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Liu X, Koyama S, Tomizuka K, Takata S, Ishikawa Y, Ito S, Kosugi S, Suzuki K, Hikino K, Koido M, Koike Y, Horikoshi M, Gakuhari T, Ikegawa S, Matsuda K, Momozawa Y, Ito K, Kamatani Y, Terao C. Decoding triancestral origins, archaic introgression, and natural selection in the Japanese population by whole-genome sequencing. SCIENCE ADVANCES 2024; 10:eadi8419. [PMID: 38630824 PMCID: PMC11023554 DOI: 10.1126/sciadv.adi8419] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2023] [Accepted: 03/07/2024] [Indexed: 04/19/2024]
Abstract
We generated Japanese Encyclopedia of Whole-Genome/Exome Sequencing Library (JEWEL), a high-depth whole-genome sequencing dataset comprising 3256 individuals from across Japan. Analysis of JEWEL revealed genetic characteristics of the Japanese population that were not discernible using microarray data. First, rare variant-based analysis revealed an unprecedented fine-scale genetic structure. Together with population genetics analysis, the present-day Japanese can be decomposed into three ancestral components. Second, we identified unreported loss-of-function (LoF) variants and observed that for specific genes, LoF variants appeared to be restricted to a more limited set of transcripts than would be expected by chance, with PTPRD as a notable example. Third, we identified 44 archaic segments linked to complex traits, including a Denisovan-derived segment at NKX6-1 associated with type 2 diabetes. Most of these segments are specific to East Asians. Fourth, we identified candidate genetic loci under recent natural selection. Overall, our work provided insights into genetic characteristics of the Japanese population.
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Affiliation(s)
- Xiaoxi Liu
- Laboratory for Statistical and Translational Genetics, RIKEN Center for Integrative Medical Sciences, Yokohama, Japan
- Clinical Research Center, Shizuoka General Hospital, Shizuoka, Japan
| | - Satoshi Koyama
- Laboratory for Cardiovascular Genomics and Informatics, RIKEN Center for Integrative Medical Sciences, Yokohama, Japan
- Medical and Population Genetics and Cardiovascular Disease Initiative, Broad Institute of Harvard and MIT, Boston, MA, USA
- Cardiovascular Research Center, Massachusetts General Hospital, Boston, MA, USA
| | - Kohei Tomizuka
- Laboratory for Statistical and Translational Genetics, RIKEN Center for Integrative Medical Sciences, Yokohama, Japan
| | - Sadaaki Takata
- Laboratory for Genotyping Development, RIKEN Center for Integrative Medical Sciences, Yokohama, Japan
| | - Yuki Ishikawa
- Laboratory for Statistical and Translational Genetics, RIKEN Center for Integrative Medical Sciences, Yokohama, Japan
| | - Shuji Ito
- Laboratory for Statistical and Translational Genetics, RIKEN Center for Integrative Medical Sciences, Yokohama, Japan
- Laboratory for Bone and Joint Diseases, RIKEN Center for Medical Sciences, Tokyo, Japan
- Department of Orthopedic Surgery, Faculty of Medicine, Shimane University, Izumo, Japan
| | - Shunichi Kosugi
- Laboratory for Statistical and Translational Genetics, RIKEN Center for Integrative Medical Sciences, Yokohama, Japan
| | - Kunihiko Suzuki
- Laboratory for Genotyping Development, RIKEN Center for Integrative Medical Sciences, Yokohama, Japan
| | - Keiko Hikino
- Laboratory for Pharmacogenomics, RIKEN Center for Integrative Medical Sciences, Yokohama, Japan
| | - Masaru Koido
- Laboratory for Statistical and Translational Genetics, RIKEN Center for Integrative Medical Sciences, Yokohama, Japan
- Laboratory of Complex Trait Genomics, Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Tokyo, Japan
| | - Yoshinao Koike
- Laboratory for Statistical and Translational Genetics, RIKEN Center for Integrative Medical Sciences, Yokohama, Japan
- Laboratory for Bone and Joint Diseases, RIKEN Center for Medical Sciences, Tokyo, Japan
- Department of Orthopedic Surgery, Hokkaido University Graduate School of Medicine, Sapporo, Japan
| | - Momoko Horikoshi
- Laboratory for Genomics of Diabetes and Metabolism, RIKEN Center for Integrative Medical Sciences, Yokohama, Japan
| | - Takashi Gakuhari
- Institute for the Study of Ancient Civilizations and Cultural Resources, College of Human and Social Sciences, Kanazawa University, Kanazawa, Japan
| | - Shiro Ikegawa
- Laboratory for Bone and Joint Diseases, RIKEN Center for Medical Sciences, Tokyo, Japan
| | - Kochi Matsuda
- Laboratory of Genome Technology, Human Genome Center, Institute of Medical Science, The University of Tokyo, Tokyo, Japan
- Laboratory of Clinical Genome Sequencing, Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Tokyo, Japan
| | - Yukihide Momozawa
- Laboratory for Genotyping Development, RIKEN Center for Integrative Medical Sciences, Yokohama, Japan
| | - Kaoru Ito
- Laboratory for Cardiovascular Genomics and Informatics, RIKEN Center for Integrative Medical Sciences, Yokohama, Japan
| | - Yoichiro Kamatani
- Laboratory for Statistical and Translational Genetics, RIKEN Center for Integrative Medical Sciences, Yokohama, Japan
- Laboratory of Complex Trait Genomics, Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Tokyo, Japan
| | - Chikashi Terao
- Laboratory for Statistical and Translational Genetics, RIKEN Center for Integrative Medical Sciences, Yokohama, Japan
- Clinical Research Center, Shizuoka General Hospital, Shizuoka, Japan
- The Department of Applied Genetics, The School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka, Japan
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Jeelani G, Balogun EO, Husain A, Nozaki T. Glycerol biosynthetic pathway plays an essential role in proliferation and antioxidative defense in the human enteric protozoan parasite Entamoeba histolytica. Sci Rep 2023; 13:14596. [PMID: 37669981 PMCID: PMC10480196 DOI: 10.1038/s41598-023-40670-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Accepted: 08/16/2023] [Indexed: 09/07/2023] Open
Abstract
Amebiasis is caused by the protozoan parasite Entamoeba histolytica. Treatment options other than metronidazole and its derivatives are few, and their low efficacy against asymptomatic cyst carriers, and experimental evidence of resistance in vitro justify the discovery/repurposing campaign for new drugs against amebiasis. Global metabolic responses to oxidative stress and cysteine deprivation by E. histolytica revealed glycerol metabolism may represent a rational target for drug development. In this study using 14C-labelled glucose, only 11% of the total glucose taken up by E. histolytica trophozoites is incorporated to lipids. To better understand the role of glycerol metabolism in this parasite, we focused on characterizing two important enzymes, glycerol kinase (GK) and glycerol 3-phosphate dehydrogenase (G3PDH). Recombinant GK was biochemically characterized in detail, while G3PDH was not due to failure of protein expression and purification. GK revealed novel characteristics and unprecedented kinetic properties in reverse reaction. Gene silencing revealed that GK is essential for optimum growth, whereas G3PDH is not. Gene silencing of G3PDH caused upregulated GK expression, while that of GK resulted in upregulation of antioxidant enzymes as shown by RNA-seq analysis. Although the precise molecular link between GK and the upregulation of antioxidant enzymes was not demonstrated, the observed increase in antioxidant enzyme expression upon GK gene silencing suggests a potential connection between GK and the cellular response to oxidative stress. Together, these results provide the first direct evidence of the biological importance and coordinated regulation of the glycerol metabolic pathways for proliferation and antioxidative defense in E. histolytica, justifying the exploitation of these enzymes as future drug targets.
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Affiliation(s)
- Ghulam Jeelani
- Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Emmanuel Oluwadare Balogun
- Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
- Department of Biochemistry, Ahmadu Bello University, Zaria, Nigeria
| | - Afzal Husain
- Department of Biochemistry, Faculty of Life Sciences, Aligarh Muslim University, Aligarh, India
| | - Tomoyoshi Nozaki
- Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan.
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The Role of Acetate Kinase in the Human Parasite Entamoeba histolytica. PARASITOLOGIA (BASEL, SWITZERLAND) 2022; 2:147-159. [PMID: 36872919 PMCID: PMC9983610 DOI: 10.3390/parasitologia2020014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The human parasite Entamoeba histolytica, which causes approximately 100 million cases of amoebic dysentery each year, relies on glycolysis as the major source of ATP production from glucose as it lacks a citric acid cycle and oxidative phosphorylation. Ethanol and acetate, the two major glycolytic end products for E. histolytica, are produced at a ratio of 2:1 under anaerobic conditions, creating an imbalance between NADH production and utilization. In this study we investigated the role of acetate kinase (ACK) in acetate production during glycolysis in E. histolytica metabolism. Analysis of intracellular and extracellular metabolites demonstrated that acetate levels were unaffected in an ACK RNAi cell line, but acetyl-CoA levels and the NAD+/NADH ratio were significantly elevated. Moreover, we demonstrated that glyceraldehyde 3-phosphate dehydrogenase catalyzes the ACK-dependent conversion of acetaldehyde to acetyl phosphate in E. histolytica. We propose that ACK is not a major contributor to acetate production, but instead provides a mechanism for maintaining the NAD+/NADH balance during ethanol production in the extended glycolytic pathway.
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Queuine Is a Nutritional Regulator of Entamoeba histolytica Response to Oxidative Stress and a Virulence Attenuator. mBio 2021; 12:mBio.03549-20. [PMID: 33688012 PMCID: PMC8092309 DOI: 10.1128/mbio.03549-20] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Entamoeba histolytica is a unicellular parasite that causes amebiasis. The parasite resides in the colon and feeds on the colonic microbiota. Queuosine is a naturally occurring modified ribonucleoside found in the first position of the anticodon of the transfer RNAs for Asp, Asn, His, and Tyr. Eukaryotes lack pathways to synthesize queuine, the nucleobase precursor to queuosine, and must obtain it from diet or gut microbiota. Here, we describe the effects of queuine on the physiology of the eukaryotic parasite Entamoeba histolytica, the causative agent of amebic dysentery. Queuine is efficiently incorporated into E. histolytica tRNAs by a tRNA-guanine transglycosylase (EhTGT) and this incorporation stimulates the methylation of C38 in
tRNAGUCAsp. Queuine protects the parasite against oxidative stress (OS) and antagonizes the negative effect that oxidation has on translation by inducing the expression of genes involved in the OS response, such as heat shock protein 70 (Hsp70), antioxidant enzymes, and enzymes involved in DNA repair. On the other hand, queuine impairs E. histolytica virulence by downregulating the expression of genes previously associated with virulence, including cysteine proteases, cytoskeletal proteins, and small GTPases. Silencing of EhTGT prevents incorporation of queuine into tRNAs and strongly impairs methylation of C38 in
tRNAGUCAsp, parasite growth, resistance to OS, and cytopathic activity. Overall, our data reveal that queuine plays a dual role in promoting OS resistance and reducing parasite virulence.
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Shrivastav MT, Malik Z, Somlata. Revisiting Drug Development Against the Neglected Tropical Disease, Amebiasis. Front Cell Infect Microbiol 2021; 10:628257. [PMID: 33718258 PMCID: PMC7943716 DOI: 10.3389/fcimb.2020.628257] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Accepted: 12/30/2020] [Indexed: 11/15/2022] Open
Abstract
Amebiasis is a neglected tropical disease which is caused by the protozoan parasite Entamoeba histolytica. This disease is one of the leading causes of diarrhea globally, affecting largely impoverished residents in developing countries. Amebiasis also remains one of the top causes of gastrointestinal diseases in returning international travellers. Despite having many side effects, metronidazole remains the drug of choice as an amebicidal tissue-active agent. However, emergence of metronidazole resistance in pathogens having similar anaerobic metabolism and also in laboratory strains of E. histolytica has necessitated the identification and development of new drug targets and therapeutic strategies against the parasite. Recent research in the field of amebiasis has led to a better understanding of the parasite’s metabolic and cellular pathways and hence has been useful in identifying new drug targets. On the other hand, new molecules effective against amebiasis have been mined by modifying available compounds, thereby increasing their potency and efficacy and also by repurposing existing approved drugs. This review aims at compiling and examining up to date information on promising drug targets and drug molecules for the treatment of amebiasis.
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Affiliation(s)
- Manish T Shrivastav
- Multidisciplinary Centre for Advanced Research and Studies, Jamia Millia Islamia, New Delhi, India
| | - Zainab Malik
- Multidisciplinary Centre for Advanced Research and Studies, Jamia Millia Islamia, New Delhi, India
| | - Somlata
- Multidisciplinary Centre for Advanced Research and Studies, Jamia Millia Islamia, New Delhi, India
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König C, Meyer M, Lender C, Nehls S, Wallaschkowski T, Holm T, Matthies T, Lercher D, Matthiesen J, Fehling H, Roeder T, Reindl S, Rosenthal M, Metwally NG, Lotter H, Bruchhaus I. An Alcohol Dehydrogenase 3 (ADH3) from Entamoeba histolytica Is Involved in the Detoxification of Toxic Aldehydes. Microorganisms 2020; 8:microorganisms8101608. [PMID: 33086693 PMCID: PMC7594077 DOI: 10.3390/microorganisms8101608] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Revised: 10/15/2020] [Accepted: 10/16/2020] [Indexed: 12/23/2022] Open
Abstract
Recently, a putative alcohol dehydrogenase 3, termed EhADH3B of the Entamoeba histolytica isolate HM-1:IMSS was identified, which is expressed at higher levels in non-pathogenic than in pathogenic amoebae and whose overexpression reduces the virulence of pathogenic amoebae. In an in silico analysis performed in this study, we assigned EhADH3B to a four-member ADH3 family, with ehadh3b present as a duplicate (ehadh3ba/ehadh3bb). In long-term laboratory cultures a mutation was identified at position 496 of ehadh3ba, which codes for a stop codon, which was not the case for amoebae isolated from human stool samples. When using transfectants that overexpress or silence ehadh3bb, we found no or little effect on growth, size, erythrophagocytosis, motility, hemolytic or cysteine peptidase activity. Biochemical characterization of the recombinant EhADH3Bb revealed that this protein forms a dimer containing Ni2+ or Zn2+ as a co-factor and that the enzyme converts acetaldehyde and formaldehyde in the presence of NADPH. A catalytic activity based on alcohols as substrates was not detected. Based on the results, we postulate that EhADH3Bb can reduce free acetaldehyde released by hydrolysis from bifunctional acetaldehyde/alcohol dehydrogenase-bound thiohemiacetal and that it is involved in detoxification of toxic aldehydes produced by the host or the gut microbiota.
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Affiliation(s)
- Constantin König
- Bernhard Nocht Institute for Tropical Medicine, 20359 Hamburg, Germany; (C.K.); (M.M.); (C.L.); (S.N.); (T.W.); (T.H.); (T.M.); (D.L.); (J.M.); (H.F.); (S.R.); (M.R.); (N.G.M.); (H.L.)
| | - Martin Meyer
- Bernhard Nocht Institute for Tropical Medicine, 20359 Hamburg, Germany; (C.K.); (M.M.); (C.L.); (S.N.); (T.W.); (T.H.); (T.M.); (D.L.); (J.M.); (H.F.); (S.R.); (M.R.); (N.G.M.); (H.L.)
| | - Corinna Lender
- Bernhard Nocht Institute for Tropical Medicine, 20359 Hamburg, Germany; (C.K.); (M.M.); (C.L.); (S.N.); (T.W.); (T.H.); (T.M.); (D.L.); (J.M.); (H.F.); (S.R.); (M.R.); (N.G.M.); (H.L.)
| | - Sarah Nehls
- Bernhard Nocht Institute for Tropical Medicine, 20359 Hamburg, Germany; (C.K.); (M.M.); (C.L.); (S.N.); (T.W.); (T.H.); (T.M.); (D.L.); (J.M.); (H.F.); (S.R.); (M.R.); (N.G.M.); (H.L.)
| | - Tina Wallaschkowski
- Bernhard Nocht Institute for Tropical Medicine, 20359 Hamburg, Germany; (C.K.); (M.M.); (C.L.); (S.N.); (T.W.); (T.H.); (T.M.); (D.L.); (J.M.); (H.F.); (S.R.); (M.R.); (N.G.M.); (H.L.)
| | - Tobias Holm
- Bernhard Nocht Institute for Tropical Medicine, 20359 Hamburg, Germany; (C.K.); (M.M.); (C.L.); (S.N.); (T.W.); (T.H.); (T.M.); (D.L.); (J.M.); (H.F.); (S.R.); (M.R.); (N.G.M.); (H.L.)
| | - Thorben Matthies
- Bernhard Nocht Institute for Tropical Medicine, 20359 Hamburg, Germany; (C.K.); (M.M.); (C.L.); (S.N.); (T.W.); (T.H.); (T.M.); (D.L.); (J.M.); (H.F.); (S.R.); (M.R.); (N.G.M.); (H.L.)
| | - Dirk Lercher
- Bernhard Nocht Institute for Tropical Medicine, 20359 Hamburg, Germany; (C.K.); (M.M.); (C.L.); (S.N.); (T.W.); (T.H.); (T.M.); (D.L.); (J.M.); (H.F.); (S.R.); (M.R.); (N.G.M.); (H.L.)
| | - Jenny Matthiesen
- Bernhard Nocht Institute for Tropical Medicine, 20359 Hamburg, Germany; (C.K.); (M.M.); (C.L.); (S.N.); (T.W.); (T.H.); (T.M.); (D.L.); (J.M.); (H.F.); (S.R.); (M.R.); (N.G.M.); (H.L.)
| | - Helena Fehling
- Bernhard Nocht Institute for Tropical Medicine, 20359 Hamburg, Germany; (C.K.); (M.M.); (C.L.); (S.N.); (T.W.); (T.H.); (T.M.); (D.L.); (J.M.); (H.F.); (S.R.); (M.R.); (N.G.M.); (H.L.)
| | - Thomas Roeder
- Molecular Physiology Department, Zoological Institute, Christian-Albrechts University Kiel, 24118 Kiel, Germany;
| | - Sophia Reindl
- Bernhard Nocht Institute for Tropical Medicine, 20359 Hamburg, Germany; (C.K.); (M.M.); (C.L.); (S.N.); (T.W.); (T.H.); (T.M.); (D.L.); (J.M.); (H.F.); (S.R.); (M.R.); (N.G.M.); (H.L.)
| | - Maria Rosenthal
- Bernhard Nocht Institute for Tropical Medicine, 20359 Hamburg, Germany; (C.K.); (M.M.); (C.L.); (S.N.); (T.W.); (T.H.); (T.M.); (D.L.); (J.M.); (H.F.); (S.R.); (M.R.); (N.G.M.); (H.L.)
| | - Nahla Galal Metwally
- Bernhard Nocht Institute for Tropical Medicine, 20359 Hamburg, Germany; (C.K.); (M.M.); (C.L.); (S.N.); (T.W.); (T.H.); (T.M.); (D.L.); (J.M.); (H.F.); (S.R.); (M.R.); (N.G.M.); (H.L.)
| | - Hannelore Lotter
- Bernhard Nocht Institute for Tropical Medicine, 20359 Hamburg, Germany; (C.K.); (M.M.); (C.L.); (S.N.); (T.W.); (T.H.); (T.M.); (D.L.); (J.M.); (H.F.); (S.R.); (M.R.); (N.G.M.); (H.L.)
| | - Iris Bruchhaus
- Bernhard Nocht Institute for Tropical Medicine, 20359 Hamburg, Germany; (C.K.); (M.M.); (C.L.); (S.N.); (T.W.); (T.H.); (T.M.); (D.L.); (J.M.); (H.F.); (S.R.); (M.R.); (N.G.M.); (H.L.)
- Correspondence:
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Espinosa A, Paz-y-Miño-C G, Santos Y, Ma H, Nadeau M, Seeram NP, Rowley DC. Anti-amebic effects of Chinese rhubarb ( Rheum palmatum) leaves' extract, the anthraquinone rhein and related compounds. Heliyon 2020; 6:e03693. [PMID: 32258515 PMCID: PMC7118315 DOI: 10.1016/j.heliyon.2020.e03693] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Revised: 12/23/2019] [Accepted: 03/25/2020] [Indexed: 01/08/2023] Open
Abstract
Entamoeba histolytica infects 50 million people worldwide and causes 55 thousand fatalities every year. Current anti-amebic drugs (e.g. paromomycin) work either at the level of the intestinal lumen (where trophozoites proliferate via cell divisions) or on the invasive trophozoites that have penetrated the gut or colonized internal organs (e.g. metronidazole). Some of these drugs are highly toxic to patients, have generated trophozoite resistance, or caused mutations and cancer in laboratory animals. Thus, alternative anti-amebic compounds need to be identified to minimize the side effects (on patients) or resistance (by amebas) to current treatments. The literature suggests that anthraquinones (chemicals found in medicinal plants) have antibacterial, antiparasitic, anti-inflammatory and antioxidant properties. Here we provide experimental evidence that Chinese rhubarb (Rheum palmatum) leaves' extract (rich in the anthraquinone rhein) inhibits E. histolytica trophozoite growth in vitro. In addition, from a set of ten isolated/synthetic anthraquinones (which we suspected to have anti-amebic properties), four analogs (rhein; AHHDAC = 1-amino-4-hydroxy-9, 10-dioxo-9, 10-dihydro-anthracene-2-carboxylic acid; unisol blue AS; and sennoside B) efficiently inhibited amebic growth at EIC50 concentrations comparable to metronidazole. The mechanism of action of these compounds still needs to be determined, although anthraquinones might enhance the production of toxic oxygen metabolites as it has been suggested for various protists (e.g. Leishmania, Plasmodium, Trypanosoma). Our research is the first to explore anti-amebic effects of Chinese rhubarb leaves' extract and isolated/synthetic anthraquinones on pathogenic Entamoeba.
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Affiliation(s)
- Avelina Espinosa
- Department of Biology, Roger Williams University, RI 02809, United States
- New England Center for the Public Understanding of Science, Roger Williams University, RI 02809, United States
| | - Guillermo Paz-y-Miño-C
- New England Center for the Public Understanding of Science, Roger Williams University, RI 02809, United States
| | - Yoly Santos
- Department of Biology, Roger Williams University, RI 02809, United States
| | - Hang Ma
- Department of Biomedical & Pharmaceutical Sciences, College of Pharmacy, University of Rhode Island, Kingston, RI 02881, United States
| | - Michael Nadeau
- Department of Biomedical & Pharmaceutical Sciences, College of Pharmacy, University of Rhode Island, Kingston, RI 02881, United States
| | - Navindra P. Seeram
- Department of Biomedical & Pharmaceutical Sciences, College of Pharmacy, University of Rhode Island, Kingston, RI 02881, United States
| | - David C. Rowley
- Department of Biomedical & Pharmaceutical Sciences, College of Pharmacy, University of Rhode Island, Kingston, RI 02881, United States
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Lowerre KM, Espinosa A, Paz-Y-Miño-C G, Hemme C. Bioinformatics Structural and Phylogenetic Characterization of Entamoeba histolytica Alcohol Dehydrogenase 2 (EhADH2). ACTA ACUST UNITED AC 2019; 90:30-41. [PMID: 34103738 DOI: 10.1893/0005-3155-90.1.30] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
An amitochondriate parasite, Entamoeba histolytica, has a bifunctional ADHE enzyme (EhADH2) that contains separate acetaldehyde (ALDH) and alcohol (ADH) dehydrogenase activities. In a cluster of 25 bifunctional enzymes of single cell eukaryotes and bacteria, we present a phylogenetic analysis that suggests a lateral gene transfer event (prokaryotic ancestor to single-cell eukaryotic ancestor) and a complex structure that aligns with key homologs in the ADHE evolutionary history based on their similarity with bacterial alcohol dehydrogenases. We show that the ADHE in Entamoeba lineage diverged independently but shows significant similarities to the structure of ADHE in Fusobacterium, and a complex model that maps its ALDH and ADH domain well with bacteria such as Geobaccillus thermoglucosidasius. Our analyses likely support a lateral acquisition of an EhADH2-like ancestral gene from bacteria. Several evolutionary analyses software programs reveal that the enzyme structure is highly conserved, and maintains a similar function within a diverse set of pathogens, including Escherichia coli and Clostridium spp.
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Affiliation(s)
- Katie M Lowerre
- Department of Biology, Roger Williams University, Bristol, Rhode Island, USA
| | - Avelina Espinosa
- Department of Biology, Roger Williams University, Bristol, Rhode Island, USA
| | - Guillermo Paz-Y-Miño-C
- New England Center for the Public Understanding of Science, Roger Williams University, Bristol, Rhode Island, USA
| | - Christopher Hemme
- RI-INBRE Bioinformatics Core, Department of Biomedical and Pharmaceutical Sciences, University of Rhode Island, Kingston, Rhode Island, USA
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Control and regulation of the pyrophosphate-dependent glucose metabolism in Entamoeba histolytica. Mol Biochem Parasitol 2019; 229:75-87. [PMID: 30772421 DOI: 10.1016/j.molbiopara.2019.02.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Revised: 01/31/2019] [Accepted: 02/09/2019] [Indexed: 01/10/2023]
Abstract
Entamoeba histolytica has neither Krebs cycle nor oxidative phosphorylation activities; therefore, glycolysis is the main pathway for ATP supply and provision of carbon skeleton precursors for the synthesis of macromolecules. Glucose is metabolized through fermentative glycolysis, producing ethanol as its main end-product as well as some acetate. Amoebal glycolysis markedly differs from the typical Embden-Meyerhof-Parnas pathway present in human cells: (i) by the use of inorganic pyrophosphate, instead of ATP, as the high-energy phospho group donor; (ii) with one exception, the pathway enzymes can catalyze reversible reactions under physiological conditions; (iii) there is no allosteric regulation and sigmoidal kinetic behavior of key enzymes; and (iv) the presence of some glycolytic and fermentation enzymes similar to those of anaerobic bacteria. These peculiarities bring about alternative mechanisms of control and regulation of the PPi-dependent fermentative glycolysis in the parasite in comparison to the ATP-dependent and allosterically regulated glycolysis in many other eukaryotic cells. In this review, the current knowledge of the carbohydrate metabolism enzymes in E. histolytica is analyzed. Thermodynamics and stoichiometric analyses indicate 2 to 3.5 ATP yield per glucose metabolized, instead of the often presumed 5 ATP/glucose ratio. PPi derived from anabolism seems insufficient for PPi-glycolysis; hence, alternative ways of PPi supply are also discussed. Furthermore, the underlying mechanisms of control and regulation of the E. histolytica carbohydrate metabolism, analyzed by applying integral and systemic approaches such as Metabolic Control Analysis and kinetic modeling, contribute to unveiling alternative and promising drug targets.
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Kumar R, Jha AK. Association between local alcoholic beverages and amoebic liver abscess in the Indian subcontinent: Weird but true! JGH OPEN 2019; 3:266-267. [PMID: 31276047 PMCID: PMC6586571 DOI: 10.1002/jgh3.12137] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Revised: 12/02/2018] [Accepted: 12/04/2018] [Indexed: 12/01/2022]
Abstract
Many studies from the Indian subcontinent have revealed a strong association between amoebic liver abscess and consumption of toddy – an alcoholic beverage containing fermented palm juice. This article discusses the issues related to this potentially important problem so that appropriate preventive steps can be taken.
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Affiliation(s)
- Ramesh Kumar
- Department of Gastroenterology All India Institute of Medical Sciences Patna India
| | - Ashish K Jha
- Department of Gastroenterology Indira Gandhi Institute of Medical Sciences Patna India
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11
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Pineda E, Perdomo D. Entamoeba histolytica under Oxidative Stress: What Countermeasure Mechanisms Are in Place? Cells 2017; 6:cells6040044. [PMID: 29160807 PMCID: PMC5755502 DOI: 10.3390/cells6040044] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Revised: 11/17/2017] [Accepted: 11/17/2017] [Indexed: 02/06/2023] Open
Abstract
Entamoeba histolytica is the causative agent of human amoebiasis; it affects 50 million people worldwide and causes approximately 100,000 deaths per year. Entamoeba histolytica is an anaerobic parasite that is primarily found in the colon; however, for unknown reasons, it can become invasive, breaching the gut barrier and migrating toward the liver causing amoebic liver abscesses. During the invasive process, it must maintain intracellular hypoxia within the oxygenated human tissues and cellular homeostasis during the host immune defense attack when it is confronted with nitric oxide and reactive oxygen species. But how? This review will address the described and potential mechanisms available to counter the oxidative stress generated during invasion and the possible role that E. histolytica’s continuous endoplasmic reticulum (Eh-ER) plays during these events.
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Affiliation(s)
- Erika Pineda
- Laboratory of Fundamental Microbiology and Pathogenicity (MFP), University of Bordeaux, CNRS UMR-5234, 33000 Bordeaux, France.
| | - Doranda Perdomo
- Laboratory of Fundamental Microbiology and Pathogenicity (MFP), University of Bordeaux, CNRS UMR-5234, 33000 Bordeaux, France.
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12
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Trebicz-Geffen M, Shahi P, Nagaraja S, Vanunu S, Manor S, Avrahami A, Ankri S. Identification of S-Nitrosylated (SNO) Proteins in Entamoeba histolytica Adapted to Nitrosative Stress: Insights into the Role of SNO Actin and In vitro Virulence. Front Cell Infect Microbiol 2017; 7:192. [PMID: 28589096 PMCID: PMC5440460 DOI: 10.3389/fcimb.2017.00192] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2017] [Accepted: 05/03/2017] [Indexed: 12/13/2022] Open
Abstract
We have recently reported that Entamoeba histolytica trophozoites can adapt to toxic levels of the nitric oxide (NO) donor, S-nitrosoglutathione (GSNO). Even if the consequences of this adaptation on the modulation of gene expression in NO-adapted trophozoites (NAT) have been previously explored, insight on S-nitrosylated (SNO) proteins in NAT is missing. Our study aims to fill this knowledge gap by performing a screening of SNO proteins in NAT. Employing SNO resin-assisted capture (RAC), we identified 242 putative SNO proteins with key functions in calcium binding, enzyme modulation, redox homeostasis, and actin cytoskeleton. Of the SNO proteins in NAT, proteins that are associated with actin family cytoskeleton protein are significantly enriched. Here we report that the formation of actin filaments (F-actin) is impaired in NAT. Consequently, the ability of NAT to ingest erythrocytes and their motility and their cytopathic activity are impaired. These phenotypes can be imitated by treating control parasite with cytochalasin D (CytD), a drug that binds to F-actin polymer and prevent polymerization of actin monomers. Removal of GSNO from the culture medium of NAT restored the sensitivity of the parasite to nitrosative stress (NS) and its ability to form F-actin formation and its virulence. These results establish the central role of NO in shaping the virulence of the parasite through its effect on F-actin formation and highlight the impressive ability of this parasite to adapt to NS.
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Affiliation(s)
- Meirav Trebicz-Geffen
- Department of Molecular Microbiology, Ruth and Bruce Rappaport Faculty of Medicine, TechnionHaifa, Israel
| | - Preeti Shahi
- Department of Molecular Microbiology, Ruth and Bruce Rappaport Faculty of Medicine, TechnionHaifa, Israel
| | - Shruti Nagaraja
- Department of Molecular Microbiology, Ruth and Bruce Rappaport Faculty of Medicine, TechnionHaifa, Israel
| | - Shai Vanunu
- Department of Molecular Microbiology, Ruth and Bruce Rappaport Faculty of Medicine, TechnionHaifa, Israel
| | - Shiran Manor
- Department of Molecular Microbiology, Ruth and Bruce Rappaport Faculty of Medicine, TechnionHaifa, Israel
| | - Amit Avrahami
- Ruth and Bruce Rappaport Faculty of Medicine, TechnionHaifa, Israel
| | - Serge Ankri
- Department of Molecular Microbiology, Ruth and Bruce Rappaport Faculty of Medicine, TechnionHaifa, Israel
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13
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Liew F, Henstra AM, Kӧpke M, Winzer K, Simpson SD, Minton NP. Metabolic engineering of Clostridium autoethanogenum for selective alcohol production. Metab Eng 2017; 40:104-114. [PMID: 28111249 PMCID: PMC5367853 DOI: 10.1016/j.ymben.2017.01.007] [Citation(s) in RCA: 130] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Revised: 11/01/2016] [Accepted: 01/19/2017] [Indexed: 01/27/2023]
Abstract
Gas fermentation using acetogenic bacteria such as Clostridium autoethanogenum offers an attractive route for production of fuel ethanol from industrial waste gases. Acetate reduction to acetaldehyde and further to ethanol via an aldehyde: ferredoxin oxidoreductase (AOR) and alcohol dehydrogenase has been postulated alongside the classic pathway of ethanol formation via a bi-functional aldehyde/alcohol dehydrogenase (AdhE). Here we demonstrate that AOR is critical to ethanol formation in acetogens and inactivation of AdhE led to consistently enhanced autotrophic ethanol production (up to 180%). Using ClosTron and allelic exchange mutagenesis, which was demonstrated for the first time in an acetogen, we generated single mutants as well as double mutants for both aor and adhE isoforms to confirm the role of each gene. The aor1+2 double knockout strain lost the ability to convert exogenous acetate, propionate and butyrate into the corresponding alcohols, further highlighting the role of these enzymes in catalyzing the thermodynamically unfavourable reduction of carboxylic acids into alcohols. 180% improvement in C. autoethanogenum ethanol production via metabolic engineering. Confirmed role of AOR in autotrophic ethanol production of acetogens. Generated both aor and adhE mutants of C. autoethanogenum.. Demonstrated allelic exchange mutagenesis for stable deletions in acetogens. Inactivation of adhE and aor2, but not aor1, improves autotrophic ethanol production.
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Affiliation(s)
- Fungmin Liew
- BBSRC/EPSRC Synthetic Biology Research Centre (SBRC), School of Life Sciences, University Park, The University of Nottingham, Nottingham NG7 2RD, UK; LanzaTech Inc., 8045 Lamon Avenue, Suite 400, Skokie, IL, USA
| | - Anne M Henstra
- BBSRC/EPSRC Synthetic Biology Research Centre (SBRC), School of Life Sciences, University Park, The University of Nottingham, Nottingham NG7 2RD, UK
| | - Michael Kӧpke
- LanzaTech Inc., 8045 Lamon Avenue, Suite 400, Skokie, IL, USA
| | - Klaus Winzer
- BBSRC/EPSRC Synthetic Biology Research Centre (SBRC), School of Life Sciences, University Park, The University of Nottingham, Nottingham NG7 2RD, UK
| | - Sean D Simpson
- LanzaTech Inc., 8045 Lamon Avenue, Suite 400, Skokie, IL, USA
| | - Nigel P Minton
- BBSRC/EPSRC Synthetic Biology Research Centre (SBRC), School of Life Sciences, University Park, The University of Nottingham, Nottingham NG7 2RD, UK.
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14
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Gaona-López C, Julián-Sánchez A, Riveros-Rosas H. Diversity and Evolutionary Analysis of Iron-Containing (Type-III) Alcohol Dehydrogenases in Eukaryotes. PLoS One 2016; 11:e0166851. [PMID: 27893862 PMCID: PMC5125639 DOI: 10.1371/journal.pone.0166851] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2016] [Accepted: 11/05/2016] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Alcohol dehydrogenase (ADH) activity is widely distributed in the three domains of life. Currently, there are three non-homologous NAD(P)+-dependent ADH families reported: Type I ADH comprises Zn-dependent ADHs; type II ADH comprises short-chain ADHs described first in Drosophila; and, type III ADH comprises iron-containing ADHs (FeADHs). These three families arose independently throughout evolution and possess different structures and mechanisms of reaction. While types I and II ADHs have been extensively studied, analyses about the evolution and diversity of (type III) FeADHs have not been published yet. Therefore in this work, a phylogenetic analysis of FeADHs was performed to get insights into the evolution of this protein family, as well as explore the diversity of FeADHs in eukaryotes. PRINCIPAL FINDINGS Results showed that FeADHs from eukaryotes are distributed in thirteen protein subfamilies, eight of them possessing protein sequences distributed in the three domains of life. Interestingly, none of these protein subfamilies possess protein sequences found simultaneously in animals, plants and fungi. Many FeADHs are activated by or contain Fe2+, but many others bind to a variety of metals, or even lack of metal cofactor. Animal FeADHs are found in just one protein subfamily, the hydroxyacid-oxoacid transhydrogenase (HOT) subfamily, which includes protein sequences widely distributed in fungi, but not in plants), and in several taxa from lower eukaryotes, bacteria and archaea. Fungi FeADHs are found mainly in two subfamilies: HOT and maleylacetate reductase (MAR), but some can be found also in other three different protein subfamilies. Plant FeADHs are found only in chlorophyta but not in higher plants, and are distributed in three different protein subfamilies. CONCLUSIONS/SIGNIFICANCE FeADHs are a diverse and ancient protein family that shares a common 3D scaffold with a patchy distribution in eukaryotes. The majority of sequenced FeADHs from eukaryotes are distributed in just two subfamilies, HOT and MAR (found mainly in animals and fungi). These two subfamilies comprise almost 85% of all sequenced FeADHs in eukaryotes.
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Affiliation(s)
- Carlos Gaona-López
- Departamento de Bioquímica, Facultad de Medicina, Universidad Nacional Autónoma de México (UNAM). Cd. Universitaria, Ciudad de México, México
| | - Adriana Julián-Sánchez
- Departamento de Bioquímica, Facultad de Medicina, Universidad Nacional Autónoma de México (UNAM). Cd. Universitaria, Ciudad de México, México
| | - Héctor Riveros-Rosas
- Departamento de Bioquímica, Facultad de Medicina, Universidad Nacional Autónoma de México (UNAM). Cd. Universitaria, Ciudad de México, México
- * E-mail:
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15
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Espinosa A, Paz-Y-Miño-C G, Hackey M, Rutherford S. Entamoeba Clone-Recognition Experiments: Morphometrics, Aggregative Behavior, and Cell-Signaling Characterization. J Eukaryot Microbiol 2016; 63:384-93. [PMID: 26990199 DOI: 10.1111/jeu.12313] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2015] [Revised: 03/09/2016] [Accepted: 03/09/2016] [Indexed: 11/30/2022]
Abstract
Studies on clone- and kin-discrimination in protists have proliferated during the past decade. We report clone-recognition experiments in seven Entamoeba lineages (E. invadens IP-1, E. invadens VK-1:NS, E. terrapinae, E. moshkovskii Laredo, E. moshkovskii Snake, E. histolytica HM-1:IMSS and E. dispar). First, we characterized morphometrically each clone (length, width, and cell-surface area) and documented how they differed statistically from one another (as per single-variable or canonical-discriminant analyses). Second, we demonstrated that amebas themselves could discriminate self (clone) from different (themselves vs. other clones). In mix-cell-line cultures between closely-related (E. invadens IP-1 vs. E. invadens VK-1:NS) or distant-phylogenetic clones (E. terrapinae vs. E. moshkovskii Laredo), amebas consistently aggregated with same-clone members. Third, we identified six putative cell-signals secreted by the amebas (RasGap/Ankyrin, coronin-WD40, actin, protein kinases, heat shock 70, and ubiquitin) and which known functions in Entamoeba spp. included: cell proliferation, cell adhesion, cell movement, and stress-induced encystation. To our knowledge, this is the first multi-clone characterization of Entamoeba spp. morphometrics, aggregative behavior, and cell-signaling secretion in the context of clone-recognition. Protists allow us to study cell-cell recognition from ecological and evolutionary perspectives. Modern protistan lineages can be central to studies about the origins and evolution of multicellularity.
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Affiliation(s)
- Avelina Espinosa
- Department of Biology, Roger Williams University, Bristol, Rhode Island, USA.,New England Center for the Public Understanding of Science, Roger Williams University, Bristol, Rhode Island, USA
| | - Guillermo Paz-Y-Miño-C
- New England Center for the Public Understanding of Science, Roger Williams University, Bristol, Rhode Island, USA
| | - Meagan Hackey
- Department of Biology, Roger Williams University, Bristol, Rhode Island, USA
| | - Scott Rutherford
- Department of Environmental Science, Roger Williams University, Bristol, Rhode Island, USA
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Biochemical characterization of a bifunctional acetaldehyde-alcohol dehydrogenase purified from a facultative anaerobic bacterium Citrobacter sp. S-77. J Biosci Bioeng 2015. [PMID: 26216639 DOI: 10.1016/j.jbiosc.2015.06.019] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Acetaldehyde-alcohol dehydrogenase (ADHE) is a bifunctional enzyme consisting of two domains of an N-terminal acetaldehyde dehydrogenase (ALDH) and a C-terminal alcohol dehydrogenase (ADH). The enzyme is known to be important in the cellular alcohol metabolism. However, the role of coenzyme A-acylating ADHE responsible for ethanol production from acetyl-CoA remains uncertain. Here, we present the purification and biochemical characterization of an ADHE from Citrobacter sp. S-77 (ADHE(S77)). Interestingly, the ADHE(S77) was unable to be solubilized from membrane with detergents either 1% Triton X-100 or 1% Sulfobetaine 3-12. However, the enzyme was easily dissociated from membrane by high-salt buffers containing either 1.0 M NaCl or (NH(4))(2)SO(4) without detergents. The molecular weight of a native protein was estimated as approximately 400 kDa, consisting of four identical subunits of 96.3 kDa. Based on the specific activity and kinetic analysis, the ADHES77 tended to have catalytic reaction towards acetaldehyde elimination rather than acetaldehyde formation. Our experimental observation suggests that the ADHES77 may play a pivotal role in modulating intracellular acetaldehyde concentration.
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17
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Cofactor Specificity of the Bifunctional Alcohol and Aldehyde Dehydrogenase (AdhE) in Wild-Type and Mutant Clostridium thermocellum and Thermoanaerobacterium saccharolyticum. J Bacteriol 2015; 197:2610-9. [PMID: 26013492 DOI: 10.1128/jb.00232-15] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Accepted: 05/21/2015] [Indexed: 02/07/2023] Open
Abstract
UNLABELLED Clostridium thermocellum and Thermoanaerobacterium saccharolyticum are thermophilic bacteria that have been engineered to produce ethanol from the cellulose and hemicellulose fractions of biomass, respectively. Although engineered strains of T. saccharolyticum produce ethanol with a yield of 90% of the theoretical maximum, engineered strains of C. thermocellum produce ethanol at lower yields (∼50% of the theoretical maximum). In the course of engineering these strains, a number of mutations have been discovered in their adhE genes, which encode both alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) enzymes. To understand the effects of these mutations, the adhE genes from six strains of C. thermocellum and T. saccharolyticum were cloned and expressed in Escherichia coli, the enzymes produced were purified by affinity chromatography, and enzyme activity was measured. In wild-type strains of both organisms, NADH was the preferred cofactor for both ALDH and ADH activities. In high-ethanol-producing (ethanologen) strains of T. saccharolyticum, both ALDH and ADH activities showed increased NADPH-linked activity. Interestingly, the AdhE protein of the ethanologenic strain of C. thermocellum has acquired high NADPH-linked ADH activity while maintaining NADH-linked ALDH and ADH activities at wild-type levels. When single amino acid mutations in AdhE that caused increased NADPH-linked ADH activity were introduced into C. thermocellum and T. saccharolyticum, ethanol production increased in both organisms. Structural analysis of the wild-type and mutant AdhE proteins was performed to provide explanations for the cofactor specificity change on a molecular level. IMPORTANCE This work describes the characterization of the AdhE enzyme from different strains of C. thermocellum and T. saccharolyticum. C. thermocellum and T. saccharolyticum are thermophilic anaerobes that have been engineered to make high yields of ethanol and can solubilize components of plant biomass and ferment the sugars to ethanol. In the course of engineering these strains, several mutations arose in the bifunctional ADH/ALDH protein AdhE, changing both enzyme activity and cofactor specificity. We show that changing AdhE cofactor specificity from mostly NADH linked to mostly NADPH linked resulted in higher ethanol production by C. thermocellum and T. saccharolyticum.
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18
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Hertz R, Ben Lulu S, Shahi P, Trebicz-Geffen M, Benhar M, Ankri S. Proteomic identification of S-nitrosylated proteins in the parasite Entamoeba histolytica by resin-assisted capture: insights into the regulation of the Gal/GalNAc lectin by nitric oxide. PLoS One 2014; 9:e91518. [PMID: 24626316 PMCID: PMC3953491 DOI: 10.1371/journal.pone.0091518] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2013] [Accepted: 02/12/2014] [Indexed: 11/19/2022] Open
Abstract
Entamoeba histolytica is a gastrointestinal protozoan parasite that causes amebiasis, a disease which has a worldwide distribution with substantial morbidity and mortality. Nitrosative stress, which is generated by innate immune cells, is one of the various environmental challenges that E. histolytica encounters during its life cycle. Although the effects of nitric oxide (NO) on the regulation of gene expression in this parasite have been previously investigated, our knowledge on S-nitrosylated proteins in E.histolytica is lacking. In order to fill this knowledge gap, we performed a large-scale detection of S-nitrosylated (SNO) proteins in E.histolytica trophozoites that were treated with the NO donor, S-nitrosocysteine by resin-assisted capture (RAC). We found that proteins involved in glycolysis, gluconeogenesis, translation, protein transport, and adherence to target cells such as the heavy subunit of Gal/GalNac lectin are among the S-nitrosylated proteins that were enriched by SNO-RAC. We also found that the S-nitrosylated cysteine residues in the carbohydrate recognition domain (CRD) of Gal/GalNAc lectin impairs its function and contributes to the inhibition of E.histolytica adherence to host cells. Collectively, these results advance our understanding of the mechanism of reduced E.histolytica adherence to mammalian cells by NO and emphasize the importance of NO as a regulator of key physiological functions in E.histolytica.
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Affiliation(s)
- Rivka Hertz
- Department of Molecular Microbiology, The Bruce Rappaport Faculty of Medicine, Technion, Haifa, Israel
| | - Shani Ben Lulu
- Department of Biochemistry, The Bruce Rappaport Faculty of Medicine, Technion, Haifa, Israel
| | - Preeti Shahi
- Department of Molecular Microbiology, The Bruce Rappaport Faculty of Medicine, Technion, Haifa, Israel
| | - Meirav Trebicz-Geffen
- Department of Molecular Microbiology, The Bruce Rappaport Faculty of Medicine, Technion, Haifa, Israel
| | - Moran Benhar
- Department of Biochemistry, The Bruce Rappaport Faculty of Medicine, Technion, Haifa, Israel
| | - Serge Ankri
- Department of Molecular Microbiology, The Bruce Rappaport Faculty of Medicine, Technion, Haifa, Israel
- * E-mail:
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19
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The Entamoeba histolytica Dnmt2 homolog (Ehmeth) confers resistance to nitrosative stress. EUKARYOTIC CELL 2014; 13:494-503. [PMID: 24562908 DOI: 10.1128/ec.00031-14] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Nitric oxide (NO) has antimicrobial properties against many pathogens due to its reactivity as an S-nitrosylating agent. It inhibits many of the key enzymes that are involved in the metabolism and virulence of the parasite Entamoeba histolytica through S-nitrosylation of essential cysteine residues. Very little information is available on the mechanism of resistance to NO by pathogens in general and by this parasite in particular. Here, we report that exposure of the parasites to S-nitrosoglutathione (GSNO), an NO donor molecule, strongly reduces their viability and protein synthesis. However, the deleterious effects of NO were significantly reduced in trophozoites overexpressing Ehmeth, the cytosine-5 methyltransferase of the Dnmt2 family. Since these trophozoites also exhibited high levels of tRNA(Asp) methylation, the high levels suggested that Ehmeth-mediated tRNA(Asp) methylation is part of the resistance mechanism to NO. We previously reported that enolase, another glycolytic enzyme, binds to Ehmeth and inhibits its activity. We observed that the amount of Ehmeth-enolase complex was significantly reduced in GSNO-treated E. histolytica, which explains the aforementioned increase of tRNA methylation. Specifically, we demonstrated via site-directed mutagenesis that cysteine residues 228 and 229 of Ehmeth are susceptible to S-nitrosylation and are crucial for Ehmeth binding to enolase and for Ehmeth-mediated resistance to NO. These results indicate that Ehmeth has a central role in the response of the parasite to NO, and they contribute to the growing evidence that NO is a regulator of epigenetic mechanisms.
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20
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Extance J, Crennell SJ, Eley K, Cripps R, Hough DW, Danson MJ. Structure of a bifunctional alcohol dehydrogenase involved in bioethanol generation inGeobacillus thermoglucosidasius. ACTA CRYSTALLOGRAPHICA SECTION D: BIOLOGICAL CRYSTALLOGRAPHY 2013; 69:2104-15. [DOI: 10.1107/s0907444913020349] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2013] [Accepted: 07/23/2013] [Indexed: 11/10/2022]
Abstract
Bifunctional alcohol/aldehyde dehydrogenase (ADHE) enzymes are found within many fermentative microorganisms. They catalyse the conversion of an acyl-coenzyme A to an alcoholviaan aldehyde intermediate; this is coupled to the oxidation of two NADH molecules to maintain the NAD+pool during fermentative metabolism. The structure of the alcohol dehydrogenase (ADH) domain of an ADHE protein from the ethanol-producing thermophileGeobacillus thermoglucosidasiushas been determined to 2.5 Å resolution. This is the first structure to be reported for such a domain.In silicomodelling has been carried out to generate a homology model of the aldehyde dehydrogenase domain, and this was subsequently docked with the ADH-domain structure to model the structure of the complete ADHE protein. This model suggests, for the first time, a structural mechanism for the formation of the large multimeric assemblies or `spirosomes' that are observed for this ADHE protein and which have previously been reported for ADHEs from other organisms.
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21
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Pineda E, Encalada R, Olivos-García A, Néquiz M, Moreno-Sánchez R, Saavedra E. The bifunctional aldehyde-alcohol dehydrogenase controls ethanol and acetate production inEntamoeba histolyticaunder aerobic conditions. FEBS Lett 2012. [DOI: 10.1016/j.febslet.2012.11.020] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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22
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Espinosa A, Socha AM, Ryke E, Rowley DC. Antiamoebic properties of the actinomycete metabolites echinomycin A and tirandamycin A. Parasitol Res 2012; 111:2473-7. [PMID: 22763704 DOI: 10.1007/s00436-012-3019-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2011] [Accepted: 06/19/2012] [Indexed: 11/30/2022]
Abstract
Entamoeba histolytica infects 50 million people per year, causing 100,000 deaths worldwide. The primary treatment for amoebiasis is metronidazole. However, increased pathogen resistance combined with the drug's toxic side effects encourages a search for alternative therapeutic agents. Secondary metabolites from marine bacteria are a promising resource for antiprotozoan drug discovery. In this study, extracts from a collection of marine-derived actinomycetes were screened for antiamoebic properties, and the activities of antibiotics echinomycin A and tirandamycin A are shown. Both antibiotics inhibited the in vitro growth of a E. histolytica laboratory strain (HM-1:IMSS) and a clinical isolate (Colombia, Col) at 30- to 60-μM concentrations. EIC(50) (estimated inhibitory concentration) values were comparable for both antibiotics (44.3-46.3 μM) against the E. histolytica clinical isolate.
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Affiliation(s)
- Avelina Espinosa
- Department of Biology, Roger Williams University, One Old Ferry Road, Bristol, RI 02809, USA.
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23
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Müller M, Mentel M, van Hellemond JJ, Henze K, Woehle C, Gould SB, Yu RY, van der Giezen M, Tielens AGM, Martin WF. Biochemistry and evolution of anaerobic energy metabolism in eukaryotes. Microbiol Mol Biol Rev 2012; 76:444-95. [PMID: 22688819 PMCID: PMC3372258 DOI: 10.1128/mmbr.05024-11] [Citation(s) in RCA: 484] [Impact Index Per Article: 40.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Major insights into the phylogenetic distribution, biochemistry, and evolutionary significance of organelles involved in ATP synthesis (energy metabolism) in eukaryotes that thrive in anaerobic environments for all or part of their life cycles have accrued in recent years. All known eukaryotic groups possess an organelle of mitochondrial origin, mapping the origin of mitochondria to the eukaryotic common ancestor, and genome sequence data are rapidly accumulating for eukaryotes that possess anaerobic mitochondria, hydrogenosomes, or mitosomes. Here we review the available biochemical data on the enzymes and pathways that eukaryotes use in anaerobic energy metabolism and summarize the metabolic end products that they generate in their anaerobic habitats, focusing on the biochemical roles that their mitochondria play in anaerobic ATP synthesis. We present metabolic maps of compartmentalized energy metabolism for 16 well-studied species. There are currently no enzymes of core anaerobic energy metabolism that are specific to any of the six eukaryotic supergroup lineages; genes present in one supergroup are also found in at least one other supergroup. The gene distribution across lineages thus reflects the presence of anaerobic energy metabolism in the eukaryote common ancestor and differential loss during the specialization of some lineages to oxic niches, just as oxphos capabilities have been differentially lost in specialization to anoxic niches and the parasitic life-style. Some facultative anaerobes have retained both aerobic and anaerobic pathways. Diversified eukaryotic lineages have retained the same enzymes of anaerobic ATP synthesis, in line with geochemical data indicating low environmental oxygen levels while eukaryotes arose and diversified.
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Affiliation(s)
| | - Marek Mentel
- Department of Biochemistry, Faculty of Natural Sciences, Comenius University, Bratislava, Slovakia
| | - Jaap J. van Hellemond
- Department of Medical Microbiology and Infectious Diseases, Erasmus University Medical Center, Rotterdam, Netherlands
| | - Katrin Henze
- Institute of Molecular Evolution, University of Düsseldorf, Düsseldorf, Germany
| | - Christian Woehle
- Institute of Molecular Evolution, University of Düsseldorf, Düsseldorf, Germany
| | - Sven B. Gould
- Institute of Molecular Evolution, University of Düsseldorf, Düsseldorf, Germany
| | - Re-Young Yu
- Institute of Molecular Evolution, University of Düsseldorf, Düsseldorf, Germany
| | - Mark van der Giezen
- Biosciences, College of Life and Environmental Sciences, University of Exeter, Exeter, United Kingdom
| | - Aloysius G. M. Tielens
- Department of Medical Microbiology and Infectious Diseases, Erasmus University Medical Center, Rotterdam, Netherlands
| | - William F. Martin
- Institute of Molecular Evolution, University of Düsseldorf, Düsseldorf, Germany
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24
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Espinosa A, Paz-Y-Miño-C G. Discrimination, crypticity, and incipient taxa in entamoeba. J Eukaryot Microbiol 2012; 59:105-10. [PMID: 22299709 DOI: 10.1111/j.1550-7408.2011.00606.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2011] [Accepted: 11/05/2011] [Indexed: 11/30/2022]
Abstract
Persistent difficulties in resolving clear lineages in diverging populations of prokaryotes or unicellular eukaryotes (protistan polyphyletic groups) are challenging the classical species concept. Although multiple integrated approaches would render holistic taxonomies, most phylogenetic studies are still based on single-gene or morphological traits. Such methodologies conceal natural lineages, which are considered "cryptic." The concept of species is considered artificial and inadequate to define natural populations. Social organisms display differential behaviors toward kin than to nonrelated individuals. In "social" microbes, kin discrimination has been used to help resolve crypticity. Aggregative behavior could be explored in a nonsocial protist to define phylogenetic varieties that are considered "cryptic." Two Entamoeba invadens strains, IP-1 and VK-1:NS are considered close populations of the same "species." This study demonstrates that IP-1 and VK-1:NS trophozoites aggregate only with alike members and discriminate members of different strains based on behavioral and chemical signals. Combined morphological, behavioral/chemical, and ecological studies could improve Archamoebae phylogenies and define cryptic varieties. Evolutionary processes in which selection acted continuously and cumulatively on ancestors of Entamoeba populations gave rise to chemical and behavioral signals that allowed individuals to discriminate nonpopulation members and, gradually, to the emergence of new lineages; alternative views that claim a "Designer" or "Creator" as responsible for protistan diversity are unfounded.
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Affiliation(s)
- Avelina Espinosa
- Department of Biology, Roger Williams University, Bristol, RI 02809, USA.
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Peng Y, Luo Y, Yu T, Xu X, Fan K, Zhao Y, Yang K. A blue native-PAGE analysis of membrane protein complexes in Clostridium thermocellum. BMC Microbiol 2011; 11:22. [PMID: 21269440 PMCID: PMC3039559 DOI: 10.1186/1471-2180-11-22] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2010] [Accepted: 01/26/2011] [Indexed: 01/01/2023] Open
Abstract
Background Clostridium thermocellum is a Gram-positive thermophilic anaerobic bacterium with the unusual capacity to convert cellulosic biomass into ethanol and hydrogen. Identification and characterization of protein complexes in C. thermocellum are important toward understanding its metabolism and physiology. Results A two dimensional blue native/SDS-PAGE procedure was developed to separate membrane protein complexes of C. thermocellum. Proteins spots were identified by MALDI-TOF/TOF Mass spectrometry. 24 proteins were identified representing 13 distinct protein complexes, including several putative intact complexes. Interestingly, subunits of both the F1-F0-ATP synthase and the V1-V0-ATP synthase were detected in the membrane sample, indicating C. thermocellum may use alternative mechanisms for ATP generation. Conclusion Two dimensional blue native/SDS-PAGE was used to detect membrane protein complexes in C. thermocellum. More than a dozen putative protein complexes were identified, revealing the simultaneous expression of two sets of ATP synthase. The protocol developed in this work paves the way for further functional characterization of these protein complexes.
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Affiliation(s)
- Yanfeng Peng
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, PR China
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Reyes-López M, Bermúdez-Cruz RM, Avila EE, de la Garza M. Acetaldehyde/alcohol dehydrogenase-2 (EhADH2) and clathrin are involved in internalization of human transferrin by Entamoeba histolytica. Microbiology (Reading) 2011; 157:209-219. [DOI: 10.1099/mic.0.040063-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Transferrin (Tf) is a host glycoprotein capable of binding two ferric-iron ions to become holotransferrin (holoTf), which transports iron in to all cells. Entamoeba histolytica is a parasitic protozoan able to use holoTf as a sole iron source in vitro. The mechanism by which this parasite scavenges iron from holoTf is unknown. An E. histolytica holoTf-binding protein (EhTfbp) was purified by using an anti-human transferrin receptor (TfR) monoclonal antibody. EhTfbp was identified by MS/MS analysis and database searches as E. histolytica acetaldehyde/alcohol dehydrogenase-2 (EhADH2), an iron-dependent enzyme. Both EhTfbp and EhADH2 bound holoTf and were recognized by the anti-human TfR antibody, indicating that they correspond to the same protein. It was found that the amoebae internalized holoTf through clathrin-coated pits, suggesting that holoTf endocytosis could be important for the parasite during colonization and invasion of the intestinal mucosa and liver.
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Affiliation(s)
- Magda Reyes-López
- Programa de Doctorado en Ciencias Biológicas de la Universidad Autónoma Metropolitana, Apdo Postal 23-181, México, DF 04960, Mexico
| | - Rosa María Bermúdez-Cruz
- Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del IPN, Apdo 14-740, México DF 07000, Mexico
| | - Eva E. Avila
- Departamento de Biología, División de Ciencias Naturales y Exactas, Universidad de Guanajuato, Colonia Noria Alta, Guanajuato, Gto, 36000, Mexico
| | - Mireya de la Garza
- Departamento de Biología Celular, Centro de Investigación y de Estudios Avanzados del IPN, Apdo 14-740, México DF 07000, Mexico
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Ginger ML, Fritz-Laylin LK, Fulton C, Cande WZ, Dawson SC. Intermediary metabolism in protists: a sequence-based view of facultative anaerobic metabolism in evolutionarily diverse eukaryotes. Protist 2010; 161:642-71. [PMID: 21036663 PMCID: PMC3021972 DOI: 10.1016/j.protis.2010.09.001] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Protists account for the bulk of eukaryotic diversity. Through studies of gene and especially genome sequences the molecular basis for this diversity can be determined. Evident from genome sequencing are examples of versatile metabolism that go far beyond the canonical pathways described for eukaryotes in textbooks. In the last 2-3 years, genome sequencing and transcript profiling has unveiled several examples of heterotrophic and phototrophic protists that are unexpectedly well-equipped for ATP production using a facultative anaerobic metabolism, including some protists that can (Chlamydomonas reinhardtii) or are predicted (Naegleria gruberi, Acanthamoeba castellanii, Amoebidium parasiticum) to produce H(2) in their metabolism. It is possible that some enzymes of anaerobic metabolism were acquired and distributed among eukaryotes by lateral transfer, but it is also likely that the common ancestor of eukaryotes already had far more metabolic versatility than was widely thought a few years ago. The discussion of core energy metabolism in unicellular eukaryotes is the subject of this review. Since genomic sequencing has so far only touched the surface of protist diversity, it is anticipated that sequences of additional protists may reveal an even wider range of metabolic capabilities, while simultaneously enriching our understanding of the early evolution of eukaryotes.
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Affiliation(s)
- Michael L Ginger
- School of Health and Medicine, Division of Biomedical and Life Sciences, Lancaster University, Lancaster LA1 4YQ, UK.
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Jagadeesan B, Koo OK, Kim KP, Burkholder KM, Mishra KK, Aroonnual A, Bhunia AK. LAP, an alcohol acetaldehyde dehydrogenase enzyme in Listeria, promotes bacterial adhesion to enterocyte-like Caco-2 cells only in pathogenic species. Microbiology (Reading) 2010; 156:2782-2795. [PMID: 20507888 DOI: 10.1099/mic.0.036509-0] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Listeria adhesion protein (LAP), an alcohol acetaldehyde dehydrogenase (lmo1634), interacts with host-cell receptor Hsp60 to promote bacterial adhesion during the intestinal phase of Listeria monocytogenes infection. The LAP homologue is present in pathogens (L. monocytogenes, L. ivanovii) and non-pathogens (L. innocua, L. welshimeri, L. seeligeri); however, its role in non-pathogens is unknown. Sequence analysis revealed 98 % amino acid similarity in LAP from all Listeria species. The N-terminus contains acetaldehyde dehydrogenase (ALDH) and the C-terminus an alcohol dehydrogenase (ADH). Recombinant LAP from L. monocytogenes, L. ivanovii, L. innocua and L. welshimeri exhibited ALDH and ADH activities, and displayed strong binding affinity (K
D 2–31 nM) towards Hsp60. Flow cytometry, ELISA and immunoelectron microscopy revealed more surface-associated LAP in pathogens than non-pathogens. Pathogens exhibited significantly higher adhesion (P<0.05) to Caco-2 cells than non-pathogens; however, pretreatment of bacteria with Hsp60 caused 47–92 % reduction in adhesion only in pathogens. These data suggest that biochemical properties of LAP from pathogenic Listeria are similar to those of the protein from non-pathogens in many respects, such as substrate specificity, immunogenicity, and binding affinity to Hsp60. However, protein fractionation analysis of extracts from pathogenic and non-pathogenic Listeria species revealed that LAP was greatly reduced in intracellular and cell-surface protein fractions, and undetectable in the extracellular milieu of non-pathogens even though the lap transcript levels were similar for both. Furthermore, a LAP preparation from L. monocytogenes restored adhesion in a lap mutant (KB208) of L. monocytogenes but not in L. innocua, indicating possible lack of surface reassociation of LAP molecules in this bacterium. Taken together, these data suggest that LAP expression level, cell-surface localization, secretion and reassociation are responsible for LAP-mediated pathogenicity and possibly evolved to adapt to a parasitic life cycle in the host.
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Affiliation(s)
- Balamurugan Jagadeesan
- Molecular Food Microbiology Laboratory, Department of Food Science, 745 Agriculture Mall Drive, Purdue University, West Lafayette, IN 47907, USA
| | - Ok Kyung Koo
- Molecular Food Microbiology Laboratory, Department of Food Science, 745 Agriculture Mall Drive, Purdue University, West Lafayette, IN 47907, USA
| | - Kwang-Pyo Kim
- Molecular Food Microbiology Laboratory, Department of Food Science, 745 Agriculture Mall Drive, Purdue University, West Lafayette, IN 47907, USA
| | - Kristin M. Burkholder
- Molecular Food Microbiology Laboratory, Department of Food Science, 745 Agriculture Mall Drive, Purdue University, West Lafayette, IN 47907, USA
| | - Krishna K. Mishra
- Molecular Food Microbiology Laboratory, Department of Food Science, 745 Agriculture Mall Drive, Purdue University, West Lafayette, IN 47907, USA
| | - Amornrat Aroonnual
- Molecular Food Microbiology Laboratory, Department of Food Science, 745 Agriculture Mall Drive, Purdue University, West Lafayette, IN 47907, USA
| | - Arun K. Bhunia
- Molecular Food Microbiology Laboratory, Department of Food Science, 745 Agriculture Mall Drive, Purdue University, West Lafayette, IN 47907, USA
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Pineda E, Encalada R, Rodríguez-Zavala JS, Olivos-García A, Moreno-Sánchez R, Saavedra E. Pyruvate:ferredoxin oxidoreductase and bifunctional aldehyde-alcohol dehydrogenase are essential for energy metabolism under oxidative stress in Entamoeba histolytica. FEBS J 2010; 277:3382-95. [DOI: 10.1111/j.1742-4658.2010.07743.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Paz-Y-Miño C G, Espinosa A. Integrating horizontal gene transfer and common descent to depict evolution and contrast it with "common design". J Eukaryot Microbiol 2009; 57:11-8. [PMID: 20021546 DOI: 10.1111/j.1550-7408.2009.00458.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Horizontal gene transfer (HGT) and common descent interact in space and time. Because events of HGT co-occur with phylogenetic evolution, it is difficult to depict evolutionary patterns graphically. Tree-like representations of life's diversification are useful, but they ignore the significance of HGT in evolutionary history, particularly of unicellular organisms, ancestors of multicellular life. Here we integrate the reticulated-tree model, ring of life, symbiogenesis whole-organism model, and eliminative pattern pluralism to represent evolution. Using Entamoeba histolytica alcohol dehydrogenase 2 (EhADH2), a bifunctional enzyme in the glycolytic pathway of amoeba, we illustrate how EhADH2 could be the product of both horizontally acquired features from ancestral prokaryotes (i.e. aldehyde dehydrogenase [ALDH] and alcohol dehydrogenase [ADH]), and subsequent functional integration of these enzymes into EhADH2, which is now inherited by amoeba via common descent. Natural selection has driven the evolution of EhADH2 active sites, which require specific amino acids (cysteine 252 in the ALDH domain; histidine 754 in the ADH domain), iron- and NAD(+) as cofactors, and the substrates acetyl-CoA for ALDH and acetaldehyde for ADH. Alternative views invoking "common design" (i.e. the non-naturalistic emergence of major taxa independent from ancestry) to explain the interaction between horizontal and vertical evolution are unfounded.
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Affiliation(s)
- Guillermo Paz-Y-Miño C
- Department of Biology, University of Massachusetts Dartmouth, North Dartmouth, Massachusetts 02747, USA
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Davis PH, Chen M, Zhang X, Clark CG, Townsend RR, Stanley SL. Proteomic comparison of Entamoeba histolytica and Entamoeba dispar and the role of E. histolytica alcohol dehydrogenase 3 in virulence. PLoS Negl Trop Dis 2009; 3:e415. [PMID: 19365541 PMCID: PMC2663792 DOI: 10.1371/journal.pntd.0000415] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2007] [Accepted: 03/17/2009] [Indexed: 11/28/2022] Open
Abstract
The protozoan intestinal parasite Entamoeba histolytica infects millions of people worldwide and is capable of causing amebic dysentery and amebic liver abscess. The closely related species Entamoeba dispar colonizes many more individuals, but this organism does not induce disease. To identify molecular differences between these two organisms that may account for their differential ability to cause disease in humans, we used two-dimensional gel-based (DIGE) proteomic analysis to compare whole cell lysates of E. histolytica and E. dispar. We observed 141 spots expressed at a substantially (>5-fold) higher level in E. histolytica HM-1∶IMSS than E. dispar and 189 spots showing the opposite pattern. Strikingly, 3 of 4 proteins consistently identified as different at a greater than 5-fold level between E. histolytica HM-1∶IMSS and E. dispar were identical to proteins recently identified as differentially expressed between E. histolytica HM-1∶IMSS and the reduced virulence strain E. histolytica Rahman. One of these was E. histolytica alcohol dehydrogenase 3 (EhADH3). We found that E. histolytica possesses a higher level of NADP-dependent alcohol dehydrogenase activity than E. dispar and that some EhADH3 can be localized to the surface of E. histolytica. Episomal overexpression of EhADH3 in E. histolytica trophozoites resulted in only subtle phenotypic differences in E. histolytica virulence in animal models of amebic colitis and amebic liver abscess, making it difficult to directly link EhADH3 levels to virulence differences between E. histolytica and less-pathogenic Entamoeba. Infection with Entamoeba histolytica can result in disabling diarrhea or even death, while the morphologically identical and genetically similar Entamoeba dispar harmlessly colonizes the human intestine. Understanding the molecular differences between these two organisms by comparing their protein repertoire may help us to understand why E. histolytica invades into colonic tissue, while E. dispar remains a benign passenger. Here, we identify four proteins that appear to be differentially expressed between the two species and show that a metabolic enzyme, which would appear to be an unlikely candidate for a role in disease, is expressed at much higher levels in the pathogenic organism.
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Affiliation(s)
- Paul H. Davis
- Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, United States of America
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Minghe Chen
- Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Xiaochun Zhang
- Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - C. Graham Clark
- Department of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - R. Reid Townsend
- Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Samuel L. Stanley
- Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, United States of America
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri, United States of America
- * E-mail:
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Espinosa A, Perdrizet G, Paz-Y-Miño C G, Lanfranchi R, Phay M. Effects of iron depletion on Entamoeba histolytica alcohol dehydrogenase 2 (EhADH2) and trophozoite growth: implications for antiamoebic therapy. J Antimicrob Chemother 2009; 63:675-8. [PMID: 19218278 DOI: 10.1093/jac/dkp015] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
OBJECTIVES The purpose of this study was to determine the mechanism by which iron chelation affects the trophozoite survival of Entamoeba histolytica. Fe2+ is a cofactor for E. histolytica alcohol dehydrogenase 2 (EhADH2), an essential bifunctional enzyme [alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH)] in the glycolytic pathway of E. histolytica. METHODS We tested the effects of iron depletion on trophozoite growth, the kinetics of iron binding to EhADH2, and the activities of ADH and ALDH. RESULTS Growth of E. histolytica trophozoites, and ADH and ALDH enzymatic activities were directly inhibited by iron chelation. Kinetics of iron binding to EhADH2 reveals the differential iron affinity of ADH (higher) and ALDH (lower). CONCLUSIONS This study demonstrates that iron chelation interrupts the completion of the fermentative pathway of E. histolytica by removing the metal cofactor indispensable for the structural and functional stability of EhADH2, thus affecting trophozoite survival. We propose that iron-starvation-based strategies could be used to treat amoebiasis.
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Affiliation(s)
- Avelina Espinosa
- Department of Biology, Roger Williams University, One Old Ferry Road, Bristol, RI 02809, USA.
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Lavi T, Siman-Tov R, Ankri S. EhMLBP is an essential constituent of theEntamoeba histolyticaepigenetic machinery and a potential drug target. Mol Microbiol 2008; 69:55-66. [DOI: 10.1111/j.1365-2958.2008.06258.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Abed M, Ankri S. Progress and prospects of gene inactivation in Entamoeba histolytica. Exp Parasitol 2008; 118:151-5. [PMID: 17889851 DOI: 10.1016/j.exppara.2007.08.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2007] [Revised: 08/14/2007] [Accepted: 08/15/2007] [Indexed: 11/16/2022]
Abstract
Over the last few years, numerous methods have been exploited in the attempt to study Entamoeba histolytica gene functions. Yet several features of E. histolytica, like their variable DNA content and complex ploidity have made it difficult to perform classical genetic studies such as homologous recombination. As a result, the methods currently in use target genes at the protein or RNA level. This review summarizes the experimental approaches that have been used to date and it provides an overview of the limitations and contributions of these methods in our understanding of E. histolytica's gene functions and biology.
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Affiliation(s)
- Mona Abed
- Department of Molecular Microbiology, Rappaport Faculty of Medicine and Research Institute, Technion--Israel Institute of Technology, 1 Efron Street, Haifa, 31096, Israel
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Kim KP, Jagadeesan B, Burkholder KM, Jaradat ZW, Wampler JL, Lathrop AA, Morgan MT, Bhunia AK. Adhesion characteristics of Listeria adhesion protein (LAP)-expressing Escherichia coli to Caco-2 cells and of recombinant LAP to eukaryotic receptor Hsp60 as examined in a surface plasmon resonance sensor. FEMS Microbiol Lett 2006; 256:324-32. [PMID: 16499624 DOI: 10.1111/j.1574-6968.2006.00140.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
Listeria adhesion protein (LAP) is an important adhesion factor in Listeria monocytogenes and interacts with its cognate receptor, mammalian heat shock protein 60 (Hsp60). The genetic identity of LAP was determined to be alcohol acetaldehyde dehydrogenase (Aad). A recombinant Escherichia coli strain expressing aad confirmed the involvement of Aad in adhesion to Caco-2 cells. Binding kinetics (ka) of recombinant LAP (rLAP) to Hsp60 was examined in a surface plasmon resonance sensor and was determined to be 5.35 x 10(8) M(-1) s(-1) and it was equivalent to the binding of anti-Hsp60 antibody (ka = 2.15 x 10(9) M(-1) s(-1)) to Hsp60. In contrast, Internalin B, an adhesion/invasion protein from L. monocytogenes, used as a control, had binding kinetics (ka) of only 2.9 x 10(6) M(-1) s(-1). The KD value of rLAP was 1.68 x 10(-8) M, which was significantly lower than Internalin B (KD = 6.5 x 10(-4) M). These results suggest that Hsp60 has significantly higher avidity for anti-Hsp60 antibody and LAP than Internalin B. In summary, LAP is identified as an alcohol acetaldehyde dehydrogenase and binding of recombinant E. coli to Caco-2 cells or rLAP to Hsp60 protein was found to be highly specific.
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Affiliation(s)
- Kwang-Pyo Kim
- Molecular Food Microbiology Laboratory, Department of Food Science, Purdue University, West Lafayette, IN 47907, USA
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Jeffries TW. Engineering yeasts for xylose metabolism. Curr Opin Biotechnol 2006; 17:320-6. [PMID: 16713243 DOI: 10.1016/j.copbio.2006.05.008] [Citation(s) in RCA: 255] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2006] [Revised: 04/25/2006] [Accepted: 05/05/2006] [Indexed: 01/11/2023]
Abstract
Technologies for the production of alternative fuels are receiving increased attention owing to concerns over the rising cost of petrol and global warming. One such technology under development is the use of yeasts for the commercial fermentation of xylose to ethanol. Several approaches have been employed to engineer xylose metabolism. These involve modeling, flux analysis, and expression analysis followed by the targeted deletion or altered expression of key genes. Expression analysis is increasingly being used to target rate-limiting steps. Quantitative metabolic models have also proved extremely useful: they can be calculated from stoichiometric balances or inferred from the labeling of intermediate metabolites. The recent determination of the genome sequence for P. stipitis is important, as its genome characteristics and regulatory patterns could serve as guides for further development in this natural xylose-fermenting yeast or in engineered Saccharomyces cerevisiae. Lastly, strain selection through mutagenesis, adaptive evolution or from nature can also be employed to further improve activity.
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Affiliation(s)
- Thomas W Jeffries
- USDA, Forest Service and University of Wisconsin - Madison, Forest Products Laboratory, 53726, USA.
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Mirelman D, Anbar M, Nuchamowitz Y, Bracha R. Epigenetic silencing of gene expression in Entamoeba histolytica. Arch Med Res 2006; 37:226-33. [PMID: 16380323 DOI: 10.1016/j.arcmed.2005.09.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2005] [Accepted: 09/30/2005] [Indexed: 01/21/2023]
Abstract
Transcriptional silencing of an amebapore (ap-a) gene occurred in Entamoeba histolytica following the transfection of plasmids containing a DNA segment (473 bp) homologous to the 5' upstream region of the gene. This segment contains the promoter region of the ap-a gene, a T-rich stretch, followed by a truncated SINE1 (short interspersed element) that is transcribed from the opposite strand. The downstream silencing of the ap-a gene did not occur with plasmids containing the entire SINE1 sequence or lacking the entire SINE1 sequences including the T-rich stretch. Such plasmids promoted the overexpression of the ap-a gene. The transcription of the SINE element required both the T-rich stretch as well as sequences from the 5' end of SINE. RNA extracts from gene-silenced cultures showed small amounts of short (approximately 140 nt), single-stranded molecules with homology to SINE1 transcripts but no siRNA. Chromatin immunoprecipitation (ChIP) analysis of silenced G3 trophozoites with an antibody against methylated K4 of histone H3 revealed a demethylation of K4 at the domain of the ap-a gene indicating transcriptional inactivation. These results suggest the involvement of the SINE1 element in triggering the gene silencing and the role of histone modification in its epigenetic maintenance. The avirulent phenotype of the silenced trophozoites was demonstrated in various assays and the results suggest they may have a potential use for vaccination.
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Affiliation(s)
- David Mirelman
- Department of Biological Chemistry, Weizmann Institute of Science, Rehovot, Israel.
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Fuentes SML, Martínez-Cadena G, Silva ME, López A, Sánchez C, Alvarez AH, Avila EE. MonoADP-ribosylation of the NAD+-dependent alcohol dehydrogenase from Entamoeba histolytica. Curr Microbiol 2005; 51:171-4. [PMID: 16086106 DOI: 10.1007/s00284-005-4538-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2004] [Accepted: 04/22/2005] [Indexed: 11/29/2022]
Abstract
The human parasite Entamoeba histolytica is an amitochondrial protozoan whose metabolism depends on glucose fermentation. Among the metabolic enzymes absolutely required for amoeba growth is the NAD+-dependent alcohol dehydrogenase (EhADH2). The polymeric form of EhADH2 was sedimented at 160,000 g, and in this fraction we observed [32P]-labeling of a 96-kDa protein under mono-ADP-ribosylation conditions with [32P]NAD+. The [32P]-labeled protein had the same molecular weight as the EhADH2 monomer. Because of the importance of monoADP-ribosylation in the regulation of many physiological processes, the aim of this study was to determine whether EhADH2 is ADP-ribosylated, and what would be the consequence of this modification on its alcohol and aldehyde dehydrogenase enzymatic activities. This study describes the ADP-ribosylation of EhADH2. This modification did not have an effect on the enzymatic activities, but it may regulate other functions of EhADH2.
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Affiliation(s)
- Susana M L Fuentes
- Instituto de Investigación en Biología Experimental, Facultad de Química, Universidad de Guanajuato, P. O. Box 187, Guanajuato, Gto, México, CP36000
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Abed M, Ankri S. Molecular characterization of Entamoeba histolytica RNase III and AGO2, two RNA interference hallmark proteins. Exp Parasitol 2005; 110:265-9. [PMID: 15955322 DOI: 10.1016/j.exppara.2005.02.023] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2005] [Revised: 02/27/2005] [Accepted: 02/28/2005] [Indexed: 11/16/2022]
Abstract
Entamoeba histolytica, a protozoan parasite with variable DNA content and complex ploidity, has defied most efforts aimed at gene depletion using classical genetic methods. In this study, we identified and characterized two proteins involved in the RNA interference (RNAi) pathway, RNase III and AGO2. Our results strengthen the findings that an RNAi pathway does exist in this parasite.
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Affiliation(s)
- Mona Abed
- Department of Molecular Microbiology, The Bruce, Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, POB 9649, Haifa 31096, Israel
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Chen M, Li E, Stanley SL. Structural analysis of the acetaldehyde dehydrogenase activity of Entamoeba histolytica alcohol dehydrogenase 2 (EhADH2), a member of the ADHE enzyme family. Mol Biochem Parasitol 2004; 137:201-5. [PMID: 15383290 DOI: 10.1016/j.molbiopara.2004.06.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2004] [Revised: 05/26/2004] [Accepted: 06/01/2004] [Indexed: 11/19/2022]
Abstract
The ADHE family of enzymes are bifunctional acetaldehyde dehydrogenase (ALDH)/alcohol dehydrogenase (ADH) enzymes that probably arose from the fusion of genes encoding separate ALDH and ADH enzymes. Here we have used the Entamoeba histolytica alcohol dehydrogenase 2 (EhADH2) enzyme as a prototype to analyze the structure and function of the ALDH domain of ADHE enzymes. We find that the N-terminal domain of EhADH2, encompassing amino acids 1-446, is sufficient for ALDH activity, consistent with the concept that EhADH2, and other members of the ADHE family comprise fusion peptides. In addition, we show, using site directed mutagenesis, that the catalytic mechanism for the ALDH activity appears to be similar to that described for other members of the ALDH extended family.
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Affiliation(s)
- Minghe Chen
- Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
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Riahi Y, Siman-Tov R, Ankri S. Molecular cloning, expression and characterization of a serine proteinase inhibitor gene from Entamoeba histolytica. Mol Biochem Parasitol 2004; 133:153-62. [PMID: 14698428 DOI: 10.1016/j.molbiopara.2003.10.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Serine proteinase inhibitors (serpins) are irreversible suicide inhibitors of proteinases that regulate a wide range of biological processes, including pathogen evasion of the host defence system. We report the cloning and characterization of a gene encoding a serpin from the protozoan parasite Entamoeba histolytica (Ehserp) that may function in this manner. The protein encoded by Ehserp contains 371 amino acids with a predicted mass of 42.6 kDa. Antibodies to a 42 kDa recombinant Ehserp react specifically with two bands of 42 and 49 kDa in trophozoite extracts. Ehserp has a cytoplasmic localization and is secreted by trophozoites incubated in the presence of mammalian cells, but not by resting trophozoites. A panel of mammalian serine proteinases was screened, but none of them was inhibited by the recombinant Ehserp. In contrast, the 49 kDa Ehserp present in the secretion product (SP) of activated macrophages interacted with human neutrophil cathepsin G to form a complex resistant to sodium dodecyl sulphate. We discuss the nature of the 42 and 49 kDa Ehserp and the possible roles that Ehserp may play in the survival of the parasite inside the host.
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Affiliation(s)
- Yael Riahi
- Department of Molecular Microbiology, The Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, POB 9649, 31096 Haifa, Israel
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Zhang X, Zhang Z, Alexander D, Bracha R, Mirelman D, Stanley SL. Expression of amoebapores is required for full expression of Entamoeba histolytica virulence in amebic liver abscess but is not necessary for the induction of inflammation or tissue damage in amebic colitis. Infect Immun 2004; 72:678-83. [PMID: 14742508 PMCID: PMC321641 DOI: 10.1128/iai.72.2.678-683.2004] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Entamoeba histolytica trophozoites produce amoebapores, a family of small amphipathic peptides capable of insertion into bacterial or eukaryotic membranes and causing cellular lysis. Recently, E. histolytica trophozoites that are totally deficient in the production of amoebapore-A were created through a gene silencing mechanism (R. Bracha, Y. Nuchamowitz, and D. Mirelman, Eukaryot. Cell 2:295-305, 2003). Here we tested the virulence of amoebapore A(-) trophozoites in models of the two major forms of amebic disease: amebic liver abscess and amebic colitis. We demonstrate that amoebapore expression is required for full virulence in the SCID mouse model of amebic liver abscess, but E. histolytica trophozoites that do not express amoebapore-A can still cause inflammation and tissue damage in infected human colonic xenografts. These data are consistent with the concept that tissue damage may proceed by different mechanisms in amebic liver abscess compared to amebic colitis.
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Affiliation(s)
- Xiaochun Zhang
- Department of Medicine, Washington University School of Medicine, St. Louis, Missouri 63110, USA
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Boxma B, Voncken F, Jannink S, van Alen T, Akhmanova A, van Weelden SWH, van Hellemond JJ, Ricard G, Huynen M, Tielens AGM, Hackstein JHP. The anaerobic chytridiomycete fungus Piromyces sp. E2 produces ethanol via pyruvate:formate lyase and an alcohol dehydrogenase E. Mol Microbiol 2004; 51:1389-99. [PMID: 14982632 DOI: 10.1046/j.1365-2958.2003.03912.x] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Anaerobic chytridiomycete fungi possess hydrogenosomes, which generate hydrogen and ATP, but also acetate and formate as end-products of a prokaryotic-type mixed-acid fermentation. Notably, the anaerobic chytrids Piromyces and Neocallimastix use pyruvate:formate lyase (PFL) for the catabolism of pyruvate, which is in marked contrast to the hydrogenosomal metabolism of the anaerobic parabasalian flagellates Trichomonas vaginalis and Tritrichomonas foetus, because these organisms decarboxylate pyruvate with the aid of pyruvate:ferredoxin oxidoreductase (PFO). Here, we show that the chytrids Piromyces sp. E2 and Neocallimastix sp. L2 also possess an alcohol dehydrogenase E (ADHE) that makes them unique among hydrogenosome-bearing anaerobes. We demonstrate that Piromyces sp. E2 routes the final steps of its carbohydrate catabolism via PFL and ADHE: in axenic culture under standard conditions and in the presence of 0.3% fructose, 35% of the carbohydrates were degraded in the cytosol to the end-products ethanol, formate, lactate and succinate, whereas 65% were degraded via the hydrogenosomes to acetate and formate. These observations require a refinement of the previously published metabolic schemes. In particular, the importance of the hydrogenase in this type of hydrogenosome has to be revisited.
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Affiliation(s)
- Brigitte Boxma
- Department of Evolutionary Microbiology, Faculty of Science, University of Nijmegen, Toernooiveld 1, NL-6525 ED Nijmegen, The Netherlands
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Echave P, Tamarit J, Cabiscol E, Ros J. Novel antioxidant role of alcohol dehydrogenase E from Escherichia coli. J Biol Chem 2003; 278:30193-8. [PMID: 12783863 DOI: 10.1074/jbc.m304351200] [Citation(s) in RCA: 87] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Alcohol dehydrogenase E (AdhE) is an Fe-enzyme that, under anaerobic conditions, is involved in dissimilation of glucose. The enzyme is also present under aerobic conditions, its amount is about one-third and its activity is only one-tenth of the values observed under anaerobic conditions. Nevertheless, its function in the presence of oxygen remained ignored. The data presented in this paper led us to propose that the enzyme has a protective role against oxidative stress. Our results indicated that cells deleted in adhE gene could not grow aerobically in minimal media, were extremely sensitive to oxidative stress and showed division defects. In addition, compared with wild type, mutant cells displayed increased levels of internal peroxides (even higher than those found in a Delta katG strain) and increased protein carbonyl content. This pleiotropic phenotype disappeared when the adhE gene was reintroduced into the defective strain. The purified enzyme was highly reactive with hydrogen peroxide (with a Ki of 5 microM), causing inactivation due to a metal-catalyzed oxidation reaction. It is possible to prevent this reactivity to hydrogen peroxide by zinc, which can replace the iron atom at the catalytic site of AdhE. This can also be achieved by addition of ZnSO4 to cell cultures. In such conditions, addition of hydrogen peroxide resulted in reduced cell viability compared with that obtained without the Zn treatment. We therefore propose that AdhE acts as a H2O2 scavenger in Escherichia coli cells grown under aerobic conditions.
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Affiliation(s)
- Pedro Echave
- Departament de Ciències Mèdiques Bàsiques, Facultat de Medicina, Universitat de Lleida, 25198 Lleida, Spain
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Avila EE, Martínez-Alcaraz ER, Barbosa-Sabanero G, Rivera-Baron EI, Arias-Negrete S, Zazueta-Sandoval R. Subcellular localization of the NAD+-dependent alcohol dehydrogenase in Entamoeba histolytica trophozoites. J Parasitol 2002; 88:217-22. [PMID: 12058720 DOI: 10.1645/0022-3395(2002)088[0217:slotnd]2.0.co;2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
The protozoan parasite Entamoeba histolytica is an ancient eukaryotic cell that shows morphologically atypical organelles and differs metabolically from higher eukaryotic cells. The aim of this study was to determine the subcellular localization of ameba NAD+-dependent alcohol dehydrogenase (ADH2). The enzyme activity was present in soluble and mainly in particulate material whose density was 1.105 in a sucrose gradient. By differential centrifugation, most of the ADH activity sedimented at 160,000 g (160,000-g pellet), similar to the Escherichia coli polymeric ADHE. In the Coomassie staining of the 160,000-g pellet analyzed by electrophoresis, a 96-kDa protein was more prominent than in other fractions; this band was recognized by antibodies against Lactococcus lactis ADHE. By gold labeling, the antibodies recognized the granular material that mainly constitutes the 160,000-g pellet and a material that sedimented along with the internal membrane vesicles. By negative staining, the 160,000-g fraction showed helical rodlike structures with an average length of 103 nm; almost no membrane vesicles were observed in this pellet. In internal membrane fractions, no rodlike structures were found, but protomerlike round structures were observed. These results indicate that the main amebic NAD+-dependent ADH2 activity is naturally organized as rodlike helical particles, similar to bacterial ADHE. Detection of ADH2 in membrane fractions might be explained by cosedimentation of the multimeric ADH during membrane purification.
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Affiliation(s)
- Eva E Avila
- Instituto de Investigación en Biología Experimental, Facultad de Química, Universidad de Guanajuato, México.
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