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Vitvitsky V, Kumar R, Diessl J, Hanna DA, Banerjee R. Rapid HPLC method reveals dynamic shifts in coenzyme Q redox state. J Biol Chem 2024:107301. [PMID: 38641068 DOI: 10.1016/j.jbc.2024.107301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2024] [Revised: 04/11/2024] [Accepted: 04/13/2024] [Indexed: 04/21/2024] Open
Abstract
Ubiquinol or coenzyme Q (CoQ) is a lipid-soluble electron carrier in the respiratory chain and an electron acceptor for various enzymes in metabolic pathways that intersect at this cofactor hub in the mitochondrial inner membrane. The reduced form of CoQ is an antioxidant, which protects against lipid peroxidation. In this study, we have optimized a UV-detected HPLC method for CoQ analysis from biological materials, which involves a rapid single-step extraction into n-propanol followed by direct sample injection onto a column. Using this method, we have measured the oxidized, reduced and total CoQ pools, and monitored shifts in the CoQ redox status in response to cell culture conditions and bioenergetic perturbations. We find that hypoxia or sulfide exposure induces a reductive shift in the intracellular CoQ pool. The effect of hypoxia is however, rapidly reversed by exposure to ambient air. Interventions at different loci in the electron transport chain can induce sizeable redox shifts in the oxidative or reductive direction, depending on whether they are up- or downstream of complex III. We have also used this method to confirm that CoQ levels are higher and more reduced in murine heart versus brain. In summary, the availability of a convenient HPLC-based method described herein, will facilitate studies on CoQ redox dynamics in response to environmental, nutritional and endogenous alterations.
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Affiliation(s)
- Victor Vitvitsky
- Department of Biological Chemistry, Michigan Medicine, University of Michigan, Ann Arbor, MI 48109,; Center for Theoretical Problems of Physico-Chemical Pharmacology, Russian Academy of Sciences, Moscow, 109029, Russia
| | - Roshan Kumar
- Department of Biological Chemistry, Michigan Medicine, University of Michigan, Ann Arbor, MI 48109
| | - Jutta Diessl
- Department of Biological Chemistry, Michigan Medicine, University of Michigan, Ann Arbor, MI 48109
| | - David A Hanna
- Department of Biological Chemistry, Michigan Medicine, University of Michigan, Ann Arbor, MI 48109
| | - Ruma Banerjee
- Department of Biological Chemistry, Michigan Medicine, University of Michigan, Ann Arbor, MI 48109,.
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Hanna DA, Diessl J, Guha A, Kumar R, Andren A, Lyssiotis C, Banerjee R. H 2S preconditioning induces long-lived perturbations in O 2 metabolism. Proc Natl Acad Sci U S A 2024; 121:e2319473121. [PMID: 38478695 PMCID: PMC10962982 DOI: 10.1073/pnas.2319473121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Accepted: 01/30/2024] [Indexed: 03/26/2024] Open
Abstract
Hydrogen sulfide exposure in moderate doses can induce profound but reversible hypometabolism in mammals. At a cellular level, H2S inhibits the electron transport chain (ETC), augments aerobic glycolysis, and glutamine-dependent carbon utilization via reductive carboxylation; however, the durability of these changes is unknown. We report that despite its volatility, H2S preconditioning increases P50(O2), the O2 pressure for half-maximal cellular respiration, and has pleiotropic effects on oxidative metabolism that persist up to 24 to 48 h later. Notably, cyanide, another complex IV inhibitor, does not induce this type of metabolic memory. Sulfide-mediated prolonged fractional inhibition of complex IV by H2S is modulated by sulfide quinone oxidoreductase, which commits sulfide to oxidative catabolism. Since induced hypometabolism can be beneficial in disease settings that involve insufficient or interrupted blood flow, our study has important implications for attenuating reperfusion-induced ischemic injury and/or prolonging the shelf life of biologics like platelets.
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Affiliation(s)
- David A. Hanna
- Department of Biological Chemistry, University of Michigan Medical Center, Ann Arbor, MI48109-0600
| | - Jutta Diessl
- Department of Biological Chemistry, University of Michigan Medical Center, Ann Arbor, MI48109-0600
| | - Arkajit Guha
- Department of Biological Chemistry, University of Michigan Medical Center, Ann Arbor, MI48109-0600
| | - Roshan Kumar
- Department of Biological Chemistry, University of Michigan Medical Center, Ann Arbor, MI48109-0600
| | - Anthony Andren
- Department of Molecular and Integrative Physiology, University of Michigan Medical Center, Ann Arbor, MI48109-0600
| | - Costas Lyssiotis
- Department of Molecular and Integrative Physiology, University of Michigan Medical Center, Ann Arbor, MI48109-0600
- Department of Internal Medicine, University of Michigan Medical Center, Ann Arbor, MI48109-0600
- Department of Rogel Cancer Center, University of Michigan Medical Center, Ann Arbor, MI48109-0600
| | - Ruma Banerjee
- Department of Biological Chemistry, University of Michigan Medical Center, Ann Arbor, MI48109-0600
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Chen B, Lynn-Nguyen TM, Jadhav P, Halligan BS, Rossiter NJ, Guerra RM, Koshkin S, Koo I, Morlacchi P, Hanna DA, Lin J, Banerjee R, Pagliarini DJ, Patterson AD, Mosalaganti S, Sexton JZ, Calì T, Lyssiotis CA, Shah YM. BRD4-mediated epigenetic regulation of endoplasmic reticulum-mitochondria contact sites is governed by the mitochondrial complex III. bioRxiv 2024:2024.02.02.578646. [PMID: 38352460 PMCID: PMC10862858 DOI: 10.1101/2024.02.02.578646] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/04/2024]
Abstract
Inter-organellar communication is critical for cellular metabolic homeostasis. One of the most abundant inter-organellar interactions are those at the endoplasmic reticulum and mitochondria contact sites (ERMCS). However, a detailed understanding of the mechanisms governing ERMCS regulation and their roles in cellular metabolism are limited by a lack of tools that permit temporal induction and reversal. Through unbiased screening approaches, we identified fedratinib, an FDA-approved drug, that dramatically increases ERMCS abundance by inhibiting the epigenetic modifier BRD4. Fedratinib rapidly and reversibly modulates mitochondrial and ER morphology and alters metabolic homeostasis. Moreover, ERMCS modulation depends on mitochondria electron transport chain complex III function. Comparison of fedratinib activity to other reported inducers of ERMCS revealed common mechanisms of induction and function, providing clarity and union to a growing body of experimental observations. In total, our results uncovered a novel epigenetic signaling pathway and an endogenous metabolic regulator that connects ERMCS and cellular metabolism.
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Hanna DA, Diessl J, Guha A, Kumar R, Andren A, Lyssiotis C, Banerjee R. H 2 S preconditioning induces long-lived perturbations in O 2 metabolism. bioRxiv 2023:2023.10.20.563353. [PMID: 37904965 PMCID: PMC10614939 DOI: 10.1101/2023.10.20.563353] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/02/2023]
Abstract
Hydrogen sulfide exposure in moderate doses can induce profound but reversible hypometabolism in mammals. At a cellular level, H 2 S inhibits the electron transport chain (ETC), augments aerobic glycolysis, and glutamine-dependent carbon utilization via reductive carboxylation; however, the durability of these changes is unknown. We report that despite its volatility, H 2 S preconditioning increases P 50(O2) , the O 2 pressure for half maximal cellular respiration, and has pleiotropic effects on oxidative metabolism that persist up to 24-48 h later. Notably, cyanide, another complex IV inhibitor, does not induce this type of metabolic memory. Sulfide-mediated prolonged fractional inhibition of complex IV by H 2 S is modulated by sulfide quinone oxidoreductase, which commits sulfide to oxidative catabolism. Since induced hypometabolism can be beneficial in disease settings that involve insufficient or interrupted blood flow, our study has important implications for attenuating reperfusion-induced ischemic injury, and/or prolonging shelf life of biologics like platelets.
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5
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Hanna DA, Vitvitsky V, Banerjee R. A growth chamber for chronic exposure of mammalian cells to H 2S. Anal Biochem 2023; 673:115191. [PMID: 37207973 PMCID: PMC10668543 DOI: 10.1016/j.ab.2023.115191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 04/30/2023] [Accepted: 05/17/2023] [Indexed: 05/21/2023]
Abstract
H2S is a redox-active signaling molecule that exerts an array of cellular and physiological effects. While intracellular H2S concentrations are estimated to be in the low nanomolar range, intestinal luminal concentrations can be significantly higher due to microbial metabolism. Studies assessing H2S effects are typically conducted with a bolus treatment with sulfide salts or slow releasing sulfide donors, which are limited by the volatility of H2S, and by potential off-target effects of the donor molecules. To address these limitations, we describe the design and performance of a mammalian cell culture incubator for sustained exposure to 20-500 ppm H2S (corresponding to a dissolved sulfide concentrations of ∼4-120 μM in the cell culture medium). We report that colorectal adenocarcinoma HT29 cells tolerate prolonged exposure to H2S with no effect on cell viability after 24 h although ≥50 ppm H2S (∼10 μM) restricts cell proliferation. Even the lowest concentration of H2S used in this study (i.e. ∼4 μM) significantly enhanced glucose consumption and lactate production, revealing a much lower threshold for impacting cellular energy metabolism and activating aerobic glycolysis than has been previously appreciated from studies with bolus H2S treatment regimens.
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Affiliation(s)
- David A Hanna
- Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, MI, 48109-0600, USA
| | - Victor Vitvitsky
- Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, MI, 48109-0600, USA; Center for Theoretical Problems of Physico-Chemical Pharmacology, Russian Academy of Sciences, Moscow, 109029, Russia
| | - Ruma Banerjee
- Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, MI, 48109-0600, USA.
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Kim H, Moore CM, Mestre-Fos S, Hanna DA, Williams LD, Reddi AR, Torres MP. Depletion assisted hemin affinity (DAsHA) proteomics reveals an expanded landscape of heme-binding proteins in the human proteome. Metallomics 2023; 15:6994529. [PMID: 36669767 PMCID: PMC10022665 DOI: 10.1093/mtomcs/mfad004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Accepted: 01/19/2023] [Indexed: 01/22/2023]
Abstract
Heme b (iron protoporphyrin IX) plays important roles in biology as a metallocofactor and signaling molecule. However, the targets of heme signaling and the network of proteins that mediate the exchange of heme from sites of synthesis or uptake to heme dependent or regulated proteins are poorly understood. Herein, we describe a quantitative mass spectrometry (MS)-based chemoproteomics strategy to identify exchange labile hemoproteins in human embryonic kidney HEK293 cells that may be relevant to heme signaling and trafficking. The strategy involves depleting endogenous heme with the heme biosynthetic inhibitor succinylacetone (SA), leaving putative heme-binding proteins in their apo-state, followed by the capture of those proteins using hemin-agarose resin, and finally elution and identification by MS. By identifying only those proteins that interact with high specificity to hemin-agarose relative to control beaded agarose in an SA-dependent manner, we have expanded the number of proteins and ontologies that may be involved in binding and buffering labile heme or are targets of heme signaling. Notably, these include proteins involved in chromatin remodeling, DNA damage response, RNA splicing, cytoskeletal organization, and vesicular trafficking, many of which have been associated with heme through complementary studies published recently. Taken together, these results provide support for the emerging role of heme in an expanded set of cellular processes from genome integrity to protein trafficking and beyond.
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Affiliation(s)
- Hyojung Kim
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Courtney M Moore
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Santi Mestre-Fos
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - David A Hanna
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Loren Dean Williams
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Amit R Reddi
- Correspondence: Amit R. Reddi, School of Chemistry and Biochemistry, Georgia Institute of Technology, 950 Atlantic Dr. Atlanta, GA 30033. E-mail:
| | - Matthew P Torres
- Correspondence: Matthew P. Torres, School of Biological Sciences, Georgia Institute of Technology, 950 Atlantic Dr. Atlanta, GA 30033. E-mail:
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Hanna DA, Moore CM, Liu L, Yuan X, Dominic IM, Fleischhacker AS, Hamza I, Ragsdale SW, Reddi AR. Heme oxygenase-2 (HO-2) binds and buffers labile ferric heme in human embryonic kidney cells. J Biol Chem 2021; 298:101549. [PMID: 34973332 PMCID: PMC8808069 DOI: 10.1016/j.jbc.2021.101549] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Revised: 12/22/2021] [Accepted: 12/23/2021] [Indexed: 01/13/2023] Open
Abstract
Heme oxygenases (HOs) detoxify heme by oxidatively degrading it into carbon monoxide, iron, and biliverdin, which is reduced to bilirubin and excreted. Humans express two isoforms of HO: the inducible HO-1, which is upregulated in response to excess heme and other stressors, and the constitutive HO-2. Much is known about the regulation and physiological function of HO-1, whereas comparatively little is known about the role of HO-2 in regulating heme homeostasis. The biochemical necessity for expressing constitutive HO-2 is dependent on whether heme is sufficiently abundant and accessible as a substrate under conditions in which HO-1 is not induced. By measuring labile heme, total heme, and bilirubin in human embryonic kidney HEK293 cells with silenced or overexpressed HO-2, as well as various HO-2 mutant alleles, we found that endogenous heme is too limiting a substrate to observe HO-2-dependent heme degradation. Rather, we discovered a novel role for HO-2 in the binding and buffering of heme. Taken together, in the absence of excess heme, we propose that HO-2 regulates heme homeostasis by acting as a heme buffering factor that controls heme bioavailability. When heme is in excess, HO-1 is induced, and both HO-2 and HO-1 can provide protection from heme toxicity via enzymatic degradation. Our results explain why catalytically inactive mutants of HO-2 are cytoprotective against oxidative stress. Moreover, the change in bioavailable heme due to HO-2 overexpression, which selectively binds ferric over ferrous heme, is consistent with labile heme being oxidized, thereby providing new insights into heme trafficking and signaling.
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Affiliation(s)
- David A. Hanna
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Courtney M. Moore
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Liu Liu
- Department of Biological Chemistry, University of Michigan, Ann Arbor, Michigan, USA
| | - Xiaojing Yuan
- Department of Animal and Avian Sciences, Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, Maryland, USA
| | - Iramofu M. Dominic
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia, USA
| | | | - Iqbal Hamza
- Department of Animal and Avian Sciences, Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, Maryland, USA
| | - Stephen W. Ragsdale
- Department of Biological Chemistry, University of Michigan, Ann Arbor, Michigan, USA
| | - Amit R. Reddi
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia, USA,School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia, USA,Parker Petit Institute for Bioengineering and Biosciences, Georgia Institute of Technology, Atlanta, Georgia, USA,For correspondence: Amit R. Reddi
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8
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Carballal S, Vitvitsky V, Kumar R, Hanna DA, Libiad M, Gupta A, Jones JW, Banerjee R. Hydrogen sulfide stimulates lipid biogenesis from glutamine that is dependent on the mitochondrial NAD(P)H pool. J Biol Chem 2021; 297:100950. [PMID: 34252456 PMCID: PMC8342795 DOI: 10.1016/j.jbc.2021.100950] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Revised: 06/24/2021] [Accepted: 07/08/2021] [Indexed: 11/04/2022] Open
Abstract
Mammalian cells synthesize H2S from sulfur-containing amino acids and are also exposed to exogenous sources of this signaling molecule, notably from gut microbes. As an inhibitor of complex IV in the electron transport chain, H2S can have a profound impact on metabolism, suggesting the hypothesis that metabolic reprogramming is a primary mechanism by which H2S signals. In this study, we report that H2S increases lipogenesis in many cell types, using carbon derived from glutamine rather than from glucose. H2S-stimulated lipid synthesis is sensitive to the mitochondrial NAD(P)H pools and is enabled by reductive carboxylation of α-ketoglutarate. Lipidomics analysis revealed that H2S elicits time-dependent changes across several lipid classes, e.g., upregulating triglycerides while downregulating phosphatidylcholine. Direct analysis of triglyceride concentration revealed that H2S induces a net increase in the size of this lipid pool. These results provide a mechanistic framework for understanding the effects of H2S on increasing lipid droplets in adipocytes and population studies that have pointed to a positive correlation between cysteine (a substrate for H2S synthesis) and fat mass.
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Affiliation(s)
- Sebastian Carballal
- Department of Biological Chemistry, Michigan Medicine, University of Michigan, Ann Arbor, Michigan, USA; Departamento de Bioquímica, Facultad de Medicina and Centro de Investigaciones Biomédicas (CEINBIO), Universidad de la República, Montevideo, Uruguay
| | - Victor Vitvitsky
- Department of Biological Chemistry, Michigan Medicine, University of Michigan, Ann Arbor, Michigan, USA
| | - Roshan Kumar
- Department of Biological Chemistry, Michigan Medicine, University of Michigan, Ann Arbor, Michigan, USA
| | - David A Hanna
- Department of Biological Chemistry, Michigan Medicine, University of Michigan, Ann Arbor, Michigan, USA
| | - Marouane Libiad
- Department of Biological Chemistry, Michigan Medicine, University of Michigan, Ann Arbor, Michigan, USA
| | - Aditi Gupta
- Department of Biological Chemistry, Michigan Medicine, University of Michigan, Ann Arbor, Michigan, USA
| | - Jace W Jones
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, Maryland, USA
| | - Ruma Banerjee
- Department of Biological Chemistry, Michigan Medicine, University of Michigan, Ann Arbor, Michigan, USA.
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Donegan RK, Moore CM, Hanna DA, Reddi AR. Handling heme: The mechanisms underlying the movement of heme within and between cells. Free Radic Biol Med 2019; 133:88-100. [PMID: 30092350 PMCID: PMC6363905 DOI: 10.1016/j.freeradbiomed.2018.08.005] [Citation(s) in RCA: 79] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Revised: 07/31/2018] [Accepted: 08/01/2018] [Indexed: 02/02/2023]
Abstract
Heme is an essential cofactor and signaling molecule required for virtually all aerobic life. However, excess heme is cytotoxic. Therefore, heme must be safely transported and trafficked from the site of synthesis in the mitochondria or uptake at the cell surface, to hemoproteins in most subcellular compartments. While heme synthesis and degradation are relatively well characterized, little is known about how heme is trafficked and transported throughout the cell. Herein, we review eukaryotic heme transport, trafficking, and mobilization, with a focus on factors that regulate bioavailable heme. We also highlight the role of gasotransmitters and small molecules in heme mobilization and bioavailability, and heme trafficking at the host-pathogen interface.
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Affiliation(s)
- Rebecca K Donegan
- School of Chemistry & Biochemistry, Georgia Institute of Technology, Atlanta, GA 30332, United States
| | - Courtney M Moore
- School of Chemistry & Biochemistry, Georgia Institute of Technology, Atlanta, GA 30332, United States
| | - David A Hanna
- School of Chemistry & Biochemistry, Georgia Institute of Technology, Atlanta, GA 30332, United States
| | - Amit R Reddi
- School of Chemistry & Biochemistry, Georgia Institute of Technology, Atlanta, GA 30332, United States; School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA 30332, United States; Parker Petit Institute for Bioengineering & Biosciences, Georgia Institute of Technology, Atlanta, GA 30332, United States.
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Hanna DA, Hu R, Kim H, Martinez-Guzman O, Torres MP, Reddi AR. Heme bioavailability and signaling in response to stress in yeast cells. J Biol Chem 2018; 293:12378-12393. [PMID: 29921585 DOI: 10.1074/jbc.ra118.002125] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2018] [Revised: 06/15/2018] [Indexed: 12/28/2022] Open
Abstract
Protoheme (hereafter referred to as heme) is an essential cellular cofactor and signaling molecule that is also potentially cytotoxic. To mitigate heme toxicity, heme synthesis and degradation are tightly coupled to heme utilization in order to limit the intracellular concentration of "free" heme. Such a model, however, would suggest that a readily accessible steady-state, bioavailable labile heme (LH) pool is not required for supporting heme-dependent processes. Using the yeast Saccharomyces cerevisiae as a model and fluorescent heme sensors, site-specific heme chelators, and molecular genetic approaches, we found here that 1) yeast cells preferentially use LH in heme-depleted conditions; 2) sequestration of cytosolic LH suppresses heme signaling; and 3) lead (Pb2+) stress contributes to a decrease in total heme, but an increase in LH, which correlates with increased heme signaling. We also observed that the proteasome is involved in the regulation of the LH pool and that loss of proteasomal activity sensitizes cells to Pb2+ effects on heme homeostasis. Overall, these findings suggest an important role for LH in supporting heme-dependent functions in yeast physiology.
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Affiliation(s)
| | - Rebecca Hu
- From the School of Chemistry and Biochemistry
| | - Hyojung Kim
- From the School of Chemistry and Biochemistry.,School of Biological Sciences, and
| | | | - Matthew P Torres
- School of Biological Sciences, and.,Parker Petit Institute for Bioengineering and Biosciences, Georgia Institute of Technology, Atlanta, Georgia 30332
| | - Amit R Reddi
- From the School of Chemistry and Biochemistry, .,Parker Petit Institute for Bioengineering and Biosciences, Georgia Institute of Technology, Atlanta, Georgia 30332
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Hanna DA, Martinez-Guzman O, Reddi AR. Heme Gazing: Illuminating Eukaryotic Heme Trafficking, Dynamics, and Signaling with Fluorescent Heme Sensors. Biochemistry 2017; 56:1815-1823. [PMID: 28316240 DOI: 10.1021/acs.biochem.7b00007] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Heme (iron protoporphyrin IX) is an essential protein prosthetic group and signaling molecule required for most life on Earth. All heme-dependent processes require the dynamic and rapid mobilization of heme from sites of synthesis or uptake to hemoproteins present in virtually every subcellular compartment. The cytotoxicity and hydrophobicity of heme necessitate that heme mobilization be carefully controlled to mitigate the deleterious effects of this essential toxin. Indeed, a number of disorders, including certain cancers, cardiovascular diseases, and aging and age-related neurodegenerative diseases, are tied to defects in heme homeostasis. However, the molecules and mechanisms that mediate heme transport and trafficking, and the dynamics of these processes, are poorly understood. This is in large part due to the lack of physical tools for probing cellular heme. Herein, we discuss the recent development of fluorescent probes that can monitor and image kinetically labile heme with respect to its mobilization and role in signaling. In particular, we will highlight how heme gazing with these tools can uncover new heme trafficking factors upon being integrated with genetic screens and illuminate the concentration, subcellular distribution, and dynamics of labile heme in various physiological contexts. Altogether, the monitoring of labile heme, along with recent biochemical and cell biological studies demonstrating the reversible regulation of certain cellular processes by heme, is challenging us to reconceptualize heme from being a static cofactor buried in protein active sites to a dynamic and mobile signaling molecule.
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Affiliation(s)
- David A Hanna
- School of Chemistry and Biochemistry and Parker H. Petit Institute for Bioengineering and Biosciences, Georgia Institute of Technology , Atlanta, Georgia 30332, United States
| | - Osiris Martinez-Guzman
- School of Chemistry and Biochemistry and Parker H. Petit Institute for Bioengineering and Biosciences, Georgia Institute of Technology , Atlanta, Georgia 30332, United States
| | - Amit R Reddi
- School of Chemistry and Biochemistry and Parker H. Petit Institute for Bioengineering and Biosciences, Georgia Institute of Technology , Atlanta, Georgia 30332, United States
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Yeh CH, Hanna DA, Everett GW, Himes RH. Nuclear magnetic resonance relaxation studies of the interaction of ligands with the monomer and tetramer forms of formyltetrahydrofolate synthetase. Biochem J 1988; 251:89-93. [PMID: 3390163 PMCID: PMC1148967 DOI: 10.1042/bj2510089] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Previous work using n.m.r. spectroscopy to investigate the binding between formyltetrahydrofolate synthetase and its ligands was done using the catalytically active tetrameric form of the enzyme. By removal of specific monovalent cations the tetramer dissociates to four identical, catalytically inactive monomers, which are capable of binding nucleotides with affinities similar to those obtained with the tetramer. In the studies reported here, we examined the interaction of metal-nucleotide, formate and monovalent cations with the monomer using n.m.r. relaxation measurements. We were able to demonstrate that formate binds to the monomer. The spin-lattice relaxation rate (1/T1) of the formate carbon in the monomer.M2+.ADP.formate complex is enhanced when Mg2+ is replaced by Mn2+. By assuming that the exchange of formate is not rate-limiting and that tau c of the monomer is the same as that of the tetramer, the distance between the Mn2+ and the formate carbon was calculated and found to be similar in the monomer and tetramer complexes. The spin-lattice relaxation rates of [13C]trimethylammonium ion (an inactive monovalent cation), [13C]methylammonium and [15N]ammonium ions (both active monovalent cations), were measured in the presence of tetramer, MnADP and formate. The relaxation rates of methylammonium and ammonium ions were enhanced under these conditions whereas the relaxation rate of trimethylammonium ion was not. The results indicate that the active monovalent cations bind near the MnADP binding site. A distance from the Mn2+ to the ammonium nitrogen of between 0.5 and 0.6 nm was calculated.
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Affiliation(s)
- C H Yeh
- Department of Biochemistry, University of Kansas, Lawrence 66045
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