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Tomaz KCP, Tavella TA, Borba JVB, Salazar-Alvarez LC, Levandoski JE, Mottin M, Sousa BKP, Moreira-Filho JT, Almeida VM, Clementino LC, Bourgard C, Massirer KB, Couñago RM, Andrade CH, Sunnerhagen P, Bilsland E, Cassiano GC, Costa FTM. Identification of potential inhibitors of casein kinase 2 alpha of Plasmodium falciparum with potent in vitro activity. Antimicrob Agents Chemother 2023; 67:e0058923. [PMID: 37819090 PMCID: PMC10649021 DOI: 10.1128/aac.00589-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Accepted: 08/11/2023] [Indexed: 10/13/2023] Open
Abstract
Drug resistance to commercially available antimalarials is a major obstacle in malaria control and elimination, creating the need to find new antiparasitic compounds with novel mechanisms of action. The success of kinase inhibitors for oncological treatments has paved the way for the exploitation of protein kinases as drug targets in various diseases, including malaria. Casein kinases are ubiquitous serine/threonine kinases involved in a wide range of cellular processes such as mitotic checkpoint signaling, DNA damage response, and circadian rhythm. In Plasmodium, it is suggested that these protein kinases are essential for both asexual and sexual blood-stage parasites, reinforcing their potential as targets for multi-stage antimalarials. To identify new putative PfCK2α inhibitors, we utilized an in silico chemogenomic strategy involving virtual screening with docking simulations and quantitative structure-activity relationship predictions. Our investigation resulted in the discovery of a new quinazoline molecule (542), which exhibited potent activity against asexual blood stages and a high selectivity index (>100). Subsequently, we conducted chemical-genetic interaction analysis on yeasts with mutations in casein kinases. Our chemical-genetic interaction results are consistent with the hypothesis that 542 inhibits yeast Cka1, which has a hinge region with high similarity to PfCK2α. This finding is in agreement with our in silico results suggesting that 542 inhibits PfCK2α via hinge region interaction.
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Affiliation(s)
- Kaira C. P. Tomaz
- Laboratory of Tropical Diseases (LDT), Institute of Biology, University of Campinas, Campinas, Brazil
| | - Tatyana A. Tavella
- Laboratory of Tropical Diseases (LDT), Institute of Biology, University of Campinas, Campinas, Brazil
| | - Joyce V. B. Borba
- Laboratory of Tropical Diseases (LDT), Institute of Biology, University of Campinas, Campinas, Brazil
- Laboratory of Molecular Modeling and Drug Design (LabMol), Faculty of Pharmacy, Universidade Federal de Goiás (UFG), Goiânia, Brazil
| | - Luis C. Salazar-Alvarez
- Laboratory of Tropical Diseases (LDT), Institute of Biology, University of Campinas, Campinas, Brazil
| | - João E. Levandoski
- Department of Materials and Bioprocesses Engineering, School of Chemical Engineering, University of Campinas, Campinas, Brazil
| | - Melina Mottin
- Laboratory of Molecular Modeling and Drug Design (LabMol), Faculty of Pharmacy, Universidade Federal de Goiás (UFG), Goiânia, Brazil
| | - Bruna K. P. Sousa
- Laboratory of Molecular Modeling and Drug Design (LabMol), Faculty of Pharmacy, Universidade Federal de Goiás (UFG), Goiânia, Brazil
| | - José T. Moreira-Filho
- Laboratory of Molecular Modeling and Drug Design (LabMol), Faculty of Pharmacy, Universidade Federal de Goiás (UFG), Goiânia, Brazil
| | - Vitor M. Almeida
- Centro de Química Medicinal (CQMED), Centro de Biologia Molecular e Engenharia Genética(CBMEG), Universidade Estadual de Campinas (UNICAMP), Campinas, Brazil
| | - Leandro C. Clementino
- Laboratory of Tropical Diseases (LDT), Institute of Biology, University of Campinas, Campinas, Brazil
| | - Catarina Bourgard
- Laboratory of Tropical Diseases (LDT), Institute of Biology, University of Campinas, Campinas, Brazil
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Katlin B. Massirer
- Centro de Química Medicinal (CQMED), Centro de Biologia Molecular e Engenharia Genética(CBMEG), Universidade Estadual de Campinas (UNICAMP), Campinas, Brazil
| | - Rafael M. Couñago
- Centro de Química Medicinal (CQMED), Centro de Biologia Molecular e Engenharia Genética(CBMEG), Universidade Estadual de Campinas (UNICAMP), Campinas, Brazil
- Structural Genomics Consortium, UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Carolina H. Andrade
- Laboratory of Molecular Modeling and Drug Design (LabMol), Faculty of Pharmacy, Universidade Federal de Goiás (UFG), Goiânia, Brazil
- Center for Research and Advancement of Fragments and Molecular Targets (CRAFT), University of São Paulo, São Paulo, Brazil
- Center for Excellence in Artificial Intelligence (CEIA), Institute of Informatics, Universidade Federal de Goiás, Goiânia, Brazil
| | - Per Sunnerhagen
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Elizabeth Bilsland
- Department of Structural and Functional Biology, Synthetic Biology Laboratory, Institute of Biology, University of Campinas, Campinas, Brazil
| | - Gustavo C. Cassiano
- Laboratory of Tropical Diseases (LDT), Institute of Biology, University of Campinas, Campinas, Brazil
- Global Health and Tropical Medicine (GHTM), Instituto de Higiene e Medicina Tropical, Universidade Nova de Lisboa, Lisbon, Portugal
| | - Fabio T. M. Costa
- Laboratory of Tropical Diseases (LDT), Institute of Biology, University of Campinas, Campinas, Brazil
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Tavella TA, da Silva NSM, Spillman N, Kayano ACAV, Cassiano GC, Vasconcelos AA, Camargo AP, da Silva DCB, Fontinha D, Salazar Alvarez LC, Ferreira LT, Peralis Tomaz KC, Neves BJ, Almeida LD, Bargieri DY, Lacerda MVGD, Lemos Cravo PV, Sunnerhagen P, Prudêncio M, Andrade CH, Pinto Lopes SC, Carazzolle MF, Tilley L, Bilsland E, Borges JC, Maranhão Costa FT. Violacein-Induced Chaperone System Collapse Underlies Multistage Antiplasmodial Activity. ACS Infect Dis 2021; 7:759-776. [PMID: 33689276 PMCID: PMC8042658 DOI: 10.1021/acsinfecdis.0c00454] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Antimalarial drugs with novel modes of action and wide therapeutic potential are needed to pave the way for malaria eradication. Violacein is a natural compound known for its biological activity against cancer cells and several pathogens, including the malaria parasite, Plasmodium falciparum (Pf). Herein, using chemical genomic profiling (CGP), we found that violacein affects protein homeostasis. Mechanistically, violacein binds Pf chaperones, PfHsp90 and PfHsp70-1, compromising the latter's ATPase and chaperone activities. Additionally, violacein-treated parasites exhibited increased protein unfolding and proteasomal degradation. The uncoupling of the parasite stress response reflects the multistage growth inhibitory effect promoted by violacein. Despite evidence of proteotoxic stress, violacein did not inhibit global protein synthesis via UPR activation-a process that is highly dependent on chaperones, in agreement with the notion of a violacein-induced proteostasis collapse. Our data highlight the importance of a functioning chaperone-proteasome system for parasite development and differentiation. Thus, a violacein-like small molecule might provide a good scaffold for development of a novel probe for examining the molecular chaperone network and/or antiplasmodial drug design.
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Affiliation(s)
- Tatyana Almeida Tavella
- Laboratory of Tropical Diseases−Prof. Dr. Luiz Jacinto da Silva, Department of Genetics, Evolution, Microbiology and Immunology, University of Campinas−UNICAMP, Campinas, SP 13083-970, Brazil
| | - Noeli Soares Melo da Silva
- Biochemistry and Biophysics of Proteins Group−São Carlos Institute of Chemistry−IQSC, University of São Paulo, Trabalhador Sancarlense Avenue, 400, BQ1, S27, São Carlos, SP 13566-590, Brazil
| | - Natalie Spillman
- Department of Biochemistry, Bio 21 Institute, University of Melbourne, 30 Flemington Rd, Parkville, Melbourne,VIC 3052, Australia
| | - Ana Carolina Andrade Vitor Kayano
- Laboratory of Tropical Diseases−Prof. Dr. Luiz Jacinto da Silva, Department of Genetics, Evolution, Microbiology and Immunology, University of Campinas−UNICAMP, Campinas, SP 13083-970, Brazil
| | - Gustavo Capatti Cassiano
- Laboratory of Tropical Diseases−Prof. Dr. Luiz Jacinto da Silva, Department of Genetics, Evolution, Microbiology and Immunology, University of Campinas−UNICAMP, Campinas, SP 13083-970, Brazil
- Global Health and Tropical Medicine (GHTM), Instituto de Higiene e Medicina Tropical, Universidade Nova de Lisboa, 1099-085 Lisboa, Portugal
| | - Adrielle Ayumi Vasconcelos
- Laboratory of Genomics and BioEnergy, Department of Genetics, Evolution, Microbiology and Immunology, Institute of Biology, University of Campinas−UNICAMP, Campinas, SP 13083-970, Brazil
| | - Antônio Pedro Camargo
- Laboratory of Genomics and BioEnergy, Department of Genetics, Evolution, Microbiology and Immunology, Institute of Biology, University of Campinas−UNICAMP, Campinas, SP 13083-970, Brazil
| | - Djane Clarys Baia da Silva
- Leônidas & Maria Deane Institute, Fundação Oswaldo Cruz−FIOCRUZ, Manaus , AM 69057070, Brazil
- Fundação de Medicina Tropical−Dr. Heitor Vieira Dourado, Manaus, AM 69040-000, Brazil
| | - Diana Fontinha
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, 1649-004 Lisboa, Portugal
| | - Luis Carlos Salazar Alvarez
- Laboratory of Tropical Diseases−Prof. Dr. Luiz Jacinto da Silva, Department of Genetics, Evolution, Microbiology and Immunology, University of Campinas−UNICAMP, Campinas, SP 13083-970, Brazil
| | - Letícia Tiburcio Ferreira
- Laboratory of Tropical Diseases−Prof. Dr. Luiz Jacinto da Silva, Department of Genetics, Evolution, Microbiology and Immunology, University of Campinas−UNICAMP, Campinas, SP 13083-970, Brazil
| | - Kaira Cristina Peralis Tomaz
- Laboratory of Tropical Diseases−Prof. Dr. Luiz Jacinto da Silva, Department of Genetics, Evolution, Microbiology and Immunology, University of Campinas−UNICAMP, Campinas, SP 13083-970, Brazil
| | - Bruno Junior Neves
- Laboratory of Molecular Modeling and Drug Design, LabMol, Faculdade de Farmácia, Universidade Federal de Goiás, Goiânia, GO 74605-170, Brazil
- LabChem−Laboratory of Cheminformatics, Centro Universitário de Anápolis−UniEVANGÉLICA, Anápolis, GO 75083-515, Brazil
| | - Ludimila Dias Almeida
- Synthetic Biology Laboratory, Department of Structural and Functional Biology, Institute of Biology, UNICAMP, Campinas, SP Brazil
| | - Daniel Youssef Bargieri
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, Cidade Universitária “Armando Salles Oliveira”, São Paulo 05508-000, Brazil
| | | | - Pedro Vitor Lemos Cravo
- LabChem−Laboratory of Cheminformatics, Centro Universitário de Anápolis−UniEVANGÉLICA, Anápolis, GO 75083-515, Brazil
- Global Health and Tropical Medicine (GHTM), Instituto de Higiene e Medicina Tropical, Universidade Nova de Lisboa, 1099-085 Lisboa, Portugal
| | - Per Sunnerhagen
- Department of Chemistry and Molecular Biology, University of Gothenburg, 405 30 Gothenburg, Sweden
| | - Miguel Prudêncio
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, 1649-004 Lisboa, Portugal
| | - Carolina Horta Andrade
- Laboratory of Tropical Diseases−Prof. Dr. Luiz Jacinto da Silva, Department of Genetics, Evolution, Microbiology and Immunology, University of Campinas−UNICAMP, Campinas, SP 13083-970, Brazil
- Laboratory of Molecular Modeling and Drug Design, LabMol, Faculdade de Farmácia, Universidade Federal de Goiás, Goiânia, GO 74605-170, Brazil
| | - Stefanie Costa Pinto Lopes
- Leônidas & Maria Deane Institute, Fundação Oswaldo Cruz−FIOCRUZ, Manaus , AM 69057070, Brazil
- Fundação de Medicina Tropical−Dr. Heitor Vieira Dourado, Manaus, AM 69040-000, Brazil
| | - Marcelo Falsarella Carazzolle
- Laboratory of Genomics and BioEnergy, Department of Genetics, Evolution, Microbiology and Immunology, Institute of Biology, University of Campinas−UNICAMP, Campinas, SP 13083-970, Brazil
| | - Leann Tilley
- Department of Biochemistry, Bio 21 Institute, University of Melbourne, 30 Flemington Rd, Parkville, Melbourne,VIC 3052, Australia
| | - Elizabeth Bilsland
- Synthetic Biology Laboratory, Department of Structural and Functional Biology, Institute of Biology, UNICAMP, Campinas, SP Brazil
| | - Júlio César Borges
- Biochemistry and Biophysics of Proteins Group−São Carlos Institute of Chemistry−IQSC, University of São Paulo, Trabalhador Sancarlense Avenue, 400, BQ1, S27, São Carlos, SP 13566-590, Brazil
| | - Fabio Trindade Maranhão Costa
- Laboratory of Tropical Diseases−Prof. Dr. Luiz Jacinto da Silva, Department of Genetics, Evolution, Microbiology and Immunology, University of Campinas−UNICAMP, Campinas, SP 13083-970, Brazil
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Silva SF, Klippel AH, Ramos PZ, Santiago ADS, Valentini SR, Bengtson MH, Massirer KB, Bilsland E, Couñago RM, Zanelli CF. Structural features and development of an assay platform of the parasite target deoxyhypusine synthase of Brugia malayi and Leishmania major. PLoS Negl Trop Dis 2020; 14:e0008762. [PMID: 33044977 PMCID: PMC7581365 DOI: 10.1371/journal.pntd.0008762] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Revised: 10/22/2020] [Accepted: 08/31/2020] [Indexed: 01/03/2023] Open
Abstract
Deoxyhypusine synthase (DHS) catalyzes the first step of the post-translational modification of eukaryotic translation factor 5A (eIF5A), which is the only known protein containing the amino acid hypusine. Both proteins are essential for eukaryotic cell viability, and DHS has been suggested as a good candidate target for small molecule-based therapies against eukaryotic pathogens. In this work, we focused on the DHS enzymes from Brugia malayi and Leishmania major, the causative agents of lymphatic filariasis and cutaneous leishmaniasis, respectively. To enable B. malayi (Bm)DHS for future target-based drug discovery programs, we determined its crystal structure bound to cofactor NAD+. We also reported an in vitro biochemical assay for this enzyme that is amenable to a high-throughput screening format. The L. major genome encodes two DHS paralogs, and attempts to produce them recombinantly in bacterial cells were not successful. Nevertheless, we showed that ectopic expression of both LmDHS paralogs can rescue yeast cells lacking the endogenous DHS-encoding gene (dys1). Thus, functionally complemented dys1Δ yeast mutants can be used to screen for new inhibitors of the L. major enzyme. We used the known human DHS inhibitor GC7 to validate both in vitro and yeast-based DHS assays. Our results show that BmDHS is a homotetrameric enzyme that shares many features with its human homologue, whereas LmDHS paralogs are likely to form a heterotetrameric complex and have a distinct regulatory mechanism. We expect our work to facilitate the identification and development of new DHS inhibitors that can be used to validate these enzymes as vulnerable targets for therapeutic interventions against B. malayi and L. major infections. Target-based drug discovery strategies hold the promise to discover safer and more effective treatments for Neglected Tropical Diseases (NTDs). Genetic manipulation techniques have been used to successfully identify essential genes in eukaryotic parasites. Unfortunately, the fact that a gene is essential under controlled laboratory conditions does not automatically make the corresponding gene-product vulnerable to pharmacological intervention in a clinical setting within the human host. To allow the discovery and development of small molecule tool compounds that can be used to validate pharmacologically vulnerable targets, one must first establish compound screening assays and obtain structural information for the candidate target. Eukaryotic cells lacking deoxyhypusine synthase (DHS) function are not viable. DHS catalyzes the first step in a post-translational modification that is critical for the function of eIF5A. Presence of mature eIF5A is also essential for eukaryotic cell viability. Here we reported compound screening assays (yeast-based for Brugia malayi and Leishmania major; in vitro for B. malayi only) and provided further regulatory and structural insights we hope will aid in the identification and development of inhibitors for the DHS enzymes from two NTD-causing organisms—B. malayi, the causative agent of lymphatic filariasis and L. major, the causative agent of cutaneous leishmaniasis.
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Affiliation(s)
| | | | - Priscila Zonzini Ramos
- Molecular Biology and Genetic Engineering Center (CBMEG), Medicinal Chemistry Center (CQMED), Structural Genomics Consortium (SGC-UNICAMP), University of Campinas-UNICAMP, Campinas, SP, Brazil
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas—UNICAMP, Campinas, SP, Brazil
| | - André da Silva Santiago
- Molecular Biology and Genetic Engineering Center (CBMEG), Medicinal Chemistry Center (CQMED), Structural Genomics Consortium (SGC-UNICAMP), University of Campinas-UNICAMP, Campinas, SP, Brazil
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas—UNICAMP, Campinas, SP, Brazil
| | | | - Mario Henrique Bengtson
- Molecular Biology and Genetic Engineering Center (CBMEG), Medicinal Chemistry Center (CQMED), Structural Genomics Consortium (SGC-UNICAMP), University of Campinas-UNICAMP, Campinas, SP, Brazil
- Department of Biochemistry and Tissue Biology, Institute of Biology, University of Campinas—UNICAMP, Campinas, SP, Brazil
| | - Katlin Brauer Massirer
- Molecular Biology and Genetic Engineering Center (CBMEG), Medicinal Chemistry Center (CQMED), Structural Genomics Consortium (SGC-UNICAMP), University of Campinas-UNICAMP, Campinas, SP, Brazil
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas—UNICAMP, Campinas, SP, Brazil
| | - Elizabeth Bilsland
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas—UNICAMP, Campinas, SP, Brazil
| | - Rafael Miguez Couñago
- Molecular Biology and Genetic Engineering Center (CBMEG), Medicinal Chemistry Center (CQMED), Structural Genomics Consortium (SGC-UNICAMP), University of Campinas-UNICAMP, Campinas, SP, Brazil
- * E-mail: (RMC); (CFZ)
| | - Cleslei Fernando Zanelli
- School of Pharmaceutical Sciences, São Paulo State University—UNESP, Araraquara, SP, Brazil
- * E-mail: (RMC); (CFZ)
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Ferreira L, Venancio VP, Kawano T, Abrão LCC, Tavella TA, Almeida LD, Pires GS, Bilsland E, Sunnerhagen P, Azevedo L, Talcott ST, Mertens-Talcott SU, Costa FTM. Chemical Genomic Profiling Unveils the in Vitro and in Vivo Antiplasmodial Mechanism of Açaí ( Euterpe oleracea Mart.) Polyphenols. ACS Omega 2019; 4:15628-15635. [PMID: 31572864 PMCID: PMC6761757 DOI: 10.1021/acsomega.9b02127] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Accepted: 09/03/2019] [Indexed: 06/10/2023]
Abstract
Malaria remains a major detrimental parasitic disease in the developing world, with more than 200 million cases annually. Widespread drug-resistant parasite strains push for the development of novel antimalarial drugs. Plant-derived natural products are key sources of antimalarial molecules. Euterpe oleracea Martius ("açaí") originates from Brazil and has anti-inflammatory and antineoplasic properties. Here, we evaluated the antimalarial efficacy of three phenolic fractions of açaí; total phenolics (1), nonanthocyanin phenolics (2), and total anthocyanins (3). In vitro, fraction 2 moderately inhibited parasite growth in chloroquine-sensitive (HB3) and multiresistant (Dd2) Plasmodium falciparum strains, while none of the fractions was toxic to noncancer cells. Despite the limited activity in vitro, the oral treatment with 20 mg/kg of fraction 1 reduced parasitemia by 89.4% in Plasmodium chabaudi-infected mice and prolonged survival. Contrasting in vitro and in vivo activities of 1 suggest key antiplasmodial roles for polyphenol metabolites rather than the fraction itself. Finally, we performed haploinsufficiency chemical genomic profiling (HIP) utilizing heterozygous Saccharomyces cerevisiae deletion mutants to identify molecular mechanisms of açaí fractions. HIP results indicate proteostasis as the main cellular pathway affected by fraction 2. These results open avenues to develop açaí polyphenols as potential new antimalarial candidates.
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Affiliation(s)
- Letícia
T. Ferreira
- Laboratory
of Tropical Diseases—Prof. Dr. Luiz Jacintho da
Silva, Department of Genetics, Evolution, Microbiology and Immunology and Synthetic Biology Laboratory, Department of Structural and Functional
Biology, Institute of Biology, University
of Campinas—UNICAMP, Campinas, SP 13083-970, Brazil
| | - Vinícius P. Venancio
- Department
of Nutrition and Food Science, Texas A&M
University, College
Station, Texas 77843, United States
| | - Taila Kawano
- Department
of Nutrition and Food Science, Texas A&M
University, College
Station, Texas 77843, United States
- Faculty
of Pharmaceutical Sciences, Federal University
of Alfenas, Alfenas, MG 37130-001, Brazil
| | - Lailah C. C. Abrão
- Department
of Nutrition and Food Science, Texas A&M
University, College
Station, Texas 77843, United States
- Faculty
of Pharmaceutical Sciences, Federal University
of Alfenas, Alfenas, MG 37130-001, Brazil
| | - Tatyana A. Tavella
- Laboratory
of Tropical Diseases—Prof. Dr. Luiz Jacintho da
Silva, Department of Genetics, Evolution, Microbiology and Immunology and Synthetic Biology Laboratory, Department of Structural and Functional
Biology, Institute of Biology, University
of Campinas—UNICAMP, Campinas, SP 13083-970, Brazil
| | - Ludimila D. Almeida
- Laboratory
of Tropical Diseases—Prof. Dr. Luiz Jacintho da
Silva, Department of Genetics, Evolution, Microbiology and Immunology and Synthetic Biology Laboratory, Department of Structural and Functional
Biology, Institute of Biology, University
of Campinas—UNICAMP, Campinas, SP 13083-970, Brazil
| | - Gabriel S. Pires
- Laboratory
of Tropical Diseases—Prof. Dr. Luiz Jacintho da
Silva, Department of Genetics, Evolution, Microbiology and Immunology and Synthetic Biology Laboratory, Department of Structural and Functional
Biology, Institute of Biology, University
of Campinas—UNICAMP, Campinas, SP 13083-970, Brazil
| | - Elizabeth Bilsland
- Laboratory
of Tropical Diseases—Prof. Dr. Luiz Jacintho da
Silva, Department of Genetics, Evolution, Microbiology and Immunology and Synthetic Biology Laboratory, Department of Structural and Functional
Biology, Institute of Biology, University
of Campinas—UNICAMP, Campinas, SP 13083-970, Brazil
| | - Per Sunnerhagen
- Department
of Chemistry and Molecular Biology, University
of Gothenburg, Gothenburg SE-405 30, Sweden
| | - Luciana Azevedo
- Laboratory
of Nutritional and Toxicological Analysis in Vivo—LANTIN, Faculty
of Nutrition, Federal University of Alfenas, Alfenas, MG, Brazil
| | - Stephen T. Talcott
- Department
of Nutrition and Food Science, Texas A&M
University, College
Station, Texas 77843, United States
| | - Susanne U. Mertens-Talcott
- Department
of Nutrition and Food Science, Texas A&M
University, College
Station, Texas 77843, United States
| | - Fabio T. M. Costa
- Laboratory
of Tropical Diseases—Prof. Dr. Luiz Jacintho da
Silva, Department of Genetics, Evolution, Microbiology and Immunology and Synthetic Biology Laboratory, Department of Structural and Functional
Biology, Institute of Biology, University
of Campinas—UNICAMP, Campinas, SP 13083-970, Brazil
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Bilsland E, Tavella TA, Krogh R, Stokes JE, Roberts A, Ajioka J, Spring DR, Andricopulo AD, Costa FTM, Oliver SG. Antiplasmodial and trypanocidal activity of violacein and deoxyviolacein produced from synthetic operons. BMC Biotechnol 2018; 18:22. [PMID: 29642881 PMCID: PMC5896143 DOI: 10.1186/s12896-018-0428-z] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Accepted: 03/15/2018] [Indexed: 02/02/2023] Open
Abstract
BACKGROUND Violacein is a deep violet compound that is produced by a number of bacterial species. It is synthesized from tryptophan by a pathway that involves the sequential action of 5 different enzymes (encoded by genes vioA to vioE). Violacein has antibacterial, antiparasitic, and antiviral activities, and also has the potential of inducing apoptosis in certain cancer cells. RESULTS Here, we describe the construction of a series of plasmids harboring the complete or partial violacein biosynthesis operon and their use to enable production of violacein and deoxyviolacein in E.coli. We performed in vitro assays to determine the biological activity of these compounds against Plasmodium, Trypanosoma, and mammalian cells. We found that, while deoxyviolacein has a lower activity against parasites than violacein, its toxicity to mammalian cells is insignificant compared to that of violacein. CONCLUSIONS We constructed E. coli strains capable of producing biologically active violacein and related compounds, and propose that deoxyviolacein might be a useful starting compound for the development of antiparasite drugs.
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Affiliation(s)
- Elizabeth Bilsland
- 0000000121885934grid.5335.0Cambridge Systems Biology Centre and Department of Biochemistry, University of Cambridge, Cambridge, UK ,0000 0001 0723 2494grid.411087.bDepartment of Structural and Functional Biology, Institute of Biology, UNICAMP, Campinas, SP Brazil ,0000 0001 0723 2494grid.411087.bLaboratory of Tropical Diseases – Prof. Dr. Luiz Jacintho da Silva - Department of Genetics, Evolution, Microbiology and Immunology, University of Campinas, Campinas, SP Brazil
| | - Tatyana A. Tavella
- 0000 0001 0723 2494grid.411087.bLaboratory of Tropical Diseases – Prof. Dr. Luiz Jacintho da Silva - Department of Genetics, Evolution, Microbiology and Immunology, University of Campinas, Campinas, SP Brazil
| | - Renata Krogh
- 0000 0004 1937 0722grid.11899.38Laboratory of Medicinal and Computational Chemistry, University of São Paulo, São Carlos, SP Brazil
| | - Jamie E. Stokes
- 0000000121885934grid.5335.0Department of Chemistry, University of Cambridge, Cambridge, UK
| | - Annabelle Roberts
- 0000000121885934grid.5335.0Cambridge Systems Biology Centre and Department of Biochemistry, University of Cambridge, Cambridge, UK
| | - James Ajioka
- 0000000121885934grid.5335.0Department of Pathology, University of Cambridge, Cambridge, UK
| | - David R. Spring
- 0000000121885934grid.5335.0Department of Chemistry, University of Cambridge, Cambridge, UK
| | - Adriano D. Andricopulo
- 0000 0004 1937 0722grid.11899.38Laboratory of Medicinal and Computational Chemistry, University of São Paulo, São Carlos, SP Brazil
| | - Fabio T. M. Costa
- 0000 0001 0723 2494grid.411087.bLaboratory of Tropical Diseases – Prof. Dr. Luiz Jacintho da Silva - Department of Genetics, Evolution, Microbiology and Immunology, University of Campinas, Campinas, SP Brazil
| | - Stephen G. Oliver
- 0000000121885934grid.5335.0Cambridge Systems Biology Centre and Department of Biochemistry, University of Cambridge, Cambridge, UK
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Williams K, Bilsland E, Sparkes A, Aubrey W, Young M, Soldatova LN, De Grave K, Ramon J, de Clare M, Sirawaraporn W, Oliver SG, King RD. Cheaper faster drug development validated by the repositioning of drugs against neglected tropical diseases. J R Soc Interface 2015; 12:20141289. [PMID: 25652463 PMCID: PMC4345494 DOI: 10.1098/rsif.2014.1289] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
There is an urgent need to make drug discovery cheaper and faster. This will enable the development of treatments for diseases currently neglected for economic reasons, such as tropical and orphan diseases, and generally increase the supply of new drugs. Here, we report the Robot Scientist ‘Eve’ designed to make drug discovery more economical. A Robot Scientist is a laboratory automation system that uses artificial intelligence (AI) techniques to discover scientific knowledge through cycles of experimentation. Eve integrates and automates library-screening, hit-confirmation, and lead generation through cycles of quantitative structure activity relationship learning and testing. Using econometric modelling we demonstrate that the use of AI to select compounds economically outperforms standard drug screening. For further efficiency Eve uses a standardized form of assay to compute Boolean functions of compound properties. These assays can be quickly and cheaply engineered using synthetic biology, enabling more targets to be assayed for a given budget. Eve has repositioned several drugs against specific targets in parasites that cause tropical diseases. One validated discovery is that the anti-cancer compound TNP-470 is a potent inhibitor of dihydrofolate reductase from the malaria-causing parasite Plasmodium vivax.
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Affiliation(s)
- Kevin Williams
- Department of Computer Science, Aberystwyth University, Aberystwyth SY23 3DB, UK
| | - Elizabeth Bilsland
- Cambridge Systems Biology Centre and Department of Biochemistry, University of Cambridge, Sanger Building, 80 Tennis Court Road, Cambridge CB2 1GA, UK Department of Structural and Functional Biology, UNICAMP, 13083-865, Campinas, São Paulo, Brazil
| | - Andrew Sparkes
- Department of Computer Science, Aberystwyth University, Aberystwyth SY23 3DB, UK
| | - Wayne Aubrey
- Department of Computer Science, Aberystwyth University, Aberystwyth SY23 3DB, UK
| | - Michael Young
- Institute of Biological, Environmental and Rural Sciences, Aberystwyth University, Aberystwyth SY23 3DD, UK
| | | | - Kurt De Grave
- Department of Computer Science, KU Leuven, 3001 Heverlee, Belgium
| | - Jan Ramon
- Department of Computer Science, KU Leuven, 3001 Heverlee, Belgium
| | - Michaela de Clare
- Cambridge Systems Biology Centre and Department of Biochemistry, University of Cambridge, Sanger Building, 80 Tennis Court Road, Cambridge CB2 1GA, UK
| | | | - Stephen G Oliver
- Cambridge Systems Biology Centre and Department of Biochemistry, University of Cambridge, Sanger Building, 80 Tennis Court Road, Cambridge CB2 1GA, UK
| | - Ross D King
- Manchester Institute of Biotechnology and School of Computer Science, University of Manchester, Manchester M1 7DN, UK
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Favrin G, Bean DM, Bilsland E, Boyer H, Fischer BE, Russell S, Crowther DC, Baylis HA, Oliver SG, Giannakou ME. Identification of novel modifiers of Aβ toxicity by transcriptomic analysis in the fruitfly. Sci Rep 2013; 3:3512. [PMID: 24336499 PMCID: PMC3863820 DOI: 10.1038/srep03512] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2013] [Accepted: 12/02/2013] [Indexed: 11/09/2022] Open
Abstract
The strongest risk factor for developing Alzheimer's Disease (AD) is age. Here, we study the relationship between ageing and AD using a systems biology approach that employs a Drosophila (fruitfly) model of AD in which the flies overexpress the human Aβ42 peptide. We identified 712 genes that are differentially expressed between control and Aβ-expressing flies. We further divided these genes according to how they change over the animal's lifetime and discovered that the AD-related gene expression signature is age-independent. We have identified a number of differentially expressed pathways that are likely to play an important role in the disease, including oxidative stress and innate immunity. In particular, we uncovered two new modifiers of the Aβ phenotype, namely Sod3 and PGRP-SC1b.
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Affiliation(s)
- G Favrin
- 1] Cambridge Systems Biology Centre, University of Cambridge, Cambridge, CB2 1GA, UK [2] Department of Biochemistry, University of Cambridge, Cambridge, CB2 1GA, UK [3]
| | - D M Bean
- 1] Cambridge Systems Biology Centre, University of Cambridge, Cambridge, CB2 1GA, UK [2] Department of Biochemistry, University of Cambridge, Cambridge, CB2 1GA, UK [3]
| | - E Bilsland
- 1] Cambridge Systems Biology Centre, University of Cambridge, Cambridge, CB2 1GA, UK [2] Department of Biochemistry, University of Cambridge, Cambridge, CB2 1GA, UK
| | - H Boyer
- Department of Zoology, University of Cambridge, Cambridge, CB2 3EJ, UK
| | - B E Fischer
- 1] Cambridge Systems Biology Centre, University of Cambridge, Cambridge, CB2 1GA, UK [2] Department of Genetics, University of Cambridge, Cambridge, CB2 3EH, UK
| | - S Russell
- 1] Cambridge Systems Biology Centre, University of Cambridge, Cambridge, CB2 1GA, UK [2] Department of Genetics, University of Cambridge, Cambridge, CB2 3EH, UK
| | - D C Crowther
- Department of Genetics, University of Cambridge, Cambridge, CB2 3EH, UK
| | - H A Baylis
- Department of Zoology, University of Cambridge, Cambridge, CB2 3EJ, UK
| | - S G Oliver
- 1] Cambridge Systems Biology Centre, University of Cambridge, Cambridge, CB2 1GA, UK [2] Department of Biochemistry, University of Cambridge, Cambridge, CB2 1GA, UK
| | - M E Giannakou
- Department of Zoology, University of Cambridge, Cambridge, CB2 3EJ, UK
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Bilsland E, Sparkes A, Williams K, Moss HJ, de Clare M, Pir P, Rowland J, Aubrey W, Pateman R, Young M, Carrington M, King RD, Oliver SG. Yeast-based automated high-throughput screens to identify anti-parasitic lead compounds. Open Biol 2013; 3:120158. [PMID: 23446112 PMCID: PMC3603448 DOI: 10.1098/rsob.120158] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
We have developed a robust, fully automated anti-parasitic drug-screening method that selects compounds specifically targeting parasite enzymes and not their host counterparts, thus allowing the early elimination of compounds with potential side effects. Our yeast system permits multiple parasite targets to be assayed in parallel owing to the strains’ expression of different fluorescent proteins. A strain expressing the human target is included in the multiplexed screen to exclude compounds that do not discriminate between host and parasite enzymes. This form of assay has the advantages of using known targets and not requiring the in vitro culture of parasites. We performed automated screens for inhibitors of parasite dihydrofolate reductases, N-myristoyltransferases and phosphoglycerate kinases, finding specific inhibitors of parasite targets. We found that our ‘hits’ have significant structural similarities to compounds with in vitro anti-parasitic activity, validating our screens and suggesting targets for hits identified in parasite-based assays. Finally, we demonstrate a 60 per cent success rate for our hit compounds in killing or severely inhibiting the growth of Trypanosoma brucei, the causative agent of African sleeping sickness.
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Affiliation(s)
- Elizabeth Bilsland
- Cambridge Systems Biology Centre and Department of Biochemistry, University of Cambridge, Sanger Building, 80 Tennis Court Road, Cambridge CB2 1GA, UK
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Lanthaler K, Bilsland E, Dobson PD, Moss HJ, Pir P, Kell DB, Oliver SG. Genome-wide assessment of the carriers involved in the cellular uptake of drugs: a model system in yeast. BMC Biol 2011; 9:70. [PMID: 22023736 PMCID: PMC3280192 DOI: 10.1186/1741-7007-9-70] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2011] [Accepted: 10/24/2011] [Indexed: 01/10/2023] Open
Abstract
Background The uptake of drugs into cells has traditionally been considered to be predominantly via passive diffusion through the bilayer portion of the cell membrane. The recent recognition that drug uptake is mostly carrier-mediated raises the question of which drugs use which carriers. Results To answer this, we have constructed a chemical genomics platform built upon the yeast gene deletion collection, using competition experiments in batch fermenters and robotic automation of cytotoxicity screens, including protection by 'natural' substrates. Using these, we tested 26 different drugs and identified the carriers required for 18 of the drugs to gain entry into yeast cells. Conclusions As well as providing a useful platform technology, these results further substantiate the notion that the cellular uptake of pharmaceutical drugs normally occurs via carrier-mediated transport and indicates that establishing the identity and tissue distribution of such carriers should be a major consideration in the design of safe and effective drugs.
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Affiliation(s)
- Karin Lanthaler
- School of Chemistry, University of Manchester, Manchester, UK
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Bilsland E, Pir P, Gutteridge A, Johns A, King RD, Oliver SG. Functional expression of parasite drug targets and their human orthologs in yeast. PLoS Negl Trop Dis 2011; 5:e1320. [PMID: 21991399 PMCID: PMC3186757 DOI: 10.1371/journal.pntd.0001320] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2011] [Accepted: 07/28/2011] [Indexed: 12/31/2022] Open
Abstract
Background The exacting nutritional requirements and complicated life cycles of parasites mean that they are not always amenable to high-throughput drug screening using automated procedures. Therefore, we have engineered the yeast Saccharomyces cerevisiae to act as a surrogate for expressing anti-parasitic targets from a range of biomedically important pathogens, to facilitate the rapid identification of new therapeutic agents. Methodology/Principal Findings Using pyrimethamine/dihydrofolate reductase (DHFR) as a model parasite drug/drug target system, we explore the potential of engineered yeast strains (expressing DHFR enzymes from Plasmodium falciparum, P. vivax, Homo sapiens, Schistosoma mansoni, Leishmania major, Trypanosoma brucei and T. cruzi) to exhibit appropriate differential sensitivity to pyrimethamine. Here, we demonstrate that yeast strains (lacking the major drug efflux pump, Pdr5p) expressing yeast (ScDFR1), human (HsDHFR), Schistosoma (SmDHFR), and Trypanosoma (TbDHFR and TcDHFR) DHFRs are insensitive to pyrimethamine treatment, whereas yeast strains producing Plasmodium (PfDHFR and PvDHFR) DHFRs are hypersensitive. Reassuringly, yeast strains expressing field-verified, drug-resistant mutants of P. falciparum DHFR (Pfdhfr51I,59R,108N) are completely insensitive to pyrimethamine, further validating our approach to drug screening. We further show the versatility of the approach by replacing yeast essential genes with other potential drug targets, namely phosphoglycerate kinases (PGKs) and N-myristoyl transferases (NMTs). Conclusions/Significance We have generated a number of yeast strains that can be successfully harnessed for the rapid and selective identification of urgently needed anti-parasitic agents. Parasites kill millions of people every year and leave countless others with chronic debilitating disease. These diseases, which include malaria and sleeping sickness, mainly affect people in developing countries. For this reason, few drugs have been developed to treat them. To make matters worse, many parasites are developing resistance to the drugs that are available. Thus, there is an urgent need to develop new drugs, but this is hampered by the fact that most parasites are difficult or impossible to grow in the laboratory. To address this, we have engineered baker's yeast to be dependent on the function of enzymes from either parasites or humans. In all, our engineered yeast constructs encompass six parasites (causing malaria, schistosomiasis, leishmaniasis, sleeping sickness, and Chagas disease) and three different enzymes that are known or potential drug targets. Further, we have increased yeast's sensitivity to drugs by deleting the gene for its major drug efflux pump. Because yeast is robust and easy to grow in the laboratory, we can use a robot to screen for drugs that will kill yeast dependent on a parasite enzyme, but not touch yeast dependent on the equivalent human enzyme.
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Affiliation(s)
- Elizabeth Bilsland
- Department of Biochemistry and Cambridge Systems Biology Centre, University of Cambridge, Cambridge, United Kingdom
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Abstract
Due to its genetic tractability and ease of manipulation, the yeast Saccharomyces cerevisiae has been extensively used as a model organism to understand how eukaryotic cells grow, divide, and respond to environmental changes. In this chapter, we reasoned that functional annotation of novel genes revealed by sequencing should adopt an integrative approach including both bioinformatics and experimental analysis to reveal functional conservation and divergence of complexes and pathways. The techniques and resources generated for systems biology studies in yeast have found a wide range of applications. Here we focused on using these technologies in revealing functions of genes from mammals, in identifying targets of novel and known drugs and in screening drugs targeting specific proteins and/or protein-protein interactions.
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Affiliation(s)
- Nianshu Zhang
- Department of Biochemistry, Cambridge Systems Biology Centre, University of Cambridge, Cambridge, UK.
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Cvijović M, Dalevi D, Bilsland E, Kemp GJL, Sunnerhagen P. Identification of putative regulatory upstream ORFs in the yeast genome using heuristics and evolutionary conservation. BMC Bioinformatics 2007; 8:295. [PMID: 17686169 PMCID: PMC1964767 DOI: 10.1186/1471-2105-8-295] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2007] [Accepted: 08/08/2007] [Indexed: 11/30/2022] Open
Abstract
Background The translational efficiency of an mRNA can be modulated by upstream open reading frames (uORFs) present in certain genes. A uORF can attenuate translation of the main ORF by interfering with translational reinitiation at the main start codon. uORFs also occur by chance in the genome, in which case they do not have a regulatory role. Since the sequence determinants for functional uORFs are not understood, it is difficult to discriminate functional from spurious uORFs by sequence analysis. Results We have used comparative genomics to identify novel uORFs in yeast with a high likelihood of having a translational regulatory role. We examined uORFs, previously shown to play a role in regulation of translation in Saccharomyces cerevisiae, for evolutionary conservation within seven Saccharomyces species. Inspection of the set of conserved uORFs yielded the following three characteristics useful for discrimination of functional from spurious uORFs: a length between 4 and 6 codons, a distance from the start of the main ORF between 50 and 150 nucleotides, and finally a lack of overlap with, and clear separation from, neighbouring uORFs. These derived rules are inherently associated with uORFs with properties similar to the GCN4 locus, and may not detect most uORFs of other types. uORFs with high scores based on these rules showed a much higher evolutionary conservation than randomly selected uORFs. In a genome-wide scan in S. cerevisiae, we found 34 conserved uORFs from 32 genes that we predict to be functional; subsequent analysis showed the majority of these to be located within transcripts. A total of 252 genes were found containing conserved uORFs with properties indicative of a functional role; all but 7 are novel. Functional content analysis of this set identified an overrepresentation of genes involved in transcriptional control and development. Conclusion Evolutionary conservation of uORFs in yeasts can be traced up to 100 million years of separation. The conserved uORFs have certain characteristics with respect to length, distance from each other and from the main start codon, and folding energy of the sequence. These newly found characteristics can be used to facilitate detection of other conserved uORFs.
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Affiliation(s)
- Marija Cvijović
- Department of Cell and Molecular Biology, Lundberg Laboratory, Göteborg University, PO Box 462 SE-405 30 Göteborg, Sweden
- Max-Planck Institute for Molecular Genetics, Ihnestraße 63, D-14195 Berlin, Germany
| | - Daniel Dalevi
- Department of Computer Science and Engineering, Chalmers University of Technology, SE-412 96 Göteborg, Sweden
| | - Elizabeth Bilsland
- Department of Cell and Molecular Biology, Lundberg Laboratory, Göteborg University, PO Box 462 SE-405 30 Göteborg, Sweden
- Biochemistry Department, University of Cambridge, 80 Tennis Court Road, Cambridge CB2 1GA, UK
| | - Graham JL Kemp
- Department of Computer Science and Engineering, Chalmers University of Technology, SE-412 96 Göteborg, Sweden
| | - Per Sunnerhagen
- Department of Cell and Molecular Biology, Lundberg Laboratory, Göteborg University, PO Box 462 SE-405 30 Göteborg, Sweden
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Bilsland E, Hult M, Bell SD, Sunnerhagen P, Downs JA. The Bre5/Ubp3 ubiquitin protease complex from budding yeast contributes to the cellular response to DNA damage. DNA Repair (Amst) 2007; 6:1471-84. [PMID: 17556048 DOI: 10.1016/j.dnarep.2007.04.010] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2007] [Revised: 04/13/2007] [Accepted: 04/17/2007] [Indexed: 11/29/2022]
Abstract
The ubiquitination status of proteins can control numerous aspects of protein function through targeted destruction or by altering protein-protein interactions, subcellular localization, or enzymatic activity. In addition to enzymes that mediate the conjugation of ubiquitin moieties to target proteins, there are enzymes that catalyze the removal of ubiquitin, termed ubiquitin proteases. One such ubiquitin protease, Ubp3, exists in a complex with a partner protein: Bre5. This complex has been implicated in a variety of cellular activities, and was recently identified in large-scale screens for genetic interactions with known components of the DNA damage response pathway. We found that this complex plays a role in the cellular response to the DNA damaging agent phleomycin and strains lacking the complex have a defect in non-homologous end joining. Although this complex is also important for telomeric silencing, maintenance of the cell wall, and global transcriptional regulation, we present evidence suggesting that the role of this complex in DNA damage responses is distinct from these other roles. First, we found that Ubp3/Bre5 functions antagonistically with Bul1 in DNA damage responses, but not in its other cellular functions. Additionally, we have generated mutants of Bre5 that are specifically defective in DNA damage responses.
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Affiliation(s)
- Elizabeth Bilsland
- Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge, United Kingdom
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Abstract
DNA double-strand breaks (DSBs) are, arguably, the most deleterious form of DNA damage. An increasing body of evidence points to the inaccurate or inefficient repair of DSBs as a key step in tumorigenesis. Therefore, it is of great importance to understand the processes by which DSBs are detected and repaired. Clearly, these events must take place in the context of chromatin in vivo, and recently, a great deal of progress has been made in understanding the dynamic and active role that histone proteins and chromatin modifying activities play in DNA DSB repair. Here, we briefly review some of the most common techniques in studying DNA DSB responses in vivo, and focus on the contributions of covalent modifications of core histone proteins to these DNA DSB responses.
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Affiliation(s)
- Elizabeth Bilsland
- Department of Biochemistry, Cambridge University, 80 Tennis Court Road, Cambridge CB2 1GA, UK
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Abstract
We demonstrate a role in oxidative and metal stress resistance for the MAPK-activated protein kinases Rck1 and Rck2 in Saccharomyces cerevisiae. We show that Hog1 is robustly phosphorylated in a Pbs2-dependent way during oxidative stress, and that Rck2 also is phosphorylated under these circumstances. Hog1 concentrates in the nucleus in oxidative stress. Hog1 localization is partially dependent on Rck2, as rck2 cells have more nuclear Hog1 than wild-type cells. We find several proteins with a role in oxidative stress resistance using Rck1 or Rck2 as baits in a two-hybrid screen. We identify the transcription factor Yap2 as a putative target for Rck1, and the Zn2+ transporter Zrc1 as a target for Rck2. Yap2 is normally cytoplasmic, but rapidly migrates to the nucleus upon exposure to oxidative stress agents. In a fraction of untreated pbs2 cells, Yap2 is nuclear. Zrc1 co-immunoprecipitates with Rck2, and ZRC1 is genetically downstream of RCK2. These data connect activation of the Hog1 MAPK cascade with effectors having a role in oxidative stress resistance.
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Affiliation(s)
- Elizabeth Bilsland
- Department of Cell and Molecular Biology, Lundberg Laboratory, Göteborg University, PO Box 462, SE-405 30 Göteborg, Sweden
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Abstract
Using PCR to construct disruption cassettes, null alleles of six genes have been created in Saccharomyces cerevisiae. In a FY1679 background, no defects were detected in any of the haploid deletion mutants with respect to growth, gross morphology, or mating. A diploid FY1679-derived delta ygl194c/delta ygl194c homozygous disruptant displayed reduced sporulation. In contrast to the lack of phenotypic consequences of delta yol100w disruptions in the FY1679 background, in the CEN.PK2 strain even a heterozygous disruption of the same gene caused striking effects, very slow vegetative growth and highly impaired sporulation. Tetrad analysis showed YOL100w to be an essential gene in this strain. A copy of the YGL194c or the YOL100w wild-type gene borne on a centromeric episomal plasmid was introduced into a corresponding disruption mutant strain, and in both cases was found to partially complement the defects.
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Affiliation(s)
- E Bilsland
- Department of Molecular Biology, Göteborg, University, Sweden
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