1
|
Minckley TF, Salvagio LA, Fudge DH, Verhey K, Markus SM, Qin Y. Zn2+ decoration of microtubules arrests axonal transport and displaces tau, doublecortin, and MAP2C. J Cell Biol 2023; 222:e202208121. [PMID: 37326602 PMCID: PMC10276529 DOI: 10.1083/jcb.202208121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Revised: 03/31/2023] [Accepted: 05/11/2023] [Indexed: 06/17/2023] Open
Abstract
Intracellular Zn2+ concentrations increase via depolarization-mediated influx or intracellular release, but the immediate effects of Zn2+ signals on neuron function are not fully understood. By simultaneous recording of cytosolic Zn2+ and organelle motility, we find that elevated Zn2+ (IC50 ≈ 5-10 nM) reduces both lysosomal and mitochondrial motility in primary rat hippocampal neurons and HeLa cells. Using live-cell confocal microscopy and in vitro single-molecule TIRF imaging, we reveal that Zn2+ inhibits activity of motor proteins (kinesin and dynein) without disrupting their microtubule binding. Instead, Zn2+ directly binds to microtubules and selectively promotes detachment of tau, DCX, and MAP2C, but not MAP1B, MAP4, MAP7, MAP9, or p150glued. Bioinformatic predictions and structural modeling show that the Zn2+ binding sites on microtubules partially overlap with the microtubule binding sites of tau, DCX, dynein, and kinesin. Our results reveal that intraneuronal Zn2+ regulates axonal transport and microtubule-based processes by interacting with microtubules.
Collapse
Affiliation(s)
- Taylor F. Minckley
- Department of Biological Sciences, University of Denver, Denver, CO, USA
| | | | - Dylan H. Fudge
- Department of Biological Sciences, University of Denver, Denver, CO, USA
| | - Kristen Verhey
- Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, MI, USA
| | - Steven M. Markus
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO, USA
| | - Yan Qin
- Department of Biological Sciences, University of Denver, Denver, CO, USA
| |
Collapse
|
2
|
Rakshit A, Holtzen SE, Lo MN, Conway KA, Palmer AE. Human cells experience a Zn 2+ pulse in early G1. Cell Rep 2023; 42:112656. [PMID: 37330912 PMCID: PMC10592493 DOI: 10.1016/j.celrep.2023.112656] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 05/07/2023] [Accepted: 05/31/2023] [Indexed: 06/20/2023] Open
Abstract
Zinc is an essential micronutrient required for all domains of life. Cells maintain zinc homeostasis using a network of transporters, buffers, and transcription factors. Zinc is required for mammalian cell proliferation, and zinc homeostasis is remodeled during the cell cycle, but whether labile zinc changes in naturally cycling cells has not been established. We use genetically encoded fluorescent reporters, long-term time-lapse imaging, and computational tools to track labile zinc over the cell cycle in response to changes in growth media zinc and knockdown of the zinc-regulatory transcription factor MTF-1. Cells experience a pulse of labile zinc in early G1, whose magnitude varies with zinc in growth media. Knockdown of MTF-1 increases labile zinc and the zinc pulse. Our results suggest that cells need a minimum zinc pulse to proliferate and that if labile zinc levels are too high, cells pause proliferation until labile cellular zinc is lowered.
Collapse
Affiliation(s)
- Ananya Rakshit
- Department of Biochemistry and BioFrontiers Institute, 3415 Colorado Avenue, University of Colorado Boulder, Boulder, CO 80303, USA
| | - Samuel E Holtzen
- Department of Molecular Cellular Developmental Biology and BioFrontiers Institute, University of Colorado Boulder, Boulder, CO 80309, USA
| | - Maria N Lo
- Department of Biochemistry and BioFrontiers Institute, 3415 Colorado Avenue, University of Colorado Boulder, Boulder, CO 80303, USA
| | - Kylie A Conway
- Department of Biochemistry and BioFrontiers Institute, 3415 Colorado Avenue, University of Colorado Boulder, Boulder, CO 80303, USA
| | - Amy E Palmer
- Department of Biochemistry and BioFrontiers Institute, 3415 Colorado Avenue, University of Colorado Boulder, Boulder, CO 80303, USA.
| |
Collapse
|
3
|
Alshawaf AJ, Alnassar SA, Al-Mohanna FA. The interplay of intracellular calcium and zinc ions in response to electric field stimulation in primary rat cortical neurons in vitro. Front Cell Neurosci 2023; 17:1118335. [PMID: 37180947 PMCID: PMC10174245 DOI: 10.3389/fncel.2023.1118335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Accepted: 04/10/2023] [Indexed: 05/16/2023] Open
Abstract
Recent pharmacological studies demonstrate a role for zinc (Zn2+) in shaping intracellular calcium (Ca2+) dynamics and vice versa in excitable cells including neurons and cardiomyocytes. Herein, we sought to examine the dynamic of intracellular release of Ca2+ and Zn2+ upon modifying excitability of primary rat cortical neurons using electric field stimulation (EFS) in vitro. We show that exposure to EFS with an intensity of 7.69 V/cm induces transient membrane hyperpolarization together with transient elevations in the cytosolic levels of Ca2+ and Zn2+ ions. The EFS-induced hyperpolarization was inhibited by prior treatment of cells with the K+ channel opener diazoxide. Chemical hyperpolarization had no apparent effect on either Ca2+ or Zn2+. The source of EFS-induced rise in Ca2+ and Zn2+ seemed to be intracellular, and that the dynamic inferred of an interplay between Ca2+ and Zn2+ ions, whereby the removal of extracellular Ca2+ augmented the release of intracellular Ca2+ and Zn2+ and caused a stronger and more sustained hyperpolarization. We demonstrate that Zn2+ is released from intracellular vesicles located in the soma, with major co-localizations in the lysosomes and endoplasmic reticulum. These studies further support the use of EFS as a tool to interrogate the kinetics of intracellular ions in response to changing membrane potential in vitro.
Collapse
Affiliation(s)
- Abdullah J. Alshawaf
- Department of Physiological Sciences, College of Medicine, Alfaisal University, Riyadh, Saudi Arabia
- Department of Cell Biology, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Sarah A. Alnassar
- Department of Cell Biology, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Futwan A. Al-Mohanna
- Department of Cell Biology, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
- *Correspondence: Futwan A. Al-Mohanna,
| |
Collapse
|
4
|
Goldberg JM, Lippard SJ. Mobile zinc as a modulator of sensory perception. FEBS Lett 2023; 597:151-165. [PMID: 36416529 PMCID: PMC10108044 DOI: 10.1002/1873-3468.14544] [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: 10/10/2022] [Revised: 11/15/2022] [Accepted: 11/16/2022] [Indexed: 11/24/2022]
Abstract
Mobile zinc is an abundant transition metal ion in the central nervous system, with pools of divalent zinc accumulating in regions of the brain engaged in sensory perception and memory formation. Here, we present essential tools that we developed to interrogate the role(s) of mobile zinc in these processes. Most important are (a) fluorescent sensors that report the presence of mobile zinc and (b) fast, Zn-selective chelating agents for measuring zinc flux in animal tissue and live animals. The results of our studies, conducted in collaboration with neuroscientist experts, are presented for sensory organs involved in hearing, smell, vision, and learning and memory. A general principle emerging from these studies is that the function of mobile zinc in all cases appears to be downregulation of the amplitude of the response following overstimulation of the respective sensory organs. Possible consequences affecting human behavior are presented for future investigations in collaboration with interested behavioral scientists.
Collapse
Affiliation(s)
| | - Stephen J Lippard
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA, USA
| |
Collapse
|
5
|
Dischler AM, Maslar D, Zhang C, Qin Y. Development and Characterization of a Red Fluorescent Protein-Based Sensor RZnP1 for the Detection of Cytosolic Zn 2. ACS Sens 2022; 7:3838-3845. [PMID: 36508266 DOI: 10.1021/acssensors.2c01774] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Fluorescent sensors have been developed to record Zn2+ dynamics and measure Zn2+ concentrations within the cell. Most previous efforts on developing single-wavelength sensors are focused on green sensors. Here, we engineer a genetically encoded, single red fluorescent protein-based Zn2+ sensor, Red Zinc Probe (RZnP1), which can detect intracellular concentrations of Zn2+. RZnP1 demonstrates a sensitive response to cytosolic Zn2+ (Kd = 438 pM), decent brightness (quantum yield (QY) = 0.15), good in situ dynamic range (Fmax/Fmin = 4.0), and specificity for Zn2+ over other biologically relevant metal cations. RZnP1 offers a way to image Zn2+ with multiple intracellular ions in tandem. We demonstrate the simultaneous recording of Zn2+ and Ca2+ using RZnP1 alongside the Ca2+ sensor GCaMP5G in HeLa cells. We also use RZnP1 with mito-GZnP2, a green fluorescent protein (GFP)-based mitochondrial Zn2+ sensor, to track Zn2+ dynamics in the cytosol and mitochondria concurrently in rat primary neuron culture. Our work not only expands the toolbox of Zn2+ sensors but also demonstrates techniques for imaging Zn2+ dynamics along with other cations and between multiple subcellular compartments simultaneously.
Collapse
Affiliation(s)
- Anna M Dischler
- Department of Biological Sciences, University of Denver, Denver, Colorado80210, United States
| | - Drew Maslar
- Department of Biological Sciences, University of Denver, Denver, Colorado80210, United States
| | - Chen Zhang
- Department of Biological Sciences, University of Denver, Denver, Colorado80210, United States
| | - Yan Qin
- Department of Biological Sciences, University of Denver, Denver, Colorado80210, United States
| |
Collapse
|
6
|
Zhang C, Dischler A, Glover K, Qin Y. Neuronal signalling of zinc: from detection and modulation to function. Open Biol 2022; 12:220188. [PMID: 36067793 PMCID: PMC9448499 DOI: 10.1098/rsob.220188] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Zinc is an essential trace element that stabilizes protein structures and allosterically modulates a plethora of enzymes, ion channels and neurotransmitter receptors. Labile zinc (Zn2+) acts as an intracellular and intercellular signalling molecule in response to various stimuli, which is especially important in the central nervous system. Zincergic neurons, characterized by Zn2+ deposits in synaptic vesicles and presynaptic Zn2+ release, are found in the cortex, hippocampus, amygdala, olfactory bulb and spinal cord. To provide an overview of synaptic Zn2+ and intracellular Zn2+ signalling in neurons, the present paper summarizes the fluorescent sensors used to detect Zn2+ signals, the cellular mechanisms regulating the generation and buffering of Zn2+ signals, as well as the current perspectives on their pleiotropic effects on phosphorylation signalling, synapse formation, synaptic plasticity, as well as sensory and cognitive function.
Collapse
Affiliation(s)
- Chen Zhang
- Department of Biological Sciences, University of Denver, Denver, CO 80210, USA
| | - Anna Dischler
- Department of Biological Sciences, University of Denver, Denver, CO 80210, USA
| | - Kaitlyn Glover
- Department of Biological Sciences, University of Denver, Denver, CO 80210, USA
| | - Yan Qin
- Department of Biological Sciences, University of Denver, Denver, CO 80210, USA
| |
Collapse
|
7
|
Kawahara M, Tanaka KI, Kato-Negishi M. Crosstalk of copper and zinc in the pathogenesis of vascular dementia. J Clin Biochem Nutr 2022; 71:7-15. [PMID: 35903609 PMCID: PMC9309079 DOI: 10.3164/jcbn.22-40] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Accepted: 05/12/2022] [Indexed: 11/23/2022] Open
Abstract
Copper and zinc are essential for normal brain functions. Both are localized in presynaptic vesicles and are secreted into synaptic clefts during neuronal excitation. Despite their significance, excesses of copper and zinc are neurotoxic. In particular, excess zinc after transient global ischemia plays a central role in the ischemia-induced neurodegeneration and pathogenesis of vascular type senile dementia. We previously found that sub-lethal concentrations of copper remarkably exacerbated zinc-induced neurotoxicity, and we investigated the molecular pathways of copper-enhanced zinc-induced neurotoxicity. The endoplasmic reticulum stress pathway, the stress-activated protein kinases/c-Jun amino-terminal kinases pathway, and mitochondrial energy production failure were revealed to be involved in the neurodegenerative processes. Regarding the upstream factors of these pathways, we focused on copper-derived reactive oxygen species and the disruption of calcium homeostasis. Because excess copper and zinc may be present in the synaptic clefts during ischemia, it is possible that secreted copper and copper-induced reactive oxygen species may enhance zinc neurotoxicity and eventually contribute to the pathogenesis of vascular type senile dementia.
Collapse
Affiliation(s)
- Masahiro Kawahara
- Department of Bio-Analytical Chemistry, Faculty of Pharmacy, Research Institute of Pharmaceutical Sciences, Musashino University, 1-1-20 Shinmachi, Nishitokyo-shi, Tokyo 202-8585, Japan
| | - Ken-Ichiro Tanaka
- Department of Bio-Analytical Chemistry, Faculty of Pharmacy, Research Institute of Pharmaceutical Sciences, Musashino University, 1-1-20 Shinmachi, Nishitokyo-shi, Tokyo 202-8585, Japan
| | - Midori Kato-Negishi
- Department of Bio-Analytical Chemistry, Faculty of Pharmacy, Research Institute of Pharmaceutical Sciences, Musashino University, 1-1-20 Shinmachi, Nishitokyo-shi, Tokyo 202-8585, Japan
| |
Collapse
|
8
|
Abstract
The functions, purposes, and roles of metallothioneins have been the subject of speculations since the discovery of the protein over 60 years ago. This article guides through the history of investigations and resolves multiple contentions by providing new interpretations of the structure-stability-function relationship. It challenges the dogma that the biologically relevant structure of the mammalian proteins is only the one determined by X-ray diffraction and NMR spectroscopy. The terms metallothionein and thionein are ambiguous and insufficient to understand biological function. The proteins need to be seen in their biological context, which limits and defines the chemistry possible. They exist in multiple forms with different degrees of metalation and types of metal ions. The homoleptic thiolate coordination of mammalian metallothioneins is important for their molecular mechanism. It endows the proteins with redox activity and a specific pH dependence of their metal affinities. The proteins, therefore, also exist in different redox states of the sulfur donor ligands. Their coordination dynamics allows a vast conformational landscape for interactions with other proteins and ligands. Many fundamental signal transduction pathways regulate the expression of the dozen of human metallothionein genes. Recent advances in understanding the control of cellular zinc and copper homeostasis are the foundation for suggesting that mammalian metallothioneins provide a highly dynamic, regulated, and uniquely biological metal buffer to control the availability, fluctuations, and signaling transients of the most competitive Zn(II) and Cu(I) ions in cellular space and time.
Collapse
Affiliation(s)
- Artur Krężel
- Department of Chemical Biology, Faculty of Biotechnology, University of Wrocław, Wrocław 50-383, Poland
| | - Wolfgang Maret
- Departments of Biochemistry and Nutritional Sciences, School of Life Course Sciences, Faculty of Life Sciences and Medicine, King's College London, London SE1 9NH, U.K
| |
Collapse
|
9
|
Berríos-Cartagena N, Rubio-Dávila MM, Rivera-Delgado I, Feliciano-Bonilla MM, De Cardona-Juliá EA, Ortiz JG. Effects of Zinc, Mercury, or Lead on [ 3H]MK-801 and [ 3H]Fluorowillardiine Binding to Rat Synaptic Membranes. Neurochem Res 2021; 46:3159-3165. [PMID: 34370167 DOI: 10.1007/s11064-021-03407-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 07/16/2021] [Accepted: 07/19/2021] [Indexed: 11/25/2022]
Abstract
Glutamate (Glu) is considered the most important excitatory amino acid neurotransmitter in the mammalian Central Nervous System. Zinc (Zn) is co-released with Glu during synaptic transmission and interacts with Glutamate receptors and transporters. We performed binding experiments using [3H]MK-801 (NMDA), and [3H]Fluorowillardine (AMPA) as ligands to study Zn-Glutamate interactions in rat cortical synaptic membranes. We also examined the effects of mercury and lead on NMDA or AMPA receptors. Zinc at 1 nM, significantly potentiates [3H]MK-801 binding. Lead inhibits [3H]MK-801 binding at micromolar concentrations. At millimolar concentrations, Hg also has a significant inhibitory effect. These effects are not reversed by Zn (1 nM). Zinc displaces the [3H]FW binding curve to the right. Lead (nM) and Hg (μM) inhibit [3H]FW binding. At certain concentrations, Zn reverses the effects of these metals on [3H]FW binding. These specific interactions serve to clarify the role of Zn, Hg, and Pb in physiological and pathological conditions.
Collapse
Affiliation(s)
- N Berríos-Cartagena
- Department of Pharmacology and Toxicology, University of Puerto Rico School of Medicine, P.O. Box 365067, San Juan, 00936-5067, Puerto Rico
| | - M M Rubio-Dávila
- Department of Pharmacology and Toxicology, University of Puerto Rico School of Medicine, P.O. Box 365067, San Juan, 00936-5067, Puerto Rico
| | - I Rivera-Delgado
- Department of Pharmacology and Toxicology, University of Puerto Rico School of Medicine, P.O. Box 365067, San Juan, 00936-5067, Puerto Rico
| | - M M Feliciano-Bonilla
- Department of Pharmacology and Toxicology, University of Puerto Rico School of Medicine, P.O. Box 365067, San Juan, 00936-5067, Puerto Rico
| | - E A De Cardona-Juliá
- Department of Pharmacology and Toxicology, University of Puerto Rico School of Medicine, P.O. Box 365067, San Juan, 00936-5067, Puerto Rico
| | - J G Ortiz
- Department of Pharmacology and Toxicology, University of Puerto Rico School of Medicine, P.O. Box 365067, San Juan, 00936-5067, Puerto Rico.
| |
Collapse
|