1
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García-Guerrero AE, Marvin RG, Blackwell AM, Sigala PA. Biogenesis of cytochromes c and c 1 in the electron transport chain of malaria parasites. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.01.575742. [PMID: 38352463 PMCID: PMC10862854 DOI: 10.1101/2024.02.01.575742] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/16/2024]
Abstract
Plasmodium malaria parasites retain an essential mitochondrional electron transport chain (ETC) that is critical for growth within humans and mosquitoes and a key antimalarial drug target. ETC function requires cytochromes c and c 1 that are unusual among heme proteins due to their covalent binding to heme via conserved CXXCH sequence motifs. Heme attachment to these proteins in most eukaryotes requires the mitochondrial enzyme holocytochrome c synthase (HCCS) that binds heme and the apo cytochrome to facilitate biogenesis of the mature cytochrome c or c 1. Although humans encode a single bifunctional HCCS that attaches heme to both proteins, Plasmodium parasites are like yeast and encode two separate HCCS homologs thought to be specific for heme attachment to cyt c (HCCS) or cyt c 1 (HCC1S). To test the function and specificity of P. falciparum HCCS and HCC1S, we used CRISPR/Cas9 to tag both genes for conditional expression. HCC1S knockdown selectively impaired cyt c 1 biogenesis and caused lethal ETC dysfunction that was not reversed by over-expression of HCCS. Knockdown of HCCS caused a more modest growth defect but strongly sensitized parasites to mitochondrial depolarization by proguanil, revealing key defects in ETC function. These results and prior heterologous studies in E. coli of cyt c hemylation by P. falciparum HCCS and HCC1S strongly suggest that both homologs are essential for mitochondrial ETC function and have distinct specificities for biogenesis of cyt c and c 1, respectively, in parasites. This study lays a foundation to develop novel strategies to selectively block ETC function in malaria parasites.
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Affiliation(s)
| | - Rebecca G. Marvin
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT, USA
| | - Amanda Mixon Blackwell
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT, USA
| | - Paul A. Sigala
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT, USA
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2
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Li H, Akella S, Engstler C, Omini JJ, Rodriguez M, Obata T, Carrie C, Cerutti H, Mower JP. Recurrent evolutionary switches of mitochondrial cytochrome c maturation systems in Archaeplastida. Nat Commun 2024; 15:1548. [PMID: 38378784 PMCID: PMC10879542 DOI: 10.1038/s41467-024-45813-y] [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: 06/15/2023] [Accepted: 02/05/2024] [Indexed: 02/22/2024] Open
Abstract
Mitochondrial cytochrome c maturation (CCM) requires heme attachment via distinct pathways termed systems I and III. The mosaic distribution of these systems in Archaeplastida raises questions about the genetic mechanisms and evolutionary forces promoting repeated evolution. Here, we show a recurrent shift from ancestral system I to the eukaryotic-specific holocytochrome c synthase (HCCS) of system III in 11 archaeplastid lineages. Archaeplastid HCCS is sufficient to rescue mutants of yeast system III and Arabidopsis system I. Algal HCCS mutants exhibit impaired growth and respiration, and altered biochemical and metabolic profiles, likely resulting from deficient CCM and reduced cytochrome c-dependent respiratory activity. Our findings demonstrate that archaeplastid HCCS homologs function as system III components in the absence of system I. These results elucidate the evolutionary trajectory and functional divergence of CCM pathways in Archaeplastida, providing insight into the causes, mechanisms, and consequences of repeated cooption of an entire biological pathway.
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Affiliation(s)
- Huang Li
- Center for Plant Science Innovation, University of Nebraska-Lincoln, Lincoln, NE, 68588, USA
| | - Soujanya Akella
- Center for Plant Science Innovation, University of Nebraska-Lincoln, Lincoln, NE, 68588, USA
- School of Biological Sciences, University of Nebraska-Lincoln, Lincoln, NE, 68588, USA
| | - Carina Engstler
- Department Biologie I-Botanik, Ludwig-Maximilians-Universität München, D-82152, Planegg-Martinsried, Germany
| | - Joy J Omini
- Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, NE, 68588, USA
| | - Moira Rodriguez
- School of Biological Sciences, University of Nebraska-Lincoln, Lincoln, NE, 68588, USA
| | - Toshihiro Obata
- Center for Plant Science Innovation, University of Nebraska-Lincoln, Lincoln, NE, 68588, USA
- Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, NE, 68588, USA
| | - Chris Carrie
- School of Biological Sciences, University of Auckland, Auckland, 1142, New Zealand
| | - Heriberto Cerutti
- Center for Plant Science Innovation, University of Nebraska-Lincoln, Lincoln, NE, 68588, USA
- School of Biological Sciences, University of Nebraska-Lincoln, Lincoln, NE, 68588, USA
| | - Jeffrey P Mower
- Center for Plant Science Innovation, University of Nebraska-Lincoln, Lincoln, NE, 68588, USA.
- Department of Agronomy and Horticulture, University of Nebraska-Lincoln, Lincoln, NE, 68583, USA.
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3
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Huynh JQ, Lowder EP, Kranz RG. Structural basis of membrane machines that traffick and attach heme to cytochromes. J Biol Chem 2023; 299:105332. [PMID: 37827288 PMCID: PMC10663686 DOI: 10.1016/j.jbc.2023.105332] [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: 08/31/2023] [Revised: 10/04/2023] [Accepted: 10/06/2023] [Indexed: 10/14/2023] Open
Abstract
We evaluate cryoEM and crystal structures of two molecular machines that traffick heme and attach it to cytochrome c (cyt c), the second activity performed by a cyt c synthase. These integral membrane proteins, CcsBA and CcmF/H, both covalently attach heme to cyt c, but carry it out via different mechanisms. A CcsB-CcsA complex transports heme through a channel to its external active site, where it forms two thioethers between reduced (Fe+2) heme and CysXxxXxxCysHis in cyt c. The active site is formed by a periplasmic WWD sequence and two histidines (P-His1 and P-His2). We evaluate each proposed functional domain in CcsBA cryoEM densities, exploring their presence in other CcsB-CcsA proteins from a wide distribution of organisms (e.g., from Gram positive to Gram negative bacteria to chloroplasts.) Two conserved pockets, for the first and second cysteines of CXXCH, explain stereochemical heme attachment. In addition to other universal features, a conserved periplasmic beta stranded structure, called the beta cap, protects the active site when external heme is not present. Analysis of CcmF/H, here called an oxidoreductase and cyt c synthase, addresses mechanisms of heme access and attachment. We provide evidence that CcmF/H receives Fe+3 heme from holoCcmE via a periplasmic entry point in CcmF, whereby heme is inserted directly into a conserved WWD/P-His domain from above. Evidence suggests that CcmF acts as a heme reductase, reducing holoCcmE (to Fe+2) through a transmembrane electron transfer conduit, which initiates a complicated series of events at the active site.
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Affiliation(s)
- Jonathan Q Huynh
- Department of Biology, Washington University, St. Louis, Missouri, USA
| | - Ethan P Lowder
- Department of Biology, Washington University, St. Louis, Missouri, USA
| | - Robert G Kranz
- Department of Biology, Washington University, St. Louis, Missouri, USA.
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4
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Genceroglu MY, Cavdar C, Manioglu S, Bayraktar H. Genetically Encoded Fluorescent Probe for Detection of Heme-Induced Conformational Changes in Cytochrome c. BIOSENSORS 2023; 13:890. [PMID: 37754124 PMCID: PMC10526477 DOI: 10.3390/bios13090890] [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] [Received: 08/08/2023] [Revised: 09/11/2023] [Accepted: 09/14/2023] [Indexed: 09/28/2023]
Abstract
Cytochrome c (Cytc) is a key redox protein for energy metabolism and apoptosis in cells. The activation of Cytc is composed of several steps, including its transfer to the mitochondrial membrane, binding to cytochrome c heme lyase (CCHL) and covalent attachment to heme. The spectroscopic methods are often applied to study the structural changes of Cytc. However, they require the isolation of Cytc from cells and have limited availability under physiological conditions. Despite recent studies to elucidate the tightly regulated folding mechanism of Cytc, the role of these events and their association with different conformational states remain elusive. Here, we provide a genetically encoded fluorescence method that allows monitoring of the conformational changes of Cytc upon binding to heme and CCHL. Cerulean and Venus fluorescent proteins attached at the N and C terminals of Cytc can be used to determine its unfolded, intermediate, and native states by measuring FRET amplitude. We found that the noncovalent interaction of heme in the absence of CCHL induced a shift in the FRET signal, indicating the formation of a partially folded state. The higher concentration of heme and coexpression of CCHL gave rise to the recovery of Cytc native structure. We also found that Cytc was weakly associated with CCHL in the absence of heme. As a result, a FRET-based fluorescence approach was demonstrated to elucidate the mechanism of heme-induced Cytc conformational changes with spatiotemporal resolution and can be applied to study its interaction with small molecules and other protein partners in living cells.
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Affiliation(s)
- Mehmet Yunus Genceroglu
- Department of Molecular Biology and Genetics, Istanbul Technical University, Istanbul 34467, Turkey
| | - Cansu Cavdar
- Department of Molecular Biology and Genetics, Istanbul Technical University, Istanbul 34467, Turkey
| | - Selen Manioglu
- Biomedical Science and Engineering Program, Koç University, Istanbul 34450, Turkey
| | - Halil Bayraktar
- Department of Molecular Biology and Genetics, Istanbul Technical University, Istanbul 34467, Turkey
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5
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WANG M, ZHANG W, WANG N. Covalent flavoproteins: types, occurrence, biogenesis and catalytic mechanisms. Chin J Nat Med 2022; 20:749-760. [DOI: 10.1016/s1875-5364(22)60194-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2022] [Indexed: 11/03/2022]
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Silva AV, Firmino MO, Costa NL, Louro RO, Paquete CM. Investigation of the Molecular Mechanisms of the Eukaryotic Cytochrome-c Maturation System. Biomolecules 2022; 12:biom12040549. [PMID: 35454139 PMCID: PMC9028165 DOI: 10.3390/biom12040549] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Revised: 04/04/2022] [Accepted: 04/05/2022] [Indexed: 02/01/2023] Open
Abstract
Cytochromes-c are ubiquitous heme proteins with enormous impact at the cellular level, being key players in metabolic processes such as electron transfer chains and apoptosis. The assembly of these proteins requires maturation systems that catalyse the formation of the covalent thioether bond between two cysteine residues and the vinyl groups of the heme. System III is the maturation system present in Eukaryotes, designated CcHL or HCCS. This System requires a specific amino acid sequence in the apocytochrome to be recognized as a substrate and for heme insertion. To explore the recognition mechanisms of CcHL, the bacterial tetraheme cytochrome STC from Shewanella oneidensis MR-1, which is not a native substrate for System III, was mutated to be identified as a substrate. The results obtained show that it is possible to convert a bacterial cytochrome as a substrate by CcHL, but the presence of the recognition sequence is not the only factor that induces the maturation of a holocytochrome by System III. The location of this sequence in the polypeptide also plays a role in the maturation of the c-type cytochrome. Furthermore, CcHL appears to be able to catalyse the binding of only one heme per polypeptide chain, being unable to assemble multiheme cytochromes c, in contrast with bacterial maturation systems.
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7
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Li L, Thompson J, Hu Y, Lesnefsky EJ, Willard B, Chen Q. Calpain-mediated protein targets in cardiac mitochondria following ischemia-reperfusion. Sci Rep 2022; 12:138. [PMID: 34997008 PMCID: PMC8741987 DOI: 10.1038/s41598-021-03947-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Accepted: 12/09/2021] [Indexed: 12/30/2022] Open
Abstract
Calpain 1 and 2 (CPN1/2) are calcium-dependent cysteine proteases that exist in cytosol and mitochondria. Pharmacologic inhibition of CPN1/2 decreases cardiac injury during ischemia (ISC)-reperfusion (REP) by improving mitochondrial function. However, the protein targets of CPN1/2 activation during ISC-REP are unclear. CPN1/2 include a large subunit and a small regulatory subunit 1 (CPNS1). Genetic deletion of CPNS1 eliminates the activities of both CPN1 and CPN2. Conditional cardiomyocyte specific CPNS1 deletion mice were used in the present study to clarify the role of CPN1/2 activation in mitochondrial damage during ISC-REP with an emphasis on identifying the potential protein targets of CPN1/2. Isolated hearts from wild type (WT) or CPNS1 deletion mice underwent 25 min in vitro global ISC and 30 min REP. Deletion of CPNS1 led to decreased cytosolic and mitochondrial calpain 1 activation compared to WT. Cardiac injury was decreased in CPNS1 deletion mice following ISC-REP as shown by the decreased infarct size compared to WT. Compared to WT, mitochondrial function was improved in CPNS1 deletion mice following ischemia-reperfusion as shown by the improved oxidative phosphorylation and decreased susceptibility to mitochondrial permeability transition pore opening. H2O2 generation was also decreased in mitochondria from deletion mice following ISC-REP compared to WT. Deletion of CPNS1 also resulted in less cytochrome c and truncated apoptosis inducing factor (tAIF) release from mitochondria. Proteomic analysis of the isolated mitochondria showed that deletion of CPNS1 increased the content of proteins functioning in regulation of mitochondrial calcium homeostasis (paraplegin and sarcalumenin) and complex III activity. These results suggest that activation of CPN1 increases cardiac injury during ischemia-reperfusion by impairing mitochondrial function and triggering cytochrome c and tAIF release from mitochondria into cytosol.
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Affiliation(s)
- Ling Li
- Proteomics Core, Cleveland Clinic, Cleveland, OH, 44195, USA
| | - Jeremy Thompson
- Division of Cardiology, Department of Internal Medicine, Virginia Commonwealth University, Richmond, VA, 23298, USA
| | - Ying Hu
- Division of Cardiology, Department of Internal Medicine, Virginia Commonwealth University, Richmond, VA, 23298, USA
| | - Edward J Lesnefsky
- Division of Cardiology, Department of Internal Medicine, Virginia Commonwealth University, Richmond, VA, 23298, USA
- Department of Biochemistry and Molecular Biology, Virginia Commonwealth University, Richmond, VA, 23298, USA
- Department of Physiology and Biophysics, Virginia Commonwealth University, Richmond, VA, 23298, USA
- McGuire Department of Veterans Affairs Medical Center, Richmond, VA, 23249, USA
| | - Belinda Willard
- Proteomics Core, Cleveland Clinic, Cleveland, OH, 44195, USA
| | - Qun Chen
- Division of Cardiology, Department of Internal Medicine, Virginia Commonwealth University, Richmond, VA, 23298, USA.
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8
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Dietz JV, Fox JL, Khalimonchuk O. Down the Iron Path: Mitochondrial Iron Homeostasis and Beyond. Cells 2021; 10:cells10092198. [PMID: 34571846 PMCID: PMC8468894 DOI: 10.3390/cells10092198] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Revised: 08/22/2021] [Accepted: 08/23/2021] [Indexed: 12/20/2022] Open
Abstract
Cellular iron homeostasis and mitochondrial iron homeostasis are interdependent. Mitochondria must import iron to form iron–sulfur clusters and heme, and to incorporate these cofactors along with iron ions into mitochondrial proteins that support essential functions, including cellular respiration. In turn, mitochondria supply the cell with heme and enable the biogenesis of cytosolic and nuclear proteins containing iron–sulfur clusters. Impairment in cellular or mitochondrial iron homeostasis is deleterious and can result in numerous human diseases. Due to its reactivity, iron is stored and trafficked through the body, intracellularly, and within mitochondria via carefully orchestrated processes. Here, we focus on describing the processes of and components involved in mitochondrial iron trafficking and storage, as well as mitochondrial iron–sulfur cluster biogenesis and heme biosynthesis. Recent findings and the most pressing topics for future research are highlighted.
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Affiliation(s)
- Jonathan V. Dietz
- Department of Biochemistry, University of Nebraska, Lincoln, NE 68588, USA;
| | - Jennifer L. Fox
- Department of Chemistry and Biochemistry, College of Charleston, Charleston, SC 29424, USA;
| | - Oleh Khalimonchuk
- Department of Biochemistry, University of Nebraska, Lincoln, NE 68588, USA;
- Nebraska Redox Biology Center, University of Nebraska, Lincoln, NE 68588, USA
- Fred and Pamela Buffett Cancer Center, Omaha, NE 68198, USA
- Correspondence:
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9
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Brausemann A, Zhang L, Ilcu L, Einsle O. Architecture of the membrane-bound cytochrome c heme lyase CcmF. Nat Chem Biol 2021; 17:800-805. [PMID: 33958791 PMCID: PMC7611092 DOI: 10.1038/s41589-021-00793-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Accepted: 04/06/2021] [Indexed: 02/02/2023]
Abstract
The covalent attachment of one or multiple heme cofactors to cytochrome c protein chains enables cytochrome c proteins to be used in electron transfer and redox catalysis in extracytoplasmic environments. A dedicated heme maturation machinery, whose core component is a heme lyase, scans nascent peptides after Sec-dependent translocation for CXnCH-binding motifs. Here we report the three-dimensional (3D) structure of the heme lyase CcmF, a 643-amino acid integral membrane protein, from Thermus thermophilus. CcmF contains a heme b cofactor at the bottom of a large cavity that opens toward the extracellular side to receive heme groups from the heme chaperone CcmE for cytochrome maturation. A surface groove on CcmF may guide the extended apoprotein to heme attachment at or near a loop containing the functionally essential WXWD motif, which is situated above the putative cofactor binding pocket. The structure suggests heme delivery from within the membrane, redefining the role of the chaperone CcmE.
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10
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Sutherland MC, Mendez DL, Babbitt SE, Tillman DE, Melnikov O, Tran NL, Prizant NT, Collier AL, Kranz RG. In vitro reconstitution reveals major differences between human and bacterial cytochrome c synthases. eLife 2021; 10:64891. [PMID: 33973521 PMCID: PMC8112865 DOI: 10.7554/elife.64891] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Accepted: 03/23/2021] [Indexed: 11/25/2022] Open
Abstract
Cytochromes c are ubiquitous heme proteins in mitochondria and bacteria, all possessing a CXXCH (CysXxxXxxCysHis) motif with covalently attached heme. We describe the first in vitro reconstitution of cytochrome c biogenesis using purified mitochondrial (HCCS) and bacterial (CcsBA) cytochrome c synthases. We employ apocytochrome c and peptide analogs containing CXXCH as substrates, examining recognition determinants, thioether attachment, and subsequent release and folding of cytochrome c. Peptide analogs reveal very different recognition requirements between HCCS and CcsBA. For HCCS, a minimal 16-mer peptide is required, comprised of CXXCH and adjacent alpha helix 1, yet neither thiol is critical for recognition. For bacterial CcsBA, both thiols and histidine are required, but not alpha helix 1. Heme attached peptide analogs are not released from the HCCS active site; thus, folding is important in the release mechanism. Peptide analogs behave as inhibitors of cytochrome c biogenesis, paving the way for targeted control. From tiny bacteria to the tallest trees, most life on Earth carries a protein called cytochrome c, which helps to create the energy that powers up cells. Cytochrome c does so thanks to its heme, a molecule that enables the chemical reactions required for the energy-creating process. Despite both relying on cytochrome c, animals and bacteria differ in the enzyme they use to attach the heme to the cytochrome. Spotting variations in how this ‘cytochrome c synthase’ works would help to find compounds that deactivate the enzyme in bacteria, but not in humans. However, studying cytochrome c synthase in living cells is challenging. To bypass this issue, Sutherland, Mendez, Babbitt et al. successfully reconstituted cytochrome c synthases from humans and bacteria in test tubes. This allowed them to examine in detail which structures the enzymes recognize to spot where to attach the heme onto their target. The experiments revealed that human and bacterial synthases actually rely on different parts of the cytochrome c to orient themselves. Different short compounds could also block either the human or bacterial enzyme. Variations between human and bacterial cytochrome c synthase could lead to new antibiotics which deactivate the cytochrome and kill bacteria while sparing patients. The next step is to identify molecules that specifically interfere with cytochrome c synthase in bacteria, and could be tested in clinical trials.
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Affiliation(s)
- Molly C Sutherland
- Department of Biology, Washington University in St. Louis, St. Louis, United States.,Department of Biological Sciences, University of Delaware, Newark, United States
| | - Deanna L Mendez
- Department of Biology, Washington University in St. Louis, St. Louis, United States
| | - Shalon E Babbitt
- Department of Biology, Washington University in St. Louis, St. Louis, United States
| | - Dustin E Tillman
- Department of Biology, Washington University in St. Louis, St. Louis, United States
| | - Olga Melnikov
- Department of Biology, Washington University in St. Louis, St. Louis, United States
| | - Nathan L Tran
- Department of Biology, Washington University in St. Louis, St. Louis, United States
| | - Noah T Prizant
- Department of Biology, Washington University in St. Louis, St. Louis, United States
| | - Andrea L Collier
- Department of Biology, Washington University in St. Louis, St. Louis, United States
| | - Robert G Kranz
- Department of Biology, Washington University in St. Louis, St. Louis, United States
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11
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Ko YK, Yabushita A, Kobayashi T. Primary Electronic and Vibrational Dynamics of Cytochrome c Observed by Sub-10 fs NUV Laser Pulses. J Phys Chem B 2020; 124:8249-8258. [PMID: 32852960 DOI: 10.1021/acs.jpcb.0c05959] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The primary reaction mechanism of cytochrome c (Cyt c) was elucidated for two redox forms of ferric (oxidized) and ferrous (reduced) Cyt c by measuring their transient absorption (TA) spectra using a homemade sub-10 fs broadband NUV laser pulses system. The TA traces measured in the broad probe wavelength region were analyzed by the global analysis method to study the electronic dynamics. The difference of relaxation dynamics dependent on the excitation bandwidth enabled us to elucidate that the 2.5 ps component in ferrous Cyt c can be assigned to intramolecular vibration energy redistribution and not to vibrational cooling, which was not clear until this work. The temporal resolution of 10 fs observes TA signal modulation caused by the molecular vibration in the time domain, which can be used to calculate the instantaneous frequency of the molecular vibration mode. The observed vibrational dynamics has visualized that the heme structure changes in 0.8 ps for ferric Cyt c and in >1.0 ps for ferrous Cyt c. These estimated lifetimes of vibrational dynamics reflect vibrational relaxation in the ground state of ferric Cyt c and electronic transition from the S2 state to the S1 state in ferrous Cyt c, respectively.
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Affiliation(s)
- Ying Kuan Ko
- Department of Electrophysics, National Chiao-Tung University, Hsinchu 300, Taiwan, R.O.C
| | - Atsushi Yabushita
- Department of Electrophysics, National Chiao-Tung University, Hsinchu 300, Taiwan, R.O.C
| | - Takayoshi Kobayashi
- Department of Electrophysics, National Chiao-Tung University, Hsinchu 300, Taiwan, R.O.C
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12
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From Synthesis to Utilization: The Ins and Outs of Mitochondrial Heme. Cells 2020; 9:cells9030579. [PMID: 32121449 PMCID: PMC7140478 DOI: 10.3390/cells9030579] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Revised: 02/19/2020] [Accepted: 02/23/2020] [Indexed: 12/14/2022] Open
Abstract
Heme is a ubiquitous and essential iron containing metallo-organic cofactor required for virtually all aerobic life. Heme synthesis is initiated and completed in mitochondria, followed by certain covalent modifications and/or its delivery to apo-hemoproteins residing throughout the cell. While the biochemical aspects of heme biosynthetic reactions are well understood, the trafficking of newly synthesized heme—a highly reactive and inherently toxic compound—and its subsequent delivery to target proteins remain far from clear. In this review, we summarize current knowledge about heme biosynthesis and trafficking within and outside of the mitochondria.
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13
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Abstract
The movement or trafficking of heme is critical for cellular functions (e.g., oxygen transport and energy production); however, intracellular heme is tightly regulated due to its inherent cytotoxicity. These factors, combined with the transient nature of transport, have resulted in a lack of direct knowledge on the mechanisms of heme binding and trafficking. Here, we used the cytochrome c biogenesis system II pathway as a model to study heme trafficking. System II is composed of two integral membrane proteins (CcsBA) which function to transport heme across the membrane and stereospecifically position it for covalent attachment to apocytochrome c. We mapped two heme binding domains in CcsBA and suggest a path for heme trafficking. These data, in combination with metagenomic coevolution data, are used to determine a structural model of CcsBA, leading to increased understanding of the mechanisms for heme transport and the cytochrome c synthetase function of CcsBA. Although intracellular heme trafficking must occur for heme protein assembly, only a few heme transporters have been unequivocally discovered and nothing is known about their structure or mechanisms. Cytochrome c biogenesis in prokaryotes requires the transport of heme from inside to outside for stereospecific attachment to cytochrome c via two thioether bonds (at CXXCH). The CcsBA integral membrane protein was shown to transport and attach heme (and thus is a cytochrome c synthetase), but the structure and mechanisms underlying these two activities are poorly understood. We employed a new cysteine/heme crosslinking tool that traps endogenous heme in heme binding sites. We combined these data with a comprehensive imidazole correction approach (for heme ligand interrogation) to map heme binding sites. Results illuminate the process of heme transfer through the membrane to an external binding site (called the WWD domain). Using meta-genomic data (GREMLIN) and Rosetta modeling programs, a structural model of the transmembrane (TM) regions in CcsBA were determined. The heme mapping data were then incorporated to model the TM heme binding site (with TM-His1 and TM-His2 as ligands) and the external heme binding WWD domain (with P-His1 and P-His2 as ligands). Other periplasmic structure/function studies facilitated modeling of the full CcsBA protein as a framework for understanding the mechanisms. Mechanisms are proposed for heme transport from TM-His to WWD/P-His and subsequent stereospecific attachment of heme. A ligand exchange of the P-His1 for histidine of CXXCH at the synthetase active site is suggested.
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14
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Alvarez-Paggi D, Hannibal L, Castro MA, Oviedo-Rouco S, Demicheli V, Tórtora V, Tomasina F, Radi R, Murgida DH. Multifunctional Cytochrome c: Learning New Tricks from an Old Dog. Chem Rev 2017; 117:13382-13460. [DOI: 10.1021/acs.chemrev.7b00257] [Citation(s) in RCA: 135] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Damián Alvarez-Paggi
- Departamento
de Química Inorgánica, Analítica y Química
Física and INQUIMAE (CONICET-UBA), Facultad de Ciencias Exactas
y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pab. 2, piso 1, Buenos Aires C1428EHA, Argentina
| | - Luciana Hannibal
- Department
of Pediatrics, Universitätsklinikum Freiburg, Mathildenstrasse 1, Freiburg 79106, Germany
- Departamento
de Bioquímica and Center for Free Radical and Biomedical Research,
Facultad de Medicina, Universidad de la República, Av.
Gral. Flores 2125, Montevideo 11800, Uruguay
| | - María A. Castro
- Departamento
de Química Inorgánica, Analítica y Química
Física and INQUIMAE (CONICET-UBA), Facultad de Ciencias Exactas
y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pab. 2, piso 1, Buenos Aires C1428EHA, Argentina
| | - Santiago Oviedo-Rouco
- Departamento
de Química Inorgánica, Analítica y Química
Física and INQUIMAE (CONICET-UBA), Facultad de Ciencias Exactas
y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pab. 2, piso 1, Buenos Aires C1428EHA, Argentina
| | - Veronica Demicheli
- Departamento
de Bioquímica and Center for Free Radical and Biomedical Research,
Facultad de Medicina, Universidad de la República, Av.
Gral. Flores 2125, Montevideo 11800, Uruguay
| | - Veronica Tórtora
- Departamento
de Bioquímica and Center for Free Radical and Biomedical Research,
Facultad de Medicina, Universidad de la República, Av.
Gral. Flores 2125, Montevideo 11800, Uruguay
| | - Florencia Tomasina
- Departamento
de Bioquímica and Center for Free Radical and Biomedical Research,
Facultad de Medicina, Universidad de la República, Av.
Gral. Flores 2125, Montevideo 11800, Uruguay
| | - Rafael Radi
- Departamento
de Bioquímica and Center for Free Radical and Biomedical Research,
Facultad de Medicina, Universidad de la República, Av.
Gral. Flores 2125, Montevideo 11800, Uruguay
| | - Daniel H. Murgida
- Departamento
de Química Inorgánica, Analítica y Química
Física and INQUIMAE (CONICET-UBA), Facultad de Ciencias Exactas
y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pab. 2, piso 1, Buenos Aires C1428EHA, Argentina
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15
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Babbitt SE, Hsu J, Mendez DL, Kranz RG. Biosynthesis of Single Thioether c-Type Cytochromes Provides Insight into Mechanisms Intrinsic to Holocytochrome c Synthase (HCCS). Biochemistry 2017; 56:3337-3346. [PMID: 28617588 DOI: 10.1021/acs.biochem.7b00286] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
C-type cytochromes (cyts c) are generally characterized by the presence of two thioether attachments between heme and two cysteine residues within a highly conserved CXXCH motif. Most eukaryotes use the System III cyt c biogenesis pathway composed of holocytochrome c synthase (HCCS) to catalyze thioether formation. Some protozoan organisms express a functionally equivalent, natural variant of cyt c with an XXXCH heme-attachment motif, resulting in a single covalent attachment. Previous studies have shown that recombinant HCCS can produce low levels of the XXXCH single thioether variant. However, cyt c variants containing substitutions at the C-terminal cysteine of the heme-attachment site (i.e., resulting in CXXXH) have never been observed in nature, and attempts to biosynthesize a recombinant version of this cyt c variant have been largely unsuccessful. In this study, we report the biochemical analyses of an HCCS-matured CXXXH cyt c variant, comparing its biosynthesis and properties to those of the XXXCH variant. The results indicate that although HCCS mediates heme attachment to the N-terminal cysteine in CXXXH cyt c variants, up to 50% of the cyt c produced is modified in an oxygen-dependent manner, resulting in a mixed population of cyt c. Since this aerobic modification occurs only in the context of CXXXH, we also propose that natural HCCS-mediated heme attachment to CXXCH likely initiates at the C-terminal cysteine.
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Affiliation(s)
- Shalon E Babbitt
- Department of Biology, Washington University , St. Louis, Missouri 63130, United States
| | - Jennifer Hsu
- Department of Biology, Washington University , St. Louis, Missouri 63130, United States
| | - Deanna L Mendez
- Department of Biology, Washington University , St. Louis, Missouri 63130, United States
| | - Robert G Kranz
- Department of Biology, Washington University , St. Louis, Missouri 63130, United States
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16
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Engineered holocytochrome c synthases that biosynthesize new cytochromes c. Proc Natl Acad Sci U S A 2017; 114:2235-2240. [PMID: 28196881 DOI: 10.1073/pnas.1615929114] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Cytochrome c (cyt c), required for electron transport in mitochondria, possesses a covalently attached heme cofactor. Attachment is catalyzed by holocytochrome c synthase (HCCS), leading to two thioether bonds between heme and a conserved CXXCH motif of cyt c In cyt c, histidine (His19) of CXXCH acts as an axial ligand to heme iron and upon release of holocytochrome c from HCCS, folding leads to formation of a second axial interaction with methionine (Met81). We previously discovered mutations in human HCCS that facilitate increased biosynthesis of cyt c in recombinant Escherichia coli Focusing on HCCS E159A, novel cyt c variants in quantities that are sufficient for biophysical analysis are biosynthesized. Cyt c H19M, the first bis-Met liganded cyt c, is compared with other axial ligand variants (M81A, M81H) and single thioether cyt c variants. For variants with axial ligand substitutions, electronic absorption, near-UV circular dichroism, and electron paramagnetic resonance spectroscopy provide evidence that axial ligands are changed and the heme environment is altered. Circular dichroism spectra in far UV and thermal denaturation analyses demonstrate that axial ligand changes do not affect secondary structures and stability. Redox potentials span a 400-mV range (+349 mV vs. standard hydrogen electrode, H19M; +252 mV, WT; -19 mV, M81A; -69 mV, M81H). We discuss the results in the context of a four-step mechanism for HCCS, whereby HCCS mutants such as E159A are enhanced in release (step 4) of cyt c from the HCCS active site; thus, we term these "release mutants."
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17
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Babbitt SE, Hsu J, Kranz RG. Molecular Basis Behind Inability of Mitochondrial Holocytochrome c Synthase to Mature Bacterial Cytochromes: DEFINING A CRITICAL ROLE FOR CYTOCHROME c α HELIX-1. J Biol Chem 2016; 291:17523-34. [PMID: 27387500 DOI: 10.1074/jbc.m116.741231] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Indexed: 11/06/2022] Open
Abstract
Mitochondrial holocytochrome c synthase (HCCS) is required for cytochrome c (cyt c) maturation and therefore respiration. HCCS efficiently attaches heme via two thioethers to CXXCH of mitochondrial but not bacterial cyt c even though they are functionally conserved. This inability is due to residues in the bacterial cyt c N terminus, but the molecular basis is unknown. Human cyts c with deletions of single residues in α helix-1, which mimic bacterial cyt c, are poorly matured by human HCCS. Focusing on ΔM13 cyt c, we co-purified this variant with HCCS, demonstrating that HCCS recognizes the bacterial-like cytochrome. Although an HCCS-WT cyt c complex contains two covalent links, HCCS-ΔM13 cyt c contains only one thioether attachment. Using multiple approaches, we show that the single attachment is to the second thiol of C(15)SQC(18)H, indicating that α helix-1 is required for positioning the first cysteine for covalent attachment, whereas the histidine of CXXCH positions the second cysteine. Modeling of the N-terminal structure suggested that the serine residue (of CSQCH) would be anchored where the first cysteine should be in ΔM13 cyt c An engineered cyt c with a CQCH motif in the ΔM13 background is matured at higher levels (2-3-fold), providing further evidence for α helix-1 positioning the first cysteine. Bacterial cyt c biogenesis pathways (Systems I and II) appear to recognize simply the CXXCH motif, not requiring α helix-1. Results here explain mechanistically how HCCS (System III) requires an extended region adjacent to CXXCH for maturation.
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Affiliation(s)
- Shalon E Babbitt
- From the Department of Biology, Washington University, St. Louis, Missouri 63130
| | - Jennifer Hsu
- From the Department of Biology, Washington University, St. Louis, Missouri 63130
| | - Robert G Kranz
- From the Department of Biology, Washington University, St. Louis, Missouri 63130
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18
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Marques Netto CGC, da Silva DG, Toma SH, Andrade LH, Nakamura M, Araki K, Toma HE. Bovine glutamate dehydrogenase immobilization on magnetic nanoparticles: conformational changes and catalysis. RSC Adv 2016. [DOI: 10.1039/c5ra24637g] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Glutamate dehydrogenase (GDH) was immobilized on different supports and systematically investigated in order to provide a better understanding of the immobilization effects on the catalysis of multimeric enzymes.
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Affiliation(s)
| | - Delmárcio G. da Silva
- Supramolecular NanotechLab
- Instituto de Quimica
- Universidade de São Paulo
- São Paulo-SP
- Brazil
| | - Sergio H. Toma
- Supramolecular NanotechLab
- Instituto de Quimica
- Universidade de São Paulo
- São Paulo-SP
- Brazil
| | - Leandro H. Andrade
- Laboratory of Fine Chemistry and Biocatalysis
- Instituto de Química
- Universidade de São Paulo
- São Paulo-SP
- Brazil
| | - Marcelo Nakamura
- Supramolecular NanotechLab
- Instituto de Quimica
- Universidade de São Paulo
- São Paulo-SP
- Brazil
| | - Koiti Araki
- Supramolecular NanotechLab
- Instituto de Quimica
- Universidade de São Paulo
- São Paulo-SP
- Brazil
| | - Henrique E. Toma
- Supramolecular NanotechLab
- Instituto de Quimica
- Universidade de São Paulo
- São Paulo-SP
- Brazil
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19
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Babbitt SE, Sutherland MC, San Francisco B, Mendez DL, Kranz RG. Mitochondrial cytochrome c biogenesis: no longer an enigma. Trends Biochem Sci 2015; 40:446-55. [PMID: 26073510 DOI: 10.1016/j.tibs.2015.05.006] [Citation(s) in RCA: 85] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2015] [Revised: 05/13/2015] [Accepted: 05/18/2015] [Indexed: 12/31/2022]
Abstract
Cytochromes c (cyt c) and c1 are heme proteins that are essential for aerobic respiration. Release of cyt c from mitochondria is an important signal in apoptosis initiation. Biogenesis of c-type cytochromes involves covalent attachment of heme to two cysteines (at a conserved CXXCH sequence) in the apocytochrome. Heme attachment is catalyzed in most mitochondria by holocytochrome c synthase (HCCS), which is also necessary for the import of apocytochrome c (apocyt c). Thus, HCCS affects cellular levels of cyt c, impacting mitochondrial physiology and cell death. Here, we review the mechanisms of HCCS function and the roles of heme and residues in the CXXCH motif. Additionally, we consider concepts emerging within the two prokaryotic cytochrome c biogenesis pathways.
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Affiliation(s)
- Shalon E Babbitt
- Department of Biology, Washington University, St Louis, MO 63130, USA
| | | | | | - Deanna L Mendez
- Department of Biology, Washington University, St Louis, MO 63130, USA
| | - Robert G Kranz
- Department of Biology, Washington University, St Louis, MO 63130, USA.
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20
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Galinato MGI, Bowman SEJ, Kleingardner JG, Martin S, Zhao J, Sturhahn W, Alp EE, Bren KL, Lehnert N. Effects of protein structure on iron-polypeptide vibrational dynamic coupling in cytochrome c. Biochemistry 2015; 54:1064-76. [PMID: 25531247 PMCID: PMC4318584 DOI: 10.1021/bi501430z] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Cytochrome c (Cyt c) has a heme covalently bound to the polypeptide via a Cys-X-X-Cys-His (CXXCH) linker that is located in the interface region for protein-protein interactions. To determine whether the polypeptide matrix influences iron vibrational dynamics, nuclear resonance vibrational spectroscopy (NRVS) measurements were performed on (57)Fe-labeled ferric Hydrogenobacter thermophilus cytochrome c-552, and variants M13V, M13V/K22M, and A7F, which have structural modifications that alter the composition or environment of the CXXCH pentapeptide loop. Simulations of the NRVS data indicate that the 150-325 cm(-1) region is dominated by NHis-Fe-SMet axial ligand and polypeptide motions, while the 325-400 cm(-1) region shows dominant contributions from ν(Fe-NPyr) (Pyr = pyrrole) and other heme-based modes. Diagnostic spectral signatures that directly relate to structural features of the heme active site are identified using a quantum chemistry-centered normal coordinate analysis (QCC-NCA). In particular, spectral features that directly correlate with CXXCH loop stiffness, the strength of the Fe-His interaction, and the degree of heme distortion are identified. Cumulative results from our investigation suggest that compared to the wild type (wt), variants M13V and M13V/K22M have a more rigid CXXCH pentapeptide segment, a stronger Fe-NHis interaction, and a more ruffled heme. Conversely, the A7F variant has a more planar heme and a weaker Fe-NHis bond. These results are correlated to the observed changes in reduction potential between wt protein and the variants studied here. Implications of these results for Cyt c biogenesis and electron transfer are also discussed.
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Affiliation(s)
- Mary Grace I Galinato
- Department of Chemistry, University of Michigan , Ann Arbor, Michigan 48109, United States
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