic activates the iron responsive transcription factor, Aft1, as a consequence of a defective high-affinity iron uptake mediated by Fet3 and Ftr1, whose mRNAs are drastically decreased upon arsenic exposure. Moreover, arsenic causes the internalization and degradation of Fet3. Most importantly, fet3ftr1 mutant exhibits increased arsenic resistance and decreased arsenic accumulation over the wild-type suggesting that Fet3 plays a role in arsenic toxicity. Finally we provide data suggesting that arsenic also disrupts iron uptake in mammals and the link between Fet3, arsenic and iron, can be relevant to clinical applications.
Collapse
|
34
|
Brickman TJ, Armstrong SK. Iron and pH-responsive FtrABCD ferrous iron utilization system of Bordetella species. Mol Microbiol 2012; 86:580-93. [PMID: 22924881 DOI: 10.1111/mmi.12003] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/17/2012] [Indexed: 12/30/2022]
Abstract
A putative operon encoding an uncharacterized ferrous iron transport (FtrABCD) system was previously identified in cDNA microarray studies. In growth studies using buffered medium at pH values ranging from pH 6.0 to 7.6, Bordetella pertussis and Bordetella bronchiseptica FtrABCD system mutants showed dramatic reductions in growth yields under iron-restricted conditions at pH 6.0, but had no growth defects at pH 7.6. Supplementation of culture medium with 2 mM ascorbate reductant was inhibitory to alcaligin siderophore-dependent growth at pH 7.6, but had a neglible effect on FtrABCD system-dependent iron assimilation at pH 6.0 consistent with its predicted specificity for ferrous iron. Unlike Bordetella siderophore-dependent and haem iron transport systems, and in agreement with its hypothesized role in transport of inorganic iron from periplasm to cytoplasm, FtrABCD system function did not require the TonB energy transduction complex. Gene fusion analysis revealed that ftrABCD promoter activity was maximal under iron-restricted growth conditions at acidic pH. The pH of human airway surface fluids ranges from pH 5.5 to 7.9, and the FtrABCD system may supply ferrous iron necessary for Bordetella growth in acidic host microenvironments in which siderophores are ineffective for iron retrieval.
Collapse
Affiliation(s)
- Timothy J Brickman
- Department of Microbiology, University of Minnesota Medical School, 925 Mayo Memorial Building, 420 Delaware Street, S.E., Minneapolis, MN 55455-0312, USA.
| | | |
Collapse
|
35
|
Strachotová D, Holoubek A, Kučerová H, Benda A, Humpolíčková J, Váchová L, Palková Z. Ato protein interactions in yeast plasma membrane revealed by fluorescence lifetime imaging (FLIM). BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2012; 1818:2126-34. [PMID: 22579979 DOI: 10.1016/j.bbamem.2012.05.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2012] [Revised: 04/29/2012] [Accepted: 05/04/2012] [Indexed: 12/27/2022]
Abstract
Each of the three plasma membrane Ato proteins is involved in ammonium signalling and the development of yeast colonies. This suggests that although these proteins are homologous, they do not functionally substitute for each other, but may form a functional complex. Here, we present a detailed combined FRET, FLIM and photobleaching study, which enabled us to detect interactions between Ato proteins found in distinct compartments of yeast cells. We thus show that the proteins Ato1p and Ato2p interact and can form complexes when present in the plasma membrane. No interaction was detected between Ato1p and Ato3p or Ato2p and Ato3p. In addition, using specially prepared strains, we were able to detect an interaction between molecules of the same Ato protein, namely Ato1p-Ato1p and Ato3p-Ato3p, but not Ato2p-Ato2p.
Collapse
|
36
|
Viau CM, Cardone JM, Guecheva TN, Yoneama ML, Dias JF, Pungartnik C, Brendel M, Saffi J, Henriques JAP. Enhanced resistance of yeast mutants deficient in low-affinity iron and zinc transporters to stannous-induced toxicity. CHEMOSPHERE 2012; 86:477-484. [PMID: 22055569 DOI: 10.1016/j.chemosphere.2011.10.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2011] [Revised: 09/26/2011] [Accepted: 10/09/2011] [Indexed: 05/31/2023]
Abstract
Tin or stannous (Sn(2+)) compounds are used as catalysts, stabilizers in plastic industries, wood preservatives, agricultural biocides and nuclear medicine. In order to verify the Sn(2+) up-take and toxicity in yeast cells we utilized a multi-elemental analysis known as particle-induced X-ray emission (PIXE) along with cell survival assays and quantitative real-time PCR. The detection of Sn(2+) by PIXE was possible only in yeast cells in stationary phase of growth (STAT cells) that survive at 25mM Sn(2+) concentration. Yeast cells in exponential phase of growth (LOG cells) tolerate only micro-molar Sn(2+) concentrations that result in intracellular concentration below of the method detection limit. Our PIXE analysis showed that STAT XV185-14c yeast cells demonstrate a significant loss of intracellular elements such as Mg, Zn, S, Fe and an increase in P levels after 1h exposure to SnCl(2). The survival assay showed enhanced tolerance of LOG yeast cells lacking the low-affinity iron and zinc transporters to stannous treatment, suggesting the possible involvement in Sn(2+) uptake. Moreover, our qRT-PCR data showed that Sn(2+) treatment could generate reactive oxygen species as it induces activation of many stress-response genes, including SOD1, YAP1, and APN1.
Collapse
Affiliation(s)
- Cassiana M Viau
- Laboratório de Genotoxicidade - Instituto Royal - Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil
| | | | | | | | | | | | | | | | | |
Collapse
|
37
|
Ziegler L, Terzulli A, Gaur R, McCarthy R, Kosman DJ. Functional characterization of the ferroxidase, permease high-affinity iron transport complex from Candida albicans. Mol Microbiol 2011; 81:473-85. [PMID: 21645130 DOI: 10.1111/j.1365-2958.2011.07704.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Saccharomyces cerevisiae expresses two proteins that together support high-affinity Fe-uptake. These are a multicopper oxidase, Fet3p, with specificity towards Fe²⁺ and a ferric iron permease, Ftr1p, which supports Fe-accumulation. Homologues of the genes encoding these two proteins are found in all fungal genomes including those for the pathogens, Candida albicans and Cryptococcus neoformans. At least one of these loci represents a virulence factor for each pathogen suggesting that this complex would be an appropriate pharmacologic target. However, the mechanism by which this protein pair supports Fe-uptake in any fungal pathogen has not been elucidated. Taking advantage of the robust molecular genetics available in S. cerevisiae, we identify the two of five candidate ferroxidases likely involved in high-affinity Fe-uptake in C. albicans, Fet31 and Fet34. Both localize to the yeast plasma membrane and both support Fe-uptake along with an Ftr1 protein, either from C. albicans or from S. cerevisiae. We express and characterize Fet34, demonstrating that it is functionally homologous to ScFet3p. Using S. cerevisiae as host for the functional expression of the C. albicans Fe-uptake proteins, we demonstrate that they support a mechanism of Fe-trafficking that involves channelling of the CaFet34-generated Fe³⁺ directly to CaFtr1 for transport into the cytoplasm.
Collapse
Affiliation(s)
- Lynn Ziegler
- Department of Biochemistry, School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY 14214, USA
| | | | | | | | | |
Collapse
|
38
|
Bleackley MR, Macgillivray RTA. Transition metal homeostasis: from yeast to human disease. Biometals 2011; 24:785-809. [PMID: 21479832 DOI: 10.1007/s10534-011-9451-4] [Citation(s) in RCA: 158] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2011] [Accepted: 03/28/2011] [Indexed: 12/16/2022]
Abstract
Transition metal ions are essential nutrients to all forms of life. Iron, copper, zinc, manganese, cobalt and nickel all have unique chemical and physical properties that make them attractive molecules for use in biological systems. Many of these same properties that allow these metals to provide essential biochemical activities and structural motifs to a multitude of proteins including enzymes and other cellular constituents also lead to a potential for cytotoxicity. Organisms have been required to evolve a number of systems for the efficient uptake, intracellular transport, protein loading and storage of metal ions to ensure that the needs of the cells can be met while minimizing the associated toxic effects. Disruptions in the cellular systems for handling transition metals are observed as a number of diseases ranging from hemochromatosis and anemias to neurodegenerative disorders including Alzheimer's and Parkinson's disease. The yeast Saccharomyces cerevisiae has proved useful as a model organism for the investigation of these processes and many of the genes and biological systems that function in yeast metal homeostasis are conserved throughout eukaryotes to humans. This review focuses on the biological roles of iron, copper, zinc, manganese, nickel and cobalt, the homeostatic mechanisms that function in S. cerevisiae and the human diseases in which these metals have been implicated.
Collapse
Affiliation(s)
- Mark R Bleackley
- Department of Biochemistry and Molecular Biology, Centre for Blood Research, Life Sciences Institute, University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC, V6T1Z3, Canada
| | | |
Collapse
|
39
|
Ziegler L, Terzulli A, Sedlak E, Kosman DJ. Core glycan in the yeast multicopper ferroxidase, Fet3p: a case study of N-linked glycosylation, protein maturation, and stability. Protein Sci 2011; 19:1739-50. [PMID: 20662012 DOI: 10.1002/pro.457] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Glycosylation is essential to the maintenance of protein quality in the vesicular protein trafficking pathway in eukaryotic cells. Using the yeast multicopper oxidase, Fet3p, the hypothesis is tested that core glycosylation suppresses Fet3p nascent chain aggregation during synthesis into the endoplasmic reticulum (ER). Fet3p has 11 crystallographically mapped N-linked core glycan units. Assembly of four of these units is specifically required for localization of Fet3p to the plasma membrane (PM). Fet3 protein lacking any one of these glycan units is found in an intracellular high-molecular mass species resolvable by blue native gel electrophoresis. Individually, the remaining glycan moieties are not required for ER exit; however, serial deletion of these by N → A substitution correlates with these desglycan species failure to exit the ER. Desglycan Fet3 proteins that localize to the PM are wild type in function indicating that the missing carbohydrate is not required for native structure and biologic activity. This native function includes the interaction with the iron permease, Ftr1p, and wild type high-affinity iron uptake activity. The four essential sequons are found within relatively nonpolar regions located in surface recesses and are strongly conserved among fungal Fet3 proteins. The remaining N-linked sites are found in more surface exposed, less nonpolar environments, and their conservation is weak or absent. The data indicate that in Fet3p the N-linked glycan has little effect on the enzyme's molecular activity but is critical to its cellular activity by maximizing the protein's exit from the ER and assembly into a functional iron uptake complex.
Collapse
Affiliation(s)
- Lynn Ziegler
- Department of Biochemistry, School of Medicine and Biomedical Sciences, State University of New York, Buffalo, New York 14214-3000, USA
| | | | | | | |
Collapse
|
40
|
Abstract
Aerobic organisms are faced with a dilemma. Environmental iron is found primarily in the relatively inert Fe(III) form, whereas the more metabolically active ferrous form is a strong pro-oxidant. This conundrum is solved by the redox cycling of iron between Fe(III) and Fe(II) at every step in the iron metabolic pathway. As a transition metal ion, iron can be "metabolized" only by this redox cycling, which is catalyzed in aerobes by the coupled activities of ferric iron reductases (ferrireductases) and ferrous iron oxidases (ferroxidases).
Collapse
Affiliation(s)
- Daniel J Kosman
- Department of Biochemistry, School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, New York 14214.
| |
Collapse
|
41
|
Luoma LM, Deeb TM, Macintyre G, Cox DW. Functional analysis of mutations in the ATP loop of the Wilson disease copper transporter, ATP7B. Hum Mutat 2010; 31:569-77. [DOI: 10.1002/humu.21228] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
42
|
abc3+ encodes an iron-regulated vacuolar ABC-type transporter in Schizosaccharomyces pombe. EUKARYOTIC CELL 2009; 9:59-73. [PMID: 19915076 DOI: 10.1128/ec.00262-09] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Studies have shown the fundamental contribution of the yeast vacuole as a site for storage and detoxification of metals. Whereas the transmembrane proteins responsible for iron transport into and out of the vacuole have been identified in Saccharomyces cerevisiae, less information is available concerning the mobilization of vacuolar iron stores in Schizosaccharomyces pombe. In this study, we report the identification of a gene designated abc3(+) that encodes a protein which exhibits sequence homology with the ABCC subfamily of ATP-binding cassette transporters. The transcription of abc3(+) is induced by low concentrations of iron but repressed by high levels of iron. The iron-mediated repression of abc3(+) required a functional fep1(+) gene. Chromatin immunoprecipitation assays showed that Fep1 associates with the abc3(+) promoter in vivo, in an iron-dependent manner. Microscopic analyses revealed that a functional Abc3-green fluorescent protein localizes to the membrane vacuole when iron levels were low. Abc3 was required for growth in low-iron medium in the absence of the transport system mediated by Fio1 and Fip1. abc3Delta cells exhibited increased levels of expression of the frp1(+)-encoded ferric reductase, suggesting a loss of Fep1 repression and, consequently, the activation of Fep1-regulated genes. When abc3(+) was expressed using the nmt1(+) promoter system, its induction led to a reduced transcriptional activity of the frp1(+) gene. Because S. pombe does not possess vacuolar membrane-localized orthologs to S. cerevisiae Fth1, Fet5, and Smf3, our findings suggested that Abc3 may be responsible for mobilizing stored iron from the vacuole to the cytosol in response to iron deficiency.
Collapse
|
43
|
Kosman DJ. Multicopper oxidases: a workshop on copper coordination chemistry, electron transfer, and metallophysiology. J Biol Inorg Chem 2009; 15:15-28. [PMID: 19816718 DOI: 10.1007/s00775-009-0590-9] [Citation(s) in RCA: 125] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2009] [Accepted: 09/15/2009] [Indexed: 01/01/2023]
Abstract
Multicopper oxidases (MCOs) are unique among copper proteins in that they contain at least one each of the three types of biologic copper sites, type 1, type 2, and the binuclear type 3. MCOs are descended from the family of small blue copper proteins (cupredoxins) that likely arose as a complement to the heme-iron-based cytochromes involved in electron transport; this event corresponded to the aerobiosis of the biosphere that resulted in the conversion of Fe(II) to Fe(III) as the predominant redox state of this essential metal and the solubilization of copper from Cu(2)S to Cu(H(2)O)( n ) (2+). MCOs are encoded in genomes in all three kingdoms and play essential roles in the physiology of essentially all aerobes. With four redox-active copper centers, MCOs share with terminal copper-heme oxidases the ability to catalyze the four-electron reduction of O(2) to two molecules of water. The electron transfers associated with this reaction are both outer and inner sphere in nature and their mechanisms have been fairly well established. A subset of MCO proteins exhibit specificity for Fe(2+), Cu(+), and/or Mn(2+) as reducing substrates and have been designated as metallooxidases. These enzymes, in particular the ferroxidases found in all fungi and metazoans, play critical roles in the metal metabolism of the expressing organism.
Collapse
Affiliation(s)
- Daniel J Kosman
- Department of Biochemistry, The University at Buffalo, NY 14214, USA.
| |
Collapse
|
44
|
Role of ferroxidases in iron uptake and virulence of Cryptococcus neoformans. EUKARYOTIC CELL 2009; 8:1511-20. [PMID: 19700638 DOI: 10.1128/ec.00166-09] [Citation(s) in RCA: 104] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Iron acquisition is a critical aspect of the virulence of many pathogenic microbes, and iron limitation is an important defense mechanism for mammalian hosts. We are examining mechanisms of iron regulation and acquisition in the fungal pathogen Cryptococcus neoformans, and here, we characterize the roles of the ferroxidases Cfo1 and Cfo2. Cfo1 is required for the reductive iron uptake system that mediates the utilization of transferrin, an important iron source for C. neoformans during infection. The virulence of a cfo1 mutant was attenuated in a mouse model of cryptococcosis, and the mutant also displayed increased sensitivities to the antifungal drugs fluconazole and amphotericin B. Wild-type levels of drug sensitivity were restored by the addition of exogenous heme, which suggested that reduced levels of intracellular iron may curtail heme levels and interfere with ergosterol biosynthesis. We constructed green fluorescent protein (GFP) fusion proteins and found elevated expression of Cfo1-GFP upon iron limitation, as well as localization of the fusion to the plasma membrane. Trafficking to this location was disrupted by a defect in the catalytic subunit of cyclic AMP-dependent protein kinase. This result is consistent with findings from studies indicating an influence of the kinase on the expression of protein-trafficking functions in C. neoformans.
Collapse
|
45
|
Terzulli AJ, Kosman DJ. The Fox1 ferroxidase of Chlamydomonas reinhardtii: a new multicopper oxidase structural paradigm. J Biol Inorg Chem 2008; 14:315-25. [PMID: 19023602 DOI: 10.1007/s00775-008-0450-z] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2008] [Accepted: 11/06/2008] [Indexed: 12/19/2022]
Abstract
Multicopper oxidases (MCO) contain at least four copper atoms arrayed in three distinct ligand fields supported by two canonical structural features: (1) multiples of the cupredoxin fold and (2) four unique sequence elements that include the ten histidine and one cysteine ligands to the four copper atoms. Ferroxidases are a subfamily of MCO proteins that contain residues supporting a specific reactivity towards ferrous iron; these MCOs play a vital role in iron metabolism in bacteria, algae, fungi, and mammals. In contrast to the fungal ferroxidases, e.g., Fet3p from Saccharomyces cerevisiae, the mammalian ceruloplasmin (Cp) is twice as large (six vs. three cupredoxin domains) and contains three type 1, or "blue," copper sites. Chlamydomonas reinhardtii expresses a putative ferroxidase, Fox1, which has sequence similarity to human Cp (hCp). Eschewing the standard sequence-based modeling paradigm, we have constructed a function-based model of the Fox1 protein which replicates hCp's six copper-site ligand arrays with an overall root mean square deviation of 1.4 A. Analysis of this model has led also to assignment of motifs in Fox1 that are unique to ferroxidases, the strongest evidence to date that the well-characterized fungal high-affinity iron uptake system is essential to iron homeostasis in green algae. The model of Fox1 also establishes a subfamily of MCO proteins with a noncanonical copper-ligand organization. These diverse structures suggest alternative mechanisms for intramolecular electron transfer and require a new trajectory for the evolution of the MCO superfamily.
Collapse
Affiliation(s)
- Alaina J Terzulli
- Department of Biochemistry, School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY 14214, USA
| | | |
Collapse
|
46
|
Localization and interaction of the proteins constituting the GAL genetic switch in Saccharomyces cerevisiae. EUKARYOTIC CELL 2008; 7:2061-8. [PMID: 18952899 DOI: 10.1128/ec.00261-08] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
In Saccharomyces cerevisiae, the GAL genes encode the enzymes required for galactose metabolism. Regulation of these genes has served as the paradigm for eukaryotic transcriptional control over the last 50 years. The switch between inert and active gene expression is dependent upon three proteins--the transcriptional activator Gal4p, the inhibitor Gal80p, and the ligand sensor Gal3p. Here, we present a detailed spatial analysis of the three GAL regulatory proteins produced from their native genomic loci. Using a novel application of photobleaching, we demonstrate, for the first time, that the Gal3p ligand sensor enters the nucleus of yeast cells in the presence of galactose. Additionally, using Förster resonance energy transfer, we show that the interaction between Gal3p and Gal80p occurs throughout the yeast cell. Taken together, these data challenge existing models for the cellular localization of the regulatory proteins during the induction of GAL gene expression by galactose and suggest a mechanism for the induction of the GAL genes in which galactose-bound Gal3p moves from the cytoplasm to the nucleus to interact with the transcriptional inhibitor Gal80p.
Collapse
|
47
|
Nishida S, Mizuno T, Obata H. Involvement of histidine-rich domain of ZIP family transporter TjZNT1 in metal ion specificity. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2008; 46:601-6. [PMID: 18434175 DOI: 10.1016/j.plaphy.2008.02.011] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2007] [Indexed: 05/23/2023]
Abstract
The Zrt/Irt-like protein (ZIP) family generally contributes to metal homeostasis by regulating cation transport into the cytoplasm. Most ZIP members have a long variable loop between transmembrane domains III and IV, and these loops are predicted to be located in the cytoplasm. The loops contain a histidine-rich domain (HRD) postulated to serve as a metal ion binding site; however, its role has not yet been determined. We previously determined that deletion of the HRD did not affect the Ni tolerance ability of TjZNT1-a ZIP transporter that confers high Ni tolerance to yeast. In this study, we investigated the effect of HRD deletion on the ion transport ability of TjZNT1. The deletion of HRD increased the specificity for Zn2+, but not for Cd2+. In addition, we confirmed subcellular localizations of TjZNT1 and HRD-deleted mutants by green fluorescence protein (GFP)-fused proteins, indicating that the deletion of HRD did not affect the localization of TjZNT1. From these results, we propose that the HRD could be involved in the ion specificity of TjZNT1.
Collapse
Affiliation(s)
- Sho Nishida
- Faculty of Bioresources, Graduate School of Bioresources, Mie University, Kurimamachiya-cho 1577, Tsu, Mie 514-8507, Japan
| | | | | |
Collapse
|
48
|
Kensche PR, Oti M, Dutilh BE, Huynen MA. Conservation of divergent transcription in fungi. Trends Genet 2008; 24:207-11. [PMID: 18375009 DOI: 10.1016/j.tig.2008.02.003] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2007] [Revised: 01/23/2008] [Accepted: 02/05/2008] [Indexed: 11/26/2022]
Abstract
The comparison of fully sequenced genomes enables the study of selective constraints that determine genome organisation. We show that, in fungi, adjacent divergently transcribed (<---->) genes are more conserved in orientation than convergent (--><--) or co-oriented (-->-->) gene pairs. Furthermore, the time divergent orientation of two genes is conserved correlates with the degree of their co-expression and with the likelihood of them being functionally related. The functional interactions of the proteins encoded by the conserved divergent gene pairs indicate a potential for protein function prediction in eukaryotes.
Collapse
Affiliation(s)
- Philip R Kensche
- Center for Molecular and Biomolecular Informatics, Nijmegen Center for Molecular Life Sciences, Radboud University Medical Center, 6500 HB Nijmegen, The Netherlands
| | | | | | | |
Collapse
|
49
|
Kosman DJ. Substrate entasis and electronic coupling elements in electron transfer from Fe in a multicopper ferroxidase. Inorganica Chim Acta 2008; 361:844-849. [PMID: 18443651 DOI: 10.1016/j.ica.2007.10.013] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Outersphere electron transfer in multicopper oxidases occurs at the type 1, blue Cu(II). One class of MCO proteins exhibits a specificity in this reaction towards Fe(II). In work carried out in collaboration with the Solomon lab over the past 7 years, we have delineated the structural motifs that support this ferroxidase specificity and have quantified the contributions that each makes to this outersphere electron transfer reaction from Fe(II) to the type 1 Cu(II). Two features of this electron transfer catalysis stand out. First, the protein provides a binding site for Fe(II) that actually favors Fe(III); this coordination sphere places the bound Fe(II) in a state of "entasis" that can be relieved by loss of an electron. In short, the E(O) of the bound Fe(II) is lowered relative to that of aqueous ferrous iron making electron transfer thermodynamically favorable. Second, carboxylates within this coordination sphere provide an electronic coupling pathway for the electron transfer via their H-bond network with type 1 Cu histidine ligands thus making electron transfer kinetically efficient. This brief report breaks down these contributions to ferroxidase specificity in terms of the semi-classical Marcus equation describing outersphere electron transfer.
Collapse
Affiliation(s)
- Daniel J Kosman
- Department of Biochemistry, The University at Buffalo, Buffalo, NY 14214
| |
Collapse
|
50
|
Park YS, Kim JH, Cho JH, Chang HI, Kim SW, Paik HD, Kang CW, Kim TH, Sung HC, Yun CW. Physical and functional interaction of FgFtr1-FgFet1 and FgFtr2-FgFet2 is required for iron uptake in Fusarium graminearum. Biochem J 2007; 408:97-104. [PMID: 17655522 PMCID: PMC2049074 DOI: 10.1042/bj20070450] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
FgFtr1 and FgFtr2 are putative iron permeases, and FgFet1 and FgFet2 are putative ferroxidases of Fusarium graminearum. They have high homologies with iron permease ScFtr1 and ferroxidase ScFet3 of Saccharomyces cerevisiae at the amino acid level. The genes encoding iron permease and ferroxidase were localized to the same chromosome in the manner of FgFtr1/FgFet1 and FgFtr2/FgFet2. The GFP (green fluorescent protein)-fused versions of FgFtr1 and FgFtr2 showed normal functions when compared with FgFtr1 and FgFtr2 in an S. cerevisiae system, and the cellular localizations of FgFtr1 and FgFtr2 in S. cerevisiae depended on the expression of their putative ferroxidase partners FgFet1 and FgFet2 respectively. Although FgFtr1 was found on the plasma membrane when FgFet1 and FgFtr1 were co-transformed in S. cerevisiae, most of the FgFtr1 was found in the endoplasmic reticulum compartment when co-expressed with FgFet2. Furthermore, FgFtr2 was found on the vacuolar membrane when FgFet2 was co-expressed. From the two-hybrid analysis, we confirmed the interaction of FgFtr1 and FgFet1, and the same result was found between FgFtr2 and FgFet2. Iron-uptake activity also depended on the existence of the respective partner. Finally, the FgFtr1 and FgFtr2 were found on the plasma and vacuolar membrane respectively, in F. graminearum. Taken together, these results strongly suggest that FgFtr1 and FgFtr2 from F. graminearum encode the iron permeases of the plasma membrane and vacuolar membrane respectively, and require their specific ferroxidases to carry out normal function. Furthermore, the present study suggests that the reductive iron-uptake system is conserved from yeast to filamentous fungi.
Collapse
Affiliation(s)
- Yong-Sung Park
- *School of Life Sciences and Biotechnology, Korea University, Anam-dong, Sungbuk-gu, Seoul, 143-701, Korea
| | - Ji-Hyun Kim
- *School of Life Sciences and Biotechnology, Korea University, Anam-dong, Sungbuk-gu, Seoul, 143-701, Korea
| | - Jin-Hwa Cho
- *School of Life Sciences and Biotechnology, Korea University, Anam-dong, Sungbuk-gu, Seoul, 143-701, Korea
| | - Hyo-Ihl Chang
- *School of Life Sciences and Biotechnology, Korea University, Anam-dong, Sungbuk-gu, Seoul, 143-701, Korea
| | - Seung-Wook Kim
- †Department of Chemical and Biological Engineering, Korea University. Anam-dong, Sungbuk-gu, Seoul, 143-701, Korea
| | - Hyun-Dong Paik
- ‡Division of Animal Life Science, Konkuk University, Seoul, 143-701, Korea
| | - Chang-Won Kang
- ‡Division of Animal Life Science, Konkuk University, Seoul, 143-701, Korea
| | - Tae-Hyoung Kim
- §Chosun University School of Medicine, Department of Biochemistry and Molecular Biology, 375 Seosuk-Dong, Dong-gu, Gwangju, 501-759, Korea
| | - Ha-Chin Sung
- *School of Life Sciences and Biotechnology, Korea University, Anam-dong, Sungbuk-gu, Seoul, 143-701, Korea
| | - Cheol-Won Yun
- *School of Life Sciences and Biotechnology, Korea University, Anam-dong, Sungbuk-gu, Seoul, 143-701, Korea
- To whom correspondence should be addressed (email )
| |
Collapse
|