1
|
Ponnusamy T, Velusamy P, Shanmughapriya S. Mrs2-mediated mitochondrial magnesium uptake is essential for the regulation of MCU-mediated mitochondrial Ca 2+ uptake and viability. Mitochondrion 2024; 76:101877. [PMID: 38599304 DOI: 10.1016/j.mito.2024.101877] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2023] [Revised: 03/07/2024] [Accepted: 04/07/2024] [Indexed: 04/12/2024]
Abstract
Mitochondrial Ca2+ uptake is essential in regulating bioenergetics, cell death, and cytosolic Ca2+ transients. Mitochondrial Calcium Uniporter (MCU) mediates the mitochondrial Ca2+ uptake. Though MCU regulation by MICUs is unequivocally established, there needs to be more knowledge of whether divalent cations regulate MCU. Here, we set out to understand the mitochondrial matrix Mg2+-dependent regulation of MCU activity. We showed that decreased matrix [Mg2+] is associated with increased MCU activity and significantly prompted mitochondrial permeability transition pore opening. Our findings support the critical role of mMg2+ in regulating MCU activity.
Collapse
Affiliation(s)
- Thiruvelselvan Ponnusamy
- Heart and Vascular Institute, Department of Medicine, Department of Cellular and Molecular Physiology, Pennsylvania State University, College of Medicine, Hershey, PA 17033, USA
| | - Prema Velusamy
- Heart and Vascular Institute, Department of Medicine, Department of Cellular and Molecular Physiology, Pennsylvania State University, College of Medicine, Hershey, PA 17033, USA
| | - Santhanam Shanmughapriya
- Heart and Vascular Institute, Department of Medicine, Department of Cellular and Molecular Physiology, Pennsylvania State University, College of Medicine, Hershey, PA 17033, USA.
| |
Collapse
|
2
|
Uthayabalan S, Vishnu N, Madesh M, Stathopulos PB. The human MRS2 magnesium-binding domain is a regulatory feedback switch for channel activity. Life Sci Alliance 2023; 6:e202201742. [PMID: 36754568 PMCID: PMC9909464 DOI: 10.26508/lsa.202201742] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Revised: 01/25/2023] [Accepted: 01/26/2023] [Indexed: 02/10/2023] Open
Abstract
Mitochondrial RNA splicing 2 (MRS2) forms a magnesium (Mg2+) entry protein channel in mitochondria. Whereas MRS2 contains two transmembrane domains constituting a pore on the inner mitochondrial membrane, most of the protein resides within the matrix. Yet, the precise structural and functional role of this obtrusive amino terminal domain (NTD) in human MRS2 is unknown. Here, we show that the MRS2 NTD self-associates into a homodimer, contrasting the pentameric assembly of CorA, an orthologous bacterial channel. Mg2+ and calcium suppress lower and higher order oligomerization of MRS2 NTD, whereas cobalt has no effect on the NTD but disassembles full-length MRS2. Mutating-pinpointed residues-mediating Mg2+ binding to the NTD not only selectively decreases Mg2+-binding affinity ∼sevenfold but also abrogates Mg2+ binding-induced secondary, tertiary, and quaternary structure changes. Disruption of NTD Mg2+ binding strikingly potentiates mitochondrial Mg2+ uptake in WT and Mrs2 knockout cells. Our work exposes a mechanism for human MRS2 autoregulation by negative feedback from the NTD and identifies a novel gain of function mutant with broad applicability to future Mg2+ signaling research.
Collapse
Affiliation(s)
- Sukanthathulse Uthayabalan
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Canada
| | - Neelanjan Vishnu
- Center for Mitochondrial Medicine, Department of Medicine, University of Texas Health San Antonio, San Antonio, TX, USA
| | - Muniswamy Madesh
- Center for Mitochondrial Medicine, Department of Medicine, University of Texas Health San Antonio, San Antonio, TX, USA
| | - Peter B Stathopulos
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Canada
| |
Collapse
|
3
|
Seo H, Lee H. Spatiotemporal control of signal-driven enzymatic reaction in artificial cell-like polymersomes. Nat Commun 2022; 13:5179. [PMID: 36056018 PMCID: PMC9440086 DOI: 10.1038/s41467-022-32889-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Accepted: 08/23/2022] [Indexed: 11/09/2022] Open
Abstract
Living cells can spatiotemporally control biochemical reactions to dynamically assemble membraneless organelles and remodel cytoskeleton. Herein, we present a microfluidic approach to prepare semi-permeable polymersomes comprising of amphiphilic triblock copolymer to achieve external signal-driven complex coacervation as well as biophysical reconstitution of cytoskeleton within the polymersomes. We also show that the microfluidic synthesis of polymersomes enables precise control over size, efficient encapsulation of enzymes as well as regulation of substrates without the use of biopores. Moreover, we demonstrate that the resulting triblock copolymer-based membrane in polymersomes is size-selective, allowing phosphoenol pyruvate to readily diffuse through the membrane and induce enzymatic reaction and successive coacervation or actin polymerization in the presence of pyruvate kinase and adenosine diphosphate inside the polymersomes. We envision that the Pluronic-based polymersomes presented in this work will shed light in the design of in vitro enzymatic reactions in artificial cell-like vesicles.
Collapse
Affiliation(s)
- Hanjin Seo
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| | - Hyomin Lee
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea.
| |
Collapse
|
4
|
Sun S, Zhang K, Wu Y, Zhu N, Wang Y, Chen J, Leng F. Transporter drives the biosorption of heavy metals by Stenotrophomonas rhizophila JC1. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:45380-45395. [PMID: 35143001 DOI: 10.1007/s11356-022-18900-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Accepted: 01/23/2022] [Indexed: 06/14/2023]
Abstract
To better understand the function of transporter in heavy metal detoxification of bacteria, the transporters associated with heavy metal detoxification in S. rhizophila JC1 were analyzed, among which four members were verified by RT-qPCR. In addition, the removal rates of four single metal ions (Cr6+, Cu2+, Zn2+, Pb2+) and polymetallic ions by strain JC1 were studied, respectively. We also researched the physiological response of strain JC1 to different metal stress via morphological observation, elemental composition, functional group and membrane permeability analysis. The results showed that in the single metal ion solution, removal capacities of Cu2+ (120 mg/L) and Cr6+ (80 mg/L) of S. rhizophila JC1 reached to 79.9% and 89.3%, respectively, while in polymetallic ions solution, the removal capacity of each metal ion all decreased, and in detail, the adsorption capacity was determined Cr6+>Cu2+>Zn2+>Pb2+ under the same condition. The physiological response analyses results showed that extracellular adsorption phenomena occurred, and the change of membrane permeability hindered the uptake of metal ions by bacteria. The analysis of transporters in strain JC1 genome illustrated that a total of 323 transporters were predicted. Among them, two, six and five proteins of the cation diffusion facilitator, resistance-nodulation-division efflux and P-type ATPase families were, respectively, predicted. The expression of corresponding genes showed that the synergistic action of correlative transporters played important roles in the process of adsorption. The comparative genomics analysis revealed that S. rhizophila JC1 has long-distance evolutionary relationships with other strains, but the efflux system of S. rhizophila JC1 contained the same types of metal transporters as other metal-resistant bacteria.
Collapse
Affiliation(s)
- Shangchen Sun
- School of Petrochemical Engineering, Lanzhou University of Technology, 730050, Lanzhou, China
| | - Kexin Zhang
- School of Life Science and Engineering, Lanzhou University of Technology, Langongping Road 287, Qilihe District, 730050, Lanzhou, China
| | - Yamiao Wu
- School of Life Science and Engineering, Lanzhou University of Technology, Langongping Road 287, Qilihe District, 730050, Lanzhou, China
| | - Ning Zhu
- School of Life Science and Engineering, Lanzhou University of Technology, Langongping Road 287, Qilihe District, 730050, Lanzhou, China
| | - Yonggang Wang
- School of Life Science and Engineering, Lanzhou University of Technology, Langongping Road 287, Qilihe District, 730050, Lanzhou, China.
| | - Jixiang Chen
- School of Petrochemical Engineering, Lanzhou University of Technology, 730050, Lanzhou, China
| | - Feifan Leng
- School of Life Science and Engineering, Lanzhou University of Technology, Langongping Road 287, Qilihe District, 730050, Lanzhou, China
| |
Collapse
|
5
|
Cunrath O, Palmer JD. An overview of Salmonella enterica metal homeostasis pathways during infection. ACTA ACUST UNITED AC 2021; 2:uqab001. [PMID: 34250489 PMCID: PMC8264917 DOI: 10.1093/femsml/uqab001] [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: 12/22/2020] [Accepted: 03/19/2021] [Indexed: 12/14/2022]
Abstract
Nutritional immunity is a powerful strategy at the core of the battlefield between host survival and pathogen proliferation. A host can prevent pathogens from accessing biological metals such as Mg, Fe, Zn, Mn, Cu, Co or Ni, or actively intoxicate them with metal overload. While the importance of metal homeostasis for the enteric pathogen Salmonella enterica Typhimurium was demonstrated many decades ago, inconsistent results across various mouse models, diverse Salmonella genotypes, and differing infection routes challenge aspects of our understanding of this phenomenon. With expanding access to CRISPR-Cas9 for host genome manipulation, it is now pertinent to re-visit past results in the context of specific mouse models, identify gaps and incongruities in current knowledge landscape of Salmonella homeostasis, and recommend a straight path forward towards a more universal understanding of this historic host-microbe relationship.
Collapse
Affiliation(s)
- Olivier Cunrath
- Department of Zoology, University of Oxford, Zoology Research and Administration Building, 11a Mansfield Rd, Oxford, UK OX1 3SZ
| | - Jacob D Palmer
- Department of Zoology, University of Oxford, Zoology Research and Administration Building, 11a Mansfield Rd, Oxford, UK OX1 3SZ
| |
Collapse
|
6
|
Abstract
CorA proteins belong to 2-TM-GxN family of membrane proteins, and play a major role in Mg2+ transport in prokaryotes and eukaryotic mitochondria. The selection of substrate is believed to occur via the signature motif GxN, however there is no consensus how strict this selection within the family. To answer this question, we employed fluorescence-based transport assays on three different family members, namely CorA from bacterium Thermotoga maritima, CorA from the archeon Methanocaldococcus jannaschii and ZntB from bacterium Escherichia coli, reconstituted into proteoliposomes. Our results show that all three proteins readily transport Mg2+, Co2+, Ni2+ and Zn2+, but not Al3+. Despite the similarity in cation specificity, ZntB differs from the CorA proteins, as in the former transport is stimulated by a proton gradient, but in the latter by the membrane potential, confirming the hypothesis that CorA and ZntB proteins diverged to different transport mechanisms within the same protein scaffold.
Collapse
|
7
|
Rangl M, Schmandt N, Perozo E, Scheuring S. Real time dynamics of Gating-Related conformational changes in CorA. eLife 2019; 8:47322. [PMID: 31774394 PMCID: PMC6927688 DOI: 10.7554/elife.47322] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Accepted: 11/26/2019] [Indexed: 01/01/2023] Open
Abstract
CorA, a divalent-selective channel in the metal ion transport superfamily, is the major Mg2+-influx pathway in prokaryotes. CorA structures in closed (Mg2+-bound), and open (Mg2+-free) states, together with functional data showed that Mg2+-influx inhibits further Mg2+-uptake completing a regulatory feedback loop. While the closed state structure is a symmetric pentamer, the open state displayed unexpected asymmetric architectures. Using high-speed atomic force microscopy (HS-AFM), we explored the Mg2+-dependent gating transition of single CorA channels: HS-AFM movies during Mg2+-depletion experiments revealed the channel’s transition from a stable Mg2+-bound state over a highly mobile and dynamic state with fluctuating subunits to asymmetric structures with varying degree of protrusion heights from the membrane. Our data shows that at Mg2+-concentration below Kd, CorA adopts a dynamic (putatively open) state of multiple conformations that imply structural rearrangements through hinge-bending in TM1. We discuss how these structural dynamics define the functional behavior of this ligand-dependent channel.
Collapse
Affiliation(s)
- Martina Rangl
- Department of Anesthesiology, Weill Cornell Medical College, New York, United States.,Department of Physiology and Biophysics, Weill Cornell Medical College, New York, United States
| | - Nicolaus Schmandt
- Department of Biochemistry and Molecular Biophysics, The University of Chicago, Chicago, United States
| | - Eduardo Perozo
- Department of Biochemistry and Molecular Biophysics, The University of Chicago, Chicago, United States
| | - Simon Scheuring
- Department of Anesthesiology, Weill Cornell Medical College, New York, United States.,Department of Physiology and Biophysics, Weill Cornell Medical College, New York, United States
| |
Collapse
|
8
|
Ishijima S, Manabe Y, Shinkawa Y, Hotta A, Tokumasu A, Ida M, Sagami I. The homologous Arabidopsis MRS2/MGT/CorA-type Mg2+ channels, AtMRS2-10 and AtMRS2-1 exhibit different aluminum transport activity. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2018; 1860:2184-2191. [DOI: 10.1016/j.bbamem.2018.08.016] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Revised: 08/24/2018] [Accepted: 08/29/2018] [Indexed: 11/30/2022]
|
9
|
The structural basis of proton driven zinc transport by ZntB. Nat Commun 2017; 8:1313. [PMID: 29101379 PMCID: PMC5670123 DOI: 10.1038/s41467-017-01483-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Accepted: 09/18/2017] [Indexed: 01/09/2023] Open
Abstract
Zinc is an essential microelement to sustain all forms of life. However, excess of zinc is toxic, therefore dedicated import, export and storage proteins for tight regulation of the zinc concentration have evolved. In Enterobacteriaceae, several membrane transporters are involved in zinc homeostasis and linked to virulence. ZntB has been proposed to play a role in the export of zinc, but the transport mechanism of ZntB is poorly understood and based only on experimental characterization of its distant homologue CorA magnesium channel. Here, we report the cryo-electron microscopy structure of full-length ZntB from Escherichia coli together with the results of isothermal titration calorimetry, and radio-ligand uptake and fluorescent transport assays on ZntB reconstituted into liposomes. Our results show that ZntB mediates Zn2+ uptake, stimulated by a pH gradient across the membrane, using a transport mechanism that does not resemble the one proposed for homologous CorA channels. The bacterial zinc transporter ZntB is important for maintaining zinc homeostasis and is mechanistically not well understood. Here, the authors present the cryo-EM structure of ZntB at 4.2 Å resolution, perform transport assays and propose a model for its Zn2+ transport mechanism.
Collapse
|
10
|
Ions channels/transporters and chloroplast regulation. Cell Calcium 2014; 58:86-97. [PMID: 25454594 DOI: 10.1016/j.ceca.2014.10.002] [Citation(s) in RCA: 90] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2014] [Revised: 10/01/2014] [Accepted: 10/04/2014] [Indexed: 12/28/2022]
Abstract
Ions play fundamental roles in all living cells and their gradients are often essential to fuel transports, to regulate enzyme activities and to transduce energy within and between cells. Their homeostasis is therefore an essential component of the cell metabolism. Ions must be imported from the extracellular matrix to their final subcellular compartments. Among them, the chloroplast is a particularly interesting example because there, ions not only modulate enzyme activities, but also mediate ATP synthesis and actively participate in the building of the photosynthetic structures by promoting membrane-membrane interaction. In this review, we first provide a comprehensive view of the different machineries involved in ion trafficking and homeostasis in the chloroplast, and then discuss peculiar functions exerted by ions in the frame of photochemical conversion of absorbed light energy.
Collapse
|
11
|
Groisman EA, Hollands K, Kriner MA, Lee EJ, Park SY, Pontes MH. Bacterial Mg2+ homeostasis, transport, and virulence. Annu Rev Genet 2013; 47:625-46. [PMID: 24079267 DOI: 10.1146/annurev-genet-051313-051025] [Citation(s) in RCA: 169] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Organisms must maintain physiological levels of Mg(2+) because this divalent cation is critical for the stabilization of membranes and ribosomes, for the neutralization of nucleic acids, and as a cofactor in a variety of enzymatic reactions. In this review, we describe the mechanisms that bacteria utilize to sense the levels of Mg(2+) both outside and inside the cytoplasm. We examine how bacteria achieve Mg(2+) homeostasis by adjusting the expression and activity of Mg(2+) transporters and by changing the composition of their cell envelope. We discuss the connections that exist between Mg(2+) sensing, Mg(2+) transport, and bacterial virulence. Additionally, we explore the logic behind the fact that bacterial genomes encode multiple Mg(2+) transporters and distinct sensing systems for cytoplasmic and extracytoplasmic Mg(2+). These analyses may be applicable to the homeostatic control of other cations.
Collapse
Affiliation(s)
- Eduardo A Groisman
- Department of Microbial Pathogenesis, Boyer Center for Molecular Medicine, Yale School of Medicine, New Haven, Connecticut 06536; , , , , ,
| | | | | | | | | | | |
Collapse
|
12
|
Schmitz J, Tierbach A, Lenz H, Meschenmoser K, Knoop V. Membrane protein interactions between different Arabidopsis thaliana MRS2-type magnesium transporters are highly permissive. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2013; 1828:2032-40. [DOI: 10.1016/j.bbamem.2013.05.019] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2012] [Revised: 05/06/2013] [Accepted: 05/22/2013] [Indexed: 12/25/2022]
|
13
|
Lenz H, Dombinov V, Dreistein J, Reinhard MR, Gebert M, Knoop V. Magnesium deficiency phenotypes upon multiple knockout of Arabidopsis thaliana MRS2 clade B genes can be ameliorated by concomitantly reduced calcium supply. PLANT & CELL PHYSIOLOGY 2013; 54:1118-31. [PMID: 23628997 DOI: 10.1093/pcp/pct062] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Plant MRS2 membrane protein family members have been shown to play important roles in magnesium uptake and homeostasis. Single and double knockouts for two Arabidopsis thaliana genes, AtMRS2-1 and AtMRS2-5, have previously not shown significant phenotypes even under limiting Mg(2+) supply although both are strongly expressed already in early seedlings. Together with AtMRS2-10, these genes form clade B of the AtMRS2 gene family. We now succeeded in obtaining homozygous AtMRS2-1/10 double and AtMRS2-1/5/10 triple knockout lines after selection under increased magnesium supply. Although wilting early, both new mutant lines develop fully and are also fertile under standard magnesium supply, but show severe developmental retardation under limiting Mg(2+) concentrations. To investigate nutrient dependency of germination and seedling development under various conditions, including variable supplies of Mg(2+), Ca(2+), Zn(2+), Mn(2+), Co(2+), Cd(2+) and Cu(2+), in a reproducible and economical way, we employed a small-scale liquid culturing system in 24-well plate set-ups. This allowed the growth and monitoring of individual plantlets of different mutant lines under several nutritional conditions in parallel, and the scoring and statistical evaluation of developmental stages and biomass accumulation. Detrimental effects of higher concentrations of these elements were similar in mutants and the wild type. However, growth retardation phenotypes seen upon hydroponic cultivation under low Mg(2+) could be ameliorated when Ca(2+) concentrations were concomitantly lowered, supporting indications for an important interplay of these two most abundant divalent cations in the nutrient homeostasis of plants.
Collapse
Affiliation(s)
- Henning Lenz
- Abteilung Molekulare Evolution, IZMB-Institut für Zelluläre und Molekulare Botanik, Universität Bonn, Kirschallee 1, D-53115 Bonn, Germany
| | | | | | | | | | | |
Collapse
|
14
|
Exploring the structure and function of Thermotoga maritima CorA reveals the mechanism of gating and ion selectivity in Co2+/Mg2+ transport. Biochem J 2013; 451:365-74. [PMID: 23425532 PMCID: PMC3629940 DOI: 10.1042/bj20121745] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The CorA family of divalent cation transporters utilizes Mg2+ and Co2+ as
primary substrates. The molecular mechanism of its function, including ion selectivity and gating,
has not been fully characterized. Recently we reported a new structure of a CorA homologue from
Methanocaldococcus jannaschii, which provided novel structural details that offered
the conception of a unique gating mechanism involving conversion of an open hydrophilic gate into a
closed hydrophobic one. In the present study we report functional evidence for this novel gating
mechanism in the Thermotoga maritima CorA together with an improved crystal
structure of this CorA to 2.7 Å (1 Å=0.1 nm) resolution. The latter reveals the
organization of the selectivity filter to be similar to that of M. jannaschii CorA
and also the previously unknown organization of the second signature motif of the CorA family. The
proposed gating is achieved by a helical rotation upon the binding of a metal ion substrate to the
regulatory binding sites. Additionally, our data suggest that the preference of this CorA for
Co2+ over Mg2+ is controlled by the presence of threonine side chains in the
channel. Finally, the roles of the intracellular metal-binding sites have been assigned to increased
thermostability and regulation of the gating. These mechanisms most likely apply to the entire CorA
family as they are regulated by the highly conserved amino acids.
Collapse
|