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Li J, Fan Y, Li N, Guo Y, Wang W, Feng K, He W, Li F, Huang J, Xu Y, Xiao L, Feng Y. Comparative genomics analysis reveals sequence characteristics potentially related to host preference in Cryptosporidium xiaoi. Int J Parasitol 2024; 54:379-390. [PMID: 38492779 DOI: 10.1016/j.ijpara.2024.03.004] [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: 10/25/2023] [Revised: 02/26/2024] [Accepted: 03/12/2024] [Indexed: 03/18/2024]
Abstract
Cryptosporidium spp. are important diarrhea-associated pathogens in humans and livestock. Among the known species, Cryptosporidium xiaoi, which causes cryptosporidiosis in sheep and goats, was previously recognized as a genotype of the bovine-specific Cryptosporidium bovis based on their high sequence identity in the ssrRNA gene. However, the lack of genomic data has limited characterization of the genetic differences between the two closely related species. In this study, we sequenced the genomes of two C. xiaoi isolates and performed comparative genomic analysis to identify the sequence uniqueness of this ovine-adapted species compared with other Cryptosporidium spp. Our results showed that C. xiaoi is genetically related to C. bovis as shown by their 95.8% genomic identity and similar gene content. Consistent with this, both C. xiaoi and C. bovis appear to have fewer genes encoding mitochondrial metabolic enzymes and invasion-related protein families. However, they appear to possess several species-specific genes. Further analysis indicates that the sequence differences between these two Cryptosporidium spp. are mainly in 24 highly polymorphic genes, half of which are located in the subtelomeric regions. Some of these subtelomeric genes encode secretory proteins that have undergone positive selection. In addition, the genomes of two C. xiaoi isolates, identified as subtypes XXIIIf and XXIIIh, share 99.9% nucleotide sequence identity, with six highly divergent genes encoding putative secretory proteins. Therefore, these species-specific genes and sequence polymorphism in subtelomeric genes probably contribute to the different host preference of C. xiaoi and C. bovis.
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Affiliation(s)
- Jiayu Li
- State Key Laboratory for Animal Disease Control and Prevention, South China Agricultural University, Guangzhou 510642, China
| | - Yingying Fan
- State Key Laboratory for Animal Disease Control and Prevention, South China Agricultural University, Guangzhou 510642, China
| | - Na Li
- State Key Laboratory for Animal Disease Control and Prevention, South China Agricultural University, Guangzhou 510642, China
| | - Yaqiong Guo
- State Key Laboratory for Animal Disease Control and Prevention, South China Agricultural University, Guangzhou 510642, China
| | - Weijian Wang
- State Key Laboratory for Animal Disease Control and Prevention, South China Agricultural University, Guangzhou 510642, China
| | - Kangli Feng
- State Key Laboratory for Animal Disease Control and Prevention, South China Agricultural University, Guangzhou 510642, China
| | - Wei He
- State Key Laboratory for Animal Disease Control and Prevention, South China Agricultural University, Guangzhou 510642, China
| | - Falei Li
- State Key Laboratory for Animal Disease Control and Prevention, South China Agricultural University, Guangzhou 510642, China
| | - Jianbo Huang
- State Key Laboratory for Animal Disease Control and Prevention, South China Agricultural University, Guangzhou 510642, China
| | - Yanhua Xu
- State Key Laboratory for Animal Disease Control and Prevention, South China Agricultural University, Guangzhou 510642, China
| | - Lihua Xiao
- State Key Laboratory for Animal Disease Control and Prevention, South China Agricultural University, Guangzhou 510642, China.
| | - Yaoyu Feng
- State Key Laboratory for Animal Disease Control and Prevention, South China Agricultural University, Guangzhou 510642, China.
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Li J, Yang S, Wu Y, Wang R, Liu Y, Liu J, Ye Z, Tang R, Whiteway M, Lv Q, Yan L. Alternative Oxidase: From Molecule and Function to Future Inhibitors. ACS OMEGA 2024; 9:12478-12499. [PMID: 38524433 PMCID: PMC10955580 DOI: 10.1021/acsomega.3c09339] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Revised: 01/31/2024] [Accepted: 02/07/2024] [Indexed: 03/26/2024]
Abstract
In the respiratory chain of the majority of aerobic organisms, the enzyme alternative oxidase (AOX) functions as the terminal oxidase and has important roles in maintaining metabolic and signaling homeostasis in mitochondria. AOX endows the respiratory system with flexibility in the coupling among the carbon metabolism pathway, electron transport chain (ETC) activity, and ATP turnover. AOX allows electrons to bypass the main cytochrome pathway to restrict the generation of reactive oxygen species (ROS). The inhibition of AOX leads to oxidative damage and contributes to the loss of adaptability and viability in some pathogenic organisms. Although AOXs have recently been identified in several organisms, crystal structures and major functions still need to be explored. Recent work on the trypanosome alternative oxidase has provided a crystal structure of an AOX protein, which contributes to the structure-activity relationship of the inhibitors of AOX. Here, we review the current knowledge on the development, structure, and properties of AOXs, as well as their roles and mechanisms in plants, animals, algae, protists, fungi, and bacteria, with a special emphasis on the development of AOX inhibitors, which will improve the understanding of respiratory regulation in many organisms and provide references for subsequent studies of AOX-targeted inhibitors.
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Affiliation(s)
- Jiye Li
- School
of Pharmacy, Naval Medical University, Shanghai 200433, China
- Institute
of Medicinal Biotechnology, Chinese Academy
of Medical Sciences and Peking Union Medical College, Beijing 100050, China
| | - Shiyun Yang
- School
of Pharmacy, Naval Medical University, Shanghai 200433, China
| | - Yujie Wu
- School
of Pharmacy, Naval Medical University, Shanghai 200433, China
| | - Ruina Wang
- School
of Pharmacy, Naval Medical University, Shanghai 200433, China
| | - Yu Liu
- School
of Pharmacy, Naval Medical University, Shanghai 200433, China
| | - Jiacun Liu
- School
of Pharmacy, Naval Medical University, Shanghai 200433, China
| | - Zi Ye
- School
of Pharmacy, Naval Medical University, Shanghai 200433, China
| | - Renjie Tang
- Beijing
South Medical District of Chinese PLA General Hospital, Beijing 100072, China
| | - Malcolm Whiteway
- Department
of Biology, Concordia University, Montreal, H4B 1R6 Quebec, Canada
| | - Quanzhen Lv
- School
of Pharmacy, Naval Medical University, Shanghai 200433, China
- Basic
Medicine Innovation Center for Fungal Infectious Diseases, (Naval Medical University), Ministry of Education, Shanghai 200433, China
- Key
Laboratory of Biosafety Defense (Naval Medical University), Ministry
of Education, Shanghai 200433, China
- Shanghai
Key Laboratory of Medical Biodefense, Shanghai 200433, China
| | - Lan Yan
- School
of Pharmacy, Naval Medical University, Shanghai 200433, China
- Basic
Medicine Innovation Center for Fungal Infectious Diseases, (Naval Medical University), Ministry of Education, Shanghai 200433, China
- Key
Laboratory of Biosafety Defense (Naval Medical University), Ministry
of Education, Shanghai 200433, China
- Shanghai
Key Laboratory of Medical Biodefense, Shanghai 200433, China
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Dąbrowska J, Sroka J, Cencek T. Investigating Cryptosporidium spp. Using Genomic, Proteomic and Transcriptomic Techniques: Current Progress and Future Directions. Int J Mol Sci 2023; 24:12867. [PMID: 37629046 PMCID: PMC10454211 DOI: 10.3390/ijms241612867] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 08/04/2023] [Accepted: 08/09/2023] [Indexed: 08/27/2023] Open
Abstract
Cryptosporidiosis is a widespread disease caused by the parasitic protozoan Cryptosporidium spp., which infects various vertebrate species, including humans. Once unknown as a gastroenteritis-causing agent, Cryptosporidium spp. is now recognized as a pathogen causing life-threatening disease, especially in immunocompromised individuals such as AIDS patients. Advances in diagnostic methods and increased awareness have led to a significant shift in the perception of Cryptosporidium spp. as a pathogen. Currently, genomic and proteomic studies play a main role in understanding the molecular biology of this complex-life-cycle parasite. Genomics has enabled the identification of numerous genes involved in the parasite's development and interaction with hosts. Proteomics has allowed for the identification of protein interactions, their function, structure, and cellular activity. The combination of these two approaches has significantly contributed to the development of new diagnostic tools, vaccines, and drugs for cryptosporidiosis. This review presents an overview of the significant achievements in Cryptosporidium research by utilizing genomics, proteomics, and transcriptomics approaches.
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Affiliation(s)
- Joanna Dąbrowska
- Department of Parasitology and Invasive Disease, National Veterinary Research Institute, Partyzantów 57 Avenue, 24-100 Puławy, Poland (T.C.)
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Funkhouser-Jones LJ, Xu R, Wilke G, Fu Y, Schriefer LA, Makimaa H, Rodgers R, Kennedy EA, VanDussen KL, Stappenbeck TS, Baldridge MT, Sibley LD. Microbiota-produced indole metabolites disrupt mitochondrial function and inhibit Cryptosporidium parvum growth. Cell Rep 2023; 42:112680. [PMID: 37384526 PMCID: PMC10530208 DOI: 10.1016/j.celrep.2023.112680] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Revised: 05/08/2023] [Accepted: 06/07/2023] [Indexed: 07/01/2023] Open
Abstract
Cryptosporidiosis is a leading cause of life-threatening diarrhea in young children in resource-poor settings. To explore microbial influences on susceptibility, we screened 85 microbiota-associated metabolites for their effects on Cryptosporidium parvum growth in vitro. We identify eight inhibitory metabolites in three main classes: secondary bile salts/acids, a vitamin B6 precursor, and indoles. Growth restriction of C. parvum by indoles does not depend on the host aryl hydrocarbon receptor (AhR) pathway. Instead, treatment impairs host mitochondrial function and reduces total cellular ATP, as well as directly reducing the membrane potential in the parasite mitosome, a degenerate mitochondria. Oral administration of indoles, or reconstitution of the gut microbiota with indole-producing bacteria, delays life cycle progression of the parasite in vitro and reduces the severity of C. parvum infection in mice. Collectively, these findings indicate that microbiota metabolites impair mitochondrial function and contribute to colonization resistance to Cryptosporidium infection.
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Affiliation(s)
- Lisa J Funkhouser-Jones
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO, USA
| | - Rui Xu
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO, USA
| | - Georgia Wilke
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO, USA
| | - Yong Fu
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO, USA
| | - Lawrence A Schriefer
- Department of Medicine, Division of Infectious Diseases, Edison Family Center for Genome Sciences and Systems Biology, Washington University School of Medicine, St. Louis, MO, USA
| | - Heyde Makimaa
- Department of Medicine, Division of Infectious Diseases, Edison Family Center for Genome Sciences and Systems Biology, Washington University School of Medicine, St. Louis, MO, USA
| | - Rachel Rodgers
- Department of Medicine, Division of Infectious Diseases, Edison Family Center for Genome Sciences and Systems Biology, Washington University School of Medicine, St. Louis, MO, USA
| | - Elizabeth A Kennedy
- Department of Medicine, Division of Infectious Diseases, Edison Family Center for Genome Sciences and Systems Biology, Washington University School of Medicine, St. Louis, MO, USA
| | - Kelli L VanDussen
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, USA
| | - Thaddeus S Stappenbeck
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, USA
| | - Megan T Baldridge
- Department of Medicine, Division of Infectious Diseases, Edison Family Center for Genome Sciences and Systems Biology, Washington University School of Medicine, St. Louis, MO, USA
| | - L David Sibley
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO, USA.
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Li J, Li N, Roellig DM, Zhao W, Guo Y, Feng Y, Xiao L. High subtelomeric GC content in the genome of a zoonotic Cryptosporidium species. Microb Genom 2023; 9:mgen001052. [PMID: 37399068 PMCID: PMC10438818 DOI: 10.1099/mgen.0.001052] [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: 01/06/2023] [Accepted: 05/24/2023] [Indexed: 07/04/2023] Open
Abstract
Cryptosporidium canis is a zoonotic species causing cryptosporidiosis in humans in addition to its natural hosts dogs and other fur animals. To understand the genetic basis for host adaptation, we sequenced the genomes of C. canis from dogs, minks, and foxes and conducted a comparative genomics analysis. While the genomes of C. canis have similar gene contents and organisations, they (~41.0 %) and C. felis (39.6 %) have GC content much higher than other Cryptosporidium spp. (24.3-32.9 %) sequenced to date. The high GC content is mostly restricted to subtelomeric regions of the eight chromosomes. Most of these GC-balanced genes encode Cryptosporidium-specific proteins that have intrinsically disordered regions and are involved in host-parasite interactions. Natural selection appears to play a more important role in the evolution of codon usage in GC-balanced C. canis, and most of the GC-balanced genes have undergone positive selection. While the identity in whole genome sequences between the mink- and dog-derived isolates is 99.9 % (9365 SNVs), it is only 96.0 % (362 894 SNVs) between them and the fox-derived isolate. In agreement with this, the fox-derived isolate possesses more subtelomeric genes encoding invasion-related protein families. Therefore, the change in subtelomeric GC content appears to be responsible for the more GC-balanced C. canis genomes, and the fox-derived isolate could represent a new Cryptosporidium species.
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Affiliation(s)
- Jiayu Li
- State Key Laboratory for Animal Disease Control and Prevention, South China Agricultural University, Guangzhou 510642, PR China
| | - Na Li
- State Key Laboratory for Animal Disease Control and Prevention, South China Agricultural University, Guangzhou 510642, PR China
| | - Dawn M. Roellig
- Division of Foodborne, Waterborne, and Environmental Diseases, Centers for Disease Control and Prevention, Atlanta, GA 30329, USA
| | - Wentao Zhao
- State Key Laboratory for Animal Disease Control and Prevention, South China Agricultural University, Guangzhou 510642, PR China
| | - Yaqiong Guo
- State Key Laboratory for Animal Disease Control and Prevention, South China Agricultural University, Guangzhou 510642, PR China
| | - Yaoyu Feng
- State Key Laboratory for Animal Disease Control and Prevention, South China Agricultural University, Guangzhou 510642, PR China
| | - Lihua Xiao
- State Key Laboratory for Animal Disease Control and Prevention, South China Agricultural University, Guangzhou 510642, PR China
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Funkhouser-Jones LJ, Xu R, Wilke G, Fu Y, Shriefer LA, Makimaa H, Rodgers R, Kennedy EA, VanDussen KL, Stappenbeck TS, Baldridge MT, Sibley LD. Microbiota produced indole metabolites disrupt host cell mitochondrial energy production and inhibit Cryptosporidium parvum growth. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.25.542157. [PMID: 37292732 PMCID: PMC10245909 DOI: 10.1101/2023.05.25.542157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Cryptosporidiosis is a leading cause of life-threatening diarrhea in young children in resource-poor settings. Susceptibility rapidly declines with age, associated with changes in the microbiota. To explore microbial influences on susceptibility, we screened 85 microbiota- associated metabolites enriched in the adult gut for their effects on C. parvum growth in vitro. We identified eight inhibitory metabolites in three main classes: secondary bile salts/acids, a vitamin B 6 precursor, and indoles. Growth restriction of C. parvum by indoles did not depend on the host aryl hydrocarbon receptor (AhR) pathway. Instead, treatment impaired host mitochondrial function and reduced total cellular ATP, as well as directly reduced the membrane potential in the parasite mitosome, a degenerate mitochondria. Oral administration of indoles, or reconstitution of the gut microbiota with indole producing bacteria, delayed life cycle progression of the parasite in vitro and reduced severity of C. parvum infection in mice. Collectively, these findings indicate that microbiota metabolites contribute to colonization resistance to Cryptosporidium infection.
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Affiliation(s)
- Lisa J. Funkhouser-Jones
- Department of Molecular Microbiology, Washington University School of Medicine, St Louis, MO, USA
| | - Rui Xu
- Department of Molecular Microbiology, Washington University School of Medicine, St Louis, MO, USA
| | - Georgia Wilke
- Department of Molecular Microbiology, Washington University School of Medicine, St Louis, MO, USA
| | - Yong Fu
- Department of Molecular Microbiology, Washington University School of Medicine, St Louis, MO, USA
| | - Lawrence A. Shriefer
- Department of Medicine, Division of Infectious Diseases, Edison Family Center for Genome Sciences and Systems Biology, Washington University School of Medicine, St Louis, MO, USA
| | - Heyde Makimaa
- Department of Medicine, Division of Infectious Diseases, Edison Family Center for Genome Sciences and Systems Biology, Washington University School of Medicine, St Louis, MO, USA
| | - Rachel Rodgers
- Department of Medicine, Division of Infectious Diseases, Edison Family Center for Genome Sciences and Systems Biology, Washington University School of Medicine, St Louis, MO, USA
| | - Elizabeth A. Kennedy
- Department of Medicine, Division of Infectious Diseases, Edison Family Center for Genome Sciences and Systems Biology, Washington University School of Medicine, St Louis, MO, USA
| | - Kelli L. VanDussen
- Department of Pathology and Immunology, Washington University School of Medicine, St Louis, MO, USA
| | - Thaddeus S. Stappenbeck
- Department of Pathology and Immunology, Washington University School of Medicine, St Louis, MO, USA
| | - Megan T. Baldridge
- Department of Medicine, Division of Infectious Diseases, Edison Family Center for Genome Sciences and Systems Biology, Washington University School of Medicine, St Louis, MO, USA
| | - L. David Sibley
- Department of Molecular Microbiology, Washington University School of Medicine, St Louis, MO, USA
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Xu S, Zhang YWQ, Habib MR, Li SZ, Yuan Y, Ke WH, Jiang N, Dong H, Zhao QP. Inhibition of alternative oxidase disrupts the development and oviposition of Biomphalaria glabrata snails. Parasit Vectors 2023; 16:73. [PMID: 36804043 PMCID: PMC9938623 DOI: 10.1186/s13071-022-05642-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Accepted: 12/28/2022] [Indexed: 02/19/2023] Open
Abstract
BACKGROUND Biomphalaria glabrata is one of the main intermediate hosts of Schistosoma mansoni, the most widespread species of Schistosoma. Our previous studies proved that alternative oxidase (AOX), the terminal oxidase in the mitochondrial respiratory chain, widely exists in several species of intermediate host snails of Schistosoma. Meanwhile, inhibition of AOX activity in Oncomelania hupensis snails could dramatically enhance the molluscicidal effect of niclosamide. As a hermaphroditic aquatic mollusc, the high fecundity and population density of B. glabrata increase the difficulty of snail control, which is one of the critical strategies for schistosomiasis elimination. The present study aimed to investigate the possible role of AOX in the development and fecundity of B. glabrata snail, which could be manipulated more manageable than other species of intermediate host snails of Schistosoma. METHODS The dynamic expression of the AOX gene was investigated in different developmental stages and tissues of B. glabrata, with morphological change and oviposition behaviour observed from juvenile to adult snails. Furtherly, dsRNA-mediated knockdown of BgAOX mRNA and the AOX protein activity inhibiting was performed to investigate the effect of AOX on the development and oviposition of snails. RESULTS The BgAOX gene expression profile is highly related to the development from late juveniles to adults, especially to the reproductive system of snails, with a positive correlation of 0.975 between egg production and BgAOX relative expression in ovotestis of snails. The inhibition of BgAOX at the transcriptional level and AOX activity could efficiently inhibit snail growth. However, the interference at the BgAOX protein activity level led to more severe tissue damage and more significant inhibition of oviposition than at the transcriptional level. This inhibition of growth and oviposition decreased gradually with the increase in the snail size. CONCLUSIONS The inhibition of AOX could efficiently disrupt the development and oviposition of B. glabrata snails, and the intervention targeting AOX at the juvenile stage is more effective for snails. This investigation explored the role of AOX in the growth and development of snails. It would benefit snail control in the future by providing a potential target while using molluscicides more efficiently.
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Affiliation(s)
- Sha Xu
- grid.49470.3e0000 0001 2331 6153Department of Parasitology, School of Basic Medical Sciences, Wuhan University, Wuhan, Hubei Province China
| | - Yang-Wen-Qing Zhang
- grid.49470.3e0000 0001 2331 6153Department of Parasitology, School of Basic Medical Sciences, Wuhan University, Wuhan, Hubei Province China
| | - Mohamed R. Habib
- grid.420091.e0000 0001 0165 571XMedical Malacology Laboratory, Theodor Bilharz Research Institute, Giza, Egypt
| | - Shi-Zhu Li
- grid.453135.50000 0004 1769 3691National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, National Center for Tropical Diseases Research, WHO Collaborating Center for Tropical Diseases, Key Laboratory of Parasite and Vector Biology, Ministry of Health, Shanghai, China
| | - Yi Yuan
- Hubei Center for Disease Control and Prevention, Wuhan, Hubei Province China
| | - Wei Hao Ke
- grid.49470.3e0000 0001 2331 6153Department of Parasitology, School of Basic Medical Sciences, Wuhan University, Wuhan, Hubei Province China
| | - Ni Jiang
- grid.49470.3e0000 0001 2331 6153Department of Parasitology, School of Basic Medical Sciences, Wuhan University, Wuhan, Hubei Province China
| | - Huifen Dong
- grid.49470.3e0000 0001 2331 6153Department of Parasitology, School of Basic Medical Sciences, Wuhan University, Wuhan, Hubei Province China
| | - Qin-Ping Zhao
- Department of Parasitology, School of Basic Medical Sciences, Wuhan University, Wuhan, Hubei Province, China.
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Cantoni D, Osborne A, Taib N, Thompson G, Martín‐Escolano R, Kazana E, Edrich E, Brown IR, Gribaldo S, Gourlay CW, Tsaousis AD. Localization and functional characterization of the alternative oxidase in Naegleria. J Eukaryot Microbiol 2022; 69:e12908. [PMID: 35322502 PMCID: PMC9540462 DOI: 10.1111/jeu.12908] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The alternative oxidase (AOX) is a protein involved in supporting enzymatic reactions of the Krebs cycle in instances when the canonical (cytochrome-mediated) respiratory chain has been inhibited, while allowing for the maintenance of cell growth and necessary metabolic processes for survival. Among eukaryotes, alternative oxidases have dispersed distribution and are found in plants, fungi, and protists, including Naegleria ssp. Naegleria species are free-living unicellular amoeboflagellates and include the pathogenic species of N. fowleri, the so-called "brain-eating amoeba." Using a multidisciplinary approach, we aimed to understand the evolution, localization, and function of AOX and the role that plays in Naegleria's biology. Our analyses suggest that AOX was present in last common ancestor of the genus and structure prediction showed that all functional residues are also present in Naegleria species. Using cellular and biochemical techniques, we also functionally characterize N. gruberi's AOX in its mitochondria, and we demonstrate that its inactivation affects its proliferation. Consequently, we discuss the benefits of the presence of this protein in Naegleria species, along with its potential pathogenicity role in N. fowleri. We predict that our findings will spearhead new explorations to understand the cell biology, metabolism, and evolution of Naegleria and other free-living relatives.
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Affiliation(s)
- Diego Cantoni
- Laboratory of Molecular & Evolutionary Parasitology, RAPID GroupSchool of BiosciencesUniversity of KentCanterburyUK
| | - Ashley Osborne
- Laboratory of Molecular & Evolutionary Parasitology, RAPID GroupSchool of BiosciencesUniversity of KentCanterburyUK
| | - Najwa Taib
- Unit Evolutionary Biology of the Microbial CellDepartment of MicrobiologyInstitut Pasteur, UMR CNRS 2001ParisFrance
- Hub Bioinformatics and BiostatisticsDepartment of Computational BiologyInstitut Pasteur, USR 3756 CNRSParisFrance
| | - Gary Thompson
- NMR FacilitySchool of BiosciencesUniversity of KentCanterburyUK
| | - Rubén Martín‐Escolano
- Laboratory of Molecular & Evolutionary Parasitology, RAPID GroupSchool of BiosciencesUniversity of KentCanterburyUK
| | - Eleanna Kazana
- Laboratory of Molecular & Evolutionary Parasitology, RAPID GroupSchool of BiosciencesUniversity of KentCanterburyUK
| | - Elizabeth Edrich
- Kent Fungal Group, RAPID GroupSchool of BiosciencesUniversity of KentCanterburyUK
| | - Ian R. Brown
- Bioimaging FacilitySchool of BiosciencesUniversity of KentCanterburyUK
| | - Simonetta Gribaldo
- Unit Evolutionary Biology of the Microbial CellDepartment of MicrobiologyInstitut Pasteur, UMR CNRS 2001ParisFrance
| | - Campbell W. Gourlay
- Kent Fungal Group, RAPID GroupSchool of BiosciencesUniversity of KentCanterburyUK
| | - Anastasios D. Tsaousis
- Laboratory of Molecular & Evolutionary Parasitology, RAPID GroupSchool of BiosciencesUniversity of KentCanterburyUK
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9
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Targeting the alternative oxidase (AOX) for human health and food security, a pharmaceutical and agrochemical target or a rescue mechanism? Biochem J 2022; 479:1337-1359. [PMID: 35748702 PMCID: PMC9246349 DOI: 10.1042/bcj20180192] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Revised: 05/23/2022] [Accepted: 06/07/2022] [Indexed: 11/25/2022]
Abstract
Some of the most threatening human diseases are due to a blockage of the mitochondrial electron transport chain (ETC). In a variety of plants, fungi, and prokaryotes, there is a naturally evolved mechanism for such threats to viability, namely a bypassing of the blocked portion of the ETC by alternative enzymes of the respiratory chain. One such enzyme is the alternative oxidase (AOX). When AOX is expressed, it enables its host to survive life-threatening conditions or, as in parasites, to evade host defenses. In vertebrates, this mechanism has been lost during evolution. However, we and others have shown that transfer of AOX into the genome of the fruit fly and mouse results in a catalytically engaged AOX. This implies that not only is the AOX a promising target for combating human or agricultural pathogens but also a novel approach to elucidate disease mechanisms or, in several cases, potentially a therapeutic cure for human diseases. In this review, we highlight the varying functions of AOX in their natural hosts and upon xenotopic expression, and discuss the resulting need to develop species-specific AOX inhibitors.
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10
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Ženíšková K, Grechnikova M, Sutak R. Copper Metabolism in Naegleria gruberi and Its Deadly Relative Naegleria fowleri. Front Cell Dev Biol 2022; 10:853463. [PMID: 35478954 PMCID: PMC9035749 DOI: 10.3389/fcell.2022.853463] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Accepted: 03/18/2022] [Indexed: 12/04/2022] Open
Abstract
Although copper is an essential nutrient crucial for many biological processes, an excessive concentration can be toxic and lead to cell death. The metabolism of this two-faced metal must be strictly regulated at the cell level. In this study, we investigated copper homeostasis in two related unicellular organisms: nonpathogenic Naegleria gruberi and the “brain-eating amoeba” Naegleria fowleri. We identified and confirmed the function of their specific copper transporters securing the main pathway of copper acquisition. Adjusting to different environments with varying copper levels during the life cycle of these organisms requires various metabolic adaptations. Using comparative proteomic analyses, measuring oxygen consumption, and enzymatic determination of NADH dehydrogenase, we showed that both amoebas respond to copper deprivation by upregulating the components of the branched electron transport chain: the alternative oxidase and alternative NADH dehydrogenase. Interestingly, analysis of iron acquisition indicated that this system is copper-dependent in N. gruberi but not in its pathogenic relative. Importantly, we identified a potential key protein of copper metabolism of N. gruberi, the homolog of human DJ-1 protein, which is known to be linked to Parkinson’s disease. Altogether, our study reveals the mechanisms underlying copper metabolism in the model amoeba N. gruberi and the fatal pathogen N. fowleri and highlights the differences between the two amoebas.
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11
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Identification and Functional Characterization of a Putative Alternative Oxidase (Aox) in Sporisorium reilianum f. sp. zeae. J Fungi (Basel) 2022; 8:jof8020148. [PMID: 35205901 PMCID: PMC8877474 DOI: 10.3390/jof8020148] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Revised: 01/26/2022] [Accepted: 01/28/2022] [Indexed: 12/04/2022] Open
Abstract
The mitochondrial electron transport chain consists of the classical protein complexes (I–IV) that facilitate the flow of electrons and coupled oxidative phosphorylation to produce metabolic energy. The canonical route of electron transport may diverge by the presence of alternative components to the electron transport chain. The following study comprises the bioinformatic identification and functional characterization of a putative alternative oxidase in the smut fungus Sporisorium reilianum f. sp. zeae. This alternative respiratory component has been previously identified in other eukaryotes and is essential for alternative respiration as a response to environmental and chemical stressors, as well as for developmental transitionaoxs during the life cycle of an organism. A growth inhibition assay, using specific mitochondrial inhibitors, functionally confirmed the presence of an antimycin-resistant/salicylhydroxamic acid (SHAM)-sensitive alternative oxidase in the respirasome of S. reilianum. Gene disruption experiments revealed that this enzyme is involved in the pathogenic stage of the fungus, with its absence effectively reducing overall disease incidence in infected maize plants. Furthermore, gene expression analysis revealed that alternative oxidase plays a prominent role in the teliospore developmental stage, in agreement with favoring alternative respiration during quiescent stages of an organism’s life cycle.
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12
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Copsey AC, Barsottini MRO, May B, Xu F, Albury MS, Young L, Moore AL. Kinetic characterisation and inhibitor sensitivity of Candida albicans and Candida auris recombinant AOX expressed in a self-assembled proteoliposome system. Sci Rep 2021; 11:14748. [PMID: 34285303 PMCID: PMC8292455 DOI: 10.1038/s41598-021-94320-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Accepted: 07/05/2021] [Indexed: 02/07/2023] Open
Abstract
Candidemia caused by Candida spp. is a serious threat in hospital settings being a major cause of acquired infection and death and a possible contributor to Covid-19 mortality. Candidemia incidence has been rising worldwide following increases in fungicide-resistant pathogens highlighting the need for more effective antifungal agents with novel modes of action. The membrane-bound enzyme alternative oxidase (AOX) promotes fungicide resistance and is absent in humans making it a desirable therapeutic target. However, the lipophilic nature of the AOX substrate (ubiquinol-10) has hindered its kinetic characterisation in physiologically-relevant conditions. Here, we present the purification and expression of recombinant AOXs from C. albicans and C. auris in a self-assembled proteoliposome (PL) system. Kinetic parameters (Km and Vmax) with respect to ubiquinol-10 have been determined. The PL system has also been employed in dose-response assays with novel AOX inhibitors. Such information is critical for the future development of novel treatments for Candidemia.
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Affiliation(s)
- Alice C Copsey
- Biochemistry and Biomedicine, School of Life Sciences, University of Sussex, Falmer, Brighton, BN1 9QG, UK
| | - Mario R O Barsottini
- Biochemistry and Biomedicine, School of Life Sciences, University of Sussex, Falmer, Brighton, BN1 9QG, UK
| | - Benjamin May
- Biochemistry and Biomedicine, School of Life Sciences, University of Sussex, Falmer, Brighton, BN1 9QG, UK
- Theradex (Europe) Ltd, 2nd Floor, The Pinnacle, Station Way, Crawley, RH10 1JH, UK
| | - Fei Xu
- Biochemistry and Biomedicine, School of Life Sciences, University of Sussex, Falmer, Brighton, BN1 9QG, UK
- Applied Biotechnology Center, Wuhan University of Bioengineering, Wuhan, China
| | - Mary S Albury
- Biochemistry and Biomedicine, School of Life Sciences, University of Sussex, Falmer, Brighton, BN1 9QG, UK
| | - Luke Young
- Biochemistry and Biomedicine, School of Life Sciences, University of Sussex, Falmer, Brighton, BN1 9QG, UK
| | - Anthony L Moore
- Biochemistry and Biomedicine, School of Life Sciences, University of Sussex, Falmer, Brighton, BN1 9QG, UK.
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13
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Molecular characterization and gene expression modulation of the alternative oxidase in a scuticociliate parasite by hypoxia and mitochondrial respiration inhibitors. Sci Rep 2020; 10:11880. [PMID: 32681023 PMCID: PMC7367826 DOI: 10.1038/s41598-020-68791-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2019] [Accepted: 07/01/2020] [Indexed: 12/26/2022] Open
Abstract
Philasterides dicentrarchi is a marine benthic microaerophilic scuticociliate and an opportunistic endoparasite that can infect and cause high mortalities in cultured turbot (Scophthalmus maximus). In addition to a cytochrome pathway (CP), the ciliate can use a cyanide-insensitive respiratory pathway, which indicates the existence of an alternative oxidase (AOX) in the mitochondrion. Although AOX activity has been described in P. dicentrarchi, based on functional assay results, genetic evidence of the presence of AOX in the ciliate has not previously been reported. In this study, we conducted genomic and transcriptomic analysis of the ciliate and identified the AOX gene and its corresponding mRNA. The AOX gene (size 1,106 bp) contains four exons and three introns that generate an open reading frame of 915 bp and a protein with a predicted molecular weight of 35.6 kDa. The amino acid (aa) sequence of the AOX includes an import signal peptide targeting the mitochondria and the protein is associated with the inner membrane of the mitochondria. Bioinformatic analysis predicted that the peptide is a homodimeric glycoprotein, although monomeric forms may also appear under native conditions, with EXXH motifs associated with the diiron active centers. The aa sequences of the AOX of different P. dicentrarchi isolates are highly conserved and phylogenetically closely related to AOXs of other ciliate species, especially scuticociliates. AOX expression increased significantly during infection in the host and after the addition of CP inhibitors. This confirms the important physiological roles of AOX in respiration under conditions of low levels of O2 and in protecting against oxidative stress generated during infection in the host.
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14
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Linzke M, Yan SLR, Tárnok A, Ulrich H, Groves MR, Wrenger C. Live and Let Dye: Visualizing the Cellular Compartments of the Malaria Parasite Plasmodium falciparum. Cytometry A 2019; 97:694-705. [PMID: 31738009 DOI: 10.1002/cyto.a.23927] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Revised: 10/03/2019] [Accepted: 10/24/2019] [Indexed: 12/15/2022]
Abstract
Malaria remains one of the deadliest diseases worldwide and it is caused by the protozoan parasite Plasmodium spp. Parasite visualization is an important tool for the correct detection of malarial cases but also to understand its biology. Advances in visualization techniques promote new insights into the complex life cycle and biology of Plasmodium parasites. Live cell imaging by fluorescence microscopy or flow cytometry are the foundation of the visualization technique for malaria research. In this review, we present an overview of possibilities in live cell imaging of the malaria parasite. We discuss some of the state-of-the-art techniques to visualize organelles and processes of the parasite and discuss limitation and advantages of each technique. © 2019 International Society for Advancement of Cytometry.
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Affiliation(s)
- Marleen Linzke
- Unit for Drug Discovery, Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, Avenida Professor Lineu Prestes 1374, São Paulo, São Paulo, 05508-000, Brazil
| | - Sun Liu Rei Yan
- Unit for Drug Discovery, Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, Avenida Professor Lineu Prestes 1374, São Paulo, São Paulo, 05508-000, Brazil
| | - Attila Tárnok
- Institute for Medical Informatics, Statistics and Epidemiology, Medical Faculty, University Leipzig, D-04107, Härtelstraße 16-18, Leipzig, Germany
| | - Henning Ulrich
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, Avenida Professor Lineu Prestes 748, São Paulo, São Paulo, 05508-900, Brazil
| | - Matthew R Groves
- Structural Biology Unit, Department of Pharmacy, Faculty of Science and Engineering, University of Groningen, 9713AV, Antonius Deusinglaan 1, AV Groningen, The Netherlands
| | - Carsten Wrenger
- Unit for Drug Discovery, Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, Avenida Professor Lineu Prestes 1374, São Paulo, São Paulo, 05508-000, Brazil
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15
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Same same, but different: Uncovering unique features of the mitochondrial respiratory chain of apicomplexans. Mol Biochem Parasitol 2019; 232:111204. [DOI: 10.1016/j.molbiopara.2019.111204] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2019] [Revised: 07/19/2019] [Accepted: 08/01/2019] [Indexed: 01/08/2023]
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16
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Ebiloma GU, Balogun EO, Cueto-Díaz EJ, de Koning HP, Dardonville C. Alternative oxidase inhibitors: Mitochondrion-targeting as a strategy for new drugs against pathogenic parasites and fungi. Med Res Rev 2019; 39:1553-1602. [PMID: 30693533 DOI: 10.1002/med.21560] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Revised: 11/07/2018] [Accepted: 12/08/2018] [Indexed: 12/11/2022]
Abstract
The alternative oxidase (AOX) is a ubiquitous terminal oxidase of plants and many fungi, catalyzing the four-electron reduction of oxygen to water alongside the cytochrome-based electron transfer chain. Unlike the classical electron transfer chain, however, the activity of AOX does not generate adenosine triphosphate but has functions such as thermogenesis and stress response. As it lacks a mammalian counterpart, it has been investigated intensely in pathogenic fungi. However, it is in African trypanosomes, which lack cytochrome-based respiration in their infective stages, that trypanosome alternative oxidase (TAO) plays the central and essential role in their energy metabolism. TAO was validated as a drug target decades ago and among the first inhibitors to be identified was salicylhydroxamic acid (SHAM), which produced the expected trypanocidal effects, especially when potentiated by coadministration with glycerol to inhibit anaerobic energy metabolism as well. However, the efficacy of this combination was too low to be of practical clinical use. The antibiotic ascofuranone (AF) proved a much stronger TAO inhibitor and was able to cure Trypanosoma vivax infections in mice without glycerol and at much lower doses, providing an important proof of concept milestone. Systematic efforts to improve the SHAM and AF scaffolds, aided with the elucidation of the TAO crystal structure, provided detailed structure-activity relationship information and reinvigorated the drug discovery effort. Recently, the coupling of mitochondrion-targeting lipophilic cations to TAO inhibitors has dramatically improved drug targeting and trypanocidal activity while retaining target protein potency. These developments appear to have finally signposted the way to preclinical development of TAO inhibitors.
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Affiliation(s)
- Godwin U Ebiloma
- Department of Applied Biology, Graduate School of Science and Technology, Kyoto Institute of Technology, Kyoto, Japan.,Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Emmanuel O Balogun
- Department of Biochemistry, Ahmadu Bello University, Zaria, Nigeria.,Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | | | - Harry P de Koning
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
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17
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Tsaousis AD, Hamblin KA, Elliott CR, Young L, Rosell-Hidalgo A, Gourlay CW, Moore AL, van der Giezen M. The Human Gut Colonizer Blastocystis Respires Using Complex II and Alternative Oxidase to Buffer Transient Oxygen Fluctuations in the Gut. Front Cell Infect Microbiol 2018; 8:371. [PMID: 30406045 PMCID: PMC6204527 DOI: 10.3389/fcimb.2018.00371] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Accepted: 10/03/2018] [Indexed: 12/12/2022] Open
Abstract
Blastocystis is the most common eukaryotic microbe in the human gut. It is linked to irritable bowel syndrome (IBS), but its role in disease has been contested considering its widespread nature. This organism is well-adapted to its anoxic niche and lacks typical eukaryotic features, such as a cytochrome-driven mitochondrial electron transport. Although generally considered a strict or obligate anaerobe, its genome encodes an alternative oxidase. Alternative oxidases are energetically wasteful enzymes as they are non-protonmotive and energy is liberated in heat, but they are considered to be involved in oxidative stress protective mechanisms. Our results demonstrate that the Blastocystis cells themselves respire oxygen via this alternative oxidase thereby casting doubt on its strict anaerobic nature. Inhibition experiments using alternative oxidase and Complex II specific inhibitors clearly demonstrate their role in cellular respiration. We postulate that the alternative oxidase in Blastocystis is used to buffer transient oxygen fluctuations in the gut and that it likely is a common colonizer of the human gut and not causally involved in IBS. Additionally the alternative oxidase could act as a protective mechanism in a dysbiotic gut and thereby explain the absence of Blastocystis in established IBS environments.
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Affiliation(s)
- Anastasios D. Tsaousis
- RAPID Group, Laboratory of Molecular & Evolutionary Parasitology, School of Biosciences, University of Kent, Canterbury, United Kingdom
| | - Karleigh A. Hamblin
- School of Biological and Chemical Sciences, Queen Mary University of London, London, United Kingdom
- Biosciences, University of Exeter, Exeter, United Kingdom
| | - Catherine R. Elliott
- Department of Biochemistry and Biomedicine, School of Life Sciences, University of Sussex, Brighton, United Kingdom
| | - Luke Young
- Department of Biochemistry and Biomedicine, School of Life Sciences, University of Sussex, Brighton, United Kingdom
| | - Alicia Rosell-Hidalgo
- Department of Biochemistry and Biomedicine, School of Life Sciences, University of Sussex, Brighton, United Kingdom
| | - Campbell W. Gourlay
- Kent Fungal Group, School of Biosciences, University of Kent, Canterbury, United Kingdom
| | - Anthony L. Moore
- Department of Biochemistry and Biomedicine, School of Life Sciences, University of Sussex, Brighton, United Kingdom
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18
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Dunn CD. Some Liked It Hot: A Hypothesis Regarding Establishment of the Proto-Mitochondrial Endosymbiont During Eukaryogenesis. J Mol Evol 2017; 85:99-106. [PMID: 28916841 PMCID: PMC5682861 DOI: 10.1007/s00239-017-9809-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Accepted: 09/11/2017] [Indexed: 01/17/2023]
Abstract
Eukaryotic cells are characterized by a considerable increase in subcellular compartmentalization when compared to prokaryotes. Most evidence suggests that the earliest eukaryotes consisted of mitochondria derived from an α-proteobacterial ancestor enclosed within an archaeal host cell. However, what benefits the archaeal host and the proto-mitochondrial endosymbiont might have obtained at the beginning of this endosymbiotic relationship remains unclear. In this work, I argue that heat generated by the proto-mitochondrion initially permitted an archaeon living at high temperatures to colonize a cooler environment, thereby removing apparent limitations on cellular complexity. Furthermore, heat generation by the endosymbiont would have provided phenotypic flexibility not available through fixed alleles selected for fitness at specific temperatures. Finally, a role for heat production by the proto-mitochondrion bridges a conceptual gap between initial endosymbiont entry to the archaeal host and a later role for mitochondrial ATP production in permitting increased cellular complexity.
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Affiliation(s)
- Cory D Dunn
- Institute of Biotechnology, Helsinki Institute of Life Science, University of Helsinki, P.O. Box 56, 00014, Helsinki, Finland. .,College of Sciences, Koç University, 34450, Sarıyer, İstanbul, Turkey.
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19
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Liu S, Roellig DM, Guo Y, Li N, Frace MA, Tang K, Zhang L, Feng Y, Xiao L. Evolution of mitosome metabolism and invasion-related proteins in Cryptosporidium. BMC Genomics 2016; 17:1006. [PMID: 27931183 PMCID: PMC5146892 DOI: 10.1186/s12864-016-3343-5] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Accepted: 11/25/2016] [Indexed: 11/10/2022] Open
Abstract
Background The switch from photosynthetic or predatory to parasitic life strategies by apicomplexans is accompanied with a reductive evolution of genomes and losses of metabolic capabilities. Cryptosporidium is an extreme example of reductive evolution among apicomplexans, with losses of both the mitosome genome and many metabolic pathways. Previous observations on reductive evolution were largely based on comparative studies of various groups of apicomplexans. In this study, we sequenced two divergent Cryptosporidium species and conducted a comparative genomic analysis to infer the reductive evolution of metabolic pathways and differential evolution of invasion-related proteins within the Cryptosporidium lineage. Results In energy metabolism, Cryptosporidium species differ from each other mostly in mitosome metabolic pathways. Compared with C. parvum and C. hominis, C. andersoni possesses more aerobic metabolism and a conventional electron transport chain, whereas C. ubiquitum has further reductions in ubiquinone and polyisprenoid biosynthesis and has lost both the conventional and alternative electron transport systems. For invasion-associated proteins, similar to C. hominis, a reduction in the number of genes encoding secreted MEDLE and insulinase-like proteins in the subtelomeric regions of chromosomes 5 and 6 was also observed in C. ubiquitum and C. andersoni, whereas mucin-type glycoproteins are highly divergent between the gastric C. andersoni and intestinal Cryptosporidium species. Conclusions Results of the study suggest that rapidly evolving mitosome metabolism and secreted invasion-related proteins could be involved in tissue tropism and host specificity in Cryptosporidium spp. The finding of progressive reduction in mitosome metabolism among Cryptosporidium species improves our knowledge of organelle evolution within apicomplexans. Electronic supplementary material The online version of this article (doi:10.1186/s12864-016-3343-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Shiyou Liu
- State Key Laboratory of Bioreactor Engineering, School of Resources and Environmental Engineering, East China University of Science and Technology, Shanghai, 200237, China.,Division of Foodborne, Waterborne, and Environmental Diseases, Centers for Disease Control and Prevention, Atlanta, GA, 30329, USA
| | - Dawn M Roellig
- Division of Foodborne, Waterborne, and Environmental Diseases, Centers for Disease Control and Prevention, Atlanta, GA, 30329, USA
| | - Yaqiong Guo
- State Key Laboratory of Bioreactor Engineering, School of Resources and Environmental Engineering, East China University of Science and Technology, Shanghai, 200237, China.,Division of Foodborne, Waterborne, and Environmental Diseases, Centers for Disease Control and Prevention, Atlanta, GA, 30329, USA
| | - Na Li
- State Key Laboratory of Bioreactor Engineering, School of Resources and Environmental Engineering, East China University of Science and Technology, Shanghai, 200237, China.,Division of Foodborne, Waterborne, and Environmental Diseases, Centers for Disease Control and Prevention, Atlanta, GA, 30329, USA
| | - Michael A Frace
- Division of Scientific Resources, Centers for Disease Control and Prevention, Atlanta, GA, 30329, USA
| | - Kevin Tang
- Division of Scientific Resources, Centers for Disease Control and Prevention, Atlanta, GA, 30329, USA
| | - Longxian Zhang
- College of Animal Science and Veterinary Medicine, Henan Agricultural University, Zhengzhou, 450002, China
| | - Yaoyu Feng
- State Key Laboratory of Bioreactor Engineering, School of Resources and Environmental Engineering, East China University of Science and Technology, Shanghai, 200237, China.
| | - Lihua Xiao
- Division of Foodborne, Waterborne, and Environmental Diseases, Centers for Disease Control and Prevention, Atlanta, GA, 30329, USA.
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20
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Pennisi R, Salvi D, Brandi V, Angelini R, Ascenzi P, Polticelli F. Molecular Evolution of Alternative Oxidase Proteins: A Phylogenetic and Structure Modeling Approach. J Mol Evol 2016; 82:207-18. [PMID: 27090422 DOI: 10.1007/s00239-016-9738-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Accepted: 04/06/2016] [Indexed: 11/30/2022]
Abstract
Alternative oxidases (AOXs) are mitochondrial cyanide-resistant membrane-bound metallo-proteins catalyzing the oxidation of ubiquinol and the reduction of oxygen to water bypassing two sites of proton pumping, thus dissipating a major part of redox energy into heat. Here, the structure of Arabidopsis thaliana AOX 1A has been modeled using the crystal structure of Trypanosoma brucei AOX as a template. Analysis of this model and multiple sequence alignment of members of the AOX family from all kingdoms of Life indicate that AOXs display a high degree of conservation of the catalytic core, which is formed by a four-α-helix bundle, hosting the di-iron catalytic site, and is flanked by two additional α-helices anchoring the protein to the membrane. Plant AOXs display a peculiar covalent dimerization mode due to the conservation in the N-terminal region of a Cys residue forming the inter-monomer disulfide bond. The multiple sequence alignment has also been used to infer a phylogenetic tree of AOXs whose analysis shows a polyphyletic origin for the AOXs found in Fungi and a monophyletic origin of the AOXs of Eubacteria, Mycetozoa, Euglenozoa, Metazoa, and Land Plants. This suggests that AOXs evolved from a common ancestral protein in each of these kingdoms. Within the Plant AOX clade, the AOXs of monocotyledon plants form two distinct clades which have unresolved relationships relative to the monophyletic clade of the AOXs of dicotyledonous plants. This reflects the sequence divergence of the N-terminal region, probably due to a low selective pressure for sequence conservation linked to the covalent homo-dimerization mode.
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Affiliation(s)
- Rosa Pennisi
- Department of Sciences, Roma Tre University, Viale Guglielmo Marconi 446, 00146, Rome, Italy
| | - Daniele Salvi
- CIBIO-InBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, Universidade do Porto, Campus Agrário de Vairão, 4485-661, Vairão, Portugal
| | - Valentina Brandi
- Department of Sciences, Roma Tre University, Viale Guglielmo Marconi 446, 00146, Rome, Italy
| | - Riccardo Angelini
- Department of Sciences, Roma Tre University, Viale Guglielmo Marconi 446, 00146, Rome, Italy
| | - Paolo Ascenzi
- Department of Sciences, Roma Tre University, Viale Guglielmo Marconi 446, 00146, Rome, Italy
| | - Fabio Polticelli
- Department of Sciences, Roma Tre University, Viale Guglielmo Marconi 446, 00146, Rome, Italy. .,National Institute of Nuclear Physics, Roma Tre Section, 00146, Rome, Italy.
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21
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Charvat RA, Arrizabalaga G. Oxidative stress generated during monensin treatment contributes to altered Toxoplasma gondii mitochondrial function. Sci Rep 2016; 6:22997. [PMID: 26976749 PMCID: PMC4792157 DOI: 10.1038/srep22997] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2015] [Accepted: 02/26/2016] [Indexed: 02/08/2023] Open
Abstract
The ionophore monensin displays potent activities against several coccidian parasites of veterinary and medical importance including the opportunistic pathogen of humans, Toxoplasma gondii. While monensin is used widely in animals, toxicity impedes its use in humans. Nonetheless, given its potency, understanding its mode of action would reveal vulnerable aspects of the parasite that can be exploited for drug development. We previously established that monensin induces Toxoplasma to undergo cell cycle arrest and an autophagy-like cell death. Interestingly, these effects are dependent on the mitochondrion-localized TgMSH-1 protein, suggesting that monensin disrupts mitochondrial function. We demonstrate that monensin treatment results in decreased mitochondrial membrane potential and altered morphology. These effects are mitigated by the antioxidant compound N-acetyl-cysteine suggesting that monensin causes an oxidative stress, which was indeed the case based on direct detection of reactive oxygen species. Moreover, over-expression of the antioxidant proteins glutaredoxin and peroxiredoxin 2 protect Toxoplasma from the deleterious effects of monensin. Thus, our studies show that the effects of monensin on Toxoplasma are due to a disruption of mitochondrial function caused by the induction of an oxidative stress and implicate parasite redox biology as a viable target for the development of drugs against Toxoplasma and related pathogenic parasites.
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Affiliation(s)
- Robert A Charvat
- Departments of Pharmacology and Toxicology Indiana University School of Medicine, Indianapolis, Indiana 46202, US
| | - Gustavo Arrizabalaga
- Departments of Pharmacology and Toxicology Indiana University School of Medicine, Indianapolis, Indiana 46202, US.,Departments of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, Indiana 46202, US
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22
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Abstract
Apicomplexan parasites include some of the most prevalent and deadly human pathogens. Novel antiparasitic drugs are urgently needed. Synthesis and metabolism of isoprenoids may present multiple targets for therapeutic intervention. The apicoplast-localized methylerythritol phosphate (MEP) pathway for isoprenoid precursor biosynthesis is distinct from the mevalonate (MVA) pathway used by the mammalian host, and this pathway is apparently essential in most Apicomplexa. In this review, we discuss the current field of research on production and metabolic fates of isoprenoids in apicomplexan parasites, including the acquisition of host isoprenoid precursors and downstream products. We describe recent work identifying the first MEP pathway regulator in apicomplexan parasites, and introduce several promising areas for ongoing research into this well-validated antiparasitic target.
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Affiliation(s)
- Leah Imlay
- Department of Molecular Microbiology Washington University School of Medicine St. Louis, MO 63110 USA
| | - Audrey R Odom
- Department of Pediatrics Washington University School of Medicine St. Louis, MO 63110 USA & Department of Molecular Microbiology Washington University School of Medicine St. Louis, MO 63110 USA
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23
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Abstract
Philasterides dicentrarchi causes a severe disease in turbot, and at present there are no drugs available to treat infected fish. We have previously demonstrated that, in addition to the classical respiratory pathway, P. dicentrarchi possesses an alternative mitochondrial respiratory pathway that is cyanide-insensitive and salicylhydroxamic acid (SHAM)-sensitive. In this study, we found that during the initial phase of growth in normoxia, ciliate respiration is sensitive to the natural polyphenol resveratrol (RESV) and to Antimycin A (AMA). However, under hypoxic conditions, the parasite utilizes AMA-insensitive respiration, which is completely inhibited by RESV and by the antioxidant propyl gallate (PG), an alternative oxidase (AOX) inhibitor. PG caused significantly dose-dependent inhibition of the in vitro growth of the parasite under normoxia and hypoxia and an over-expression of heat shock proteins of the Hsp70 subfamily. RESV and PG may affect the protective role of the AOX against mitochondrial oxidative stress, leading to an impaired mitochondrial membrane potential and mitochondrial dysfunction, which the parasite attempts to neutralize by increasing the expression of Hsp70. In view of the antiparasitic effects induced by AOX inhibitors and the absence of AOX in their host, this enzyme constitutes a potential target for the development of new drugs against scuticociliatosis.
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24
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Antos-Krzeminska N, Jarmuszkiewicz W. Functional expression of the Acanthamoeba castellanii alternative oxidase in Escherichia coli; regulation of the activity and evidence for Acaox gene function. Biochem Cell Biol 2014; 92:235-41. [PMID: 24860925 DOI: 10.1139/bcb-2014-0014] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
To evidence Acanthamoeba castellanii alternative oxidase (AcAOX) gene product function, we studied alterations in the levels of mRNA and protein and AcAOX activity during growth in amoeba batch culture. Moreover, heterologous expression of AcAOX in AOX-deficient Escherichia coli confirmed by the protein immunodetection and functional studies was performed. Despite the presence of native bo and bd quinol oxidases in E. coli membrane, from which the latter is known to be cyanide-resistant, functional expression of AcAOX in E. coli conferred cyanide-resistant benzohydroxamate-sensitive respiration on the bacteria. Moreover, AcAOX activity in transformed bacteria was stimulated by GMP and inhibited by ATP, indicating that AcAOX is regulated by mutual exclusion of purine nucleotides, which was previously demonstrated in the mitochondria of A. castellanii.
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Affiliation(s)
- Nina Antos-Krzeminska
- Department of Bioenergetics, Adam Mickiewicz University, Umultowska 89, 61-614 Poznan, Poland
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25
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Highly divergent mitochondrion-related organelles in anaerobic parasitic protozoa. Biochimie 2014; 100:3-17. [DOI: 10.1016/j.biochi.2013.11.018] [Citation(s) in RCA: 103] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2013] [Accepted: 11/24/2013] [Indexed: 11/20/2022]
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Maas AK. Considerations and conditions involving protozoal inhabitation of the reptilian gastrointestinal tract. Vet Clin North Am Exot Anim Pract 2014; 17:263-97. [PMID: 24767746 DOI: 10.1016/j.cvex.2014.01.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
In mammals, gastrointestinal protozoal organism inhabitation has been well studied, with hundreds of species defined as parasites. While the mammalian protozoal relationships have been identified and categorized by anatomy, tropism, pathogenicity, and life cycles, relatively few species of protozoal organism relationships have been categorized in reptiles. Species of parasites are still being segregated from each other, and conflicting information needs to be clarified to completely understand the data already available. This article presents the information available to help reptile practitioners make evidence-based decisions regarding both the determination of a pathologic parasitic condition and direct appropriate treatment of patients.
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Affiliation(s)
- Adolf K Maas
- ZooVet Consulting, PLLC, PO Box 1007, Bothell, WA 98041, USA.
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The alternative oxidases: simple oxidoreductase proteins with complex functions. Biochem Soc Trans 2014; 41:1305-11. [PMID: 24059524 DOI: 10.1042/bst20130073] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The alternative oxidases are membrane-bound monotopic terminal electron transport proteins found in all plants and in some agrochemically important fungi and parasites including Trypansoma brucei, which is the causative agent of trypanosomiasis. They are integral membrane proteins and reduce oxygen to water in a four electron process. The recent elucidation of the crystal structure of the trypanosomal alternative oxidase at 2.85 Å (1 Å=0.1 nm) has revealed salient structural features necessary for its function. In the present review we compare the primary and secondary ligation spheres of the alternative oxidases with other di-iron carboxylate proteins and propose a mechanism for the reduction of oxygen to water.
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Purification and characterisation of recombinant DNA encoding the alternative oxidase from Sauromatum guttatum. Mitochondrion 2014; 19 Pt B:261-8. [PMID: 24632469 DOI: 10.1016/j.mito.2014.03.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2013] [Revised: 02/27/2014] [Accepted: 03/04/2014] [Indexed: 11/21/2022]
Abstract
The alternative oxidase (AOX) is a non-protonmotive ubiquinol oxidase that is found in mitochondria of all higher plants studied to date. Structural and functional characterisation of this important but enigmatic plant diiron protein has been hampered by an inability to obtain sufficient native protein from plant sources. In the present study recombinant SgAOX (rSgAOX), overexpressed in a ΔhemA-deficient Escherichia coli strain (FN102), was solubilized from E. coli membranes and purified to homogeneity in a stable and highly active form. The kinetics of ubiquinol-1 oxidation by purified rSgAOX showed typical Michaelis-Menten kinetics (K(m) of 332 μM and Vmax of 30 μmol(-1) min(-1) mg(-1)), a turnover number 20 μmol s(-1) and a remarkable stability. The enzyme was potently inhibited not only by conventional inhibitors such as SHAM and n-propyl gallate but also by the potent TAO inhibitors ascofuranone, an ascofuranone-derivative colletochlorin B and the cytochrome bc1 inhibitor ascochlorin. Circular dichroism studies revealed that AOX was approximately 50% α-helical and furthermore such studies revealed that rSgAOX and rTAO partially retained the helical absorbance signal even at 90 °C (58% and 64% respectively) indicating a high conformational stability. It is anticipated that highly purified and active AOX and its mutants will facilitate investigations into the structure and reaction mechanisms of AOXs through the provision of large amounts of purified protein for crystallography and contribute to further progress of the study on this important plant terminal oxidase.
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Young L, May B, Pendlebury-Watt A, Shearman J, Elliott C, Albury MS, Shiba T, Inaoka DK, Harada S, Kita K, Moore AL. Probing the ubiquinol-binding site of recombinant Sauromatum guttatum alternative oxidase expressed in E. coli membranes through site-directed mutagenesis. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2014; 1837:1219-25. [PMID: 24530866 DOI: 10.1016/j.bbabio.2014.01.027] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2013] [Revised: 01/23/2014] [Accepted: 01/28/2014] [Indexed: 11/16/2022]
Abstract
In the present paper we have investigated the effect of mutagenesis of a number of highly conserved residues (R159, D163, L177 and L267) which we have recently shown to line the hydrophobic inhibitor/substrate cavity in the alternative oxidases (AOXs). Measurements of respiratory activity in rSgAOX expressed in Escherichia coli FN102 membranes indicate that all mutants result in a decrease in maximum activity of AOX and in some cases (D163 and L177) a decrease in the apparent Km (O2). Of particular importance was the finding that when the L177 and L267 residues, which appear to cause a bottleneck in the hydrophobic cavity, are mutated to alanine the sensitivity to AOX antagonists is reduced. When non-AOX anti-malarial inhibitors were also tested against these mutants widening the bottleneck through removal of isobutyl side chain allowed access of these bulkier inhibitors to the active-site and resulted in inhibition. Results are discussed in terms of how these mutations have altered the way in which the AOX's catalytic cycle is controlled and since maximum activity is decreased we predict that such mutations result in an increase in the steady state level of at least one O2-derived AOX intermediate. Such mutations should therefore prove to be useful in future stopped-flow and electron paramagnetic resonance experiments in attempts to understand the catalytic cycle of the alternative oxidase which may prove to be important in future rational drug design to treat diseases such as trypanosomiasis. Furthermore since single amino acid mutations in inhibitor/substrate pockets have been found to be the cause of multi-drug resistant strains of malaria, the decrease in sensitivity to main AOX antagonists observed in the L-mutants studied in this report suggests that an emergence of drug resistance to trypanosomiasis may also be possible. Therefore we suggest that the design of future AOX inhibitors should have structures that are less reliant on the orientation by the two-leucine residues. This article is part of a Special Issue entitled: 18th European Bioenergetic Conference.
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Affiliation(s)
- Luke Young
- Biochemistry and Molecular Sciences, School of Life Sciences, University of Sussex, Falmer, Brighton BN1 9QG, UK
| | - Benjamin May
- Biochemistry and Molecular Sciences, School of Life Sciences, University of Sussex, Falmer, Brighton BN1 9QG, UK
| | - Alice Pendlebury-Watt
- Biochemistry and Molecular Sciences, School of Life Sciences, University of Sussex, Falmer, Brighton BN1 9QG, UK
| | - Julia Shearman
- Biochemistry and Molecular Sciences, School of Life Sciences, University of Sussex, Falmer, Brighton BN1 9QG, UK
| | - Catherine Elliott
- Biochemistry and Molecular Sciences, School of Life Sciences, University of Sussex, Falmer, Brighton BN1 9QG, UK
| | - Mary S Albury
- Biochemistry and Molecular Sciences, School of Life Sciences, University of Sussex, Falmer, Brighton BN1 9QG, UK
| | - Tomoo Shiba
- Department of Applied Biology, Graduate School of Science and Technology, Kyoto Institute of Technology, Kyoto 606-8585, Japan
| | - Daniel Ken Inaoka
- Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan
| | - Shigeharu Harada
- Department of Applied Biology, Graduate School of Science and Technology, Kyoto Institute of Technology, Kyoto 606-8585, Japan
| | - Kiyoshi Kita
- Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan
| | - Anthony L Moore
- Biochemistry and Molecular Sciences, School of Life Sciences, University of Sussex, Falmer, Brighton BN1 9QG, UK.
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Mallo N, Lamas J, Leiro JM. Evidence of an alternative oxidase pathway for mitochondrial respiration in the scuticociliate Philasterides dicentrarchi. Protist 2013; 164:824-36. [PMID: 24211656 DOI: 10.1016/j.protis.2013.09.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2013] [Revised: 09/25/2013] [Accepted: 09/28/2013] [Indexed: 11/17/2022]
Abstract
The presence of an alternative oxidase (AOX) in the mitochondria of the scuticociliate P. dicentrarchi was investigated. The mitochondrial oxygen consumption was measured in the presence of KCN, an inhibitor of cytochrome pathway (CP) respiration and salicylhydroxamic acid (SHAM), a specific inhibitor of alternative pathway (AP) respiration. AOX expression was monitored by western blotting with an AOX polyclonal antibody. The results showed that P. dicentrarchi possesses a branched mitochondrial electron transport chain with both cyanide-sensitive and -insensitive oxygen consumption. Mitochondrial respiration was partially inhibited by cyanide and completely inhibited by the combination of cyanide and SHAM, which is direct evidence for the existence of an AP in this ciliate. SHAM significantly inhibited in vitro growth of trophozoites both under normoxic and hypoxic conditions. AOX is a 42kD monomeric protein inducible by hypoxic conditions in experimental infections and by CP inhibitors such as cyanide and antimycin A, or by AP inhibitors such as SHAM. CP respiration was greatly stimulated during the exponential growth phase, while AP respiration increased during the stationary phase, in which AOX expression is induced. As the host does not possess AOX, and because during infection P. dicentrarchi respires via AP, it may be possible to develop inhibitors targeting the AP as a novel anti-scuticociliate therapy.
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Affiliation(s)
- Natalia Mallo
- Laboratorio de Parasitología, Departamento de Microbiología y Parasitología, Instituto de Investigación y Análisis Alimentarios, c/ Constantino Candeira s/n, 15782, Universidad de Santiago de Compostela; Santiago de Compostela (La Coruña, Spain)
| | - Jesús Lamas
- Departamento de Biología Celular y Ecología; Universidad de Santiago de Compostela; Santiago de Compostela, (La Coruña, Spain)
| | - José Manuel Leiro
- Laboratorio de Parasitología, Departamento de Microbiología y Parasitología, Instituto de Investigación y Análisis Alimentarios, c/ Constantino Candeira s/n, 15782, Universidad de Santiago de Compostela; Santiago de Compostela (La Coruña, Spain).
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Stec J, Fomovska A, Afanador GA, Muench SP, Zhou Y, Lai BS, El Bissati K, Hickman MR, Lee PJ, Leed SE, Auschwitz JM, Sommervile C, Woods S, Roberts CW, Rice D, Prigge ST, McLeod R, Kozikowski AP. Modification of triclosan scaffold in search of improved inhibitors for enoyl-acyl carrier protein (ACP) reductase in Toxoplasma gondii. ChemMedChem 2013; 8:1138-60. [PMID: 23776166 DOI: 10.1002/cmdc.201300050] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2013] [Revised: 04/26/2013] [Indexed: 11/08/2022]
Abstract
Through our focused effort to discover new and effective agents against toxoplasmosis, a structure-based drug design approach was used to develop a series of potent inhibitors of the enoyl-acyl carrier protein (ACP) reductase (ENR) enzyme in Toxoplasma gondii (TgENR). Modifications to positions 5 and 4' of the well-known ENR inhibitor triclosan afforded a series of 29 new analogues. Among the resulting compounds, many showed high potency and improved physicochemical properties in comparison with the lead. The most potent compounds 16 a and 16 c have IC50 values of 250 nM against Toxoplasma gondii tachyzoites without apparent toxicity to the host cells. Their IC50 values against recombinant TgENR were found to be 43 and 26 nM, respectively. Additionally, 11 other analogues in this series had IC50 values ranging from 17 to 130 nM in the enzyme-based assay. With respect to their excellent in vitro activity as well as improved drug-like properties, the lead compounds 16 a and 16 c are deemed to be excellent starting points for the development of new medicines to effectively treat Toxoplasma gondii infections.
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Affiliation(s)
- Jozef Stec
- Drug Discovery Program, Department of Medicinal Chemistry and Pharmacognosy, University of Illinois at Chicago, 833 South Wood Street, Chicago, IL 60612, USA
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Shiba T, Kido Y, Sakamoto K, Inaoka DK, Tsuge C, Tatsumi R, Takahashi G, Balogun EO, Nara T, Aoki T, Honma T, Tanaka A, Inoue M, Matsuoka S, Saimoto H, Moore AL, Harada S, Kita K. Structure of the trypanosome cyanide-insensitive alternative oxidase. Proc Natl Acad Sci U S A 2013; 110:4580-5. [PMID: 23487766 PMCID: PMC3607012 DOI: 10.1073/pnas.1218386110] [Citation(s) in RCA: 128] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
In addition to haem copper oxidases, all higher plants, some algae, yeasts, molds, metazoans, and pathogenic microorganisms such as Trypanosoma brucei contain an additional terminal oxidase, the cyanide-insensitive alternative oxidase (AOX). AOX is a diiron carboxylate protein that catalyzes the four-electron reduction of dioxygen to water by ubiquinol. In T. brucei, a parasite that causes human African sleeping sickness, AOX plays a critical role in the survival of the parasite in its bloodstream form. Because AOX is absent from mammals, this protein represents a unique and promising therapeutic target. Despite its bioenergetic and medical importance, however, structural features of any AOX are yet to be elucidated. Here we report crystal structures of the trypanosomal alternative oxidase in the absence and presence of ascofuranone derivatives. All structures reveal that the oxidase is a homodimer with the nonhaem diiron carboxylate active site buried within a four-helix bundle. Unusually, the active site is ligated solely by four glutamate residues in its oxidized inhibitor-free state; however, inhibitor binding induces the ligation of a histidine residue. A highly conserved Tyr220 is within 4 Å of the active site and is critical for catalytic activity. All structures also reveal that there are two hydrophobic cavities per monomer. Both inhibitors bind to one cavity within 4 Å and 5 Å of the active site and Tyr220, respectively. A second cavity interacts with the inhibitor-binding cavity at the diiron center. We suggest that both cavities bind ubiquinol and along with Tyr220 are required for the catalytic cycle for O2 reduction.
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Affiliation(s)
- Tomoo Shiba
- Department of Biomedical Chemistry, Graduate School of Medicine, and
| | - Yasutoshi Kido
- Department of Biomedical Chemistry, Graduate School of Medicine, and
| | | | - Daniel Ken Inaoka
- Department of Biomedical Chemistry, Graduate School of Medicine, and
| | - Chiaki Tsuge
- Department of Biomedical Chemistry, Graduate School of Medicine, and
| | - Ryoko Tatsumi
- Department of Biomedical Chemistry, Graduate School of Medicine, and
| | - Gen Takahashi
- Department of Applied Biology, Graduate School of Science and Technology, Kyoto Institute of Technology, Kyoto 606-8585, Japan
| | - Emmanuel Oluwadare Balogun
- Department of Biomedical Chemistry, Graduate School of Medicine, and
- Department of Applied Biology, Graduate School of Science and Technology, Kyoto Institute of Technology, Kyoto 606-8585, Japan
- Department of Biochemistry, Ahmadu Bello University, Zaria 2222, Nigeria
| | - Takeshi Nara
- Department of Molecular and Cellular Parasitology, Juntendo University School of Medicine, Tokyo 113-8421, Japan
| | - Takashi Aoki
- Department of Molecular and Cellular Parasitology, Juntendo University School of Medicine, Tokyo 113-8421, Japan
| | - Teruki Honma
- Systems and Structural Biology Center, RIKEN, Tsurumi, Yokohama 230-0045, Japan;
| | - Akiko Tanaka
- Systems and Structural Biology Center, RIKEN, Tsurumi, Yokohama 230-0045, Japan;
| | - Masayuki Inoue
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo 113-0033, Japan
| | - Shigeru Matsuoka
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo 113-0033, Japan
| | - Hiroyuki Saimoto
- Department of Chemistry and Biotechnology, Graduate School of Engineering, Tottori University, Tottori 680-8552, Japan; and
| | - Anthony L. Moore
- Biochemistry and Molecular Biology, School of Life Sciences, University of Sussex, Brighton BN1 9QG, United Kingdom
| | - Shigeharu Harada
- Department of Applied Biology, Graduate School of Science and Technology, Kyoto Institute of Technology, Kyoto 606-8585, Japan
| | - Kiyoshi Kita
- Department of Biomedical Chemistry, Graduate School of Medicine, and
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van Dooren GG, Kennedy AT, McFadden GI. The use and abuse of heme in apicomplexan parasites. Antioxid Redox Signal 2012; 17:634-56. [PMID: 22320355 DOI: 10.1089/ars.2012.4539] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
SIGNIFICANCE Heme is an essential prosthetic group for most life on Earth. It functions in numerous cellular redox reactions, including in antioxidant defenses and at several stages of the electron transport chain in prokaryotes and eukaryotic mitochondria. Heme also functions as a sensor and transport molecule for gases such as oxygen. Heme is a complex organic molecule and can only be synthesized through a multienzyme pathway from simpler precursors. Most free-living organisms synthesize their own heme by a broadly conserved metabolic pathway. Parasites are adept at scavenging molecules from their hosts, and heme is no exception. RECENT ADVANCES In this review we examine recent advances in understanding heme usage and acquisition in Apicomplexa, a group of parasites that include the causative agents of malaria, toxoplasmosis, and several major parasites of livestock. CRITICAL ISSUES Heme is critical to the survival of Apicomplexa, although the functions of heme in these organisms remain poorly understood. Some Apicomplexa likely scavenge heme from their host organisms, while others retain the ability to synthesize heme. Surprisingly, some Apicomplexa may be able to both synthesize and scavenge heme. Several Apicomplexa live in intracellular environments that contain high levels of heme. Since heme is toxic at high concentrations, parasites must carefully regulate intracellular heme levels and develop mechanisms to detoxify excess heme. Indeed, drugs interfering with heme detoxification serve as major antimalarials. FUTURE DIRECTIONS Understanding heme requirements and regulation in apicomplexan parasites promises to reveal multiple targets for much-needed therapeutic intervention against these parasites.
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Affiliation(s)
- Giel G van Dooren
- Research School of Biology, Australian National University, Canberra, ACT, Australia.
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Stec J, Huang Q, Pieroni M, Kaiser M, Fomovska A, Mui E, Witola WH, Bettis S, McLeod R, Brun R, Kozikowski AP. Synthesis, biological evaluation, and structure-activity relationships of N-benzoyl-2-hydroxybenzamides as agents active against P. falciparum (K1 strain), Trypanosomes, and Leishmania. J Med Chem 2012; 55:3088-100. [PMID: 22352841 DOI: 10.1021/jm2015183] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In our efforts to identify novel chemical scaffolds for the development of new antiprotozoal drugs, a compound library was screened against Toxoplasma gondii tachyzoites with activity discovered for N-(4-ethylbenzoyl)-2-hydroxybenzamide 1a against T. gondii as described elsewhere. Synthesis of a compound set was guided by T. gondii SAR with 1r found to be superior for T. gondii , also active against Thai and Sierra Leone strains of Plasmodium falciparum , and with superior ADMET properties as described elsewhere. Herein, synthesis methods and details of the chemical analysis of the compounds in this series are described. Further, this series of N-benzoyl-2-hydroxybenzamides was repurposed for testing against four other protozoan parasites: Trypanosoma brucei rhodesiense , Trypanosoma cruzi , Leishmania donovani , and P. falciparum (K1 isolate). Structure-activity analyses led to the identification of compounds in this set with excellent antileishmanial activity (compound 1d). Overall, compound 1r was the best and had activity 21-fold superior to that of the standard antimalarial drug chloroquine against the K1 P. falciparum isolate.
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Affiliation(s)
- Jozef Stec
- Drug Discovery Program, Department of Medicinal Chemistry and Pharmacognosy, University of Illinois at Chicago, 833 South Wood Street, Chicago, Illinois 60612, USA
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Novel N-benzoyl-2-hydroxybenzamide disrupts unique parasite secretory pathway. Antimicrob Agents Chemother 2012; 56:2666-82. [PMID: 22354304 DOI: 10.1128/aac.06450-11] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Toxoplasma gondii is a protozoan parasite that can damage the human brain and eyes. There are no curative medicines. Herein, we describe our discovery of N-benzoyl-2-hydroxybenzamides as a class of compounds effective in the low nanomolar range against T. gondii in vitro and in vivo. Our lead compound, QQ-437, displays robust activity against the parasite and could be useful as a new scaffold for development of novel and improved inhibitors of T. gondii. Our genome-wide investigations reveal a specific mechanism of resistance to N-benzoyl-2-hydroxybenzamides mediated by adaptin-3β, a large protein from the secretory protein complex. N-Benzoyl-2-hydroxybenzamide-resistant clones have alterations of their secretory pathway, which traffics proteins to micronemes, rhoptries, dense granules, and acidocalcisomes/plant-like vacuole (PLVs). N-Benzoyl-2-hydroxybenzamide treatment also alters micronemes, rhoptries, the contents of dense granules, and, most markedly, acidocalcisomes/PLVs. Furthermore, QQ-437 is active against chloroquine-resistant Plasmodium falciparum. Our studies reveal a novel class of compounds that disrupts a unique secretory pathway of T. gondii, with the potential to be used as scaffolds in the search for improved compounds to treat the devastating diseases caused by apicomplexan parasites.
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Hydrogenosomes and Mitosomes: Mitochondrial Adaptations to Life in Anaerobic Environments. CELLULAR ORIGIN, LIFE IN EXTREME HABITATS AND ASTROBIOLOGY 2012. [DOI: 10.1007/978-94-007-1896-8_5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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Torrentino-Madamet M, Almeras L, Travaillé C, Sinou V, Pophillat M, Belghazi M, Fourquet P, Jammes Y, Parzy D. Proteomic analysis revealed alterations of the Plasmodium falciparum metabolism following salicylhydroxamic acid exposure. Res Rep Trop Med 2011; 2:109-119. [PMID: 30881184 DOI: 10.2147/rrtm.s23127] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
OBJECTIVES Although human respiratory metabolism is characterized by the mitochondrial electron transport chain, some organisms present a "branched respiratory chain." This branched pathway includes both a classical and an alternative respiratory chain. The latter involves an alternative oxidase. Though the Plasmodium falciparum alternative oxidase is not yet identified, a specific inhibitor of this enzyme, salicylhydroxamic acid (SHAM), showed a drug effect on P. falciparum respiratory function using oxygen consumption measurements. The present study aimed to highlight the metabolic pathways that are affected in P. falciparum following SHAM exposure. DESIGN A proteomic approach was used to analyze the P. falciparum proteome and determine the metabolic pathways altered following SHAM treatment. To evaluate the SHAM effect on parasite growth, the phenotypic alterations of P. falciparum after SHAM or/and hyperoxia exposure were observed. RESULTS After SHAM exposure, 26 proteins were significantly deregulated using a fluorescent two dimensional-differential gel electrophoresis. Among these deregulated proteins, some were particularly involved in energetic metabolism. And the combinatory effect of SHAM/hyperoxia seems deleterious for the growth of P. falciparum. CONCLUSION Our results indicated that SHAM appears to activate glycolysis and decrease stress defense systems. These data provide a better understanding of parasite biology.
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Affiliation(s)
| | - Lionel Almeras
- Unité de Recherche en Biologie et Epidémiologie Parasitaires, Antenne IRBA de Marseille (IMTSSA, Le Pharo)
| | - Christelle Travaillé
- UMR-MD3, Université de la Méditerranée, Antenne IRBA de Marseille (IMTSSA, Le Pharo),
| | - Véronique Sinou
- UMR-MD3, Université de la Méditerranée, Antenne IRBA de Marseille (IMTSSA, Le Pharo),
| | - Matthieu Pophillat
- Centre d'Immunologie de Marseille Luminy, Institut National de la Santé et de la Recherche Médicale, Centre National de la Recherche Scientifique, Université de la Méditerranée
| | - Maya Belghazi
- Centre d'Analyse Protéomique de Marseille, Institut Fédératif de Recherche Jean Roche, Faculté de Médecine Nord
| | - Patrick Fourquet
- Centre d'Immunologie de Marseille Luminy, Institut National de la Santé et de la Recherche Médicale, Centre National de la Recherche Scientifique, Université de la Méditerranée
| | - Yves Jammes
- UMR-MD2, Physiologie et Physiopathologie en Conditions d'Oxygénations Extrêmes, Institut Fédératif de Recherche Jean Roche, Faculté de Médecine Nord, Marseille, France
| | - Daniel Parzy
- UMR-MD3, Université de la Méditerranée, Antenne IRBA de Marseille (IMTSSA, Le Pharo),
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Martins VDP, Dinamarco TM, Curti C, Uyemura SA. Classical and alternative components of the mitochondrial respiratory chain in pathogenic fungi as potential therapeutic targets. J Bioenerg Biomembr 2011; 43:81-8. [PMID: 21271279 DOI: 10.1007/s10863-011-9331-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The frequency of opportunistic fungal infection has increased drastically, mainly in patients who are immunocompromised due to organ transplant, leukemia or HIV infection. In spite of this, only a few classes of drugs with a limited array of targets, are available for antifungal therapy. Therefore, more specific and less toxic drugs with new molecular targets is desirable for the treatment of fungal infections. In this context, searching for differences between mitochondrial mammalian hosts and fungi in the classical and alternative components of the mitochondrial respiratory chain may provide new potential therapeutic targets for this purpose.
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Affiliation(s)
- Vicente de Paulo Martins
- Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil
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Martins VP, Dinamarco TM, Soriani FM, Tudella VG, Oliveira SC, Goldman GH, Curti C, Uyemura SA. Involvement of an alternative oxidase in oxidative stress and mycelium-to-yeast differentiation in Paracoccidioides brasiliensis. EUKARYOTIC CELL 2011; 10:237-48. [PMID: 21183691 PMCID: PMC3067407 DOI: 10.1128/ec.00194-10] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2010] [Accepted: 12/10/2010] [Indexed: 11/20/2022]
Abstract
Paracoccidioides brasiliensis is a thermodimorphic human pathogenic fungus that causes paracoccidioidomycosis (PCM), which is the most prevalent systemic mycosis in Latin America. Differentiation from the mycelial to the yeast form (M-to-Y) is an essential step for the establishment of PCM. We evaluated the involvement of mitochondria and intracellular oxidative stress in M-to-Y differentiation. M-to-Y transition was delayed by the inhibition of mitochondrial complexes III and IV or alternative oxidase (AOX) and was blocked by the association of AOX with complex III or IV inhibitors. The expression of P. brasiliensis aox (Pbaox) was developmentally regulated through M-to-Y differentiation, wherein the highest levels were achieved in the first 24 h and during the yeast exponential growth phase; Pbaox was upregulated by oxidative stress. Pbaox was cloned, and its heterologous expression conferred cyanide-resistant respiration in Saccharomyces cerevisiae and Escherichia coli and reduced oxidative stress in S. cerevisiae cells. These results reinforce the role of PbAOX in intracellular redox balancing and demonstrate its involvement, as well as that of other components of the mitochondrial respiratory chain complexes, in the early stages of the M-to-Y differentiation of P. brasiliensis.
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Affiliation(s)
| | | | | | | | - Sergio C. Oliveira
- Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Gustavo H. Goldman
- Departamento de Ciências Farmacêuticas
- Laboratório Nacional de Ciência e Tecnologia do Bioetanol (CTBE), São Paulo, Brazil
| | - Carlos Curti
- Departamento de Física e Química, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brazil
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40
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Interaction of purified alternative oxidase from thermogenic Arum maculatum with pyruvate. FEBS Lett 2010; 585:397-401. [PMID: 21187094 DOI: 10.1016/j.febslet.2010.12.026] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2010] [Revised: 12/06/2010] [Accepted: 12/16/2010] [Indexed: 10/18/2022]
Abstract
Plant alternative oxidase (AOX) activity in isolated mitochondria is regulated by carboxylic acids, but reaction and regulatory mechanisms remain unclear. We show that activity of AOX protein purified from thermogenic Arum maculatum spadices is sensitive to pyruvate and glyoxylate but not succinate. Rapid, irreversible AOX inactivation occurs in the absence of pyruvate, whether or not duroquinol oxidation has been initiated, and is insensitive to duroquinone. Our data indicate that pyruvate stabilises an active conformation of AOX, increasing the population of active protein in a manner independent of reducing substrate and product, and are thus consistent with an exclusive effect of pyruvate on the enzyme's apparent V(max).
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Abstract
The discovery of mitochondrion-type genes in organisms thought to lack mitochondria led to the demonstration that hydrogenosomes share a common ancestry with mitochondria, as well as the discovery of mitosomes in multiple eukaryotic lineages. No examples of examined eukaryotes lacking a mitochondrion-related organelle exist, implying that the endosymbiont that gave rise to the mitochondrion was present in the first eukaryote. These organelles, known as hydrogenosomes, mitosomes, or mitochondrion-like organelles, are typically reduced, both structurally and biochemically, relative to classical mitochondria. However, despite their diversification and adaptation to different niches, all appear to play a role in Fe-S cluster assembly, as observed for mitochondria. Although evidence supports the use of common protein targeting mechanisms in the biogenesis of these diverse organelles, divergent features are also apparent. This review examines the metabolism and biogenesis of these organelles in divergent unicellular microbes, with a focus on parasitic protists.
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Affiliation(s)
- April M Shiflett
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, California 90095-1489, USA
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42
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Albury MS, Elliott C, Moore AL. Ubiquinol-binding site in the alternative oxidase: Mutagenesis reveals features important for substrate binding and inhibition. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2010; 1797:1933-9. [DOI: 10.1016/j.bbabio.2010.01.013] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2009] [Revised: 01/11/2010] [Accepted: 01/12/2010] [Indexed: 11/16/2022]
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Abstract
Although the origin of mitochondria from the endosymbiosis of an α-proteobacterium is well established, the nature of the host cell, the metabolic complexity of the endosymbiont and the subsequent evolution of the proto-mitochondrion into all its current appearances are still the subject of discovery and sometimes debate. Here we review what has been inferred about the original composition and subsequent evolution of the mitochondrial proteome and essential mitochondrial systems. The evolutionary mosaic that currently constitutes mitochondrial proteomes contains (i) endosymbiotic proteins (15-45%), (ii) proteins without detectable orthologs outside the eukaryotic lineage (40%), and (iii) proteins that are derived from non-proteobacterial Bacteria, Bacteriophages and Archaea (15%, specifically multiple tRNA-modification proteins). Protein complexes are of endosymbiotic origin, but have greatly expanded with novel eukaryotic proteins; in contrast to mitochondrial enzymes that are both of proteobacterial and non-proteobacterial origin. This disparity is consistent with the complexity hypothesis, which argues that proteins that are a part of large, multi-subunit complexes are unlikely to undergo horizontal gene transfer. We observe that they neither change their subcellular compartments in the course of evolution, even when their genes do.
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Affiliation(s)
- Radek Szklarczyk
- Radboud University Nijmegen Medical Centre, CMBI/NCMLS, Nijmegen, The Netherlands
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44
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Crichton PG, Albury MS, Affourtit C, Moore AL. Mutagenesis of the Sauromatum guttatum alternative oxidase reveals features important for oxygen binding and catalysis. BIOCHIMICA ET BIOPHYSICA ACTA 2010; 1797:732-7. [PMID: 20026041 DOI: 10.1016/j.bbabio.2009.12.010] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2009] [Revised: 12/10/2009] [Accepted: 12/14/2009] [Indexed: 11/19/2022]
Abstract
The alternative oxidase (AOX) is a non-protonmotive ubiquinol oxidase that is found in mitochondria of all higher plants studied to date. To investigate the role of highly conserved amino acid residues in catalysis we have expressed site-directed mutants of Cys-172, Thr-179, Trp-206, Tyr-253, and Tyr-299 in AOX in the yeast Schizosaccharomyces pombe. Assessment of AOX activity in isolated yeast mitochondria reveals that mutagenesis of Trp-206 to phenylalanine or tyrosine abolishes activity, in contrast to that observed with either Tyr-253 or 299 both mutants of which retained activity. None of the mutants exhibited sensitivity to Q-like inhibitors that differed significantly from the wild type AOX. Interestingly, however, mutagenesis of Thr-179 or Cys-172 (a residue implicated in AOX regulation by alpha-keto acids) to alanine not only resulted in a decrease of maximum AOX activity but also caused a significant increase in the enzyme's affinity for oxygen (4- and 2-fold, respectively). These results provide important new insights in the mechanism of AOX catalysis and regulation by pyruvate.
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Affiliation(s)
- Paul G Crichton
- Department of Biochemistry and Biomedical Sciences, School of Life Sciences, University of Sussex, Falmer, Brighton BN1 9QG, UK
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45
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Kido Y, Sakamoto K, Nakamura K, Harada M, Suzuki T, Yabu Y, Saimoto H, Yamakura F, Ohmori D, Moore A, Harada S, Kita K. Purification and kinetic characterization of recombinant alternative oxidase from Trypanosoma brucei brucei. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2010; 1797:443-50. [DOI: 10.1016/j.bbabio.2009.12.021] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2009] [Revised: 12/23/2009] [Accepted: 12/25/2009] [Indexed: 10/20/2022]
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Williams BAP, Elliot C, Burri L, Kido Y, Kita K, Moore AL, Keeling PJ. A broad distribution of the alternative oxidase in microsporidian parasites. PLoS Pathog 2010; 6:e1000761. [PMID: 20169184 PMCID: PMC2820529 DOI: 10.1371/journal.ppat.1000761] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2009] [Accepted: 01/11/2010] [Indexed: 11/19/2022] Open
Abstract
Microsporidia are a group of obligate intracellular parasitic eukaryotes that were considered to be amitochondriate until the recent discovery of highly reduced mitochondrial organelles called mitosomes. Analysis of the complete genome of Encephalitozoon cuniculi revealed a highly reduced set of proteins in the organelle, mostly related to the assembly of iron-sulphur clusters. Oxidative phosphorylation and the Krebs cycle proteins were absent, in keeping with the notion that the microsporidia and their mitosomes are anaerobic, as is the case for other mitosome bearing eukaryotes, such as Giardia. Here we provide evidence opening the possibility that mitosomes in a number of microsporidian lineages are not completely anaerobic. Specifically, we have identified and characterized a gene encoding the alternative oxidase (AOX), a typically mitochondrial terminal oxidase in eukaryotes, in the genomes of several distantly related microsporidian species, even though this gene is absent from the complete genome of E. cuniculi. In order to confirm that these genes encode functional proteins, AOX genes from both A. locustae and T. hominis were over-expressed in E. coli and AOX activity measured spectrophotometrically using ubiquinol-1 (UQ-1) as substrate. Both A. locustae and T. hominis AOX proteins reduced UQ-1 in a cyanide and antimycin-resistant manner that was sensitive to ascofuranone, a potent inhibitor of the trypanosomal AOX. The physiological role of AOX microsporidia may be to reoxidise reducing equivalents produced by glycolysis, in a manner comparable to that observed in trypanosomes.
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Affiliation(s)
- Bryony A. P. Williams
- School of Biosciences, Geoffrey Pope Building, University of Exeter, Exeter, Devon, United Kingdom
- Department of Botany, University of British Columbia, Vancouver, British Columbia, Canada
| | - Catherine Elliot
- Department of Biochemistry and Biomedical Sciences, School of Life Sciences, University of Sussex, Falmer, Brighton, United Kingdom
| | - Lena Burri
- Department of Botany, University of British Columbia, Vancouver, British Columbia, Canada
| | - Yasutoshi Kido
- Department of Biomedical Chemistry, Graduate School of Medicine, University of Tokyo, Tokyo, Japan
| | - Kiyoshi Kita
- Department of Biomedical Chemistry, Graduate School of Medicine, University of Tokyo, Tokyo, Japan
| | - Anthony L. Moore
- Department of Biochemistry and Biomedical Sciences, School of Life Sciences, University of Sussex, Falmer, Brighton, United Kingdom
| | - Patrick J. Keeling
- Department of Botany, University of British Columbia, Vancouver, British Columbia, Canada
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Albury MS, Elliott C, Moore AL. Towards a structural elucidation of the alternative oxidase in plants. PHYSIOLOGIA PLANTARUM 2009; 137:316-27. [PMID: 19719482 DOI: 10.1111/j.1399-3054.2009.01270.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
In addition to the conventional cytochrome c oxidase, mitochondria of all plants studied to date contain a second cyanide-resistant terminal oxidase or alternative oxidase (AOX). The AOX is located in the inner mitochondrial membrane and branches from the cytochrome pathway at the level of the quinone pool. It is non-protonmotive and couples the oxidation of ubiquinone to the reduction of oxygen to water. For many years, the AOX was considered to be confined to plants, fungi and a small number of protists. Recently, it has become apparent that the AOX occurs in wide range of organisms including prokaryotes and a moderate number of animal species. In this paper, we provide an overview of general features and current knowledge available about the AOX with emphasis on structure, the active site and quinone-binding site. Characterisation of the AOX has advanced considerably over recent years with information emerging about the role of the protein, regulatory regions and functional sites. The large number of sequences available is now enabling us to obtain a clearer picture of evolutionary origins and diversity.
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Affiliation(s)
- Mary S Albury
- Division of Biochemistry and Biomedical Sciences, School of Life Sciences, University of Sussex, Falmer, Brighton BN19QG, UK
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48
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Huynen MA, de Hollander M, Szklarczyk R. Mitochondrial proteome evolution and genetic disease. Biochim Biophys Acta Mol Basis Dis 2009; 1792:1122-9. [DOI: 10.1016/j.bbadis.2009.03.005] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2008] [Revised: 03/04/2009] [Accepted: 03/20/2009] [Indexed: 11/16/2022]
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Henriquez FL, McBride J, Campbell SJ, Ramos T, Ingram PR, Roberts F, Tinney S, Roberts CW. Acanthamoeba alternative oxidase genes: Identification, characterisation and potential as antimicrobial targets. Int J Parasitol 2009; 39:1417-24. [DOI: 10.1016/j.ijpara.2009.04.011] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2009] [Revised: 04/15/2009] [Accepted: 04/28/2009] [Indexed: 11/24/2022]
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50
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Maréchal A, Kido Y, Kita K, Moore AL, Rich PR. Three redox states of Trypanosoma brucei alternative oxidase identified by infrared spectroscopy and electrochemistry. J Biol Chem 2009; 284:31827-33. [PMID: 19767647 DOI: 10.1074/jbc.m109.059980] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Electrochemistry coupled with Fourier transform infrared (IR) spectroscopy was used to investigate the redox properties of recombinant alternative ubiquinol oxidase from Trypanosoma brucei, the organism responsible for African sleeping sickness. Stepwise reduction of the fully oxidized resting state of recombinant alternative ubiquinol oxidase revealed two distinct IR redox difference spectra. The first of these, signal 1, titrates in the reductive direction as an n = 2 Nernstian component with an apparent midpoint potential of 80 mV at pH 7.0. However, reoxidation of signal 1 in the same potential range under anaerobic conditions did not occur and only began with potentials in excess of 500 mV. Reoxidation by introduction of oxygen was also unsuccessful. Signal 1 contained clear features that can be assigned to protonation of at least one carboxylate group, further perturbations of carboxylic and histidine residues, bound ubiquinone, and a negative band at 1554 cm(-1) that might arise from a radical in the fully oxidized protein. A second distinct IR redox difference spectrum, signal 2, appeared more slowly once signal 1 had been reduced. This component could be reoxidized with potentials above 100 mV. In addition, when both signals 1 and 2 were reduced, introduction of oxygen caused rapid oxidation of both components. These data are interpreted in terms of the possible active site structure and mechanism of oxygen reduction to water.
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Affiliation(s)
- Amandine Maréchal
- Glynn Laboratory of Bioenergetics, Institute of Structural and Molecular Biology, University College London, Gower Street, London WC1E 6BT, United Kingdom
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