1
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Ahn SY, Lee SJ, Yoon SI. Structural and biochemical analysis of the unique interactions of the Campylobacter jejuni CorA channel protein with divalent cations. Biochem Biophys Res Commun 2024; 723:150166. [PMID: 38810321 DOI: 10.1016/j.bbrc.2024.150166] [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: 05/17/2024] [Accepted: 05/22/2024] [Indexed: 05/31/2024]
Abstract
CorA is a Mg2+ channel that plays a key role in the homeostasis of intracellular Mg2+ in bacteria and archaea. CorA consists of a cytoplasmic domain and a transmembrane domain and generates a Mg2+ pathway by forming a pentamer in the cell membrane. CorA gating is regulated via negative feedback by Mg2+, which is accommodated by the pentamerization interface of the CorA cytoplasmic domain (CorACD). The Mg2+-binding sites of CorACD differ depending on the species, suggesting that the Mg2+-binding modes and Mg2+-mediated gating mechanisms of CorA vary across prokaryotes. To define the Mg2+-binding mechanism of CorA in the Campylobacter jejuni pathogen, we structurally and biochemically characterized C. jejuni CorACD (cjCorACD). cjCorACD adopts a three-layered α/β/α structure as observed in other CorA orthologs. Interestingly, cjCorACD exhibited enhanced thermostability in the presence of Ca2+, Ni2+, Zn2+, or Mn2+ in addition to Mg2+, indicating that cjCorACD interacts with diverse divalent cations. This cjCorACD stabilization is mediated by divalent cation accommodation by negatively charged residues located at the bottom of the cjCorACD structure away from the pentamerization interface. Consistently, cjCorACD exists as a monomer irrespective of the presence of divalent cations. We concluded that cjCorACD binds divalent cations in a unique pentamerization-independent manner.
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Affiliation(s)
- Si Yeon Ahn
- Division of Biomedical Convergence, College of Biomedical Science, Kangwon National University, Chuncheon, 24341, Republic of Korea
| | - Su-Jin Lee
- Division of Biomedical Convergence, College of Biomedical Science, Kangwon National University, Chuncheon, 24341, Republic of Korea
| | - Sung-Il Yoon
- Division of Biomedical Convergence, College of Biomedical Science, Kangwon National University, Chuncheon, 24341, Republic of Korea.
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2
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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.
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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.
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3
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Porfetye AT, Stege P, Rebollido-Rios R, Hoffmann D, Schrader T, Vetter IR. How Do Molecular Tweezers Bind to Proteins? Lessons from X-ray Crystallography. Molecules 2024; 29:1764. [PMID: 38675584 PMCID: PMC11051928 DOI: 10.3390/molecules29081764] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2024] [Revised: 04/03/2024] [Accepted: 04/05/2024] [Indexed: 04/28/2024] Open
Abstract
To understand the biological relevance and mode of action of artificial protein ligands, crystal structures with their protein targets are essential. Here, we describe and investigate all known crystal structures that contain a so-called "molecular tweezer" or one of its derivatives with an attached natural ligand on the respective target protein. The aromatic ring system of these compounds is able to include lysine and arginine side chains, supported by one or two phosphate groups that are attached to the half-moon-shaped molecule. Due to their marked preference for basic amino acids and the fully reversible binding mode, molecular tweezers are able to counteract pathologic protein aggregation and are currently being developed as disease-modifying therapies against neurodegenerative diseases such as Alzheimer's and Parkinson's disease. We analyzed the corresponding crystal structures with 14-3-3 proteins in complex with mono- and diphosphate tweezers. Furthermore, we solved crystal structures of two different tweezer variants in complex with the enzyme Δ1-Pyrroline-5-carboxyl-dehydrogenase (P5CDH) and found that the tweezers are bound to a lysine and methionine side chain, respectively. The different binding modes and their implications for affinity and specificity are discussed, as well as the general problems in crystallizing protein complexes with artificial ligands.
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Affiliation(s)
- Arthur T. Porfetye
- Department of Mechanistic Cell Biology, Max-Planck Institute of Molecular Physiology, Otto-Hahn-Straße 11, 44227 Dortmund, Germany
| | - Patricia Stege
- Department of Mechanistic Cell Biology, Max-Planck Institute of Molecular Physiology, Otto-Hahn-Straße 11, 44227 Dortmund, Germany
| | - Rocio Rebollido-Rios
- Faculty of Biology, University of Duisburg-Essen, Universitätsstrasse 5, 45141 Essen, Germany
| | - Daniel Hoffmann
- Faculty of Biology, University of Duisburg-Essen, Universitätsstrasse 5, 45141 Essen, Germany
| | - Thomas Schrader
- Faculty of Chemistry, University of Duisburg-Essen, Universitätsstrasse 7, 45117 Essen, Germany
| | - Ingrid R. Vetter
- Department of Mechanistic Cell Biology, Max-Planck Institute of Molecular Physiology, Otto-Hahn-Straße 11, 44227 Dortmund, Germany
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4
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Balint E, Unk I. For the Better or for the Worse? The Effect of Manganese on the Activity of Eukaryotic DNA Polymerases. Int J Mol Sci 2023; 25:363. [PMID: 38203535 PMCID: PMC10779026 DOI: 10.3390/ijms25010363] [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: 12/08/2023] [Revised: 12/22/2023] [Accepted: 12/24/2023] [Indexed: 01/12/2024] Open
Abstract
DNA polymerases constitute a versatile group of enzymes that not only perform the essential task of genome duplication but also participate in various genome maintenance pathways, such as base and nucleotide excision repair, non-homologous end-joining, homologous recombination, and translesion synthesis. Polymerases catalyze DNA synthesis via the stepwise addition of deoxynucleoside monophosphates to the 3' primer end in a partially double-stranded DNA. They require divalent metal cations coordinated by active site residues of the polymerase. Mg2+ is considered the likely physiological activator because of its high cellular concentration and ability to activate DNA polymerases universally. Mn2+ can also activate the known DNA polymerases, but in most cases, it causes a significant decrease in fidelity and/or processivity. Hence, Mn2+ has been considered mutagenic and irrelevant during normal cellular function. Intriguingly, a growing body of evidence indicates that Mn2+ can positively influence some DNA polymerases by conferring translesion synthesis activity or altering the substrate specificity. Here, we review the relevant literature focusing on the impact of Mn2+ on the biochemical activity of a selected set of polymerases, namely, Polβ, Polλ, and Polµ, of the X family, as well as Polι and Polη of the Y family of polymerases, where congruous data implicate the physiological relevance of Mn2+ in the cellular function of these enzymes.
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Affiliation(s)
| | - Ildiko Unk
- Institute of Genetics, HUN-REN Biological Research Centre Szeged, H-6726 Szeged, Hungary;
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5
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Nietmann P, Kaub K, Suchenko A, Stenz S, Warnecke C, Balasubramanian MK, Janshoff A. Cytosolic actin isoforms form networks with different rheological properties that indicate specific biological function. Nat Commun 2023; 14:7989. [PMID: 38042893 PMCID: PMC10693642 DOI: 10.1038/s41467-023-43653-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Accepted: 11/15/2023] [Indexed: 12/04/2023] Open
Abstract
The implications of the existence of different actins expressed in epithelial cells for network mechanics and dynamics is investigated by microrheology and confocal imaging. γ-actin predominately found in the apical cortex forms stiffer networks compared to β-actin, which is preferentially organized in stress fibers. We attribute this to selective interactions with Mg2+-ions interconnecting the filaments' N-termini. Bundling propensity of the isoforms is different in the presence of Mg2+-ions, while crosslinkers such as α-actinin, fascin, and heavy meromyosin alter the mechanical response independent of the isoform. In the presence of myosin, β-actin networks show a large number of small contraction foci, while γ-actin displays larger but fewer foci indicative of a stronger interaction with myosin motors. We infer that subtle changes in the amino acid sequence of actin isoforms lead to alterations of the mechanical properties on the network level with potential implications for specific biological functions.
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Affiliation(s)
- Peter Nietmann
- Institute of Physical Chemistry, University of Goettingen, Tammannstr. 6, Göttingen, 37077, Germany
| | - Kevin Kaub
- Institute of Physical Chemistry, University of Goettingen, Tammannstr. 6, Göttingen, 37077, Germany
- Max Planck School Matter to Life, Max Planck Institute for Medical Research, Jahnstr. 29, Heidelberg, 69120, Germany
| | - Andrejus Suchenko
- Warwick Medical School, University of Warwick, Coventry, CV4 7AL, UK
| | - Susanne Stenz
- Institute of Physical Chemistry, University of Goettingen, Tammannstr. 6, Göttingen, 37077, Germany
| | - Claas Warnecke
- Institute of Physical Chemistry, University of Goettingen, Tammannstr. 6, Göttingen, 37077, Germany
| | | | - Andreas Janshoff
- Institute of Physical Chemistry, University of Goettingen, Tammannstr. 6, Göttingen, 37077, Germany.
- Max Planck School Matter to Life, Max Planck Institute for Medical Research, Jahnstr. 29, Heidelberg, 69120, Germany.
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6
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Baltrusaitis EE, Ravitch EE, Fenton AR, Perez TA, Holzbaur ELF, Dominguez R. Interaction between the mitochondrial adaptor MIRO and the motor adaptor TRAK. J Biol Chem 2023; 299:105441. [PMID: 37949220 PMCID: PMC10746525 DOI: 10.1016/j.jbc.2023.105441] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Accepted: 10/16/2023] [Indexed: 11/12/2023] Open
Abstract
MIRO (mitochondrial Rho GTPase) consists of two GTPase domains flanking two Ca2+-binding EF-hand domains. A C-terminal transmembrane helix anchors MIRO to the outer mitochondrial membrane, where it functions as a general adaptor for the recruitment of cytoskeletal proteins that control mitochondrial dynamics. One protein recruited by MIRO is TRAK (trafficking kinesin-binding protein), which in turn recruits the microtubule-based motors kinesin-1 and dynein-dynactin. The mechanism by which MIRO interacts with TRAK is not well understood. Here, we map and quantitatively characterize the interaction of human MIRO1 and TRAK1 and test its potential regulation by Ca2+ and/or GTP binding. TRAK1 binds MIRO1 with low micromolar affinity. The interaction was mapped to a fragment comprising MIRO1's EF-hands and C-terminal GTPase domain and to a conserved sequence motif within TRAK1 residues 394 to 431, immediately C-terminal to the Spindly motif. This sequence is sufficient for MIRO1 binding in vitro and is necessary for MIRO1-dependent localization of TRAK1 to mitochondria in cells. MIRO1's EF-hands bind Ca2+ with dissociation constants (KD) of 3.9 μM and 300 nM. This suggests that under cellular conditions one EF-hand may be constitutively bound to Ca2+ whereas the other EF-hand binds Ca2+ in a regulated manner, depending on its local concentration. Yet, the MIRO1-TRAK1 interaction is independent of Ca2+ binding to the EF-hands and of the nucleotide state (GDP or GTP) of the C-terminal GTPase. The interaction is also independent of TRAK1 dimerization, such that a TRAK1 dimer can be expected to bind two MIRO1 molecules on the mitochondrial surface.
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Affiliation(s)
- Elana E Baltrusaitis
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA; Biochemistry and Molecular Biophysics Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Erika E Ravitch
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Adam R Fenton
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA; Cell and Molecular Biology Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, USA
| | - Tania A Perez
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA; Cell and Molecular Biology Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, USA
| | - Erika L F Holzbaur
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA; Biochemistry and Molecular Biophysics Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA; Cell and Molecular Biology Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, USA
| | - Roberto Dominguez
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA; Biochemistry and Molecular Biophysics Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
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7
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Gudimchuk NB, Alexandrova VV. Measuring and modeling forces generated by microtubules. Biophys Rev 2023; 15:1095-1110. [PMID: 37974983 PMCID: PMC10643784 DOI: 10.1007/s12551-023-01161-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Accepted: 09/25/2023] [Indexed: 11/19/2023] Open
Abstract
Tubulins are essential proteins, which are conserved across all eukaryotic species. They polymerize to form microtubules, cytoskeletal components of paramount importance for cellular mechanics. The microtubules combine an extraordinarily high flexural rigidity and a non-equilibrium behavior, manifested in their intermittent assembly and disassembly. These chemically fueled dynamics allow microtubules to generate significant pushing and pulling forces at their ends to reposition intracellular organelles, remodel membranes, bear compressive forces, and transport chromosomes during cell division. In this article, we review classical and recent studies, which have allowed the quantification of microtubule-generated forces. The measurements, to which we owe most of the quantitative information about microtubule forces, were carried out in biochemically reconstituted systems in vitro. We also discuss how mathematical and computational modeling has contributed to the interpretations of these results and shaped our understanding of the mechanisms of force production by tubulin polymerization and depolymerization.
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Affiliation(s)
- Nikita B. Gudimchuk
- Department of Physics, Lomonosov Moscow State University, Moscow, Russia
- Department of Biology, Lomonosov Moscow State University, Moscow, Russia
- Center for Theoretical Problems of Physicochemical Pharmacology, Moscow, Russia
- Pskov State University, Pskov, Russia
| | - Veronika V. Alexandrova
- Department of Physics, Lomonosov Moscow State University, Moscow, Russia
- Department of Biology, Lomonosov Moscow State University, Moscow, Russia
- Center for Theoretical Problems of Physicochemical Pharmacology, Moscow, Russia
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8
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Lee E, Choi S, Zhao Y, Yu J. Open Linear Polymer Host-Guest Interactions Sensed by Luminescent Silver Nanodots. ACS Sens 2023; 8:3240-3247. [PMID: 37480154 DOI: 10.1021/acssensors.3c01042] [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] [Indexed: 07/23/2023]
Abstract
The selectivity of the linear polymer chain toward its binding moieties has been considered negligible; thus, a clear demonstration showing the best-fit binding of a linear polymer to its guest counterpart is still unknown. Luminescent poly(acrylic acid) (PAA)-stabilized silver nanodots (PAA-AgNDs) have been applied as a turn-on sensor to monitor the interaction between the PAA chain and its binding cations. The binding of cations ions to the PAA chain may cross-link the linear PAA chain via coordination with carboxylate, which increases the rigidity of the polymer chain, retards the nonradiative decay of PAA-AgNDs, and consequently enhances the emission of silver nanodots while inducing a blue-shift of its emission spectrum. For the first time, we have demonstrated that a linear polymer chain can act as an open host to selectively bind to its best-matching cations. Specifically, among Group 2 cations (Mg2+, Ca2+, Sr2+, Ba2+), calcium ions show the strongest bonding to the PAA polymer chain. Our research suggests that, with extra rigidity, the polymer improves its chemical stability as calcium ions cross-linked the linear polymer. Meanwhile, it has also been demonstrated that luminescent silver nanodots can be excellent probes for the detection of polymer activities with straightforward and simple visualization methods.
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Affiliation(s)
- Eunhye Lee
- Department of Chemistry Education, Seoul National University, Seoul 08826, Republic of Korea
| | - Sungmoon Choi
- Center for Educational Research, Seoul National University, Seoul 08826, Republic of Korea
| | - Yanlu Zhao
- Department of Chemistry Education, Seoul National University, Seoul 08826, Republic of Korea
| | - Junhua Yu
- Department of Chemistry Education, Seoul National University, Seoul 08826, Republic of Korea
- Department of Science Education, Science Education Research Center, Seoul National University, Seoul 08826, Republic of Korea
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9
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Fujita K, Shindo Y, Katsuta Y, Goto M, Hotta K, Oka K. Intracellular Mg 2+ protects mitochondria from oxidative stress in human keratinocytes. Commun Biol 2023; 6:868. [PMID: 37620401 PMCID: PMC10449934 DOI: 10.1038/s42003-023-05247-6] [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: 03/05/2023] [Accepted: 08/15/2023] [Indexed: 08/26/2023] Open
Abstract
Reactive oxygen species (ROS) are harmful for the human body, and exposure to ultraviolet irradiation triggers ROS generation. Previous studies have demonstrated that ROS decrease mitochondrial membrane potential (MMP) and that Mg2+ protects mitochondria from oxidative stress. Therefore, we visualized the spatio-temporal dynamics of Mg2+ in keratinocytes (a skin component) in response to H2O2 (a type of ROS) and found that it increased cytosolic Mg2+ levels. H2O2-induced responses in both Mg2+ and ATP were larger in keratinocytes derived from adults than in keratinocytes derived from newborns, and inhibition of mitochondrial ATP synthesis enhanced the H2O2-induced Mg2+ response, indicating that a major source of Mg2+ was dissociation from ATP. Simultaneous imaging of Mg2+ and MMP revealed that larger Mg2+ responses corresponded to lower decreases in MMP in response to H2O2. Moreover, Mg2+ supplementation attenuated H2O2-induced cell death. These suggest the potential of Mg2+ as an active ingredient to protect skin from oxidative stress.
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Affiliation(s)
- Keigo Fujita
- Department of Bioscience and Informatics, Faculty of Science and Technology, Keio University, Yokohama, Japan
| | - Yutaka Shindo
- Department of Bioscience and Informatics, Faculty of Science and Technology, Keio University, Yokohama, Japan
- School of Frontier Engineering, Kitasato University, Sagamihara, Japan
| | - Yuji Katsuta
- MIRAI Technology Institute, Shiseido Co. Ltd., Yokohama, Japan
| | - Makiko Goto
- MIRAI Technology Institute, Shiseido Co. Ltd., Yokohama, Japan
| | - Kohji Hotta
- Department of Bioscience and Informatics, Faculty of Science and Technology, Keio University, Yokohama, Japan
| | - Kotaro Oka
- Department of Bioscience and Informatics, Faculty of Science and Technology, Keio University, Yokohama, Japan.
- School of Frontier Engineering, Kitasato University, Sagamihara, Japan.
- Waseda Research Institute for Science and Engineering, Waseda University, Tokyo, Japan.
- Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung City, Taiwan.
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10
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Alexander S, Moghadam MG, Rothenbroker M, Y T Chou L. Addressing the in vivo delivery of nucleic-acid nanostructure therapeutics. Adv Drug Deliv Rev 2023; 199:114898. [PMID: 37230305 DOI: 10.1016/j.addr.2023.114898] [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: 02/24/2023] [Revised: 05/02/2023] [Accepted: 05/18/2023] [Indexed: 05/27/2023]
Abstract
DNA and RNA nanostructures are being investigated as therapeutics, vaccines, and drug delivery systems. These nanostructures can be functionalized with guests ranging from small molecules to proteins with precise spatial and stoichiometric control. This has enabled new strategies to manipulate drug activity and to engineer devices with novel therapeutic functionalities. Although existing studies have offered encouraging in vitro or pre-clinical proof-of-concepts, establishing mechanisms of in vivo delivery is the new frontier for nucleic-acid nanotechnologies. In this review, we first provide a summary of existing literature on the in vivo uses of DNA and RNA nanostructures. Based on their application areas, we discuss current models of nanoparticle delivery, and thereby highlight knowledge gaps on the in vivo interactions of nucleic-acid nanostructures. Finally, we describe techniques and strategies for investigating and engineering these interactions. Together, we propose a framework to establish in vivo design principles and advance the in vivo translation of nucleic-acid nanotechnologies.
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Affiliation(s)
- Shana Alexander
- Institute of Biomedical Engineering, University of Toronto, Toronto, ON M5S 3G9, Canada
| | | | - Meghan Rothenbroker
- Institute of Biomedical Engineering, University of Toronto, Toronto, ON M5S 3G9, Canada
| | - Leo Y T Chou
- Institute of Biomedical Engineering, University of Toronto, Toronto, ON M5S 3G9, Canada.
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11
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Livingstone JD, Gingras MJ, Leonenko Z, Beazely MA. Search for lithium isotope effects in neuronal HT22 cells. Biochem Biophys Rep 2023; 34:101461. [PMID: 37063814 PMCID: PMC10102007 DOI: 10.1016/j.bbrep.2023.101461] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Revised: 03/11/2023] [Accepted: 03/22/2023] [Indexed: 04/03/2023] Open
Abstract
Lithium has been used as a treatment for bipolar disorder for over half a century, but there has thus far been no clinical differentiation made between the two naturally occurring stable isotopes (6Li and 7Li). While the natural lithium salts commonly used in treatments are composed of a mixture of these two stable isotopes (approximately 7.59% 6Li and 92.41% 7Li), some preliminary research indicates the above two stable isotopes of lithium may have differential effects on rat behaviour and neurophysiology. Here, we evaluate whether lithium isotopes may have distinct effects on HT22 neuronal cell viability, GSK-3-β phosphorylation in HT22 cells, and GSK-3-β kinase activity. We report no significant difference in lithium isotope toxicity on HT22 cells, nor in GSK-3-β phosphorylation, nor in GSK-3-β kinase activity between the two isotopes of lithium.
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12
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Lee S, Jiao M, Zhang Z, Yu Y. Nanoparticles for Interrogation of Cell Signaling. ANNUAL REVIEW OF ANALYTICAL CHEMISTRY (PALO ALTO, CALIF.) 2023; 16:333-351. [PMID: 37314874 PMCID: PMC10627408 DOI: 10.1146/annurev-anchem-092822-085852] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Cell functions rely on signal transduction-the cascades of molecular interactions and biochemical reactions that relay extracellular signals to the cell interior. Dissecting principles governing the signal transduction process is critical for the fundamental understanding of cell physiology and the development of biomedical interventions. The complexity of cell signaling is, however, beyond what is accessible by conventional biochemistry assays. Thanks to their unique physical and chemical properties, nanoparticles (NPs) have been increasingly used for the quantitative measurement and manipulation of cell signaling. Even though research in this area is still in its infancy, it has the potential to yield new, paradigm-shifting knowledge of cell biology and lead to biomedical innovations. To highlight this importance, we summarize in this review studies that pioneered the development and application of NPs for cell signaling, from quantitative measurements of signaling molecules to spatiotemporal manipulation of cell signal transduction.
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Affiliation(s)
- Seonik Lee
- Department of Chemistry, Indiana University, Bloomington, Indiana, USA;
| | - Mengchi Jiao
- Department of Chemistry, Indiana University, Bloomington, Indiana, USA;
| | - Zihan Zhang
- Department of Chemistry, Indiana University, Bloomington, Indiana, USA;
| | - Yan Yu
- Department of Chemistry, Indiana University, Bloomington, Indiana, USA;
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13
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Chang CH, Few LL, Lim BH, Yvonne-Tee GB, Chew AL, See Too WC. Unusual metal ion cofactor requirement of Entamoeba histolytica choline and ethanolamine kinase isoforms. Parasitol Res 2023:10.1007/s00436-023-07869-5. [PMID: 37202563 DOI: 10.1007/s00436-023-07869-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Accepted: 05/08/2023] [Indexed: 05/20/2023]
Abstract
The de novo biosynthesis of phosphatidylcholine and phosphatidylethanolamine in Entamoeba histolytica is largely dependent on the CDP-choline and CDP-ethanolamine pathways. Although the first enzymes of these pathways, EhCK1 and EhCK2, have been previously characterized, their enzymatic activity was found to be low and undetectable, respectively. This study aimed to identify the unusual characteristics of these enzymes in this deadly parasite. The discovery that EhCKs prefer Mn2+ over the typical Mg2+ as a metal ion cofactor is intriguing for CK/EK family of enzymes. In the presence of Mn2+, the activity of EhCK1 increased by approximately 108-fold compared to that in Mg2+. Specifically, in Mg2+, EhCK1 exhibited a Vmax and K0.5 of 3.5 ± 0.1 U/mg and 13.9 ± 0.2 mM, respectively. However, in Mn2+, it displayed a Vmax of 149.1 ± 2.5 U/mg and a K0.5 of 9.5 ± 0.1 mM. Moreover, when Mg2+ was present at a constant concentration of 12 mM, the K0.5 value for Mn2+ was ~ 2.4-fold lower than that in Mn2+ alone, without affecting its Vmax. Although the enzyme efficiency of EhCK1 was significantly improved by about 25-fold in Mn2+, it is worth noting that its Km for choline and ATP were higher than in equimolar of Mg2+ in a previous study. In contrast, EhCK2 showed specific activity towards ethanolamine in Mn2+, exhibiting Michaelis-Menten kinetic with ethanolamine (Km = 312 ± 27 µM) and cooperativity with ATP (K0.5 = 2.1 ± 0.2 mM). Additionally, we investigated the effect of metal ions on the substrate recognition of human choline and ethanolamine kinase isoforms. Human choline kinase α2 was found to absolutely require Mg2+, while choline kinase β differentially recognized choline and ethanolamine in Mg2+ and Mn2+, respectively. Finally, mutagenesis studies revealed that EhCK1 Tyr129 was critical for Mn2+ binding, while Lys233 was essential for substrate catalysis but not metal ion binding. Overall, these findings provide insight into the unique characteristics of the EhCKs and highlight the potential for new approaches to treating amoebiasis. Amoebiasis is a challenging disease for clinicians to diagnose and treat, as many patients are asymptomatic. However, by studying the enzymes involved in the CDP-choline and CDP-ethanolamine pathways, which are crucial for de novo biosynthesis of phosphatidylcholine and phosphatidylethanolamine in Entamoeba histolytica, there is great potential to discover new therapeutic approaches to combat this disease.
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Affiliation(s)
- Chiat Han Chang
- School of Health Sciences, Health Campus, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan, Malaysia
| | - Ling Ling Few
- School of Health Sciences, Health Campus, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan, Malaysia
| | - Boon Huat Lim
- School of Health Sciences, Health Campus, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan, Malaysia
| | - Get Bee Yvonne-Tee
- School of Health Sciences, Health Campus, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan, Malaysia
| | - Ai Lan Chew
- Institute for Research in Molecular Medicine (INFORMM), Universiti Sains Malaysia, 11800 USM, Penang, Malaysia
| | - Wei Cun See Too
- School of Health Sciences, Health Campus, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan, Malaysia.
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14
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Shi D, Huang Y, Bai C. Studies of the Mechanism of Nucleosome Dynamics: A Review on Multifactorial Regulation from Computational and Experimental Cases. Polymers (Basel) 2023; 15:polym15071763. [PMID: 37050377 PMCID: PMC10096840 DOI: 10.3390/polym15071763] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Revised: 03/28/2023] [Accepted: 03/31/2023] [Indexed: 04/05/2023] Open
Abstract
The nucleosome, which organizes the long coil of genomic DNA in a highly condensed, polymeric way, is thought to be the basic unit of chromosomal structure. As the most important protein–DNA complex, its structural and dynamic features have been successively revealed in recent years. However, its regulatory mechanism, which is modulated by multiple factors, still requires systemic discussion. This study summarizes the regulatory factors of the nucleosome’s dynamic features from the perspective of histone modification, DNA methylation, and the nucleosome-interacting factors (transcription factors and nucleosome-remodeling proteins and cations) and focuses on the research exploring the molecular mechanism through both computational and experimental approaches. The regulatory factors that affect the dynamic features of nucleosomes are also discussed in detail, such as unwrapping, wrapping, sliding, and stacking. Due to the complexity of the high-order topological structures of nucleosomes and the comprehensive effects of regulatory factors, the research on the functional modulation mechanism of nucleosomes has encountered great challenges. The integration of computational and experimental approaches, the construction of physical modes for nucleosomes, and the application of deep learning techniques will provide promising opportunities for further exploration.
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Affiliation(s)
- Danfeng Shi
- Warshel Institute for Computational Biology, School of Life and Health Sciences, School of Medicine, The Chinese University of Hong Kong (Shenzhen), Shenzhen 518172, China
- School of Chemistry and Materials Science, University of Science and Technology of China, Hefei 230026, China
| | - Yuxin Huang
- Warshel Institute for Computational Biology, School of Life and Health Sciences, School of Medicine, The Chinese University of Hong Kong (Shenzhen), Shenzhen 518172, China
| | - Chen Bai
- Warshel Institute for Computational Biology, School of Life and Health Sciences, School of Medicine, The Chinese University of Hong Kong (Shenzhen), Shenzhen 518172, China
- Chenzhu (MoMeD) Biotechnology Co., Ltd., Hangzhou 310005, China
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15
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Murray LE, Kim H, Rice LM, Asbury CL. Working strokes produced by curling protofilaments at disassembling microtubule tips can be biochemically tuned and vary with species. eLife 2022; 11:e83225. [PMID: 36580070 PMCID: PMC9799970 DOI: 10.7554/elife.83225] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2022] [Accepted: 11/25/2022] [Indexed: 12/30/2022] Open
Abstract
The disassembly of microtubules can generate force and drive intracellular motility. During mitosis, for example, chromosomes remain persistently attached via kinetochores to the tips of disassembling microtubules, which pull the sister chromatids apart. According to the conformational wave hypothesis, such force generation requires that protofilaments curl outward from the disassembling tips to exert pulling force directly on kinetochores. Rigorously testing this idea will require modifying the mechanical and energetic properties of curling protofilaments, but no way to do so has yet been described. Here, by direct measurement of working strokes generated in vitro by curling protofilaments, we show that their mechanical energy output can be increased by adding magnesium, and that yeast microtubules generate larger and more energetic working strokes than bovine microtubules. Both the magnesium and species-dependent increases in work output can be explained by lengthening the protofilament curls, without any change in their bending stiffness or intrinsic curvature. These observations demonstrate how work output from curling protofilaments can be tuned and suggest evolutionary conservation of the amount of curvature strain energy stored in the microtubule lattice.
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Affiliation(s)
- Lucas E Murray
- Department of Physiology and Biophysics, University of WashingtonSeattleUnited States
| | - Haein Kim
- Department of Physiology and Biophysics, University of WashingtonSeattleUnited States
| | - Luke M Rice
- Department of Biophysics, UT Southwestern Medical CenterDallasUnited States
- Department of Biochemistry, UT Southwestern Medical CenterDallasUnited States
| | - Charles L Asbury
- Department of Physiology and Biophysics, University of WashingtonSeattleUnited States
- Department of Biochemistry, University of WashingtonSeattleUnited States
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16
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Dong Y, Fu L, Song J, Zhang S, Li X, Fang W, Cui Q, Gao L. Thermodynamic Driving Forces for Divalent Cations Binding to Zwitterionic Phospholipid Membranes. J Phys Chem Lett 2022; 13:11237-11244. [PMID: 36448843 DOI: 10.1021/acs.jpclett.2c03019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
We calculated the free energies for calcium, magnesium, and zinc ions binding to a zwitterionic phospholipid bilayer by using molecular dynamics simulations and the enhanced umbrella sampling technique. By decomposing the free energy into entropic and enthalpic contributions, we found that Ca2+ has the highest binding affinity and that the overall process is endothermic combined with a secondary exothermic process at higher ion concentrations. The relatively low dehydration free energy of Ca2+ allows it to release coordinated water upon binding to the membrane. The dehydrated Ca2+ further coordinates with lipids, resulting in a weaker influence on the water orientation and increased entropy. However, when sufficient Ca2+ ions are adsorbed, the concentrated cation layer induces a positive electrostatic field, which enhances the energy barrier for further ion binding and orients the adjacent water, resulting in decreased entropy. In contrast, binding of Mg2+ and Zn2+ is exothermic and less favored because they remain fully hydrated when interacting with lipids.
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Affiliation(s)
- Yi Dong
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, 19 Xin-Jie-Kou-Wai Street, Beijing100875, China
| | - Lei Fu
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, 19 Xin-Jie-Kou-Wai Street, Beijing100875, China
- Department of Chemistry, Boston University, 590 Commonwealth Avenue, Boston, Massachusetts02215, United States
| | - Junjie Song
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, 19 Xin-Jie-Kou-Wai Street, Beijing100875, China
| | - Shan Zhang
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, 19 Xin-Jie-Kou-Wai Street, Beijing100875, China
| | - Xiangyuan Li
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, 19 Xin-Jie-Kou-Wai Street, Beijing100875, China
| | - Weihai Fang
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, 19 Xin-Jie-Kou-Wai Street, Beijing100875, China
| | - Qiang Cui
- Department of Chemistry, Boston University, 590 Commonwealth Avenue, Boston, Massachusetts02215, United States
| | - Lianghui Gao
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, 19 Xin-Jie-Kou-Wai Street, Beijing100875, China
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17
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Rayani K, Hantz ER, Haji-Ghassemi O, Li AY, Spuches AM, Van Petegem F, Solaro RJ, Lindert S, Tibbits GF. The effect of Mg 2+ on Ca 2+ binding to cardiac troponin C in hypertrophic cardiomyopathy associated TNNC1 variants. FEBS J 2022; 289:7446-7465. [PMID: 35838319 PMCID: PMC9836626 DOI: 10.1111/febs.16578] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Revised: 05/14/2022] [Accepted: 07/13/2022] [Indexed: 01/14/2023]
Abstract
Cardiac troponin C (cTnC) is the critical Ca2+ -sensing component of the troponin complex. Binding of Ca2+ to cTnC triggers a cascade of conformational changes within the myofilament that culminate in force production. Hypertrophic cardiomyopathy (HCM)-associated TNNC1 variants generally induce a greater degree and duration of Ca2+ binding, which may underly the hypertrophic phenotype. Regulation of contraction has long been thought to occur exclusively through Ca2+ binding to site II of cTnC. However, work by several groups including ours suggest that Mg2+ , which is several orders of magnitude more abundant in the cell than Ca2+ , may compete for binding to the same cTnC regulatory site. We previously used isothermal titration calorimetry (ITC) to demonstrate that physiological concentrations of Mg2+ may decrease site II Ca2+ -binding in both N-terminal and full-length cTnC. Here, we explore the binding of Ca2+ and Mg2+ to cTnC harbouring a series of TNNC1 variants thought to be causal in HCM. ITC and thermodynamic integration (TI) simulations show that A8V, L29Q and A31S elevate the affinity for both Ca2+ and Mg2+ . Further, L48Q, Q50R and C84Y that are adjacent to the EF hand binding motif of site II have a more significant effect on affinity and the thermodynamics of the binding interaction. To the best of our knowledge, this work is the first to explore the role of Mg2+ in modifying the Ca2+ affinity of cTnC mutations linked to HCM. Our results indicate a physiologically significant role for cellular Mg2+ both at baseline and when elevated on modifying the Ca2+ binding properties of cTnC and the subsequent conformational changes which precede cardiac contraction.
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Affiliation(s)
- Kaveh Rayani
- Molecular Cardiac Physiology Group, Simon Fraser University, Burnaby, Canada
| | - Eric R Hantz
- Department of Chemistry and Biochemistry, Ohio State University, Columbus, OH, USA
| | - Omid Haji-Ghassemi
- Department of Biochemistry and Molecular Biology, The University of British Columbia, Vancouver, Canada
| | - Alison Y Li
- Molecular Cardiac Physiology Group, Simon Fraser University, Burnaby, Canada
| | - Anne M Spuches
- Department of Chemistry, 300 Science and Technology, East Carolina University, Greenville, NC, USA
| | - Filip Van Petegem
- Department of Biochemistry and Molecular Biology, The University of British Columbia, Vancouver, Canada
| | - R John Solaro
- Department of Physiology and Biophysics and the Center for Cardiovascular Research, College of Medicine, University of Illinois at Chicago, USA
| | - Steffen Lindert
- Department of Chemistry and Biochemistry, Ohio State University, Columbus, OH, USA
| | - Glen F Tibbits
- Molecular Cardiac Physiology Group, Simon Fraser University, Burnaby, Canada
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, Canada
- BC Children's Hospital Research Institute, Vancouver, Canada
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18
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Kurakin S, Ivankov O, Skoi V, Kuklin A, Uhríková D, Kučerka N. Cations Do Not Alter the Membrane Structure of POPC—A Lipid With an Intermediate Area. Front Mol Biosci 2022; 9:926591. [PMID: 35898308 PMCID: PMC9312375 DOI: 10.3389/fmolb.2022.926591] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Accepted: 06/07/2022] [Indexed: 12/02/2022] Open
Abstract
Combining small-angle neutron scattering (SANS), small-angle X-ray scattering (SAXS), and densitometric measurements, we have studied the interactions of the divalent cations Ca2+ and Mg2+ with the lipid vesicles prepared of a mixed-chain palmitoyl-oleoyl-phosphatidylcholine (POPC) at 25°C. The structural parameters of the POPC bilayer, such as the bilayer thickness, lateral area, and volume per lipid, displayed no changes upon the ion addition at concentrations up to 30 mM and minor changes at > 30 mM Ca2+ and Mg2+, while some decrease in the vesicle radius was observed over the entire concentration range studied. This examination allows us to validate the concept of lipid–ion interactions governed by the area per lipid suggested previously and to propose the mixed mode of those interactions that emerge in the POPC vesicles. We speculate that the average area per POPC lipid that corresponds to the cutoff length of lipid–ion interactions generates an equal but opposite impact on ion bridges and separate lipid–ion pairs. As a result of the dynamic equilibrium, the overall structural properties of bilayers are not affected. As the molecular mechanism proposed is affected by the structural properties of a particular lipid, it might help us to understand the fundamentals of processes occurring in complex multicomponent membrane systems.
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Affiliation(s)
- Sergei Kurakin
- Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, Dubna, Russia
- Institute of Physics, Kazan Federal University, Kazan, Russia
| | - Oleksandr Ivankov
- Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, Dubna, Russia
| | - Vadim Skoi
- Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, Dubna, Russia
- Moscow Institute of Physics and Technology, Dolgoprudnyi, Russia
| | - Alexander Kuklin
- Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, Dubna, Russia
- Moscow Institute of Physics and Technology, Dolgoprudnyi, Russia
| | - Daniela Uhríková
- Department of Physical Chemistry of Drugs, Faculty of Pharmacy, Comenius University Bratislava, Bratislava, Slovakia
| | - Norbert Kučerka
- Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, Dubna, Russia
- Department of Physical Chemistry of Drugs, Faculty of Pharmacy, Comenius University Bratislava, Bratislava, Slovakia
- *Correspondence: Norbert Kučerka,
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19
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Al-Hakeim HK, Al-Jassas HK, Morris G, Maes M. Increased ACE2, sRAGE, and Immune Activation, but Lowered Calcium and Magnesium in COVID-19. RECENT ADVANCES IN INFLAMMATION & ALLERGY DRUG DISCOVERY 2022; 16:32-43. [PMID: 35307003 DOI: 10.2174/2772270816666220318103929] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 01/17/2022] [Accepted: 01/19/2022] [Indexed: 01/08/2023]
Abstract
BACKGROUND The characterization of new biomarkers that could help externally validate the diagnosis of COVID-19 and optimize treatments is extremely important. Many studies have established changes in immune-inflammatory and antibody levels, but few studies measured the soluble receptor for the advanced glycation end product (sRAGE), angiotensin-converting enzyme 2 (ACE2), calcium, and magnesium in COVID-19. OBJECTIVE To evaluate serum advanced glycation end-product receptor (sRAGE) and angiotensin converting enzyme (ACE)2 and peripheral oxygen saturation (SpO2) and chest CT scan abnormalities (CCTA) in COVID-19. METHODS sRAGE, ACE2, interleukin (IL)-6, IL-10, C-reactive protein (CRP), calcium, magnesium, and albumin were measured in 60 COVID-19 patients and 30 healthy controls. RESULTS COVID-19 is characterized by significantly increased IL-6, CRP, IL-10, sRAGE, ACE2, and lowered SpO2, albumin, magnesium, and calcium. COVID-19 with CCTAs showed lower SpO2 and albumin. SpO2 was significantly inversely correlated with IL-6, IL-10, CRP, sRAGE, and ACE2, and positively with albumin, magnesium, and calcium. Neural networks showed that a combination of calcium, IL-6, CRP, and sRAGE yielded an accuracy of 100% in detecting COVID-19 patients, with calcium being the most important predictor followed by IL-6 and CRP. Patients with positive IgG results showed a significant elevation in the serum level of IL-6, sRAGE, and ACE2 compared to the negatively IgG patient subgroup. CONCLUSION The results show that immune-inflammatory and RAGE pathways biomarkers may be used as an external validating criterion for the diagnosis of COVID-19. Those pathways coupled with lowered SpO2, calcium, and magnesium are drug targets that may help reduce the consequences of COVID-19.
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Affiliation(s)
| | | | - Gerwyn Morris
- School of Medicine, IMPACT-the Institute for Mental and Physical Health and Clinical Translation, Deakin University, Barwon Health, Geelong, Australia
| | - Michael Maes
- School of Medicine, IMPACT-the Institute for Mental and Physical Health and Clinical Translation, Deakin University, Barwon Health, Geelong, Australia.,Department of Psychiatry, Medical University of Plovdiv, Plovdiv, Bulgaria.,Department of Psychiatry, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
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20
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Magnesium Status and Calcium/Magnesium Ratios in a Series of Cystic Fibrosis Patients. Nutrients 2022; 14:nu14091793. [PMID: 35565764 PMCID: PMC9104329 DOI: 10.3390/nu14091793] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Revised: 04/21/2022] [Accepted: 04/22/2022] [Indexed: 02/04/2023] Open
Abstract
Magnesium (Mg) is an essential micronutrient that participates in various enzymatic reactions that regulate vital biological functions. The main aim was to assess the Mg status and its association with nutritional indicators in seventeen cystic fibrosis (CF) patients. The serum Mg and calcium (Ca) levels were determined using standardized methods and the dietary Mg intake by prospective 72 h dietary surveys. The mean serum Ca (2.45 mmol/L) and Mg (0.82 mmol/L) had normal levels, and the mean dietary intake of the Ca (127% DRI: Dietary Reference Intake) and Mg (125% DRI) were high. No patients had an abnormal serum Ca. A total of 47% of the subjects had hypomagnesemia and 12% insufficient Mg consumption. One patient had a serum Mg deficiency and inadequate Mg intake. A total of 47 and 82% of our series had a high serum Ca/Mg ratio of >4.70 (mean 4.89) and a low Ca/Mg intake ratio of <1.70 (mean 1.10), respectively. The likelihood of a high Ca/Mg ratio was 49 times higher in patients with a serum Mg deficiency than in normal serum Mg patients. Both Ca/Mg ratios were associated with the risk of developing cardiovascular disease (CVD), type 2 diabetes (T2D), metabolic syndrome (MetS), and even several cancers. Therefore, 53% of the CF patients were at high risk of a Mg deficiency and developing other chronic diseases.
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21
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Dal Cortivo G, Dell’Orco D. Calcium- and Integrin-Binding Protein 2 (CIB2) in Physiology and Disease: Bright and Dark Sides. Int J Mol Sci 2022; 23:ijms23073552. [PMID: 35408910 PMCID: PMC8999013 DOI: 10.3390/ijms23073552] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2022] [Revised: 03/19/2022] [Accepted: 03/22/2022] [Indexed: 12/04/2022] Open
Abstract
Calcium- and integrin-binding protein 2 (CIB2) is a small EF-hand protein capable of binding Mg2+ and Ca2+ ions. While its biological function remains largely unclear, an increasing number of studies have shown that CIB2 is an essential component of the mechano-transduction machinery that operates in cochlear hair cells. Mutations in the gene encoding CIB2 have been associated with non-syndromic deafness. In addition to playing an important role in the physiology of hearing, CIB2 has been implicated in a multitude of very different processes, ranging from integrin signaling in platelets and skeletal muscle to autophagy, suggesting extensive functional plasticity. In this review, we summarize the current understanding of biochemical and biophysical properties of CIB2 and the biological roles that have been proposed for the protein in a variety of processes. We also highlight the many molecular aspects that remain unclarified and deserve further investigation.
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22
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Lewalle A, Campbell KS, Campbell SG, Milburn GN, Niederer SA. Functional and structural differences between skinned and intact muscle preparations. J Gen Physiol 2022; 154:e202112990. [PMID: 35045156 PMCID: PMC8929306 DOI: 10.1085/jgp.202112990] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2021] [Accepted: 12/16/2021] [Indexed: 11/20/2022] Open
Abstract
Myofilaments and their associated proteins, which together constitute the sarcomeres, provide the molecular-level basis for contractile function in all muscle types. In intact muscle, sarcomere-level contraction is strongly coupled to other cellular subsystems, in particular the sarcolemmal membrane. Skinned muscle preparations (where the sarcolemma has been removed or permeabilized) are an experimental system designed to probe contractile mechanisms independently of the sarcolemma. Over the last few decades, experiments performed using permeabilized preparations have been invaluable for clarifying the understanding of contractile mechanisms in both skeletal and cardiac muscle. Today, the technique is increasingly harnessed for preclinical and/or pharmacological studies that seek to understand how interventions will impact intact muscle contraction. In this context, intrinsic functional and structural differences between skinned and intact muscle pose a major interpretational challenge. This review first surveys measurements that highlight these differences in terms of the sarcomere structure, passive and active tension generation, and calcium dependence. We then highlight the main practical challenges and caveats faced by experimentalists seeking to emulate the physiological conditions of intact muscle. Gaining an awareness of these complexities is essential for putting experiments in due perspective.
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Affiliation(s)
- Alex Lewalle
- Department of Biomedical Engineering, School of Biomedical Engineering and Imaging Sciences, King’s College London, London, UK
| | - Kenneth S. Campbell
- Department of Physiology and Division of Cardiovascular Medicine, University of Kentucky, Lexington, KY
| | - Stuart G. Campbell
- Departments of Biomedical Engineering and Cellular and Molecular Physiology, Yale University, New Haven, CT
| | - Gregory N. Milburn
- Department of Physiology and Division of Cardiovascular Medicine, University of Kentucky, Lexington, KY
| | - Steven A. Niederer
- Department of Biomedical Engineering, School of Biomedical Engineering and Imaging Sciences, King’s College London, London, UK
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23
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Baj J, Teresiński G, Forma A, Flieger M, Proch J, Niedzielski P, Grochowski C, Blicharska E, Buszewicz G, Bogucki J, Majerek D, Karakuła K, Czeczelewski M, Flieger J. Chronic Alcohol Abuse Alters Hepatic Trace Element Concentrations-Metallomic Study of Hepatic Elemental Composition by Means of ICP-OES. Nutrients 2022; 14:nu14030546. [PMID: 35276905 PMCID: PMC8838438 DOI: 10.3390/nu14030546] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Revised: 01/25/2022] [Accepted: 01/25/2022] [Indexed: 02/06/2023] Open
Abstract
Trace element accumulation varies in different human tissues. Distribution of several elements was found to be disrupted in the case of excessive alcohol consumption, causing negative effects and exacerbation of pathological processes in the liver. In this study, we analyzed the levels and interactions between seven trace elements including calcium (Ca), cobalt (Co), chromium (Cr), copper (Cu), iron (Fe), potassium (K), and magnesium (Mg), manganese (Mn), sodium (Na), zinc (Zn), and selenium (Se) in individuals with alcohol-use disorder (AUD) and patients without AUD (control group). The liver samples were collected during autopsy from 39 individuals with AUD and 45 control subjects. Elemental composition inductively coupled plasma optical emission spectrometry (ICP-OES) after wet mineralization by nitric acid was applied for the evaluation of the samples. Positive correlations dominated in the AUD group, mainly in relation to Mg, which strongly positively correlated with Ca, Mn, Fe; K correlated with Mn and Zn, and Cu positively correlated with K and Zn. The strongest positive correlation in the AUD group was observed for the Mg-Mn pair (r = 0.87). Significant statistical differences (p < 0.05) between the groups concerned the average concentration of Co, Cu, Mn, and Mg, which were lower in the AUD group, and Fe, the level of which was significantly higher in the AUD group compared to the control group. Evaluation of the chronic alcohol consumption effect on the accumulation of trace elements in the liver allows a better understanding of the pathological processes taking place in this organ.
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Affiliation(s)
- Jacek Baj
- Department of Anatomy, Medical University of Lublin, Jaczewskiego 4 (Collegium Anatomicum), 20-090 Lublin, Poland;
- Correspondence:
| | - Grzegorz Teresiński
- Department of Forensic Medicine, Medical University of Lublin, Jaczewskiego 8b (Collegium Pathologicum), 20-090 Lublin, Poland; (G.T.); (A.F.); (G.B.); (M.C.)
| | - Alicja Forma
- Department of Forensic Medicine, Medical University of Lublin, Jaczewskiego 8b (Collegium Pathologicum), 20-090 Lublin, Poland; (G.T.); (A.F.); (G.B.); (M.C.)
| | - Michał Flieger
- Department of Anatomy, Medical University of Lublin, Jaczewskiego 4 (Collegium Anatomicum), 20-090 Lublin, Poland;
| | - Jędrzej Proch
- Department of Analytical Chemistry, Faculty of Chemistry, Adam Mickiewicz University, 89B Umultowska Street, 61-614 Poznan, Poland; (J.P.); (P.N.)
| | - Przemysław Niedzielski
- Department of Analytical Chemistry, Faculty of Chemistry, Adam Mickiewicz University, 89B Umultowska Street, 61-614 Poznan, Poland; (J.P.); (P.N.)
| | - Cezary Grochowski
- Laboratory of Virtual Man, Medical University of Lublin, Jaczewskiego 4 (Collegium Anatomicum), 20-439 Lublin, Poland;
| | - Eliza Blicharska
- Department of Analytical Chemistry, Medical University of Lublin, Chodźki 4A, 20-093 Lublin, Poland; (E.B.); (J.F.)
| | - Grzegorz Buszewicz
- Department of Forensic Medicine, Medical University of Lublin, Jaczewskiego 8b (Collegium Pathologicum), 20-090 Lublin, Poland; (G.T.); (A.F.); (G.B.); (M.C.)
| | - Jacek Bogucki
- Department of Organic Chemistry, Medical University of Lublin, Chodźki 4A, 20-093 Lublin, Poland;
| | - Dariusz Majerek
- Department of Applied Mathematics, University of Technology, Nadbystrzycka 38D, 20-618 Lublin, Poland;
| | - Kaja Karakuła
- Department of Psychiatry, Psychotherapy and Early Intervention, Medical University of Lublin, Głuska 1 (SPSK Nr 1), 20-439 Lublin, Poland;
| | - Marcin Czeczelewski
- Department of Forensic Medicine, Medical University of Lublin, Jaczewskiego 8b (Collegium Pathologicum), 20-090 Lublin, Poland; (G.T.); (A.F.); (G.B.); (M.C.)
| | - Jolanta Flieger
- Department of Analytical Chemistry, Medical University of Lublin, Chodźki 4A, 20-093 Lublin, Poland; (E.B.); (J.F.)
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24
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van der Linden FH, Mahlandt EK, Arts JJG, Beumer J, Puschhof J, de Man SMA, Chertkova AO, Ponsioen B, Clevers H, van Buul JD, Postma M, Gadella TWJ, Goedhart J. A turquoise fluorescence lifetime-based biosensor for quantitative imaging of intracellular calcium. Nat Commun 2021; 12:7159. [PMID: 34887382 PMCID: PMC8660884 DOI: 10.1038/s41467-021-27249-w] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Accepted: 11/10/2021] [Indexed: 11/08/2022] Open
Abstract
The most successful genetically encoded calcium indicators (GECIs) employ an intensity or ratiometric readout. Despite a large calcium-dependent change in fluorescence intensity, the quantification of calcium concentrations with GECIs is problematic, which is further complicated by the sensitivity of all GECIs to changes in the pH in the biological range. Here, we report on a sensing strategy in which a conformational change directly modifies the fluorescence quantum yield and fluorescence lifetime of a circular permutated turquoise fluorescent protein. The fluorescence lifetime is an absolute parameter that enables straightforward quantification, eliminating intensity-related artifacts. An engineering strategy that optimizes lifetime contrast led to a biosensor that shows a 3-fold change in the calcium-dependent quantum yield and a fluorescence lifetime change of 1.3 ns. We dub the biosensor Turquoise Calcium Fluorescence LIfeTime Sensor (Tq-Ca-FLITS). The response of the calcium sensor is insensitive to pH between 6.2-9. As a result, Tq-Ca-FLITS enables robust measurements of intracellular calcium concentrations by fluorescence lifetime imaging. We demonstrate quantitative imaging of calcium concentrations with the turquoise GECI in single endothelial cells and human-derived organoids.
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Affiliation(s)
- Franka H van der Linden
- Section of Molecular Cytology, van Leeuwenhoek Centre for Advanced Microscopy, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, The Netherlands
| | - Eike K Mahlandt
- Section of Molecular Cytology, van Leeuwenhoek Centre for Advanced Microscopy, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, The Netherlands
| | - Janine J G Arts
- Section of Molecular Cytology, van Leeuwenhoek Centre for Advanced Microscopy, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, The Netherlands
- Department of Molecular Hematology at Sanquin Research and Landsteiner Laboratory, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands
| | - Joep Beumer
- Oncode Institute, Hubrecht Institute, Royal Netherlands Academy of Arts and Sciences and University Medical Center, Utrecht, The Netherlands
| | - Jens Puschhof
- Oncode Institute, Hubrecht Institute, Royal Netherlands Academy of Arts and Sciences and University Medical Center, Utrecht, The Netherlands
| | - Saskia M A de Man
- Section of Molecular Cytology, van Leeuwenhoek Centre for Advanced Microscopy, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, The Netherlands
| | - Anna O Chertkova
- Section of Molecular Cytology, van Leeuwenhoek Centre for Advanced Microscopy, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, The Netherlands
| | - Bas Ponsioen
- Center for Molecular Medicine, Oncode Institute, University Medical Centre Utrecht, Utrecht, The Netherlands
| | - Hans Clevers
- Oncode Institute, Hubrecht Institute, Royal Netherlands Academy of Arts and Sciences and University Medical Center, Utrecht, The Netherlands
| | - Jaap D van Buul
- Section of Molecular Cytology, van Leeuwenhoek Centre for Advanced Microscopy, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, The Netherlands
- Department of Molecular Hematology at Sanquin Research and Landsteiner Laboratory, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands
| | - Marten Postma
- Section of Molecular Cytology, van Leeuwenhoek Centre for Advanced Microscopy, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, The Netherlands
| | - Theodorus W J Gadella
- Section of Molecular Cytology, van Leeuwenhoek Centre for Advanced Microscopy, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, The Netherlands
| | - Joachim Goedhart
- Section of Molecular Cytology, van Leeuwenhoek Centre for Advanced Microscopy, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, The Netherlands.
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Wang J, Anastasia A, Bains H, Giza JI, Clossey DG, Deng J, Neubert TA, Rice WJ, Lee FS, Hempstead BL, Bracken C. Zinc induced structural changes in the intrinsically disordered BDNF Met prodomain confer synaptic elimination. Metallomics 2021; 12:1208-1219. [PMID: 32744273 DOI: 10.1039/d0mt00108b] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Human brain derived neurotrophic factor (BDNF) encodes a protein product consisting of a C-terminal mature domain (mature BDNF) and an N-terminal prodomain, which is an intrinsically disordered protein. A common single nucleotide polymorphism in humans results in a methionine substitution for valine at position 66 of the prodomain, and is associated with memory deficits, depression and anxiety disorders. The BDNF Met66 prodomain, but not the Val66 prodomain, promotes rapid structural remodeling of hippocampal neurons' growth cones and dendritic spines by interacting directly with the SorCS2 receptor. While it has been reported that the Met66 and Val66 prodomains exhibit only modest differences in structural propensities in the apo state, here we show that Val66 and Met66 prodomains differentially bind zinc (Zn). Zn2+ binds with higher affinity and more broadly impacts residues on the Met66 prodomain compared to the Val66 prodomain as shown by NMR and ITC. Zn2+ binding to the Met66 and Val66 prodomains results in distinct conformational and macroscopic differences observed by NMR, light scattering and cryoEM. To determine if Zn2+ mediated conformational change in the Met66 prodomain is required for biological effect, we mutated His40, a Zn2+ binding site, and observed a loss of Met66 prodomain bioactivity. As the His40 site is distant from the known region of the prodomain involved in receptor binding, we suggest that Met66 prodomain bioactivity involves His40 mediated stabilization of the multimeric structure. Our results point to the necessity of a Zn2+-mediated higher order molecular assembly of the Met66 prodomain to mediate neuronal remodeling.
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Affiliation(s)
- Jing Wang
- Weill Cornell Medicine, Department of Biochemistry, New York, NY, USA.
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26
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Bystranowska D, Skorupska A, Sołtys K, Padjasek M, Krężel A, Żak A, Kaus-Drobek M, Taube M, Kozak M, Ożyhar A. Nucleobindin-2 consists of two structural components: The Zn 2+-sensitive N-terminal half, consisting of nesfatin-1 and -2, and the Ca 2+-sensitive C-terminal half, consisting of nesfatin-3. Comput Struct Biotechnol J 2021; 19:4300-4318. [PMID: 34429849 PMCID: PMC8361300 DOI: 10.1016/j.csbj.2021.07.036] [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: 06/15/2021] [Revised: 07/27/2021] [Accepted: 07/28/2021] [Indexed: 12/01/2022] Open
Abstract
Nucleobindin-2 (Nucb2) is a protein that has been suggested to play roles in a variety of biological processes. Nucb2 contains two Ca2+/Mg2+-binding EF-hand domains separated by an acidic amino acid residue-rich region and a leucine zipper. All of these domains are located within the C-terminal half of the protein. At the N-terminal half, Nucb2 also possesses a putative Zn2+-binding motif. In our recent studies, we observed that Nucb2 underwent Ca2+-dependent compaction and formed a mosaic-like structure consisting of intertwined disordered and ordered regions at its C-terminal half. The aim of this study was to investigate the impact of two other potential ligands: Mg2+, which possesses chemical properties similar to those of Ca2+, and Zn2+, for which a putative binding motif was identified. In this study, we demonstrated that the binding of Mg2+ led to oligomerization state changes with no significant secondary or tertiary structural alterations of Nucb2. In contrast, Zn2+ binding had a more pronounced effect on the structure of Nucb2, leading to the local destabilization of its N-terminal half while also inducing changes within its C-terminal half. These structural rearrangements resulted in the oligomerization and/or aggregation of Nucb2 molecules. Taken together, the results of our previous and current research help to elucidate the structure of the Nucb2, which can be divided into two parts: the Zn2+-sensitive N-terminal half (consisting of nesfatin-1 and -2) and the Ca2+-sensitive C-terminal half (consisting of nesfatin-3). These results may also help to open a new discussion regarding the diverse roles that metal cations play in regulating the structure of Nucb2 and the various physiological functions of this protein.
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Affiliation(s)
- Dominika Bystranowska
- Department of Biochemistry, Molecular Biology and Biotechnology, Faculty of Chemistry, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland
| | - Anna Skorupska
- Department of Biochemistry, Molecular Biology and Biotechnology, Faculty of Chemistry, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland
| | - Katarzyna Sołtys
- Department of Biochemistry, Molecular Biology and Biotechnology, Faculty of Chemistry, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland
| | - Michał Padjasek
- Department of Chemical Biology, Faculty of Biotechnology, University of Wrocław, Joliot-Curie 14a, 50-383 Wrocław, Poland
| | - Artur Krężel
- Department of Chemical Biology, Faculty of Biotechnology, University of Wrocław, Joliot-Curie 14a, 50-383 Wrocław, Poland
| | - Andrzej Żak
- Faculty of Mechanical Engineering, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland
| | - Magdalena Kaus-Drobek
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, 02-106 Warsaw, Poland
| | - Michał Taube
- Department of Macromolecular Physics, Faculty of Physics, Adam Mickiewicz University, Umultowska 85, 61-614 Poznań, Poland
| | - Maciej Kozak
- Department of Macromolecular Physics, Faculty of Physics, Adam Mickiewicz University, Umultowska 85, 61-614 Poznań, Poland
- National Synchrotron Radiation Centre SOLARIS, Jagiellonian University, Czerwone Maki 98, 30-392 Kraków, Poland
| | - Andrzej Ożyhar
- Department of Biochemistry, Molecular Biology and Biotechnology, Faculty of Chemistry, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland
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27
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Neuroprotective effect of magnesium supplementation on cerebral ischemic diseases. Life Sci 2021; 272:119257. [PMID: 33631176 DOI: 10.1016/j.lfs.2021.119257] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Revised: 01/31/2021] [Accepted: 02/19/2021] [Indexed: 02/07/2023]
Abstract
Ischemic encephalopathy is associated with a high mortality and rate of disability. The most common type of ischemic encephalopathy, ischemic stroke, is the second leading cause of death in the world. At present, the main treatment for ischemic stroke is to reopen blocked blood vessels. However, despite revascularization, many patients are not able to achieve good functional results. At the same time, the strict time window (<4.5 h) of thrombolytic therapy limits clinical application. Therefore, it is important to explore effective neuroprotective drugs for the treatment of ischemic stroke. Magnesium is a natural calcium antagonist, which exerts neuroprotective effects through various mechanisms. However, while most basic studies have shown that magnesium supplementation can help treat cerebral ischemia, intravenous magnesium supplementation in large clinical trials has failed to improve prognosis of ischemic patients. Therefore, we review the basic and clinical studies of magnesium supplementation for cerebral ischemia. According to the route of administration, treatment can be divided into intraperitoneal magnesium supplementation, intravenous magnesium supplementation, arterial magnesium supplementation and intracranial magnesium supplementation. We also summarized the potential influencing factors of magnesium ion intervention in cerebral ischemia injury. Finally, in combination with influencing factors derived from basic research, this article proposes three future research directions, including magnesium supplementation into the circulatory system combined with magnesium supplementation in the lateral ventricle, magnesium supplementation in the lateral ventricle combined with hypothermia therapy, and lateral ventricle magnesium supplementation combined with intracarotid magnesium supplementation combined with selective hypothermia.
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Rayani K, Seffernick J, Li AY, Davis JP, Spuches AM, Van Petegem F, Solaro RJ, Lindert S, Tibbits GF. Binding of calcium and magnesium to human cardiac troponin C. J Biol Chem 2021; 296:100350. [PMID: 33548225 PMCID: PMC7961095 DOI: 10.1016/j.jbc.2021.100350] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 01/25/2021] [Accepted: 01/27/2021] [Indexed: 01/03/2023] Open
Abstract
Cardiac muscle thin filaments are composed of actin, tropomyosin, and troponin that change conformation in response to Ca2+ binding, triggering muscle contraction. Human cardiac troponin C (cTnC) is the Ca2+-sensing component of the thin filament. It contains structural sites (III/IV) that bind both Ca2+ and Mg2+ and a regulatory site (II) that has been thought to bind only Ca2+. Binding of Ca2+ at this site initiates a series of conformational changes that culminate in force production. However, the mechanisms that underpin the regulation of binding at site II remain unclear. Here, we have quantified the interaction between site II and Ca2+/Mg2+ through isothermal titration calorimetry and thermodynamic integration simulations. Direct and competitive binding titrations with WT N-terminal cTnC and full-length cTnC indicate that physiologically relevant concentrations of both Ca2+/Mg2+ interacted with the same locus. Moreover, the D67A/D73A N-terminal cTnC construct in which two coordinating residues within site II were removed was found to have significantly reduced affinity for both cations. In addition, 1 mM Mg2+ caused a 1.4-fold lower affinity for Ca2+. These experiments strongly suggest that cytosolic-free Mg2+ occupies a significant population of the available site II. Interaction of Mg2+ with site II of cTnC likely has important functional consequences for the heart both at baseline as well as in diseased states that decrease or increase the availability of Mg2+, such as secondary hyperparathyroidism or ischemia, respectively.
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Affiliation(s)
- Kaveh Rayani
- Molecular Cardiac Physiology Group, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Justin Seffernick
- Department of Chemistry and Biochemistry, Ohio State University, Columbus, Ohio, USA
| | - Alison Yueh Li
- Molecular Cardiac Physiology Group, Simon Fraser University, Burnaby, British Columbia, Canada; Department of Biochemistry and Molecular Biology, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Jonathan P Davis
- Department of Physiology and Cell Biology, The Ohio State University, Columbus, Ohio, USA
| | - Anne Marie Spuches
- Department of Chemistry, East Carolina University, 300 Science and Technology Building, Greenville, North Carolina, USA
| | - Filip Van Petegem
- Department of Biochemistry and Molecular Biology, The University of British Columbia, Vancouver, British Columbia, Canada
| | - R John Solaro
- Department of Physiology and Biophysics and the Center for Cardiovascular Research, College of Medicine, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Steffen Lindert
- Department of Chemistry and Biochemistry, Ohio State University, Columbus, Ohio, USA
| | - Glen F Tibbits
- Molecular Cardiac Physiology Group, Simon Fraser University, Burnaby, British Columbia, Canada; Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia, Canada; Cardiac Group, BC Children's Hospital Research Institute, Vancouver, British Columbia, Canada.
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Kleczkowski LA, Igamberdiev AU. Magnesium Signaling in Plants. Int J Mol Sci 2021; 22:1159. [PMID: 33503839 PMCID: PMC7865908 DOI: 10.3390/ijms22031159] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2020] [Revised: 01/16/2021] [Accepted: 01/19/2021] [Indexed: 01/02/2023] Open
Abstract
Free magnesium (Mg2+) is a signal of the adenylate (ATP+ADP+AMP) status in the cells. It results from the equilibrium of adenylate kinase (AK), which uses Mg-chelated and Mg-free adenylates as substrates in both directions of its reaction. The AK-mediated primary control of intracellular [Mg2+] is finely interwoven with the operation of membrane-bound adenylate- and Mg2+-translocators, which in a given compartment control the supply of free adenylates and Mg2+ for the AK-mediated equilibration. As a result, [Mg2+] itself varies both between and within the compartments, depending on their energetic status and environmental clues. Other key nucleotide-utilizing/producing enzymes (e.g., nucleoside diphosphate kinase) may also be involved in fine-tuning of the intracellular [Mg2+]. Changes in [Mg2+] regulate activities of myriads of Mg-utilizing/requiring enzymes, affecting metabolism under both normal and stress conditions, and impacting photosynthetic performance, respiration, phloem loading and other processes. In compartments controlled by AK equilibrium (cytosol, chloroplasts, mitochondria, nucleus), the intracellular [Mg2+] can be calculated from total adenylate contents, based on the dependence of the apparent equilibrium constant of AK on [Mg2+]. Magnesium signaling, reflecting cellular adenylate status, is likely widespread in all eukaryotic and prokaryotic organisms, due simply to the omnipresent nature of AK and to its involvement in adenylate equilibration.
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Affiliation(s)
- Leszek A. Kleczkowski
- Department of Plant Physiology, Umeå Plant Science Centre, University of Umeå, 901 87 Umeå, Sweden
| | - Abir U. Igamberdiev
- Department of Biology, Memorial University of Newfoundland, St. John’s, NL A1B3X9, Canada;
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31
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Wang Q, Xu L, Helmholz H, Willumeit-Römer R, Luthringer-Feyerabend BJC. Effects of degradable magnesium on paracrine signaling between human umbilical cord perivascular cells and peripheral blood mononuclear cells. Biomater Sci 2020; 8:5969-5983. [PMID: 32975550 DOI: 10.1039/d0bm00834f] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Human mesenchymal stem cells (MSC) interact with numerous immune cells that can promote regenerative processes and inhibit inflammatory responses. We hypothesised that the cross-talk between human umbilical cord perivascular cells (HUCPV; an alternative source of MSC) and peripheral blood mononuclear cells (PBMC) could be influenced by degradable transwell magnesium (Mg). To study the correlations between paracrine signaling and specific cellular behaviour during the host response to Mg, we used a transwell coculture system for up to 7 days. The proliferation and viability of both cell types were not significantly influenced by Mg. When HUCPV were cultured with degradable Mg, a moderate inflammation (e.g., lower secretions of pro-inflammatory interleukin 1 beta and IL2, and tumour necrosis factor alpha, interferon gamma, anti-inflammatory interleukins 4, 5, 10, 13, and 1 receptor antagonists and granulocyte colony stimulating factor), and an increased pro-healing M2 macrophage phenotype were observed. Moreover, when PBMC were cultured with degradable Mg, the expression of migration/wound healing related cytokines (interleukin 8, granulocyte-macrophage colony-stimulating factor, monocyte chemoattractant protein 1 and macrophage inflammatory protein 1α/β) was upregulated, accompanied by an increase in the migration ability of HUCPV (cell scratch assay). In addition, an increased pro-osteogenic potential was demonstrated via an increase of osteoblastic markers (e.g., alkaline phosphatase activity, specific gene expression and cytokine release). These results collectively imply that Mg possesses osteo-immunomodulatory properties. They also help to design Mg-based bone substitute biomaterials capable of exhibiting desired immune reactions and good clinical performance.
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Affiliation(s)
- Qian Wang
- Institute of Materials Research, Division for Metallic Biomaterials, Helmholtz-Zentrum Geesthacht (HZG), Geesthacht, Germany.
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32
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Calcium modulates the domain flexibility and function of an α-actinin similar to the ancestral α-actinin. Proc Natl Acad Sci U S A 2020; 117:22101-22112. [PMID: 32848067 DOI: 10.1073/pnas.1917269117] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The actin cytoskeleton, a dynamic network of actin filaments and associated F-actin-binding proteins, is fundamentally important in eukaryotes. α-Actinins are major F-actin bundlers that are inhibited by Ca2+ in nonmuscle cells. Here we report the mechanism of Ca2+-mediated regulation of Entamoeba histolytica α-actinin-2 (EhActn2) with features expected for the common ancestor of Entamoeba and higher eukaryotic α-actinins. Crystal structures of Ca2+-free and Ca2+-bound EhActn2 reveal a calmodulin-like domain (CaMD) uniquely inserted within the rod domain. Integrative studies reveal an exceptionally high affinity of the EhActn2 CaMD for Ca2+, binding of which can only be regulated in the presence of physiological concentrations of Mg2+ Ca2+ binding triggers an increase in protein multidomain rigidity, reducing conformational flexibility of F-actin-binding domains via interdomain cross-talk and consequently inhibiting F-actin bundling. In vivo studies uncover that EhActn2 plays an important role in phagocytic cup formation and might constitute a new drug target for amoebic dysentery.
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33
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Chu H, Perea W, Greenbaum NL. Role of the central junction in folding topology of the protein-free human U2-U6 snRNA complex. RNA (NEW YORK, N.Y.) 2020; 26:836-850. [PMID: 32220895 PMCID: PMC7297123 DOI: 10.1261/rna.073379.119] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Accepted: 03/16/2020] [Indexed: 06/02/2023]
Abstract
U2 and U6 small nuclear (sn)RNAs are the only snRNAs directly implicated in catalyzing the splicing of pre-mRNA, but assembly and rearrangement steps prior to catalysis require numerous proteins. Previous studies have shown that the protein-free U2-U6 snRNA complex adopts two conformations in equilibrium, characterized by four and three helices surrounding a central junction. The four-helix conformer is strongly favored in the in vitro protein-free state, but the three-helix conformer predominates in spliceosomes. To analyze the role of the central junction in positioning elements forming the active site, we derived three-dimensional models of the two conformations from distances measured between fluorophores at selected locations in constructs representing the protein-free human U2-U6 snRNA complex by time-resolved fluorescence resonance energy transfer. Data describing four angles in the four-helix conformer suggest tetrahedral geometry; addition of Mg2+ results in shortening of the distances between neighboring helices, indicating compaction of the complex around the junction. In contrast, the three-helix conformer shows a closer approach between helices bearing critical elements, but the addition of Mg2+ widens the distance between them; thus in neither conformer are the critical helices positioned to favor the proposed triplex interaction. The presence of Mg2+ also enhances the fraction of the three-helix conformer, as does incubation with the Prp19-related protein RBM22, which has been implicated in the remodeling of the U2-U6 snRNA complex to render it catalytically active. These data suggest that although the central junction assumes a significant role in orienting helices, spliceosomal proteins and Mg2+ facilitate formation of the catalytically active conformer.
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Affiliation(s)
- Huong Chu
- Department of Chemistry, Hunter College of the City University of New York, New York, New York 10065, USA
- Ph.D. Program in Chemistry, The Graduate Center of the City University of New York, New York, New York 10016, USA
| | - William Perea
- Department of Chemistry, Hunter College of the City University of New York, New York, New York 10065, USA
| | - Nancy L Greenbaum
- Department of Chemistry, Hunter College of the City University of New York, New York, New York 10065, USA
- Ph.D. Program in Chemistry, The Graduate Center of the City University of New York, New York, New York 10016, USA
- Ph.D. Program in Biochemistry, The Graduate Center of the City University of New York, New York, New York 10016, USA
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Stelling MP, Motta JM, Mashid M, Johnson WE, Pavão MS, Farrell NP. Metal ions and the extracellular matrix in tumor migration. FEBS J 2020; 286:2950-2964. [PMID: 31379111 DOI: 10.1111/febs.14986] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Revised: 05/22/2019] [Accepted: 07/06/2019] [Indexed: 12/15/2022]
Abstract
In this review, we explore the roles of divalent metal ions in structure and function within the extracellular matrix (ECM), specifically, their interaction with glycosaminoglycans (GAGs) during tumor progression. Metals and GAGs have been individually associated with physiological and pathological processes, however, their combined activities in regulating cell behavior and ECM remodeling have not been fully explored to date. During tumor progression, divalent metals and GAGs participate in central processes, such as cell migration and angiogenesis, either by modulating cell surface molecules, as well as soluble signaling factors. In addition, studies on metals and polysaccharides interactions have been of great value, as they provide structural information that can be correlated with function. Finally, we believe that understanding how metals are regulated in physiological and pathological conditions is paramount for the development of new treatment strategies, as well as diagnostic and exploratory tools.
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Affiliation(s)
- Mariana P Stelling
- Instituto Federal de Educacao, Educação, Ciência e Tecnologia do Rio de Janeiro, Brazil
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Copley SD. The physical basis and practical consequences of biological promiscuity. Phys Biol 2020; 17:10.1088/1478-3975/ab8697. [PMID: 32244231 PMCID: PMC9291633 DOI: 10.1088/1478-3975/ab8697] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Proteins interact with metabolites, nucleic acids, and other proteins to orchestrate the myriad catalytic, structural and regulatory functions that support life from the simplest microbes to the most complex multicellular organisms. These molecular interactions are often exquisitely specific, but never perfectly so. Adventitious "promiscuous" interactions are ubiquitous due to the thousands of macromolecules and small molecules crowded together in cells. Such interactions may perturb protein function at the molecular level, but as long as they do not compromise organismal fitness, they will not be removed by natural selection. Although promiscuous interactions are physiologically irrelevant, they are important because they can provide a vast reservoir of potential functions that can provide the starting point for evolution of new functions, both in nature and in the laboratory.
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Affiliation(s)
- Shelley D Copley
- Department of Molecular, Cellular and Developmental Biology and Cooperative Institute for Research in Environmental Sciences, University of Colorado Boulder, Boulder, Colorado, UNITED STATES
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Li G, Moore JK. Microtubule dynamics at low temperature: evidence that tubulin recycling limits assembly. Mol Biol Cell 2020; 31:1154-1166. [PMID: 32213119 PMCID: PMC7353160 DOI: 10.1091/mbc.e19-11-0634] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
How temperature specifically affects microtubule dynamics and how these lead to changes in microtubule networks in cells have not been established. We investigated these questions in budding yeast, an organism found in diverse environments and therefore predicted to exhibit dynamic microtubules across a broad temperature range. We measured the dynamics of GFP-labeled microtubules in living cells and found that lowering temperature from 37°C to 10°C decreased the rates of both polymerization and depolymerization, decreased the amount of polymer assembled before catastrophes, and decreased the frequency of microtubule emergence from nucleation sites. Lowering to 4°C caused rapid loss of almost all microtubule polymer. We provide evidence that these effects on microtubule dynamics may be explained in part by changes in the cofactor-dependent conformational dynamics of tubulin proteins. Ablation of tubulin-binding cofactors (TBCs) further sensitizes cells and their microtubules to low temperatures, and we highlight a specific role for TBCB/Alf1 in microtubule maintenance at low temperatures. Finally, we show that inhibiting the maturation cycle of tubulin by using a point mutant in β-tubulin confers hyperstable microtubules at low temperatures and rescues the requirement for TBCB/Alf1 in maintaining microtubule polymer at low temperatures. Together, these results reveal an unappreciated step in the tubulin cycle.
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Affiliation(s)
- Gabriella Li
- Department of Cell and Developmental Biology, University of Colorado School of Medicine, Aurora, CO 80045
| | - Jeffrey K Moore
- Department of Cell and Developmental Biology, University of Colorado School of Medicine, Aurora, CO 80045
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Kwun MS, Lee DG. Quercetin-induced yeast apoptosis through mitochondrial dysfunction under the accumulation of magnesium in Candida albicans. Fungal Biol 2020; 124:83-90. [DOI: 10.1016/j.funbio.2019.11.009] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Revised: 11/23/2019] [Accepted: 11/25/2019] [Indexed: 02/02/2023]
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Solute carrier transporters: the metabolic gatekeepers of immune cells. Acta Pharm Sin B 2020; 10:61-78. [PMID: 31993307 PMCID: PMC6977534 DOI: 10.1016/j.apsb.2019.12.006] [Citation(s) in RCA: 107] [Impact Index Per Article: 26.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 09/29/2019] [Accepted: 10/31/2019] [Indexed: 02/06/2023] Open
Abstract
Solute carrier (SLC) transporters meditate many essential physiological functions, including nutrient uptake, ion influx/efflux, and waste disposal. In its protective role against tumors and infections, the mammalian immune system coordinates complex signals to support the proliferation, differentiation, and effector function of individual cell subsets. Recent research in this area has yielded surprising findings on the roles of solute carrier transporters, which were discovered to regulate lymphocyte signaling and control their differentiation, function, and fate by modulating diverse metabolic pathways and balanced levels of different metabolites. In this review, we present current information mainly on glucose transporters, amino-acid transporters, and metal ion transporters, which are critically important for mediating immune cell homeostasis in many different pathological conditions.
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Key Words
- 3-PG, 3-phosphoglyceric acid
- ABC, ATP-binding cassette
- AIF, apoptosis-inducing factor
- AP-1, activator protein 1
- ASCT2, alanine serine and cysteine transporter system 2
- ATP, adenosine triphosphate
- BCR, B cell receptor
- BMDMs, bone marrow-derived macrophages
- CD45R, a receptor-type protein tyrosine phosphatase
- CTL, cytotoxic T lymphocytes
- DC, dendritic cells
- EAATs, excitatory amino acid transporters
- ER, endoplasmic reticulum
- ERRα, estrogen related receptor alpha
- FFA, free fatty acids
- G-6-P, glucose 6-phosphate
- GLUT, glucose transporters
- GSH, glutathione
- Glucose
- Glutamine
- HIF-1α, hypoxia-inducible factor 1-alpha
- HIV-1, human immunodeficiency virus type 1
- Hk1, hexokinase-1
- IFNβ, interferon beta
- IFNγ, interferon gamma
- IKK, IκB kinase
- IKKβ, IκB kinase beta subunit
- IL, interleukin
- LDHA, lactate dehydrogenase A
- LPS, lipopolysaccharide
- Lymphocytes
- Lyn, tyrosine-protein kinase
- MAPK, mitogen-activated protein kinase
- MCT, monocarboxylate transporters
- MS, multiple sclerosis
- Metal ion
- NADPH, nicotinamide adenine dinucleotide phosphate
- NF-κB, nuclear factor kappa-light-chain-enhancer of activated B cells
- NO, nitric oxide
- NOD2, nucleotide-binding oligomerization domain containing 2
- PEG2, prostaglandin E2
- PI-3K/AKT, phosphatidylinositol-3-OH kinase/serine–threonine kinase
- PPP, pentose phosphate pathway
- Pfk, phosphofructokinase
- RA, rheumatoid arthritis
- RLR, RIG-I-like receptor
- ROS, reactive oxygen species
- SLC, solute carrier
- SLE, systemic lupus erythematosus
- SNAT, sodium-coupled neutral amino acid transporters
- STAT, signal transducers and activators of transcription
- Solute carrier
- TAMs, tumor-associated macrophages
- TCA, tricarboxylic acid
- TCR, T cell receptor
- TLR, toll-like receptor
- TNF, tumor necrosis factor
- TRPM7, transient receptor potential cation channel subfamily M member 7
- Teffs, effector T cells
- Th1/2/17, type 1/2/17 helper T cells
- Tregs, regulatory T cells
- VEGF, vascular endothelial growth factor
- ZIP, zrt/irt-like proteins
- iNOS, inducible nitric oxide synthase
- iTregs, induced regulatory T cells
- mTORC1, mammalian target of rapamycin complex 1
- α-KG, α-ketoglutaric acid
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Murata O, Shindo Y, Ikeda Y, Iwasawa N, Citterio D, Oka K, Hiruta Y. Near-Infrared Fluorescent Probes for Imaging of Intracellular Mg 2+ and Application to Multi-Color Imaging of Mg 2+, ATP, and Mitochondrial Membrane Potential. Anal Chem 2019; 92:966-974. [PMID: 31724392 DOI: 10.1021/acs.analchem.9b03872] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
The magnesium ion (Mg2+) is an essential cation to maintain proper cellular activities. To visualize the dynamics and functions of Mg2+, there is a great need for the development of Mg2+-selective fluorescent probes. However, conventional Mg2+ fluorescent probes are falling behind in low selectivity and poor fluorescence color variation. In this report, to make available a distinct color window for multi-color imaging, we designed and synthesized highly Mg2+-selective and near-infrared (NIR) fluorescent probes, the KMG-500 series consisting of a charged β-diketone as a selective binding site for Mg2+ and a Si-rhodamine residue as the NIR fluorophore, which showed photoinduced electron transfer (PeT)-type OFF-ON response to the concentration of Mg2+. Two types of KMG-500 series probes, tetramethyl substituted Si-rhodamine KMG-501 and tetraethyl substituted Si-rhodamine KMG-502, were synthesized for the evaluation of cell permeability. For intracellular application, the membrane-permeable acetoxymethyl derivative KMG-501 (KMG-501AM) was synthesized and allowed to stably stain cultured rat hippocampal neurons during imaging of intracellular Mg2+. On the other hand, KMG-502 was cell membrane permeable without AM modification, preventing the probe from staying inside cells during imaging. KMG-501 distributed mainly in the cytoplasm and partially localized in lysosomes and mitochondria in cultured rat hippocampal neurons. Mg2+ increase in response to the FCCP uncoupler inducing depolarization of the mitochondrial inner membrane potential was detected in the KMG-501 stained neurons. For the first time, KMG-501 succeeded in imaging intracellular Mg2+ dynamics with NIR fluorescence. Moreover, it allows one to simultaneously visualize changes in Mg2+ and ATP concentration and also mitochondrial inner membrane potential and their interactions. This probe is expected to be a strong tool for multi-color imaging of intracellular Mg2+.
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Affiliation(s)
- Osamu Murata
- Department of Applied Chemistry , Keio University , 3-14-1 Hiyoshi, Kohoku-ku , Yokohama , Kanagawa , Japan
| | - Yutaka Shindo
- Department of Biosciences and Informatics , Keio University , 3-14-1 Hiyoshi, Kohoku-ku , Yokohama , Kanagawa , Japan
| | - Yuma Ikeda
- Department of Applied Chemistry , Keio University , 3-14-1 Hiyoshi, Kohoku-ku , Yokohama , Kanagawa , Japan
| | - Naoko Iwasawa
- Department of Applied Chemistry , Keio University , 3-14-1 Hiyoshi, Kohoku-ku , Yokohama , Kanagawa , Japan
| | - Daniel Citterio
- Department of Applied Chemistry , Keio University , 3-14-1 Hiyoshi, Kohoku-ku , Yokohama , Kanagawa , Japan
| | - Kotaro Oka
- Department of Biosciences and Informatics , Keio University , 3-14-1 Hiyoshi, Kohoku-ku , Yokohama , Kanagawa , Japan.,Graduate Institute of Medicine, College of Medicine , Kaohsiung Medical University , Kaohsiung , Taiwan.,Waseda Research Institute for Science and Engineering , 2-2 Wakamatsucho , Shinjuku , Tokyo , Japan
| | - Yuki Hiruta
- Department of Applied Chemistry , Keio University , 3-14-1 Hiyoshi, Kohoku-ku , Yokohama , Kanagawa , Japan
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Ohyama T. New Aspects of Magnesium Function: A Key Regulator in Nucleosome Self-Assembly, Chromatin Folding and Phase Separation. Int J Mol Sci 2019; 20:ijms20174232. [PMID: 31470631 PMCID: PMC6747271 DOI: 10.3390/ijms20174232] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 08/21/2019] [Accepted: 08/26/2019] [Indexed: 02/07/2023] Open
Abstract
Metal cations are associated with many biological processes. The effects of these cations on nucleic acids and chromatin were extensively studied in the early stages of nucleic acid and chromatin research. The results revealed that some monovalent and divalent metal cations, including Mg2+, profoundly affect the conformations and stabilities of nucleic acids, the folding of chromatin fibers, and the extent of chromosome condensation. Apart from these effects, there have only been a few reports on the functions of these cations. In 2007 and 2013, however, Mg2+-implicated novel phenomena were found: Mg2+ facilitates or enables both self-assembly of identical double-stranded (ds) DNA molecules and self-assembly of identical nucleosomes in vitro. These phenomena may be deeply implicated in the heterochromatin domain formation and chromatin-based phase separation. Furthermore, a recent study showed that elevation of the intranuclear Mg2+ concentration causes unusual differentiation of mouse ES (embryonic stem) cells. All of these phenomena seem to be closely related to one another. Mg2+ seems to be a key regulator of chromatin dynamics and chromatin-based biological processes.
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Affiliation(s)
- Takashi Ohyama
- Department of Biology, Faculty of Education and Integrated Arts and Sciences, Waseda University, 2-2 Wakamatsu-cho, Shinjuku-ku, Tokyo 162-8480, Japan.
- Major in Integrative Bioscience and Biomedical Engineering, Graduate School of Science and Engineering, Waseda University, 2-2 Wakamatsu-cho, Shinjuku-ku, Tokyo 162-8480, Japan.
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41
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Díaz-García CM, Lahmann C, Martínez-François JR, Li B, Koveal D, Nathwani N, Rahman M, Keller JP, Marvin JS, Looger LL, Yellen G. Quantitative in vivo imaging of neuronal glucose concentrations with a genetically encoded fluorescence lifetime sensor. J Neurosci Res 2019; 97:946-960. [PMID: 31106909 PMCID: PMC6565483 DOI: 10.1002/jnr.24433] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Revised: 04/08/2019] [Accepted: 04/08/2019] [Indexed: 01/07/2023]
Abstract
Glucose is an essential source of energy for the brain. Recently, the development of genetically encoded fluorescent biosensors has allowed real time visualization of glucose dynamics from individual neurons and astrocytes. A major difficulty for this approach, even for ratiometric sensors, is the lack of a practical method to convert such measurements into actual concentrations in ex vivo brain tissue or in vivo. Fluorescence lifetime imaging provides a strategy to overcome this. In a previous study, we reported the lifetime glucose sensor iGlucoSnFR-TS (then called SweetieTS) for monitoring changes in neuronal glucose levels in response to stimulation. This genetically encoded sensor was generated by combining the Thermus thermophilus glucose-binding protein with a circularly permuted variant of the monomeric fluorescent protein T-Sapphire. Here, we provide more details on iGlucoSnFR-TS design and characterization, as well as pH and temperature sensitivities. For accurate estimation of glucose concentrations, the sensor must be calibrated at the same temperature as the experiments. We find that when the extracellular glucose concentration is in the range 2-10 mM, the intracellular glucose concentration in hippocampal neurons from acute brain slices is ~20% of the nominal external glucose concentration (~0.4-2 mM). We also measured the cytosolic neuronal glucose concentration in vivo, finding a range of ~0.7-2.5 mM in cortical neurons from awake mice.
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Affiliation(s)
| | - Carolina Lahmann
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
| | | | - Binsen Li
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
| | - Dorothy Koveal
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
| | - Nidhi Nathwani
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
| | - Mahia Rahman
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
| | - Jacob P. Keller
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Jonathan S. Marvin
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Loren L. Looger
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Gary Yellen
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
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42
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Bactericidal Disruption of Magnesium Metallostasis in Mycobacterium tuberculosis Is Counteracted by Mutations in the Metal Ion Transporter CorA. mBio 2019; 10:mBio.01405-19. [PMID: 31289182 PMCID: PMC6747715 DOI: 10.1128/mbio.01405-19] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Antimycobacterial agents might shorten the course of treatment by reducing the number of phenotypically tolerant bacteria if they could kill M. tuberculosis in diverse metabolic states. Here we report two chemically disparate classes of agents that kill M. tuberculosis both when it is replicating and when it is not. Under replicating conditions, the tricyclic 4-hydroxyquinolines and a barbituric acid analogue deplete intrabacterial magnesium as a mechanism of action, and for both compounds, mutations in CorA, a putative Mg2+/Co2+ transporter, conferred resistance to the compounds when M. tuberculosis was under replicating conditions but not under nonreplicating conditions, illustrating that a given compound can kill M. tuberculosis in different metabolic states by disparate mechanisms. Targeting magnesium metallostasis represents a previously undescribed antimycobacterial mode of action that might cripple M. tuberculosis in a Mg2+-deficient intraphagosomal environment of macrophages. A defining characteristic of treating tuberculosis is the need for prolonged administration of multiple drugs. This may be due in part to subpopulations of slowly replicating or nonreplicating Mycobacterium tuberculosis bacilli exhibiting phenotypic tolerance to most antibiotics in the standard treatment regimen. Confounding this problem is the increasing incidence of heritable multidrug-resistant M. tuberculosis. A search for new antimycobacterial chemical scaffolds that can kill phenotypically drug-tolerant mycobacteria uncovered tricyclic 4-hydroxyquinolines and a barbituric acid derivative with mycobactericidal activity against both replicating and nonreplicating M. tuberculosis. Both families of compounds depleted M. tuberculosis of intrabacterial magnesium. Complete or partial resistance to both chemotypes arose from mutations in the putative mycobacterial Mg2+/Co2+ ion channel, CorA. Excess extracellular Mg2+, but not other divalent cations, diminished the compounds’ cidality against replicating M. tuberculosis. These findings establish depletion of intrabacterial magnesium as an antimicrobial mechanism of action and show that M. tuberculosis magnesium homeostasis is vulnerable to disruption by structurally diverse, nonchelating, drug-like compounds.
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43
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Killoran RC, Smith MJ. Conformational resolution of nucleotide cycling and effector interactions for multiple small GTPases determined in parallel. J Biol Chem 2019; 294:9937-9948. [PMID: 31088913 DOI: 10.1074/jbc.ra119.008653] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Revised: 05/09/2019] [Indexed: 12/31/2022] Open
Abstract
Small GTPases alternatively bind GDP/GTP guanine nucleotides to gate signaling pathways that direct most cellular processes. Numerous GTPases are implicated in oncogenesis, particularly the three RAS isoforms HRAS, KRAS, and NRAS and the RHO family GTPase RAC1. Signaling networks comprising small GTPases are highly connected, and there is some evidence of direct biochemical cross-talk between their functional G-domains. The activation potential of a given GTPase is contingent on a codependent interaction with the nucleotide and a Mg2+ ion, which bind to individual variants with distinct affinities coordinated by residues in the GTPase nucleotide-binding pocket. Here, we utilized a selective-labeling strategy coupled with real-time NMR spectroscopy to monitor nucleotide exchange, GTP hydrolysis, and effector interactions of multiple small GTPases in a single complex system. We provide insight into nucleotide preference and the role of Mg2+ in activating both WT and oncogenic mutant enzymes. Multiplexing revealed guanine nucleotide exchange factor (GEF), GTPase-activating protein (GAP), and effector-binding specificities in mixtures of GTPases and resolved that the three related RAS isoforms are biochemically equivalent. This work establishes that direct quantitation of the nucleotide-bound conformation is required to accurately determine an activation potential for any given GTPase, as small GTPases such as RAS-like proto-oncogene A (RALA) or the G12C mutant of KRAS display fast exchange kinetics but have a high affinity for GDP. Furthermore, we propose that the G-domains of small GTPases behave autonomously in solution and that nucleotide cycling proceeds independently of protein concentration but is highly impacted by Mg2+ abundance.
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Affiliation(s)
- Ryan C Killoran
- From the Institute for Research in Immunology and Cancer and
| | - Matthew J Smith
- From the Institute for Research in Immunology and Cancer and .,Department of Pathology and Cell Biology, Faculty of Medicine, Université de Montréal, Montréal, Québec H3T 1J4, Canada
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44
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Tsvetkov PO, Roman AY, Baksheeva VE, Nazipova AA, Shevelyova MP, Vladimirov VI, Buyanova MF, Zinchenko DV, Zamyatnin AA, Devred F, Golovin AV, Permyakov SE, Zernii EY. Functional Status of Neuronal Calcium Sensor-1 Is Modulated by Zinc Binding. Front Mol Neurosci 2018; 11:459. [PMID: 30618610 PMCID: PMC6302015 DOI: 10.3389/fnmol.2018.00459] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2018] [Accepted: 11/28/2018] [Indexed: 11/29/2022] Open
Abstract
Neuronal calcium sensor-1 (NCS-1) protein is abundantly expressed in the central nervous system and retinal neurons, where it regulates many vital processes such as synaptic transmission. It coordinates three calcium ions by EF-hands 2-4, thereby transducing Ca2+ signals to a wide range of protein targets, including G protein-coupled receptors and their kinases. Here, we demonstrate that NCS-1 also has Zn2+-binding sites, which affect its structural and functional properties upon filling. Fluorescence and circular dichroism experiments reveal the impact of Zn2+ binding on NCS-1 secondary and tertiary structure. According to atomic absorption spectroscopy and isothermal titration calorimetry studies, apo-NCS-1 has two high-affinity (4 × 106 M-1) and one low-affinity (2 × 105 M-1) Zn2+-binding sites, whereas Mg2+-loaded and Ca2+-loaded forms (which dominate under physiological conditions) bind two zinc ions with submicromolar affinity. Metal competition analysis and circular dichroism studies suggest that Zn2+-binding sites of apo- and Mg2+-loaded NCS-1 overlap with functional EF-hands of the protein. Consistently, high Zn2+ concentrations displace Mg2+ from the EF-hands and decrease the stoichiometry of Ca2+ binding. Meanwhile, one of the EF-hands of Zn2+-saturated NCS-1 exhibits a 14-fold higher calcium affinity, which increases the overall calcium sensitivity of the protein. Based on QM/MM molecular dynamics simulations, Zn2+ binding to Ca2+-loaded NCS-1 could occur at EF-hands 2 and 4. The high-affinity zinc binding increases the thermal stability of Ca2+-free NCS-1 and favours the interaction of its Ca2+-loaded form with target proteins, such as dopamine receptor D2R and GRK1. In contrast, low-affinity zinc binding promotes NCS-1 aggregation accompanied by the formation of twisted rope-like structures. Altogether, our findings suggest a complex interplay between magnesium, calcium and zinc binding to NCS-1, leading to the appearance of multiple conformations of the protein, in turn modulating its functional status.
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Affiliation(s)
- Philipp O Tsvetkov
- Aix-Marseille University, CNRS, INP, Institute of Neurophysiopathology, Faculty of Pharmacy, Marseille, France
| | - Andrei Yu Roman
- Institute of Physiologically Active Compounds (RAS), Chernogolovka, Russia
| | - Viktoriia E Baksheeva
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
| | - Aliya A Nazipova
- Institute for Biological Instrumentation of the Russian Academy of Sciences, Pushchino, Russia
| | - Marina P Shevelyova
- Institute for Biological Instrumentation of the Russian Academy of Sciences, Pushchino, Russia
| | - Vasiliy I Vladimirov
- Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Pushchino, Russia
| | - Michelle F Buyanova
- Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, Moscow, Russia
| | - Dmitry V Zinchenko
- Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Pushchino, Russia
| | - Andrey A Zamyatnin
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
- Institute of Molecular Medicine, Sechenov First Moscow State Medical University, Moscow, Russia
| | - François Devred
- Aix-Marseille University, CNRS, INP, Institute of Neurophysiopathology, Faculty of Pharmacy, Marseille, France
| | - Andrey V Golovin
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
- Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, Moscow, Russia
- Institute of Molecular Medicine, Sechenov First Moscow State Medical University, Moscow, Russia
- Faculty of Computer Science, Higher School of Economics, Moscow, Russia
| | - Sergei E Permyakov
- Institute for Biological Instrumentation of the Russian Academy of Sciences, Pushchino, Russia
| | - Evgeni Yu Zernii
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
- Institute of Molecular Medicine, Sechenov First Moscow State Medical University, Moscow, Russia
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45
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Sheridan CM, Garcia VE, Ahyong V, DeRisi JL. The Plasmodium falciparum cytoplasmic translation apparatus: a promising therapeutic target not yet exploited by clinically approved anti-malarials. Malar J 2018; 17:465. [PMID: 30541569 PMCID: PMC6292128 DOI: 10.1186/s12936-018-2616-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Accepted: 12/06/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The continued spectre of resistance to existing anti-malarials necessitates the pursuit of novel targets and mechanisms of action for drug development. One class of promising targets consists of the 80S ribosome and its associated components comprising the parasite translational apparatus. Development of translation-targeting therapeutics requires a greater understanding of protein synthesis and its regulation in the malaria parasite. Research in this area has been limited by the lack of appropriate experimental methods, particularly a direct measure of parasite translation. METHODS An in vitro method directly measuring translation in whole-cell extracts from the malaria parasite Plasmodium falciparum, the PfIVT assay, and a historically-utilized indirect measure of translation, S35-radiolabel incorporation, were compared utilizing a large panel of known translation inhibitors as well as anti-malarial drugs. RESULTS Here, an extensive pharmacologic assessment of the PfIVT assay is presented, using a wide range of known inhibitors demonstrating its utility for studying activity of both ribosomal and non-ribosomal elements directly involved in translation. Further, the superiority of this assay over a historically utilized indirect measure of translation, S35-radiolabel incorporation, is demonstrated. Additionally, the PfIVT assay is utilized to investigate a panel of clinically approved anti-malarial drugs, many with unknown or unclear mechanisms of action, and show that none inhibit translation, reaffirming Plasmodium translation to be a viable alternative drug target. Within this set, mefloquine is unambiguously found to lack translation inhibition activity, despite having been recently mischaracterized as a ribosomal inhibitor. CONCLUSIONS This work exploits a direct and reproducible assay for measuring P. falciparum translation, demonstrating its value in the continued study of protein synthesis in malaria and its inhibition as a drug target.
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Affiliation(s)
- Christine Moore Sheridan
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, CA, USA
| | - Valentina E Garcia
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, CA, USA
| | - Vida Ahyong
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, CA, USA
| | - Joseph L DeRisi
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, CA, USA. .,Chan Zuckerberg Biohub, San Francisco, CA, USA.
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46
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Abstract
Modulation of neurotransmitter exocytosis by activated Gi/o coupled G-protein coupled receptors (GPCRs) is a universal regulatory mechanism used both to avoid overstimulation and to influence circuitry. One of the known modulation mechanisms is the interaction between Gβγ and the soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNAREs). There are 5 Gβ and 12 Gγ subunits, but specific Gβγs activated by a given GPCR and the specificity to effectors, such as SNARE, in vivo are not known. Although less studied, Gβγ binding to the exocytic fusion machinery (i.e. SNARE) provides a more direct regulatory mechanism for neurotransmitter release. Here, we review some recent insights in the architecture of the synaptic terminal, modulation of synaptic transmission, and implications of G protein modulation of synaptic transmission in diseases. Numerous presynaptic proteins are involved in the architecture of synaptic terminals, particularly the active zone, and their importance in the regulation of exocytosis is still not completely understood. Further understanding of the Gβγ-SNARE interaction and the architecture and mechanisms of exocytosis may lead to the discovery of novel therapeutic targets to help patients with various disorders such as hypertension, attention-deficit/hyperactivity disorder, post-traumatic stress disorder, and acute/chronic pain.
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Affiliation(s)
- Yun Young Yim
- Department of Pharmacology, Vanderbilt University, Nashville 37232-6600, TN, United States
| | - Zack Zurawski
- Department of Pharmacology, Vanderbilt University, Nashville 37232-6600, TN, United States
| | - Heidi Hamm
- Department of Pharmacology, Vanderbilt University, Nashville 37232-6600, TN, United States.
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Akhtar MJ, Ahamed M, Alhadlaq HA, Alrokayan SA. MgO nanoparticles cytotoxicity caused primarily by GSH depletion in human lung epithelial cells. J Trace Elem Med Biol 2018; 50:283-290. [PMID: 30262293 DOI: 10.1016/j.jtemb.2018.07.016] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Revised: 07/17/2018] [Accepted: 07/20/2018] [Indexed: 12/14/2022]
Abstract
Bio-response of magnesium oxide nanoparticles (MgO NPs) is emerging, obviously, with a conflicting flavor. This study evaluates the underlying mechanism of bio-responses of MgO NPs in human lung epithelial (A549) cell. TEM size of NPs was 40-50 nm and cuboidal in shape. EDS data showed no detectable impurity. Zeta potential of MgO NPs suggested a fair dispersion in complete culture media and in PBS. MgO NPs induced a concentration dependent cytotoxicity when measured by MTT and NRU. MgO NPs induced cytotoxicity strongly correlated with intracellular depletion of antioxidant GSH. MgO NPs did not induce concentration dependent ROS. All live treatment conditions caused autophagy, a survival mechanism when deprived of nutrients and antioxidant. At highest cytotoxic concentration of MgO NPs, there was significant elevation in MMP and caspase-3 activity. GSH depletion mediated autophagy failure lead to MgO NPs induced death at higher concentrations that might have potentiated by induced ROS. This study suggested a mechanism of cytotoxicity caused by MgO NPs that was primarily dependent on GSH depletion, and ROS induction played secondary role in toxicity. Significantly higher toxicity observed for MgO NPs in comparison to Mg salt clearly indicated the involvement of nanoparticulate form in toxicity.
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Affiliation(s)
- Mohd Javed Akhtar
- King Abdullah Institute for Nanotechnology, King Saud University, Riyadh 11451, Saudi Arabia.
| | - Maqusood Ahamed
- King Abdullah Institute for Nanotechnology, King Saud University, Riyadh 11451, Saudi Arabia
| | - Hisham A Alhadlaq
- Department of Physics and Astronomy, College of Science, King Saud University, Riyadh 11451, Saudi Arabia; King Abdullah Institute for Nanotechnology, King Saud University, Riyadh 11451, Saudi Arabia
| | - Salman A Alrokayan
- Research Chair for Biomedical Applications of Nanomaterials, Biochemistry Department, College of Science, Building 5, PO Box 2455, King Saud University, Riyadh, Saudi Arabia
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48
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Pokharel R, Gerrits R, Schuessler JA, Frings PJ, Sobotka R, Gorbushina AA, von Blanckenburg F. Magnesium Stable Isotope Fractionation on a Cellular Level Explored by Cyanobacteria and Black Fungi with Implications for Higher Plants. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:12216-12224. [PMID: 30351034 DOI: 10.1021/acs.est.8b02238] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
In a controlled growth experiment we found that the cyanobacterium Nostoc punctiforme has a bulk cell 26Mg/24Mg ratio (expressed as δ26Mg) that is -0.27‰ lower than the growth solution at a pH of ca. 5.9. This contrasts with a recently published δ26Mg value that was 0.65‰ higher than growth solution for the black fungus Knufia petricola at similar laboratory conditions, interpreted to reflect loss of 24Mg during cell growth. By a mass balance model constrained by δ26Mg in chlorophyll extract we inferred the δ26 Mg value of the main Mg compartments in a cyanobacteria cell: free cytosolic Mg (-2.64‰), chlorophyll (1.85‰), and the nonchlorophyll-bonded Mg compartments like ATP and ribosomes (-0.64‰). The lower δ26Mg found in Nostoc punctiforme would thus result from the absence of significant Mg efflux during cell growth in combination with either (a) discrimination against 26Mg during uptake by desolvation of Mg or transport across protein channels or (b) discrimination against 24Mg in the membrane transporter during efflux. The model predicts the preferential incorporation of 26Mg in cells and plant organs low in Mg and the absence of isotope fractionation in those high in Mg, corroborated by a compilation of Mg isotope ratios from fungi, bacteria, and higher plants.
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Affiliation(s)
- Rasesh Pokharel
- GFZ German Research Centre for Geosciences , Section 3.3, Earth Surface Geochemistry, Telegrafenberg, 14473 Potsdam , Germany
- Institute of Geological Sciences , Freie Universität Berlin , 12249 Berlin , Germany
| | - Ruben Gerrits
- Department 4, Materials & Environment , BAM Federal Institute for Materials Research & Testing , 12205 Berlin , Germany
- Department of Biology, Chemistry and Pharmacy , Freie Universität Berlin , 14195 Berlin , Germany
| | - Jan A Schuessler
- GFZ German Research Centre for Geosciences , Section 3.3, Earth Surface Geochemistry, Telegrafenberg, 14473 Potsdam , Germany
| | - Patrick J Frings
- GFZ German Research Centre for Geosciences , Section 3.3, Earth Surface Geochemistry, Telegrafenberg, 14473 Potsdam , Germany
| | - Roman Sobotka
- Institute of Microbiology , Centre Algatech , 379 81 Třebon , Czech Republic
| | - Anna A Gorbushina
- Institute of Geological Sciences , Freie Universität Berlin , 12249 Berlin , Germany
- Department 4, Materials & Environment , BAM Federal Institute for Materials Research & Testing , 12205 Berlin , Germany
- Department of Biology, Chemistry and Pharmacy , Freie Universität Berlin , 14195 Berlin , Germany
| | - Friedhelm von Blanckenburg
- GFZ German Research Centre for Geosciences , Section 3.3, Earth Surface Geochemistry, Telegrafenberg, 14473 Potsdam , Germany
- Institute of Geological Sciences , Freie Universität Berlin , 12249 Berlin , Germany
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49
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Kimura T, Lorenz-Fonfria VA, Douki S, Motoki H, Ishitani R, Nureki O, Higashi M, Furutani Y. Vibrational and Molecular Properties of Mg2+ Binding and Ion Selectivity in the Magnesium Channel MgtE. J Phys Chem B 2018; 122:9681-9696. [DOI: 10.1021/acs.jpcb.8b07967] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Tetsunari Kimura
- Department of Life and Coordination-Complex Molecular Science, Institute for Molecular Science, National Institutes of Natural Sciences, 38 Nishigo-Naka, Myodaiji, Okazaki 444-8585, Japan
- Department of Structural Molecular Science, The Graduate University for Advanced Studies (SOKENDAI), 38 Nishigo-Naka, Myodaiji, Okazaki 444-8585, Japan
| | - Victor A. Lorenz-Fonfria
- Institute of Molecular Science (ICMol), Universitat de València, Catedràtic José Beltrán Martínez 2, 46980 Paterna, Spain
- Department of Biochemistry and Molecular Biology, Universitat de València, Carrer Doctor Moliner 50, 46100 Burjassot, Spain
| | - Shintaro Douki
- Department of Biophysics and Biochemistry, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Hideyoshi Motoki
- Department of Chemistry, Biology and Marine Science, University of the Ryukyus, 1 Senbaru, Nishihara, Nakagami, Okinawa 903-0213, Japan
| | - Ryuichiro Ishitani
- Department of Biophysics and Biochemistry, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Osamu Nureki
- Department of Biophysics and Biochemistry, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Masahiro Higashi
- Department of Chemistry, Biology and Marine Science, University of the Ryukyus, 1 Senbaru, Nishihara, Nakagami, Okinawa 903-0213, Japan
| | - Yuji Furutani
- Department of Life and Coordination-Complex Molecular Science, Institute for Molecular Science, National Institutes of Natural Sciences, 38 Nishigo-Naka, Myodaiji, Okazaki 444-8585, Japan
- Department of Structural Molecular Science, The Graduate University for Advanced Studies (SOKENDAI), 38 Nishigo-Naka, Myodaiji, Okazaki 444-8585, Japan
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Vallone R, Dal Cortivo G, D'Onofrio M, Dell'Orco D. Preferential Binding of Mg 2+ Over Ca 2+ to CIB2 Triggers an Allosteric Switch Impaired in Usher Syndrome Type 1J. Front Mol Neurosci 2018; 11:274. [PMID: 30174586 PMCID: PMC6107761 DOI: 10.3389/fnmol.2018.00274] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Accepted: 07/20/2018] [Indexed: 12/20/2022] Open
Abstract
Calcium and integrin binding protein 2 (CIB2) shares with the other members of the CIB family the ability to bind Ca2+ and Mg2+ via two functional EF-hand motifs, namely EF3 and EF4. As a cation sensor, CIB2 is able to switch to a conformation likely associated with specific biological functions yet to be clarified. Recent findings demonstrate the involvement of CIB2 in hearing physiology and a single, conservative point mutation (p.E64D) has been related to Usher Syndrome type 1J (USH1J) and non-syndromic hearing loss. We present an exhaustive biochemical and biophysical characterization of human wild type (WT) and E64D CIB2. We found that CIB2 does not possibly work as a calcium sensor under physiological conditions, its affinity for Ca2+ (Kdapp = 0.5 mM) being too low for detecting normal intracellular levels. Instead, CIB2 displays a significantly high affinity for Mg2+ (Kdapp = 290 μM), and it is probably Mg2+ -bound under physiological conditions. At odds with the homologous protein CIB1, CIB2 forms a non-covalent dimer under conditions that mimic the physiological ones, and as such it interacts with its physiological target α7B integrin. NMR spectroscopy revealed a long-range allosteric communication between the residue E64, located at the N-terminal domain, and the metal cation binding site EF3, located at the C-terminal domain. The conservative E64D mutation breaks up such inter-domain communication resulting in the impaired ability of CIB2 to switch to its Mg2+-bound form. The ability to bind the target integrin peptide was substantially conserved for E64D CIB2, thus suggesting that the molecular defect associated with USH1J resides in its inability to sense Mg2+ and adopt the required conformation.
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Affiliation(s)
- Rosario Vallone
- Section of Biological Chemistry, Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Giuditta Dal Cortivo
- Section of Biological Chemistry, Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | | | - Daniele Dell'Orco
- Section of Biological Chemistry, Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
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