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Sharma S, Ahmed M, Akhter Y. Fungal acetyltransferases structures, mechanisms and inhibitors: A review. Int J Biol Macromol 2019; 157:626-640. [PMID: 31786301 DOI: 10.1016/j.ijbiomac.2019.11.214] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Revised: 11/26/2019] [Accepted: 11/26/2019] [Indexed: 12/31/2022]
Abstract
Acetylation of proteins is vital and mediate many processes within the cells like protein interactions, intercellular localization, protein stability, transcriptional regulation, enzyme activity and many more. Acetylation, an evolutionarily conserved process, attracted more attention due to its key regulatory role in many cellular processes and its effect on proteome and metabolome. In eukaryotes, protein acetylation also contribute to the epigenetic regulation of gene expression. Acetylation involves the transfer of acetyl group from donor acetyl coenzyme A to a suitable acceptor molecule and the reaction is catalyzed by acetyltransferase enzymes. The review focuses on current understanding of different acetyltransferase families: their discovery, structure and catalytic mechanism in fungal species. Fungal acetyltransferases use divergent catalytic mechanisms and carry out catalysis in a substrate-specific manner. The studies have explored different fungal acetyltransferases in relation to secondary metabolite production and the fungal pathogenesis. Although, the functions and catalytic mechanism of acetyltransferases are well known, however further enhanced knowledge may improve their utilization in various applications of biotechnology.
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Affiliation(s)
- Shikha Sharma
- School of Earth and Environmental Sciences, Central University of Himachal Pradesh, Shahpur, District-Kangra, Himachal Pradesh 176206, India
| | - Mushtaq Ahmed
- School of Earth and Environmental Sciences, Central University of Himachal Pradesh, Shahpur, District-Kangra, Himachal Pradesh 176206, India
| | - Yusuf Akhter
- Department of Biotechnology, Babasaheb Bhimrao Ambedkar University, VidyaVihar, Raebareli Road, Lucknow, Uttar Pradesh 226025, India.
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2
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All about that fat: Lipid modification of proteins in Cryptococcus neoformans. J Microbiol 2016; 54:212-22. [PMID: 26920881 DOI: 10.1007/s12275-016-5626-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Revised: 02/01/2016] [Accepted: 02/01/2016] [Indexed: 12/17/2022]
Abstract
Lipid modification of proteins is a widespread, essential process whereby fatty acids, cholesterol, isoprenoids, phospholipids, or glycosylphospholipids are attached to polypeptides. These hydrophobic groups may affect protein structure, function, localization, and/or stability; as a consequence such modifications play critical regulatory roles in cellular systems. Recent advances in chemical biology and proteomics have allowed the profiling of modified proteins, enabling dissection of the functional consequences of lipid addition. The enzymes that mediate lipid modification are specific for both the lipid and protein substrates, and are conserved from fungi to humans. In this article we review these enzymes, their substrates, and the processes involved in eukaryotic lipid modification of proteins. We further focus on its occurrence in the fungal pathogen Cryptococcus neoformans, highlighting unique features that are both relevant for the biology of the organism and potentially important in the search for new therapies.
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Singh N, Shah P, Dwivedi H, Mishra S, Tripathi R, Sahasrabuddhe AA, Siddiqi MI. Integrated machine learning, molecular docking and 3D-QSAR based approach for identification of potential inhibitors of trypanosomal N-myristoyltransferase. MOLECULAR BIOSYSTEMS 2016; 12:3711-3723. [DOI: 10.1039/c6mb00574h] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Integrated in silico approaches for the identification of antitrypanosomal inhibitors.
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Affiliation(s)
- Nidhi Singh
- Molecular and Structural Biology Division
- CSIR-Central Drug Research Institute
- Lucknow 226031
- India
| | - Priyanka Shah
- Molecular and Structural Biology Division
- CSIR-Central Drug Research Institute
- Lucknow 226031
- India
| | - Hemlata Dwivedi
- Division of Parasitology
- CSIR-Central Drug Research Institute
- Lucknow
- India
| | - Shikha Mishra
- Molecular and Structural Biology Division
- CSIR-Central Drug Research Institute
- Lucknow 226031
- India
| | - Renu Tripathi
- Division of Parasitology
- CSIR-Central Drug Research Institute
- Lucknow
- India
- Academy of Scientific and Innovative Research (AcSIR)
| | - Amogh A. Sahasrabuddhe
- Molecular and Structural Biology Division
- CSIR-Central Drug Research Institute
- Lucknow 226031
- India
- Academy of Scientific and Innovative Research (AcSIR)
| | - Mohammad Imran Siddiqi
- Molecular and Structural Biology Division
- CSIR-Central Drug Research Institute
- Lucknow 226031
- India
- Academy of Scientific and Innovative Research (AcSIR)
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4
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Brannigan JA, Roberts SM, Bell AS, Hutton JA, Hodgkinson MR, Tate EW, Leatherbarrow RJ, Smith DF, Wilkinson AJ. Diverse modes of binding in structures of Leishmania major N-myristoyltransferase with selective inhibitors. IUCRJ 2014; 1:250-60. [PMID: 25075346 PMCID: PMC4107925 DOI: 10.1107/s2052252514013001] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2014] [Accepted: 06/04/2014] [Indexed: 05/08/2023]
Abstract
The leishmaniases are a spectrum of global diseases of poverty associated with immune dysfunction and are the cause of high morbidity. Despite the long history of these diseases, no effective vaccine is available and the currently used drugs are variously compromised by moderate efficacy, complex side effects and the emergence of resistance. It is therefore widely accepted that new therapies are needed. N-Myristoyltransferase (NMT) has been validated pre-clinically as a target for the treatment of fungal and parasitic infections. In a previously reported high-throughput screening program, a number of hit compounds with activity against NMT from Leishmania donovani have been identified. Here, high-resolution crystal structures of representative compounds from four hit series in ternary complexes with myristoyl-CoA and NMT from the closely related L. major are reported. The structures reveal that the inhibitors associate with the peptide-binding groove at a site adjacent to the bound myristoyl-CoA and the catalytic α-carboxylate of Leu421. Each inhibitor makes extensive apolar contacts as well as a small number of polar contacts with the protein. Remarkably, the compounds exploit different features of the peptide-binding groove and collectively occupy a substantial volume of this pocket, suggesting that there is potential for the design of chimaeric inhibitors with significantly enhanced binding. Despite the high conservation of the active sites of the parasite and human NMTs, the inhibitors act selectively over the host enzyme. The role of conformational flexibility in the side chain of Tyr217 in conferring selectivity is discussed.
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Affiliation(s)
- James A. Brannigan
- Structural Biology Laboratory, Department of Chemistry, University of York, York YO10 5DD, England
| | - Shirley M. Roberts
- Structural Biology Laboratory, Department of Chemistry, University of York, York YO10 5DD, England
| | - Andrew S. Bell
- Department of Chemistry, Imperial College London, South Kensington Campus, London SW7 2AZ, England
| | - Jennie A. Hutton
- Department of Chemistry, Imperial College London, South Kensington Campus, London SW7 2AZ, England
| | - Michael R. Hodgkinson
- Centre for Immunology and Infection, Department of Biology, University of York, York YO10 5DD, England
| | - Edward W. Tate
- Department of Chemistry, Imperial College London, South Kensington Campus, London SW7 2AZ, England
| | - Robin J. Leatherbarrow
- Department of Chemistry, Imperial College London, South Kensington Campus, London SW7 2AZ, England
| | - Deborah F. Smith
- Centre for Immunology and Infection, Department of Biology, University of York, York YO10 5DD, England
| | - Anthony J. Wilkinson
- Structural Biology Laboratory, Department of Chemistry, University of York, York YO10 5DD, England
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Ryu CK, Nho JH, Jin G, Oh SY, Choi SJ. Synthesis of Benzofuro[6,7- d]thiazoles, Benzofuro[7,6- d]thiazoles and 6-Arylaminobenzo[ d]thiazole-4,7-diones as Antifungal Agent. Chem Pharm Bull (Tokyo) 2014; 62:668-74. [DOI: 10.1248/cpb.c14-00146] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Chung-Kyu Ryu
- College of Pharmacy & Graduate School of Pharmaceutical Sciences, Ewha Womans University
| | - Ji-Hee Nho
- College of Pharmacy & Graduate School of Pharmaceutical Sciences, Ewha Womans University
| | - Guohua Jin
- College of Pharmacy & Graduate School of Pharmaceutical Sciences, Ewha Womans University
| | - Sun Young Oh
- College of Pharmacy & Graduate School of Pharmaceutical Sciences, Ewha Womans University
| | - Soo Jung Choi
- College of Pharmacy & Graduate School of Pharmaceutical Sciences, Ewha Womans University
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Ryu CK, Kim YH, Im HA, Kim JY, Yoon JH, Kim A. Synthesis and antifungal activity of 6,7-bis(arylthio)-quinazoline-5,8-diones and furo[2,3-f]quinazolin-5-ols. Bioorg Med Chem Lett 2012; 22:500-3. [DOI: 10.1016/j.bmcl.2011.10.099] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2011] [Revised: 10/18/2011] [Accepted: 10/27/2011] [Indexed: 10/15/2022]
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N-myristoyltransferase in the leukocytic development processes. Cell Tissue Res 2011; 345:203-11. [PMID: 21698528 DOI: 10.1007/s00441-011-1202-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2011] [Accepted: 06/03/2011] [Indexed: 02/07/2023]
Abstract
The lipidic modification of proteins has recently been shown to be of immense importance, although many of the roles of these modifications remain as yet unidentified. One of such key modifications occurring on several proteins is the covalent addition of a 14-carbon long saturated fatty acid, a process termed myristoylation. Myristoylation can occur during both co-translational protein synthesis and posttranslationally, confers lipophilicity to protein molecules, and controls protein functions. The protein myristoylation process is catalyzed by the enzyme N-myristoyltransferase (NMT), which exists as two isoforms: NMT1 and NMT2. NMT1 is essential for growth and development, during which rapid cellular proliferation is required, in a variety of organisms. NMT1 is also reported to be elevated in many cancerous states, which also involve rapid cellular growth, albeit in an unwanted and uncontrolled manner. The delineation of myristoylation-dependent cellular functions is still in a state of infancy, and many of the roles of the myristoylated proteins remain to be established. The development of cells of the leukocytic lineage represents a phase of rapid growth and development, and we have observed that NMT1 plays a role in this process. The current review outlines the roles of NMT1 in the growth and differentiation of the cells of leukocytic origin. The described studies clearly demonstrate the roles of NMT1 in the regulation of the developmental processes of the leukocytes cells and provide a basis for further research with the aim of unraveling the roles of protein myristoylation in both cellular and physiological context.
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Ryu CK, Kim YH, Nho JH, Hong JA, Yoon JH, Kim A. Synthesis and antifungal activity of furo[2,3-f]quinolin-5-ols. Bioorg Med Chem Lett 2010; 21:952-5. [PMID: 21215618 DOI: 10.1016/j.bmcl.2010.12.058] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2010] [Revised: 11/25/2010] [Accepted: 12/09/2010] [Indexed: 11/17/2022]
Abstract
Furo[2,3-f]quinolin-5-ol derivatives were synthesized and tested for in vitro antifungal activity against Candida,Aspergillus species, and Cryptococcus neoformans. Among them tested, many furo[2,3-f]quinolin-5-ols showed good antifungal activity. The results suggest that furo[2,3-f]quinolin-5-ols would be promising antifungal agents.
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Affiliation(s)
- Chung-Kyu Ryu
- College of Pharmacy, Ewha Womans University, Seoul, Republic of Korea.
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Ryu CK, Song AL, Lee JY, Hong JA, Yoon JH, Kim A. Synthesis and antifungal activity of benzofuran-5-ols. Bioorg Med Chem Lett 2010; 20:6777-80. [PMID: 20851600 DOI: 10.1016/j.bmcl.2010.08.129] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2010] [Revised: 08/18/2010] [Accepted: 08/27/2010] [Indexed: 10/19/2022]
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Brannigan JA, Smith BA, Yu Z, Brzozowski AM, Hodgkinson MR, Maroof A, Price HP, Meier F, Leatherbarrow RJ, Tate EW, Smith DF, Wilkinson AJ. N-myristoyltransferase from Leishmania donovani: structural and functional characterisation of a potential drug target for visceral leishmaniasis. J Mol Biol 2010; 396:985-99. [PMID: 20036251 PMCID: PMC2829124 DOI: 10.1016/j.jmb.2009.12.032] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2009] [Revised: 12/15/2009] [Accepted: 12/16/2009] [Indexed: 12/30/2022]
Abstract
N-Myristoyltransferase (NMT) catalyses the attachment of the 14-carbon saturated fatty acid, myristate, to the amino-terminal glycine residue of a subset of eukaryotic proteins that function in multiple cellular processes, including vesicular protein trafficking and signal transduction. In these pathways, N-myristoylation facilitates association of substrate proteins with membranes or the hydrophobic domains of other partner peptides. NMT function is essential for viability in all cell types tested to date, demonstrating that this enzyme has potential as a target for drug development. Here, we provide genetic evidence that NMT is likely to be essential for viability in insect stages of the pathogenic protozoan parasite, Leishmania donovani, causative agent of the tropical infectious disease, visceral leishmaniasis. The open reading frame of L. donovani NMT has been amplified and used to overproduce active recombinant enzyme in Escherichia coli, as demonstrated by gel mobility shift assays of ligand binding and peptide-myristoylation activity in scintillation proximity assays. The purified protein has been crystallized in complex with the non-hydrolysable substrate analogue S-(2-oxo)pentadecyl-CoA, and its structure was solved by molecular replacement at 1.4 A resolution. The structure has as its defining feature a 14-stranded twisted beta-sheet on which helices are packed so as to form an extended and curved substrate-binding groove running across two protein lobes. The fatty acyl-CoA is largely buried in the N-terminal lobe, its binding leading to the loosening of a flap, which in unliganded NMT structures, occludes the protein substrate binding site in the carboxy-terminal lobe. These studies validate L. donovani NMT as a potential target for development of new therapeutic agents against visceral leishmaniasis.
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Key Words
- arf, adp-ribosylation factor
- dig, digoxigenin
- hasp, hydrophilic acylated surface protein
- hyg, hygromycin
- neo, neomycin
- nhm, non-hydrolysable myristoyl-coa analogue
- nmt, n-myristoyltransferase
- orf, open reading frame
- pac, puromycin
- spa, scintillation proximity assay
- vl, visceral leishmaniasis
- canmt, hsnmt, ldnmt and scnmt, n-myristoyltransferase from candida albicans, homo sapiens, leishmania donovani and saccharomyces cerevisiae, respectively
- n-myristoyltransferase
- leishmania
- visceral leishmaniasis
- crystal structure
- drug target
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Affiliation(s)
- James A. Brannigan
- York Structural Biology Laboratory, Department of Chemistry, University of York, York YO10 5YW, UK
| | - Barbara A. Smith
- Centre for Immunology and Infection, Department of Biology/Hull York Medical School, University of York, York YO10 5YW, UK
| | - Zhiyong Yu
- Department of Chemistry, Imperial College, London SW7 2AZ, UK
| | - Andrzej M. Brzozowski
- York Structural Biology Laboratory, Department of Chemistry, University of York, York YO10 5YW, UK
| | - Michael R. Hodgkinson
- Centre for Immunology and Infection, Department of Biology/Hull York Medical School, University of York, York YO10 5YW, UK
| | - Asher Maroof
- Centre for Immunology and Infection, Department of Biology/Hull York Medical School, University of York, York YO10 5YW, UK
| | - Helen P. Price
- Centre for Immunology and Infection, Department of Biology/Hull York Medical School, University of York, York YO10 5YW, UK
| | - Franziska Meier
- Department of Chemistry, Imperial College, London SW7 2AZ, UK
| | | | - Edward W. Tate
- Department of Chemistry, Imperial College, London SW7 2AZ, UK
| | - Deborah F. Smith
- Centre for Immunology and Infection, Department of Biology/Hull York Medical School, University of York, York YO10 5YW, UK
| | - Anthony J. Wilkinson
- York Structural Biology Laboratory, Department of Chemistry, University of York, York YO10 5YW, UK
- Corresponding author.
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11
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Wright MH, Heal WP, Mann DJ, Tate EW. Protein myristoylation in health and disease. J Chem Biol 2010; 3:19-35. [PMID: 19898886 PMCID: PMC2816741 DOI: 10.1007/s12154-009-0032-8] [Citation(s) in RCA: 181] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2009] [Revised: 10/05/2009] [Accepted: 10/19/2009] [Indexed: 02/07/2023] Open
Abstract
N-myristoylation is the attachment of a 14-carbon fatty acid, myristate, onto the N-terminal glycine residue of target proteins, catalysed by N-myristoyltransferase (NMT), a ubiquitous and essential enzyme in eukaryotes. Many of the target proteins of NMT are crucial components of signalling pathways, and myristoylation typically promotes membrane binding that is essential for proper protein localisation or biological function. NMT is a validated therapeutic target in opportunistic infections of humans by fungi or parasitic protozoa. Additionally, NMT is implicated in carcinogenesis, particularly colon cancer, where there is evidence for its upregulation in the early stages of tumour formation. However, the study of myristoylation in all organisms has until recently been hindered by a lack of techniques for detection and identification of myristoylated proteins. Here we introduce the chemistry and biology of N-myristoylation and NMT, and discuss new developments in chemical proteomic technologies that are meeting the challenge of studying this important co-translational modification in living systems.
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Affiliation(s)
- Megan H. Wright
- Chemical Biology Centre, Imperial College London, Exhibition Rd., London, SW72AZ UK
- Department of Chemistry, Imperial College London, Exhibition Rd., London, SW72AZ UK
- Department of Life Sciences, Imperial College London, Exhibition Rd., London, SW72AZ UK
| | - William P. Heal
- Department of Chemistry, Imperial College London, Exhibition Rd., London, SW72AZ UK
- Department of Life Sciences, Imperial College London, Exhibition Rd., London, SW72AZ UK
| | - David J. Mann
- Chemical Biology Centre, Imperial College London, Exhibition Rd., London, SW72AZ UK
- Department of Life Sciences, Imperial College London, Exhibition Rd., London, SW72AZ UK
| | - Edward W. Tate
- Chemical Biology Centre, Imperial College London, Exhibition Rd., London, SW72AZ UK
- Department of Chemistry, Imperial College London, Exhibition Rd., London, SW72AZ UK
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Caffrey CR, Rohwer A, Oellien F, Marhöfer RJ, Braschi S, Oliveira G, McKerrow JH, Selzer PM. A comparative chemogenomics strategy to predict potential drug targets in the metazoan pathogen, Schistosoma mansoni. PLoS One 2009; 4:e4413. [PMID: 19198654 PMCID: PMC2635471 DOI: 10.1371/journal.pone.0004413] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2008] [Accepted: 12/15/2008] [Indexed: 12/11/2022] Open
Abstract
Schistosomiasis is a prevalent and chronic helmintic disease in tropical regions. Treatment and control relies on chemotherapy with just one drug, praziquantel and this reliance is of concern should clinically relevant drug resistance emerge and spread. Therefore, to identify potential target proteins for new avenues of drug discovery we have taken a comparative chemogenomics approach utilizing the putative proteome of Schistosoma mansoni compared to the proteomes of two model organisms, the nematode, Caenorhabditis elegans and the fruitfly, Drosophila melanogaster. Using the genome comparison software Genlight, two separate in silico workflows were implemented to derive a set of parasite proteins for which gene disruption of the orthologs in both the model organisms yielded deleterious phenotypes (e.g., lethal, impairment of motility), i.e., are essential genes/proteins. Of the 67 and 68 sequences generated for each workflow, 63 were identical in both sets, leading to a final set of 72 parasite proteins. All but one of these were expressed in the relevant developmental stages of the parasite infecting humans. Subsequent in depth manual curation of the combined workflow output revealed 57 candidate proteins. Scrutiny of these for 'druggable' protein homologs in the literature identified 35 S. mansoni sequences, 18 of which were homologous to proteins with 3D structures including co-crystallized ligands that will allow further structure-based drug design studies. The comparative chemogenomics strategy presented generates a tractable set of S. mansoni proteins for experimental validation as drug targets against this insidious human pathogen.
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Affiliation(s)
- Conor R. Caffrey
- Sandler Center for Basic Research in Parasitic Diseases, California Institute for Quantitative Biosciences, University of California San Francisco, San Francisco, California, United States of America
| | - Andreas Rohwer
- Intervet Innovation GmbH, BioChemInformatics, Schwabenheim, Germany
| | - Frank Oellien
- Intervet Innovation GmbH, BioChemInformatics, Schwabenheim, Germany
| | | | - Simon Braschi
- Sandler Center for Basic Research in Parasitic Diseases, California Institute for Quantitative Biosciences, University of California San Francisco, San Francisco, California, United States of America
| | - Guilherme Oliveira
- Laboratory of Cellular and Molecular Parasitology, Centro de Pesquisas René Rachou, Fundação Oswaldo Cruz, Belo Horizonte, Brazil
| | - James H. McKerrow
- Sandler Center for Basic Research in Parasitic Diseases, California Institute for Quantitative Biosciences, University of California San Francisco, San Francisco, California, United States of America
| | - Paul M. Selzer
- Intervet Innovation GmbH, BioChemInformatics, Schwabenheim, Germany
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Ruff JA, Lodge JK, Baker LG. Three galactose inducible promoters for use in C. neoformans var. grubii. Fungal Genet Biol 2008; 46:9-16. [PMID: 18952189 DOI: 10.1016/j.fgb.2008.10.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2008] [Revised: 10/07/2008] [Accepted: 10/07/2008] [Indexed: 10/21/2022]
Abstract
Cryptococcus neoformans is the causative agent of cryptococcal meningoencephalitis, most frequently occurring in immunocompromised individuals. There are three varieties of C. neoformans, var. grubii, var. neoformans, and var. gatti. Worldwide var. grubii is the most prevalent clinical isolate. However, few tools for the study of essential genes in var. grubii exist. Here we describe three endogenous inducible promoters for use in the study of this important opportunistic pathogen. We identified eight potential homologs of S. cerevisiae galactose genes in var. grubii. We found that GAL1, GAL7, and UGE2 were regulated by glucose and galactose and can be used successfully during mating. Our analysis indicated these promoters should prove to be excellent tools for analysis of genes in var. grubii.
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Affiliation(s)
- Jack A Ruff
- Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, 1100 S. Grand Boulevard, Saint Louis, MO 63104, USA
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15
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Bowyer PW, Tate EW, Leatherbarrow RJ, Holder AA, Smith DF, Brown KA. N-myristoyltransferase: a prospective drug target for protozoan parasites. ChemMedChem 2008; 3:402-8. [PMID: 18324715 DOI: 10.1002/cmdc.200700301] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Paul W Bowyer
- Division of Cell and Molecular Biology, Centre for Molecular Microbiology and Infection, Imperial College London, London SW7 2AZ, UK
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Wu J, Tao Y, Zhang M, Howard MH, Gutteridge S, Ding J. Crystal structures of Saccharomyces cerevisiae N-myristoyltransferase with bound myristoyl-CoA and inhibitors reveal the functional roles of the N-terminal region. J Biol Chem 2007; 282:22185-94. [PMID: 17513302 DOI: 10.1074/jbc.m702696200] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Protein N-myristoylation catalyzed by myristoyl-CoA:protein N-myristoyltransferase (NMT) plays an important role in a variety of critical cellular processes and thus is an attractive target for development of antifungal drugs. We report here three crystal structures of Saccharomyces cerevisiae NMT: in binary complex with myristoyl-CoA (MYA) alone and in two ternary complexes involving MYA and two different non-peptidic inhibitors. In all three structures, the majority of the N-terminal region, absent in all previously reported structures, forms a well defined motif that is located in the vicinity of the peptide substrate-binding site and is involved in the binding of MYA. The Ab loop, which might be involved in substrate recognition, adopts an open conformation, whereas a loop of the N-terminal region (residues 22-24) that covers the top of the substrate-binding site is in the position occupied by the Ab loop when in the closed conformation. Structural comparisons with other NMTs, together with mutagenesis data, suggest that the N-terminal region of NMT plays an important role in the binding of both MYA and peptide substrate, but not in subsequent steps of the catalytic mechanism. The two inhibitors occupy the peptide substrate-binding site and interact with the protein through primarily hydrophobic contacts. Analyses of the inhibitorenzyme interactions provide valuable information for further improvement of antifungal inhibitors targeting NMT.
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Affiliation(s)
- Jian Wu
- State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
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Selvakumar P, Lakshmikuttyamma A, Shrivastav A, Das SB, Dimmock JR, Sharma RK. Potential role of N-myristoyltransferase in cancer. Prog Lipid Res 2007; 46:1-36. [PMID: 16846646 DOI: 10.1016/j.plipres.2006.05.002] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Colorectal cancer is the second leading cause of malignant death, and better preventive strategies are needed. The treatment of colonic cancer remains difficult because of the lack of effective chemotherapeutic agents; therefore it is important to continue to search for cellular functions that can be disrupted by chemotherapeutic drugs resulting in the inhibition of the development and progression of cancer. The current knowledge of the modification of proteins by myristoylation involving myristoyl-CoA: protein N-myristoyltransferase (NMT) is in its infancy. This process is involved in the pathogenesis of cancer. We have reported for the first time that NMT activity and protein expression were higher in human colorectal cancer, gallbladder carcinoma and brain tumors. In addition, an increase in NMT activity appeared at an early stage in colonic carcinogenesis. It is conceivable therefore that NMT can be used as a potential marker for the early detection of cancer. These observations lead to the possibility of developing NMT specific inhibitors, which may be therapeutically useful. We proposed that HSC70 and/or enolase could be used as an anticancer therapeutic target. This review summarized the status of NMT in cancer which has been carried in our laboratory.
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Affiliation(s)
- Ponniah Selvakumar
- Department of Pathology and Laboratory Medicine, College of Medicine, and Health Research Division, Saskatchewan Cancer Agency, University of Saskatchewan, 20 Campus Drive, Saskatoon, Sask., Canada S7N 4H4
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Panethymitaki C, Bowyer P, Price H, Leatherbarrow R, Brown K, Smith D. Characterization and selective inhibition of myristoyl-CoA:protein N-myristoyltransferase from Trypanosoma brucei and Leishmania major. Biochem J 2006; 396:277-85. [PMID: 16480339 PMCID: PMC1462705 DOI: 10.1042/bj20051886] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The eukaryotic enzyme NMT (myristoyl-CoA:protein N-myristoyltransferase) has been characterized in a range of species from Saccharomyces cerevisiae to Homo sapiens. NMT is essential for viability in a number of human pathogens, including the fungi Candida albicans and Cryptococcus neoformans, and the parasitic protozoa Leishmania major and Trypanosoma brucei. We have purified the Leishmania and T. brucei NMTs as active recombinant proteins and carried out kinetic analyses with their essential fatty acid donor, myristoyl-CoA and specific peptide substrates. A number of inhibitory compounds that target NMT in fungal species have been tested against the parasite enzymes in vitro and against live parasites in vivo. Two of these compounds inhibit TbNMT with IC50 values of <1 microM and are also active against mammalian parasite stages, with ED50 (the effective dose that allows 50% cell growth) values of 16-66 microM and low toxicity to murine macrophages. These results suggest that targeting NMT could be a valid approach for the development of chemotherapeutic agents against infectious diseases including African sleeping sickness and Nagana.
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Affiliation(s)
- Chrysoula Panethymitaki
- *Wellcome Trust Laboratories for Molecular Parasitology, Imperial College London, London SW7 2AZ, U.K
- †Centre for Molecular Microbiology and Infection, Imperial College London, London SW7 2AZ, U.K
| | - Paul W. Bowyer
- *Wellcome Trust Laboratories for Molecular Parasitology, Imperial College London, London SW7 2AZ, U.K
- †Centre for Molecular Microbiology and Infection, Imperial College London, London SW7 2AZ, U.K
- ‡Department of Chemistry, Imperial College London, London SW7 2AZ, U.K
| | - Helen P. Price
- *Wellcome Trust Laboratories for Molecular Parasitology, Imperial College London, London SW7 2AZ, U.K
- †Centre for Molecular Microbiology and Infection, Imperial College London, London SW7 2AZ, U.K
- §Immunology and Infection Unit, Department of Biology/Hull York Medical School, University of York, Heslington, York YO10 5YW, U.K
| | | | - Katherine A. Brown
- †Centre for Molecular Microbiology and Infection, Imperial College London, London SW7 2AZ, U.K
| | - Deborah F. Smith
- *Wellcome Trust Laboratories for Molecular Parasitology, Imperial College London, London SW7 2AZ, U.K
- †Centre for Molecular Microbiology and Infection, Imperial College London, London SW7 2AZ, U.K
- §Immunology and Infection Unit, Department of Biology/Hull York Medical School, University of York, Heslington, York YO10 5YW, U.K
- To whom correspondence should be addressed, at Immunology and Infection Unit, Department of Biology/Hull York Medical School, University of York (email )
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Vetting MW, S de Carvalho LP, Yu M, Hegde SS, Magnet S, Roderick SL, Blanchard JS. Structure and functions of the GNAT superfamily of acetyltransferases. Arch Biochem Biophys 2005; 433:212-26. [PMID: 15581578 DOI: 10.1016/j.abb.2004.09.003] [Citation(s) in RCA: 458] [Impact Index Per Article: 24.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2004] [Revised: 09/02/2004] [Indexed: 11/15/2022]
Abstract
The Gcn5-related N-acetyltransferases are an enormous superfamily of enzymes that are universally distributed in nature and that use acyl-CoAs to acylate their cognate substrates. In this review, we will examine those members of this superfamily that have been both structurally and mechanistically characterized. These include aminoglycoside N-acetyltransferases, serotonin N-acetyltransferase, glucosamine-6-phosphate N-acetyltransferase, the histone acetyltransferases, mycothiol synthase, protein N-myristoyltransferase, and the Fem family of amino acyl transferases.
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Affiliation(s)
- Matthew W Vetting
- Department of Biochemistry, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA
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20
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Masubuchi M, Ebiike H, Kawasaki KI, Sogabe S, Morikami K, Shiratori Y, Tsujii S, Fujii T, Sakata K, Hayase M, Shindoh H, Aoki Y, Ohtsuka T, Shimma N. Synthesis and biological activities of benzofuran antifungal agents targeting fungal N-myristoyltransferase. Bioorg Med Chem 2003; 11:4463-78. [PMID: 13129583 DOI: 10.1016/s0968-0896(03)00429-2] [Citation(s) in RCA: 98] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The C-4 side chain modification of lead compound 1 has resulted in the identification of a potent and selective Candida albicans N-myristoyltransferase (CaNmt) inhibitor RO-09-4609, which exhibits antifungal activity against C. albicans in vitro. Further modification of its C-2 substituent has led to the discovery of RO-09-4879, which exhibits antifungal activity in vivo. The drug design is based on X-ray crystal analysis of a CaNmt complex with benzofuran derivative 4a. The optimization incorporates various biological investigations including a quasi in vivo assay and pharmacokinetic study. The computer aided drug design, synthesis, structure-activity relationships, and biological properties of RO-09-4879 are described in detail.
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Affiliation(s)
- Miyako Masubuchi
- Chugai Pharmaceutical Kamakura Research Center (formerly Nippon Roche Research Center), 200 Kajiwara, Kamakura, Kanagawa 247-8530, Japan
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21
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Lin SS, Manchester JK, Gordon JI. Sip2, an N-myristoylated beta subunit of Snf1 kinase, regulates aging in Saccharomyces cerevisiae by affecting cellular histone kinase activity, recombination at rDNA loci, and silencing. J Biol Chem 2003; 278:13390-7. [PMID: 12562756 DOI: 10.1074/jbc.m212818200] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Saccharomyces cerevisiae has evolved a number of mechanisms for sensing glucose. In the present study we examine the mechanism by which one of these pathways, involving Snf1, regulates cellular aging. Snf1 is a heterotrimer composed of a catalytic alpha subunit (Snf1p) that phosphorylates target proteins at Ser/Thr residues, an activating gamma subunit (Snf4p), and a beta subunit (Sip1p, Sip2p, or Gal83). We previously showed that forced expression of Snf1p or loss of Sip2p, but not the other beta subunits, causes accelerated aging, while removal of Snf4p extends life span (Ashrafi, K., Lin, S. S., Manchester, J. K., and Gordon, J. I. (2000) Genes Dev. 14, 1872-1885). We now demonstrate that in wild type cells, there is an age-associated shift in Sip2p from the plasma membrane to the cytoplasm, a prominent redistribution of Snf4p from the plasma membrane to the nucleus, a modest increase in nuclear Snf1p, and a concomitant increase in cellular Snf1 histone H3 kinase activity. Covalent attachment of myristate to the N-terminal Gly of Sip2p is essential for normal cellular life span. When plasma membrane association of Sip2p is abolished by a mutation that blocks its N-myristoylation, Snf4p is shifted to the nucleus. Rapidly aging sip2 Delta cells have higher levels of histone H3 kinase activity than their generation-matched isogenic wild type counterparts. Increased Snf1 activity is associated with augmented recombination at rDNA loci, plus desilencing at sites affected by Snf1-catalyzed Ser(10) phosphorylation of histone H3 (the INO1 promoter plus targets of the transcription factor Adr1p). The rapid-aging phenotype of sip2 Delta cells is fully rescued by blocking recombination at rDNA loci with a fob1 Delta allele; rescue is not accompanied by amelioration of an age-associated shift toward gluconeogenesis and glucose storage. Together, these findings suggest that Sip2p acts as a negative regulator of nuclear Snf1 activity in young cells by sequestering its activating gamma subunit at the plasma membrane and that loss of Sip2p from the plasma membrane to the cytoplasm in aging cells facilities Snf4p entry into the nucleus so that Snf1 can modify chromatin structure.
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Affiliation(s)
- Stephen S Lin
- Department of Molecular Biology and Pharmacology, Washington University School of Medicine, St. Louis, Missouri 63110, USA
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22
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Price HP, Menon MR, Panethymitaki C, Goulding D, McKean PG, Smith DF. Myristoyl-CoA:protein N-myristoyltransferase, an essential enzyme and potential drug target in kinetoplastid parasites. J Biol Chem 2003; 278:7206-14. [PMID: 12488459 DOI: 10.1074/jbc.m211391200] [Citation(s) in RCA: 137] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Co-translational modification of eukaryotic proteins by N-myristoylation aids subcellular targeting and protein-protein interactions. The enzyme that catalyzes this process, N-myristoyltransferase (NMT), has been characterized in the kinetoplastid protozoan parasites, Leishmania and Trypanosoma brucei. In Leishmania major, the single copy NMT gene is constitutively expressed in all parasite stages as a 48.5-kDa protein that localizes to both membrane and cytoplasmic fractions. Leishmania NMT myristoylates the target acylated Leishmania protein, HASPA, when both are co-expressed in Escherichia coli. Gene targeting experiments have shown that NMT activity is essential for viability in Leishmania. In addition, overexpression of NMT causes gross changes in parasite morphology, including the subcellular accumulation of lipids, leading to cell death. This phenotype is more extreme than that observed in Saccharomyces cerevisiae, in which overexpression of NMT activity has no obvious effects on growth kinetics or cell morphology. RNA interference assays in T. brucei have confirmed that NMT is also an essential protein in both life cycle stages of this second kinetoplastid species, suggesting that this enzyme may be an appropriate target for the development of anti-parasitic agents.
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Affiliation(s)
- Helen P Price
- Wellcome Trust Laboratories for Molecular Parasitology, Centre for Molecular Microbiology and Infection, Department of Biological Sciences, Imperial College of Science, Technology and Medicine, London SW7 2AZ, United Kingdom
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23
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Gelb MH, Van Voorhis WC, Buckner FS, Yokoyama K, Eastman R, Carpenter EP, Panethymitaki C, Brown KA, Smith DF. Protein farnesyl and N-myristoyl transferases: piggy-back medicinal chemistry targets for the development of antitrypanosomatid and antimalarial therapeutics. Mol Biochem Parasitol 2003; 126:155-63. [PMID: 12615314 DOI: 10.1016/s0166-6851(02)00282-7] [Citation(s) in RCA: 105] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
To accelerate progress in the development of therapeutics for protozoan parasitic diseases, we are studying enzymes active in co- and post-translational protein modification that are already the focus of drug development in other eukaryotic systems. Inhibitors of the protein farnesyltransferases (PFT) are well-established antitumour agents of low cytotoxicity and known pharmokinetic properties, while inhibitors of N-myristoyl transferase show both selectivity and specificity in the treatment of fungal infections. Here, we summarise the current evidence that supports the targeting of these ubiquitous eukaryotic enzymes for drug development against trypanosomatid infections and malaria.
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Affiliation(s)
- Michael H Gelb
- Department of Chemistry, University of Washington, Seattle, WA 98195, USA.
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24
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Sogabe S, Masubuchi M, Sakata K, Fukami TA, Morikami K, Shiratori Y, Ebiike H, Kawasaki K, Aoki Y, Shimma N, D'Arcy A, Winkler FK, Banner DW, Ohtsuka T. Crystal structures of Candida albicans N-myristoyltransferase with two distinct inhibitors. CHEMISTRY & BIOLOGY 2002; 9:1119-28. [PMID: 12401496 DOI: 10.1016/s1074-5521(02)00240-5] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Myristoyl-CoA:protein N-myristoyltransferase (Nmt) is a monomeric enzyme that catalyzes the transfer of the fatty acid myristate from myristoyl-CoA to the N-terminal glycine residue of a variety of eukaryotic and viral proteins. Genetic and biochemical studies have established that Nmt is an attractive target for antifungal drugs. We present here crystal structures of C. albicans Nmt complexed with two classes of inhibitor competitive for peptide substrates. One is a peptidic inhibitor designed from the peptide substrate; the other is a nonpeptidic inhibitor having a benzofuran core. Both inhibitors are bound into the same binding groove, generated by some structural rearrangements of the enzyme, with the peptidic inhibitor showing a substrate-like binding mode and the nonpeptidic inhibitor binding differently. Further, site-directed mutagenesis for C. albicans Nmt has been utilized in order to define explicitly which amino acids are critical for inhibitor binding. The results suggest that the enzyme has some degree of flexibility for substrate binding and provide valuable information for inhibitor design.
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Affiliation(s)
- Satoshi Sogabe
- Nippon Roche Research Center, 200 Kajiwara, Kamakura, Kanagawa 247-8530, Japan.
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25
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Georgopapadakou NH. Antifungals targeted to protein modification: focus on protein N-myristoyltransferase. Expert Opin Investig Drugs 2002; 11:1117-25. [PMID: 12150705 DOI: 10.1517/13543784.11.8.1117] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Invasive fungal infections have increased dramatically in recent years to become important causes of morbidity and mortality in hospitalised patients. Currently available antifungal drugs for such infections essentially have three molecular targets: 14 alpha demethylase (azoles), ergosterol (polyenes) and beta-1,3-glucan synthase (echinocandins). The first is a fungistatic target vulnerable to resistance development; the second, while a fungicidal target, is not sufficiently different from the host to ensure high selectivity; the third, a fungistatic (Aspergillus) or fungicidal (Candida) target, has limited activity spectrum (gaps: Cryptococcus, emerging fungi) and potential host toxicity that might preclude dose escalation. Drugs aimed at totally new targets are thus needed to increase our chemotherapeutic options and to forestall, alone or in combination chemotherapy, the emergence of drug resistance. Protein N-myristoylation, the cotranslational transfer of the 14-carbon saturated fatty acid myristate from CoA to the amino-terminal glycine of several fungal proteins such as the ADP-ribosylation factor (ARF), presents such an attractive new target. The reaction, catalysed by myristoyl-CoA:protein N-myristoyltransferase (NMT), is essential for viability, is biochemically tractable and has proven potential for selectivity. In the past five years, a number of selective inhibitors of the fungal enzyme, some with potent, broad spectrum antifungal activity, have been reported: myristate analogues, myristoylpeptide derivatives, histidine analogues (peptidomimetics), aminobenzothiazoles, quinolines and benzofurans. A major development has been the publication of the crystal structure of Candida albicans and Saccharomyces cerevisiae NMTs, which has allowed virtual docking of inhibitors on the enzyme and refinement of structure-activity relationships of lead compounds.
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26
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Maurer-Stroh S, Eisenhaber B, Eisenhaber F. N-terminal N-myristoylation of proteins: refinement of the sequence motif and its taxon-specific differences. J Mol Biol 2002; 317:523-40. [PMID: 11955007 DOI: 10.1006/jmbi.2002.5425] [Citation(s) in RCA: 150] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
N-terminal N-myristoylation is a lipid anchor modification of eukaryotic and viral proteins targeting them to membrane locations, thus changing the cellular function of modified proteins. Protein myristoylation is critical in many pathways; e.g. in signal transduction, apoptosis, or alternative extracellular protein export. The myristoyl-CoA:protein N-myristoyltransferase (NMT) recognizes the sequence motif of appropriate substrate proteins at the N terminus and attaches the lipid moiety to the absolutely required N-terminal glycine residue. Reliable recognition of capacity for N-terminal myristoylation from the substrate protein sequence alone is desirable for proteome-wide function annotation projects but the existing PROSITE motif is not practical, since it produces huge numbers of false positive and even some false negative predictions. As a first step towards a new prediction method, it is necessary to refine the sequence motif coding for N-terminal N-myristoylation. Relying on the in-depth study of the amino acid sequence variability of substrate proteins, on binding site analyses in X-ray structures or 3D homology models for NMTs from various taxa, and on consideration of biochemical data extracted from the scientific literature, we found indications that, at least within a complete substrate protein, the N-terminal 17 protein residues experience different types of variability restrictions. We identified three motif regions: region 1 (positions 1-6) fitting the binding pocket; region 2 (positions 7-10) interacting with the NMT's surface at the mouth of the catalytic cavity; and region 3 (positions 11-17) comprising a hydrophilic linker. Each region was characterized by physical requirements to single sequence positions or groups of positions regarding volume, polarity, backbone flexibility and other typical properties of amino acids (http://mendel.imp.univie.ac.at/myristate/). These specificity differences are confined partly to taxonomic ranges and are proposed for the design of NMT inhibitors in pathogenic fungal and protozoan systems including Aspergillus fumigatus, Leishmania major, Trypanosoma cruzi, Trypanosoma brucei, Giardia intestinalis, Entamoeba histolytica, Pneumocystis carinii, Strongyloides stercoralis and Schistosoma mansoni. An exhaustive search for NMT-homologues led to the discovery of two putative entomopoxviral NMTs.
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27
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Affiliation(s)
- T A Farazi
- Department of Molecular Biology and Pharmacology, Washington University School of Medicine, St. Louis, MO 63110, USA
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Farazi TA, Waksman G, Gordon JI. Structures of Saccharomyces cerevisiae N-myristoyltransferase with bound myristoylCoA and peptide provide insights about substrate recognition and catalysis. Biochemistry 2001; 40:6335-43. [PMID: 11371195 DOI: 10.1021/bi0101401] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
MyristoylCoA:protein N-myristoyltransferase (Nmt) attaches myristate to the N-terminal Gly residue of proteins involved in a variety of signal transduction cascades, and other critical cellular functions. To gain insight about the structural basis of substrate recognition and catalysis, we determined the structures of a binary complex of Saccharomyces cerevisiae Nmt1p with myristoylCoA to 2.2 A resolution and of a ternary complex of Nmt1p with a nonhydrolyzable myristoylCoA analogue [S-(2-oxo)pentadecylCoA] and an octapeptide substrate (GLYASKLA) to 2.5 A resolution. The binary complex reveals how myristoylCoA alters the conformation of the enzyme to promote binding of both myristoylCoA and peptide and identifies the backbone amides of F170 and L171 as an oxyanion hole which polarizes the reactive thioester carbonyl. The ternary complex structure reveals details of the enzyme's peptide binding specificity and illuminates its mechanism of acyl transfer. The N-terminal Gly ammonium is positioned in close proximity to the C-terminal carboxylate of the protein, where it is poised to undergo the required deprotonation to an amine. In this conformation, the nucleophile is 6.3 A away from the thioester carbonyl. A catalytic mechanism is proposed whereby, once deprotonation is initiated, the N-terminal Gly amine can approximate the thioester carbonyl by rotating along Psi. This motion is facilitated by a H-bond network and leads to reaction between the glycine nitrogen nucleophile and the carbonyl. Loss of CoA from the tetrahedral intermediate may be facilitated by intramolecular H-bonding of the sulfur to the adenylamine of CoA. This affords a compact leaving group and lends a role for the observed bends in the CoA structure. The absolute requirement for Gly at the N-terminus of substrates is explained by the requirement for flexible rotation of its amine.
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Affiliation(s)
- T A Farazi
- Departments of Molecular Biology and Pharmacology, and Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, Missouri 63110, USA
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Nelson RT, Hua J, Pryor B, Lodge JK. Identification of virulence mutants of the fungal pathogen Cryptococcus neoformans using signature-tagged mutagenesis. Genetics 2001; 157:935-47. [PMID: 11238384 PMCID: PMC1461580 DOI: 10.1093/genetics/157.3.935] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Cryptococcus neoformans var. neoformans is an important opportunistic fungal pathogen of patients whose immune system has been compromised due to viral infection, antineoplastic chemotherapy, or tissue transplantation. As many as 13% of all AIDS patients suffer a life-threatening cryptococcal infection at some time during the course of their HIV disease. To begin to understand the molecular basis for virulence in Cryptococcus neoformans var. neoformans serotype A, we have employed signature-tagged mutagenesis (STM) to identify mutants with altered virulence in a mouse model. The critical parameters of signature-tagged mutagenesis in C. neoformans are explored. Data are presented showing that at least 100 different strains can be mixed together in a single animal with each participating in the infection and that there is no apparent interaction between a virulent strain and an avirulent strain in our animal model. Using signature-tagged mutagenesis, we identified 39 mutants with significantly altered growth in a competitive assay. Molecular analyses of these mutants indicated that 19 (49%) contained an insertion in the actin promoter by homologous recombination from a single crossover event, creating a duplication of the actin promoter and the integration of single or multiple copies of the vector. Analysis of the chromosomal insertion sites of those mutants that did not have an integration event in the actin promoter revealed an approximately random distribution among the chromosomes. Individual challenge of the putative mutants in a mouse model revealed five hypovirulent mutants and one hypervirulent mutant.
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Affiliation(s)
- R T Nelson
- Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, St. Louis, Missouri 63104, USA
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30
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Bhatnagar RS, Ashrafi K, Fütterer K, Waksman G, Gordon JI. 9 Biology and enzymology of protein N-myristoylation. PROTEIN LIPIDATION 2001. [DOI: 10.1016/s1874-6047(01)80022-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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Farazi TA, Manchester JK, Gordon JI. Transient-state kinetic analysis of Saccharomyces cerevisiae myristoylCoA:protein N-myristoyltransferase reveals that a step after chemical transformation is rate limiting. Biochemistry 2000; 39:15807-16. [PMID: 11123906 DOI: 10.1021/bi002074t] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
MyristoylCoA:protein N-myristoyltransferase is a member of the superfamily of GCN5-related N-acetyltransferases and catalyzes the covalent attachment of myristate to the N-terminal Gly residue of proteins with diverse functions. Saccharomyces cerevisiae Nmt1p is a monomeric protein with an ordered bi-bi reaction mechanism: myristoylCoA is bound prior to peptide substrate; after catalysis, CoA is released followed by myristoylpeptide. Analysis of the X-ray structure of Nmt1p with bound substrate analogues indicates that the active site contains an oxyanion hole and a catalytic base and that catalysis proceeds through the nucleophilic addition-elimination mechanism. To determine the rate-limiting step in the enzyme reaction, pre-steady-state kinetic analyses were performed using a new, sensitive nonradioactive assay that detects CoA. Multiple turnover quenched flow studies disclosed that a step after the chemical transformation limits the overall rate of the reaction. Multiple and single turnover analyses revealed that the rate for the chemical transformation step is 13.8+/-0.6 s(-1) while the slower steady-state phase is 0.10+/-0.01 s(-1). Stopped flow kinetic studies of substrate acquisition indicated that binding of myristoylCoA to the apo-enzyme occurs through at least a two-step process, with a fast phase rate of 3.2 x 10(8) M(-1) s(-1) and a slow phase rate of 23+/-2 s(-1) (defined at 5 degrees C). Binding of an octapeptide substrate, representing the N-terminal sequence of a known yeast N-myristoylprotein (Cnb1p), to a binary complex composed of Nmt1p and a nonhydrolyzable myristoylCoA analogue (S-(2-oxo)pentadecylCoA) has a second-order rate constant of 2.1+/-0.3 x 10(6) M(-1) s(-1) and a dissociation rate of 26+/-15 s(-1) (defined at 10 degrees C). These results are interpreted in light of the X-ray structures of this enzyme.
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Affiliation(s)
- T A Farazi
- Department of Molecular Biology and Pharmacology, Washington University School of Medicine, St. Louis, Missouri 63110, USA
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32
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Hua J, Meyer JD, Lodge JK. Development of positive selectable markers for the fungal pathogen Cryptococcus neoformans. CLINICAL AND DIAGNOSTIC LABORATORY IMMUNOLOGY 2000; 7:125-8. [PMID: 10618292 PMCID: PMC95837 DOI: 10.1128/cdli.7.1.125-128.2000] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Cryptococcus neoformans is an opportunistic fungal pathogen that causes meningitis in approximately 10% of patients with AIDS. New selectable markers which confer resistance to G418 or phleomycin when transformed into C. neoformans were made. A hygromycin-selectable marker was modified to allow selection with a single copy of the marker.
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Affiliation(s)
- J Hua
- Edward A. Doisy Department of Biochemistry and Molecular Biology, St. Louis University School of Medicine, St. Louis, Missouri 63104, USA
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33
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Bhatnagar RS, Fütterer K, Waksman G, Gordon JI. The structure of myristoyl-CoA:protein N-myristoyltransferase. BIOCHIMICA ET BIOPHYSICA ACTA 1999; 1441:162-72. [PMID: 10570244 DOI: 10.1016/s1388-1981(99)00155-9] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Protein N-myristoylation is a covalent modification that occurs co-translationally in eukaryotes. Myristate, a rare 14 carbon saturated fatty acid (C14:0), is attached, via an amide linkage, to the N-terminal glycine of a subset of eukaryotic and viral proteins by myristoyl-CoA:protein N-myristoyltransferase (Nmt). Genetic and biochemical studies have established that Nmt is a target for development of a new class of fungicidal drugs. The enzyme is also a potential target for development of antiviral and antineoplastic agents. The structure of Saccharomyces cerevisiae Nmt1p has been determined recently with bound substrate analogs. The Nmt fold resembles the fold of members of the GCN5-related N-acetyltransferase superfamily. The structure reveals how Nmt's myristoyl-CoA and peptide substrates are recognized and bound, and what elements control the enzyme's ordered kinetic mechanism. Acyl transfer occurs through the nucleophilic addition-elimination reaction: an oxyanion hole formed by main chain atoms polarizes the thioester carbonyl and stabilizes the transition state while deprotonation of the ammonium of the Gly acceptor appears to be mediated by Nmt's C-terminal carboxylate. The use of main chain carboxylate atoms as general base catalyst is a novel feature.
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Affiliation(s)
- R S Bhatnagar
- Department of Molecular Biology and Pharmacology, Box 8103, Washington University School of Medicine, 660 So. Euclid Ave., St. Louis, MO 63110, USA
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Cardenas ME, Cruz MC, Del Poeta M, Chung N, Perfect JR, Heitman J. Antifungal activities of antineoplastic agents: Saccharomyces cerevisiae as a model system to study drug action. Clin Microbiol Rev 1999; 12:583-611. [PMID: 10515904 PMCID: PMC88926 DOI: 10.1128/cmr.12.4.583] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Recent evolutionary studies reveal that microorganisms including yeasts and fungi are more closely related to mammals than was previously appreciated. Possibly as a consequence, many natural-product toxins that have antimicrobial activity are also toxic to mammalian cells. While this makes it difficult to discover antifungal agents without toxic side effects, it also has enabled detailed studies of drug action in simple genetic model systems. We review here studies on the antifungal actions of antineoplasmic agents. Topics covered include the mechanisms of action of inhibitors of topoisomerases I and II; the immunosuppressants rapamycin, cyclosporin A, and FK506; the phosphatidylinositol 3-kinase inhibitor wortmannin; the angiogenesis inhibitors fumagillin and ovalicin; the HSP90 inhibitor geldanamycin; and agents that inhibit sphingolipid metabolism. In general, these natural products inhibit target proteins conserved from microorganisms to humans. These studies highlight the potential of microorganisms as screening tools to elucidate the mechanisms of action of novel pharmacological agents with unique effects against specific mammalian cell types, including neoplastic cells. In addition, this analysis suggests that antineoplastic agents and derivatives might find novel indications in the treatment of fungal infections, for which few agents are presently available, toxicity remains a serious concern, and drug resistance is emerging.
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Affiliation(s)
- M E Cardenas
- Department of Genetics, Duke University Medical Center, Durham, North Carolina 27710, USA
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Resh MD. Fatty acylation of proteins: new insights into membrane targeting of myristoylated and palmitoylated proteins. BIOCHIMICA ET BIOPHYSICA ACTA 1999; 1451:1-16. [PMID: 10446384 DOI: 10.1016/s0167-4889(99)00075-0] [Citation(s) in RCA: 958] [Impact Index Per Article: 38.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Covalent attachment of myristate and/or palmitate occurs on a wide variety of viral and cellular proteins. This review will highlight the latest advances in our understanding of the enzymology of N-myristoylation and palmitoylation as well as the functional consequences of fatty acylation of key signaling proteins. The role of myristate and palmitate in promoting membrane binding as well as specific membrane targeting will be reviewed, with emphasis on the Src family of tyrosine protein kinases and alpha subunits of heterotrimeric G proteins. The use of myristoyl switches and regulated depalmitoylation as mechanisms for achieving reversible membrane binding and regulated signaling will also be explored.
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Affiliation(s)
- M D Resh
- Cell Biology Program, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, Box 143, New York, NY 10021, USA.
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