1
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McLaughlin E, Zavala Martinez MG, Dujeancourt-Henry A, Chaze T, Gianetto QG, Matondo M, Urbaniak MD, Glover L. Phosphoproteomic analysis of the response to DNA damage in Trypanosoma brucei. J Biol Chem 2024; 300:107657. [PMID: 39128729 DOI: 10.1016/j.jbc.2024.107657] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2024] [Revised: 07/29/2024] [Accepted: 07/31/2024] [Indexed: 08/13/2024] Open
Abstract
Damage to the genetic material of the cell poses a universal threat to all forms of life. The DNA damage response is a coordinated cellular response to a DNA break, key to which is the phosphorylation signaling cascade. Identifying which proteins are phosphorylated is therefore crucial to understanding the mechanisms that underlie it. We have used stable isotopic labeling of amino acids in cell culture-based quantitative phosphoproteomics to profile changes in phosphorylation site abundance following double stranded DNA breaks, at two distinct loci in the genome of the single cell eukaryote Trypanosoma brucei. Here, we report on the T. brucei phosphoproteome following a single double-strand break at either a chromosome internal or subtelomeric locus, specifically the bloodstream form expression site. We detected >6500 phosphorylation sites, of which 211 form a core set of double-strand break responsive phosphorylation sites. Along with phosphorylation of canonical DNA damage factors, we have identified two novel phosphorylation events on histone H2A and found that in response to a chromosome internal break, proteins are predominantly phosphorylated, while a greater proportion of proteins dephosphorylated following a DNA break at a subtelomeric bloodstream form expression site. Our data represent the first DNA damage phosphoproteome and provides novel insights into repair at distinct chromosomal contexts in T. brucei.
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Affiliation(s)
- Emilia McLaughlin
- Institut Pasteur, Université Paris Cité, Trypanosome Molecular Biology, Department of Parasites and Insect Vectors, Paris, France; Sorbonne Université, Collège doctoral, Paris, France
| | - Monica Gabriela Zavala Martinez
- Institut Pasteur, Université Paris Cité, Trypanosome Molecular Biology, Department of Parasites and Insect Vectors, Paris, France
| | - Annick Dujeancourt-Henry
- Institut Pasteur, Université Paris Cité, Trypanosome Molecular Biology, Department of Parasites and Insect Vectors, Paris, France
| | - Thibault Chaze
- Institut Pasteur, Université Paris Cité, Proteomics Platform, Mass Spectrometry for Biology Unit, Centre National de la Recherche Scientifique, UAR 2024, Paris, France
| | - Quentin Giai Gianetto
- Institut Pasteur, Université Paris Cité, Proteomics Platform, Mass Spectrometry for Biology Unit, Centre National de la Recherche Scientifique, UAR 2024, Paris, France; Institut Pasteur, Université Paris Cité, Bioinformatics and Biostatistics HUB, Paris, France
| | - Mariette Matondo
- Institut Pasteur, Université Paris Cité, Proteomics Platform, Mass Spectrometry for Biology Unit, Centre National de la Recherche Scientifique, UAR 2024, Paris, France
| | - Michael D Urbaniak
- Division of Biomedical and Life Sciences, Faculty of Health and Medicine, Lancaster University, Lancaster, UK
| | - Lucy Glover
- Institut Pasteur, Université Paris Cité, Trypanosome Molecular Biology, Department of Parasites and Insect Vectors, Paris, France.
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2
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Schichler D, Konle A, Spath EM, Riegler S, Klein A, Seleznev A, Jung S, Wuppermann T, Wetterich N, Borges A, Meyer-Natus E, Havlicek K, Pérez Cabrera S, Niedermüller K, Sajko S, Dohn M, Malzer X, Riemer E, Tumurbaatar T, Djinovic-Carugo K, Dong G, Janzen CJ, Morriswood B. Characterisation of TbSmee1 suggests endocytosis allows surface-bound cargo to enter the trypanosome flagellar pocket. J Cell Sci 2023; 136:jcs261548. [PMID: 37737012 PMCID: PMC10652038 DOI: 10.1242/jcs.261548] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Accepted: 08/11/2023] [Indexed: 09/23/2023] Open
Abstract
All endocytosis and exocytosis in the African trypanosome Trypanosoma brucei occurs at a single subdomain of the plasma membrane. This subdomain, the flagellar pocket, is a small vase-shaped invagination containing the root of the single flagellum of the cell. Several cytoskeleton-associated multiprotein complexes are coiled around the neck of the flagellar pocket on its cytoplasmic face. One of these, the hook complex, was proposed to affect macromolecule entry into the flagellar pocket lumen. In previous work, knockdown of T. brucei (Tb)MORN1, a hook complex component, resulted in larger cargo being unable to enter the flagellar pocket. In this study, the hook complex component TbSmee1 was characterised in bloodstream form T. brucei and found to be essential for cell viability. TbSmee1 knockdown resulted in flagellar pocket enlargement and impaired access to the flagellar pocket membrane by surface-bound cargo, similar to depletion of TbMORN1. Unexpectedly, inhibition of endocytosis by knockdown of clathrin phenocopied TbSmee1 knockdown, suggesting that endocytic activity itself is a prerequisite for the entry of surface-bound cargo into the flagellar pocket.
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Affiliation(s)
- Daja Schichler
- Department of Cell and Developmental Biology, Biocenter, University of Würzburg, 97074 Würzburg, Germany
| | - Antonia Konle
- Department of Cell and Developmental Biology, Biocenter, University of Würzburg, 97074 Würzburg, Germany
| | - Eva-Maria Spath
- Department of Cell and Developmental Biology, Biocenter, University of Würzburg, 97074 Würzburg, Germany
| | - Sina Riegler
- Department of Cell and Developmental Biology, Biocenter, University of Würzburg, 97074 Würzburg, Germany
| | - Alexandra Klein
- Department of Cell and Developmental Biology, Biocenter, University of Würzburg, 97074 Würzburg, Germany
| | - Anna Seleznev
- Department of Cell and Developmental Biology, Biocenter, University of Würzburg, 97074 Würzburg, Germany
| | - Sisco Jung
- Department of Cell and Developmental Biology, Biocenter, University of Würzburg, 97074 Würzburg, Germany
| | - Timothy Wuppermann
- Department of Cell and Developmental Biology, Biocenter, University of Würzburg, 97074 Würzburg, Germany
| | - Noah Wetterich
- Department of Cell and Developmental Biology, Biocenter, University of Würzburg, 97074 Würzburg, Germany
| | - Alyssa Borges
- Department of Cell and Developmental Biology, Biocenter, University of Würzburg, 97074 Würzburg, Germany
| | - Elisabeth Meyer-Natus
- Department of Cell and Developmental Biology, Biocenter, University of Würzburg, 97074 Würzburg, Germany
| | - Katharina Havlicek
- Department of Biochemistry and Cell Biology, Max Perutz Labs, University of Vienna, Vienna Biocenter (VBC), 1030 Vienna, Austria
| | | | - Korbinian Niedermüller
- Department of Cell and Developmental Biology, Biocenter, University of Würzburg, 97074 Würzburg, Germany
| | - Sara Sajko
- Department of Structural and Computational Biology, Max Perutz Labs, University of Vienna, Vienna Biocenter (VBC), 1030 Vienna, Austria
| | - Maximilian Dohn
- Department of Cell and Developmental Biology, Biocenter, University of Würzburg, 97074 Würzburg, Germany
| | - Xenia Malzer
- Department of Cell and Developmental Biology, Biocenter, University of Würzburg, 97074 Würzburg, Germany
| | - Emily Riemer
- Department of Cell and Developmental Biology, Biocenter, University of Würzburg, 97074 Würzburg, Germany
| | - Tuguldur Tumurbaatar
- Department of Cell and Developmental Biology, Biocenter, University of Würzburg, 97074 Würzburg, Germany
| | - Kristina Djinovic-Carugo
- Department of Structural and Computational Biology, Max Perutz Labs, University of Vienna, Vienna Biocenter (VBC), 1030 Vienna, Austria
- Department of Biochemistry, Faculty of Chemistry and Chemical Technology, University of Ljubljana, 1000 Ljubljana, Slovenia
- European Molecular Biology Laboratory (EMBL) Grenoble, 38000 Grenoble, France
| | - Gang Dong
- Center for Medical Biochemistry, Max Perutz Labs, Medical University of Vienna, Vienna Biocenter (VBC), 1030 Vienna, Austria
| | - Christian J. Janzen
- Department of Cell and Developmental Biology, Biocenter, University of Würzburg, 97074 Würzburg, Germany
| | - Brooke Morriswood
- Department of Cell and Developmental Biology, Biocenter, University of Würzburg, 97074 Würzburg, Germany
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3
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Briggs EM, Marques CA, Oldrieve GR, Hu J, Otto TD, Matthews KR. Profiling the bloodstream form and procyclic form Trypanosoma brucei cell cycle using single-cell transcriptomics. eLife 2023; 12:e86325. [PMID: 37166108 PMCID: PMC10212563 DOI: 10.7554/elife.86325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Accepted: 05/10/2023] [Indexed: 05/12/2023] Open
Abstract
African trypanosomes proliferate as bloodstream forms (BSFs) and procyclic forms in the mammal and tsetse fly midgut, respectively. This allows them to colonise the host environment upon infection and ensure life cycle progression. Yet, understanding of the mechanisms that regulate and drive the cell replication cycle of these forms is limited. Using single-cell transcriptomics on unsynchronised cell populations, we have obtained high resolution cell cycle regulated (CCR) transcriptomes of both procyclic and slender BSF Trypanosoma brucei without prior cell sorting or synchronisation. Additionally, we describe an efficient freeze-thawing protocol that allows single-cell transcriptomic analysis of cryopreserved T. brucei. Computational reconstruction of the cell cycle using periodic pseudotime inference allowed the dynamic expression patterns of cycling genes to be profiled for both life cycle forms. Comparative analyses identify a core cycling transcriptome highly conserved between forms, as well as several genes where transcript levels dynamics are form specific. Comparing transcript expression patterns with protein abundance revealed that the majority of genes with periodic cycling transcript and protein levels exhibit a relative delay between peak transcript and protein expression. This work reveals novel detail of the CCR transcriptomes of both forms, which are available for further interrogation via an interactive webtool.
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Affiliation(s)
- Emma M Briggs
- Institute for Immunology and Infection Research, School of Biological Sciences, University of EdinburghEdinburghUnited Kingdom
- Wellcome Centre for Integrative Parasitology, School of Infection & Immunity, University of GlasgowGlasgowUnited Kingdom
| | - Catarina A Marques
- Wellcome Centre for Integrative Parasitology, School of Infection & Immunity, University of GlasgowGlasgowUnited Kingdom
| | - Guy R Oldrieve
- Institute for Immunology and Infection Research, School of Biological Sciences, University of EdinburghEdinburghUnited Kingdom
| | - Jihua Hu
- Institute for Immunology and Infection Research, School of Biological Sciences, University of EdinburghEdinburghUnited Kingdom
| | - Thomas D Otto
- Wellcome Centre for Integrative Parasitology, School of Infection & Immunity, University of GlasgowGlasgowUnited Kingdom
| | - Keith R Matthews
- Institute for Immunology and Infection Research, School of Biological Sciences, University of EdinburghEdinburghUnited Kingdom
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4
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Geoghegan V, Carnielli JBT, Jones NG, Saldivia M, Antoniou S, Hughes C, Neish R, Dowle A, Mottram JC. CLK1/CLK2-driven signalling at the Leishmania kinetochore is captured by spatially referenced proximity phosphoproteomics. Commun Biol 2022; 5:1305. [PMID: 36437406 PMCID: PMC9701682 DOI: 10.1038/s42003-022-04280-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Accepted: 11/18/2022] [Indexed: 11/29/2022] Open
Abstract
Kinetochores in the parasite Leishmania and related kinetoplastids appear to be unique amongst eukaryotes and contain protein kinases as core components. Using the kinetochore kinases KKT2, KKT3 and CLK2 as baits, we developed a BirA* proximity biotinylation methodology optimised for sensitivity, XL-BioID, to investigate the composition and function of the Leishmania kinetochore. We could detect many of the predicted components and also discovered two novel kinetochore proteins, KKT24 and KKT26. Using KKT3 tagged with a fast-acting promiscuous biotin ligase variant, we took proximity biotinylation snapshots of the kinetochore in synchronised parasites. To quantify proximal phosphosites at the kinetochore as the parasite progressed through the cell cycle, we further developed a spatially referenced proximity phosphoproteomics approach. This revealed a group of phosphosites at the kinetochore that were highly dynamic during kinetochore assembly. We show that the kinase inhibitor AB1 targets CLK1/CLK2 (KKT10/KKT19) in Leishmania leading to defective cytokinesis. Using AB1 to uncover CLK1/CLK2 driven signalling pathways important for kinetochore function at G2/M, we found a set of 16 inhibitor responsive kinetochore-proximal phosphosites. Our results exploit new proximity labelling approaches to provide a direct analysis of the Leishmania kinetochore, which is emerging as a promising drug target.
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Affiliation(s)
- Vincent Geoghegan
- grid.5685.e0000 0004 1936 9668York Biomedical Research Institute and Department of Biology, University of York, Wentworth Way, Heslington, York, YO10 5DD UK
| | - Juliana B. T. Carnielli
- grid.5685.e0000 0004 1936 9668York Biomedical Research Institute and Department of Biology, University of York, Wentworth Way, Heslington, York, YO10 5DD UK
| | - Nathaniel G. Jones
- grid.5685.e0000 0004 1936 9668York Biomedical Research Institute and Department of Biology, University of York, Wentworth Way, Heslington, York, YO10 5DD UK
| | - Manuel Saldivia
- grid.418424.f0000 0004 0439 2056Novartis Institute for Tropical Diseases, Emeryville, CA USA
| | - Sergios Antoniou
- grid.5685.e0000 0004 1936 9668York Biomedical Research Institute and Department of Biology, University of York, Wentworth Way, Heslington, York, YO10 5DD UK
| | - Charlotte Hughes
- grid.5685.e0000 0004 1936 9668York Biomedical Research Institute and Department of Biology, University of York, Wentworth Way, Heslington, York, YO10 5DD UK
| | - Rachel Neish
- grid.5685.e0000 0004 1936 9668York Biomedical Research Institute and Department of Biology, University of York, Wentworth Way, Heslington, York, YO10 5DD UK
| | - Adam Dowle
- grid.5685.e0000 0004 1936 9668Bioscience Technology Facility, Department of Biology, University of York, York, YO10 5DD UK
| | - Jeremy C. Mottram
- grid.5685.e0000 0004 1936 9668York Biomedical Research Institute and Department of Biology, University of York, Wentworth Way, Heslington, York, YO10 5DD UK
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5
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Cayla M, Nievas YR, Matthews KR, Mottram JC. Distinguishing functions of trypanosomatid protein kinases. Trends Parasitol 2022; 38:950-961. [PMID: 36075845 DOI: 10.1016/j.pt.2022.08.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Revised: 08/12/2022] [Accepted: 08/15/2022] [Indexed: 01/13/2023]
Abstract
Trypanosomatid parasitic protozoa are divergent from opisthokont models and have evolved unique mechanisms to regulate their complex life cycles and to adapt to a range of hosts. Understanding how these organisms respond, adapt, and persist in their different hosts could reveal optimal drug-control strategies. Protein kinases are fundamental to many biological processes such as cell cycle control, adaptation to stress, and cellular differentiation. Therefore, we have focused this review on the features and functions of protein kinases that distinguish trypanosomatid kinomes from other eukaryotes. We describe the latest research, highlighting similarities and differences between two groups of trypanosomatid parasites, Leishmania and African trypanosomes.
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Affiliation(s)
- Mathieu Cayla
- Institute for Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh, UK
| | - Y Romina Nievas
- York Biomedical Research Institute, Department of Biology, University of York, York, UK
| | - Keith R Matthews
- Institute for Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh, UK
| | - Jeremy C Mottram
- York Biomedical Research Institute, Department of Biology, University of York, York, UK.
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6
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Kurasawa Y, Lee KJ, Hu H, Pham KTM, Li Z. Polo-like kinase and Aurora B kinase phosphorylate and cooperate with the CIF1-CIF2 complex to promote cytokinesis initiation in Trypanosoma brucei. Open Biol 2022; 12:220197. [PMID: 36196534 PMCID: PMC9532997 DOI: 10.1098/rsob.220197] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Cytokinesis in eukaryotes is regulated by a Polo-like kinase-mediated and Aurora B kinase-mediated signalling pathway that promotes the assembly of the actomyosin contractile ring, a cytokinesis machinery conserved across evolution from yeast to humans. Trypanosoma brucei, an early divergent parasitic protozoan, employs an actomyosin-independent mechanism for its unusual cytokinesis that is controlled by a regulatory pathway comprising the Polo-like kinase TbPLK, the Aurora B kinase TbAUK1 and multiple trypanosomatid-specific regulators. However, whether any of these trypanosomatid-specific regulators function as substrates of TbPLK and/or TbAUK1 and how they cooperate with TbPLK and TbAUK1 to promote cytokinesis remain unknown. Here, we demonstrate that TbPLK and TbAUK1 phosphorylate the cytokinesis regulators CIF1 and CIF2 on multiple sites within their intrinsically disordered regions. We further show that TbPLK localization depends on its interaction with CIF1 from S/G2 phases, that TbPLK maintains CIF1 and CIF2 localization from G2 phase until early mitosis, and that TbAUK1 maintains CIF1 and CIF2 localization from late mitosis. Finally, we demonstrate that the cytokinesis regulators CIF4 and FPRC are not substrates of TbPLK and TbAUK1, and that they function upstream of TbPLK and TbAUK1 in the cytokinesis regulatory pathway. Together, these results provide insights into the functional interplay and the order of actions between the two protein kinases and the trypanosomatid-specific cytokinesis regulators in T. brucei.
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Affiliation(s)
- Yasuhiro Kurasawa
- Department of Microbiology and Molecular Genetics, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Kyu Joon Lee
- Department of Microbiology and Molecular Genetics, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Huiqing Hu
- Department of Microbiology and Molecular Genetics, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Kieu T. M. Pham
- Department of Microbiology and Molecular Genetics, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Ziyin Li
- Department of Microbiology and Molecular Genetics, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
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7
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Genome-scale RNA interference profiling of Trypanosoma brucei cell cycle progression defects. Nat Commun 2022; 13:5326. [PMID: 36088375 PMCID: PMC9464253 DOI: 10.1038/s41467-022-33109-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Accepted: 08/31/2022] [Indexed: 11/21/2022] Open
Abstract
Trypanosomatids, which include major pathogens of humans and livestock, are flagellated protozoa for which cell cycle controls and the underlying mechanisms are not completely understood. Here, we describe a genome-wide RNA-interference library screen for cell cycle defects in Trypanosoma brucei. We induced massive parallel knockdown, sorted the perturbed population using high-throughput flow cytometry, deep-sequenced RNAi-targets from each stage and digitally reconstructed cell cycle profiles at a genomic scale; also enabling data visualisation using an online tool ( https://tryp-cycle.pages.dev/ ). Analysis of several hundred genes that impact cell cycle progression reveals >100 flagellar component knockdowns linked to genome endoreduplication, evidence for metabolic control of the G1-S transition, surface antigen regulatory mRNA-binding protein knockdowns linked to G2M accumulation, and a putative nucleoredoxin required for both mitochondrial genome segregation and for mitosis. The outputs provide comprehensive functional genomic evidence for the known and novel machineries, pathways and regulators that coordinate trypanosome cell cycle progression.
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8
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Juretić D. Designed Multifunctional Peptides for Intracellular Targets. Antibiotics (Basel) 2022; 11:antibiotics11091196. [PMID: 36139975 PMCID: PMC9495127 DOI: 10.3390/antibiotics11091196] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 08/25/2022] [Accepted: 08/29/2022] [Indexed: 11/25/2022] Open
Abstract
Nature’s way for bioactive peptides is to provide them with several related functions and the ability to cooperate in performing their job. Natural cell-penetrating peptides (CPP), such as penetratins, inspired the design of multifunctional constructs with CPP ability. This review focuses on known and novel peptides that can easily reach intracellular targets with little or no toxicity to mammalian cells. All peptide candidates were evaluated and ranked according to the predictions of low toxicity to mammalian cells and broad-spectrum activity. The final set of the 20 best peptide candidates contains the peptides optimized for cell-penetrating, antimicrobial, anticancer, antiviral, antifungal, and anti-inflammatory activity. Their predicted features are intrinsic disorder and the ability to acquire an amphipathic structure upon contact with membranes or nucleic acids. In conclusion, the review argues for exploring wide-spectrum multifunctionality for novel nontoxic hybrids with cell-penetrating peptides.
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Affiliation(s)
- Davor Juretić
- Mediterranean Institute for Life Sciences, 21000 Split, Croatia;
- Faculty of Science, University of Split, 21000 Split, Croatia;
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9
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Falk F, Melo Palhares R, Waithaka A, Clayton C. Roles and interactions of the specialized initiation factors EIF4E2, EIF4E5 and EIF4E6 in Trypanosoma brucei: EIF4E2 maintains the abundances of S-phase mRNAs. Mol Microbiol 2022; 118:457-476. [PMID: 36056730 DOI: 10.1111/mmi.14978] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Revised: 08/14/2022] [Accepted: 08/30/2022] [Indexed: 11/29/2022]
Abstract
Trypanosoma brucei has six versions of the cap-binding translation initiation factor EIF4E. We investigated the functions of EIF4E2, EIF4E3, EIF4E5 and EIF4E6 in bloodstream forms. We confirmed the protein associations previously found in procyclic forms, and detected specific co-purification of some RNA-binding proteins. Bloodstream forms lacking EIF4E5 grew normally and differentiated to replication-incompetent procyclic forms. Depletion of EIF4E6 inhibited bloodstream-form trypanosome growth and translation. EIF4E2 co-purified only the putative RNA binding protein SLBP2. Bloodstream forms lacking EIF4E2 multiplied slowly, had a low maximal cell density, and expressed the stumpy-form marker PAD1, but showed no evidence for enhanced stumpy-form signalling. EIF4E2 knock-out cells differentiated readily to replication-competent procyclic forms. EIF4E2 was strongly associated with a subset of mRNAs that are maximally abundant in S-phase, and these all had decreased abundances in EIF4E2 knock-out cells. Three EIF4E2 target mRNAs are also bound and stabilized by the Pumilio domain protein PUF9. Yeast 2-hybrid results suggested that PUF9 interacts directly with SLBP2, but PUF9 was not detected in EIF4E2 pull-downs. We speculate that the EIF4E2-SLBP2 complex might interact with its target mRNAs, perhaps via PUF9, only early during G1/S, stabilizing the mRNAs in preparation for translation later in S-phase or in early G2.
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Affiliation(s)
- Franziska Falk
- Heidelberg University Centre for Molecular Biology (ZMBH), Im Neuenheimer Feld, Heidelberg, Germany
| | - Rafael Melo Palhares
- Heidelberg University Centre for Molecular Biology (ZMBH), Im Neuenheimer Feld, Heidelberg, Germany.,Institut für Mikro- und Molekularbiologie, Justus-Liebig-Universität Giessen, IFZ, Heinrich-Buff-Ring 26-32, 35392 Giessen, Germany
| | - Albina Waithaka
- Heidelberg University Centre for Molecular Biology (ZMBH), Im Neuenheimer Feld, Heidelberg, Germany
| | - Christine Clayton
- Heidelberg University Centre for Molecular Biology (ZMBH), Im Neuenheimer Feld, Heidelberg, Germany
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10
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Ishii M, Akiyoshi B. Plasticity in centromere organization and kinetochore composition: Lessons from diversity. Curr Opin Cell Biol 2022; 74:47-54. [PMID: 35108654 PMCID: PMC9089191 DOI: 10.1016/j.ceb.2021.12.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2021] [Revised: 12/27/2021] [Accepted: 12/29/2021] [Indexed: 11/16/2022]
Abstract
Kinetochores are the macromolecular protein complexes that govern chromosome movement by binding spindle microtubules during mitosis and meiosis. Centromeres are the specific chromosomal regions that serve as the platform on which kinetochores assemble. Despite their essentiality for proper chromosome segregation, the size and organization of centromeres vary dramatically between species, while different compositions of kinetochores are found among eukaryotes. Here we discuss recent progress in understanding centromeres and kinetochores in non-traditional model eukaryotes. We specifically focus on select lineages (holocentric insects, early diverging fungi, and kinetoplastids) that lack CENP-A, a centromere-specific histone H3 variant that is critical for kinetochore specification and assembly in many eukaryotes. We also highlight some organisms that might have hitherto unknown types of kinetochore proteins.
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Affiliation(s)
- Midori Ishii
- Department of Biochemistry, University of Oxford, UK
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11
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Benz C, Urbaniak MD. Synchronization of Trypanosoma brucei by Counter-Flow Centrifugal Elutriation. Methods Mol Biol 2022; 2579:137-144. [PMID: 36045204 DOI: 10.1007/978-1-0716-2736-5_11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Centrifugal counter-flow elutriation is a non-invasive technique that separates cells based on their hydrodynamic volume in a specialized centrifugation chamber that allows the application of a counter-flow of buffer to oppose sedimentation. Here, we report a centrifugal counter-flow elutriation protocol for Trypanosoma brucei cells that is able to rapidly isolate highly enriched G1 subpopulations (>95%) of synchronized cells. The cells obtained are viable and proliferate without lag, allowing subsequent cell cycle phases to be obtained by continued culture. The synchronized cell cultures obtained by this process have uniform DNA content, a narrow size distribution, undergo synchronous division, and maintain synchrony into subsequent cell cycles.
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Affiliation(s)
- Corinna Benz
- Division of Biomedical and Life Sciences, Faculty of Health and Medicine, Lancaster University, Lancaster, UK
| | - Michael D Urbaniak
- Division of Biomedical and Life Sciences, Faculty of Health and Medicine, Lancaster University, Lancaster, UK.
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12
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Abstract
Abstract
In Trypanosoma brucei and related Kinetoplastids, regulation of gene expression occurs mostly post-transcriptionally, and RNA-binding proteins play a critical role in the regulation of mRNA and protein abundance. Trypanosoma brucei ZC3H28 is a 114 KDa cytoplasmic mRNA-binding protein with a single C(x)7C(x)5C(x)sH zinc finger at the C-terminus and numerous proline-, histidine- or glutamine-rich regions. ZC3H28 is essential for normal bloodstream-form trypanosome growth, and when tethered to a reporter mRNA, ZC3H28 increased reporter mRNA and protein levels. Purification of N-terminally tagged ZC3H28 followed by mass spectrometry showed enrichment of ribosomal proteins, various RNA-binding proteins including both poly(A) binding proteins, the translation initiation complex EIF4E4/EIF4G3, and the activator MKT1. Tagged ZC3H28 was preferentially associated with long RNAs that have low complexity sequences in their 3′-untranslated regions; their coding regions also have low ribosome densities. In agreement with the tethering results, after ZC3H28 depletion, the levels of a significant proportion of its bound mRNAs decreased. We suggest that ZC3H28 is implicated in the stabilization of long mRNAs that are poorly translated.
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13
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Extensive Translational Regulation through the Proliferative Transition of Trypanosoma cruzi Revealed by Multi-Omics. mSphere 2021; 6:e0036621. [PMID: 34468164 PMCID: PMC8550152 DOI: 10.1128/msphere.00366-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Trypanosoma cruzi is the etiological agent for Chagas disease, a neglected parasitic disease in Latin America. Gene transcription control governs the eukaryotic cell replication but is absent in trypanosomatids; thus, it must be replaced by posttranscriptional regulatory events. We investigated the entrance into the T. cruzi replicative cycle using ribosome profiling and proteomics on G1/S epimastigote cultures synchronized with hydroxyurea. We identified 1,784 translationally regulated genes (change > 2, false-discovery rate [FDR] < 0.05) and 653 differentially expressed proteins (change > 1.5, FDR < 0.05), respectively. A major translational remodeling accompanied by an extensive proteome change is found, while the transcriptome remains largely unperturbed at the replicative entrance of the cell cycle. The differentially expressed genes comprise specific cell cycle processes, confirming previous findings while revealing candidate cell cycle regulators that undergo previously unnoticed translational regulation. Clusters of genes showing a coordinated regulation at translation and protein abundance share related biological functions such as cytoskeleton organization and mitochondrial metabolism; thus, they may represent posttranscriptional regulons. The translatome and proteome of the coregulated clusters change in both coupled and uncoupled directions, suggesting that complex cross talk between the two processes is required to achieve adequate protein levels of different regulons. This is the first simultaneous assessment of the transcriptome, translatome, and proteome of trypanosomatids, which represent a paradigm for the absence of transcriptional control. The findings suggest that gene expression chronology along the T. cruzi cell cycle is controlled mainly by translatome and proteome changes coordinated using different mechanisms for specific gene groups. IMPORTANCE Trypanosoma cruzi is an ancient eukaryotic unicellular parasite causing Chagas disease, a potentially life-threatening illness that affects 6 to 7 million people, mostly in Latin America. The antiparasitic treatments for the disease have incomplete efficacy and adverse reactions; thus, improved drugs are needed. We study the mechanisms governing the replication of the parasite, aiming to find differences with the human host, valuable for the development of parasite-specific antiproliferative drugs. Transcriptional regulation is essential for replication in most eukaryotes, but in trypanosomatids, it must be replaced by subsequent gene regulation steps since they lack transcription initiation control. We identified the genome-wide remodeling of mRNA translation and protein abundance during the entrance to the replicative phase of the cell cycle. We found that translation is strongly regulated, causing variation in protein levels of specific cell cycle processes, representing the first simultaneous study of the translatome and proteome in trypanosomatids.
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14
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Campbell PC, de Graffenried CL. Alternate histories of cytokinesis: lessons from the trypanosomatids. Mol Biol Cell 2021; 31:2631-2639. [PMID: 33180676 PMCID: PMC7927182 DOI: 10.1091/mbc.e19-12-0696] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
Popular culture has recently produced several “alternate histories” that describe worlds where key historical events had different outcomes. Beyond entertainment, asking “could this have happened a different way?” and “what would the consequences be?” are valuable approaches for exploring molecular mechanisms in many areas of research, including cell biology. Analogous to alternate histories, studying how the evolutionary trajectories of related organisms have been selected to provide a range of outcomes can tell us about the plasticity and potential contained within the genome of the ancestral cell. Among eukaryotes, a group of model organisms has been employed with great success to identify a core, conserved framework of proteins that segregate the duplicated cellular organelles into two daughter cells during cell division, a process known as cytokinesis. However, these organisms provide relatively sparse sampling across the broad evolutionary distances that exist, which has limited our understanding of the true potential of the ancestral eukaryotic toolkit. Recent work on the trypanosomatids, a group of eukaryotic parasites, exemplifies alternate historical routes for cytokinesis that illustrate the range of eukaryotic diversity, especially among unicellular organisms.
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Affiliation(s)
- Paul C Campbell
- Department of Molecular Microbiology and Immunology, Brown University, Providence, RI 02912
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15
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Saldivia M, Wollman AJM, Carnielli JBT, Jones NG, Leake MC, Bower-Lepts C, Rao SPS, Mottram JC. A CLK1-KKT2 Signaling Pathway Regulating Kinetochore Assembly in Trypanosoma brucei. mBio 2021; 12:e0068721. [PMID: 34128702 PMCID: PMC8262961 DOI: 10.1128/mbio.00687-21] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Accepted: 05/07/2021] [Indexed: 01/17/2023] Open
Abstract
During mitosis, eukaryotic cells must duplicate and separate their chromosomes in a precise and timely manner. The apparatus responsible for this is the kinetochore, which is a large protein structure that links chromosomal DNA and spindle microtubules to facilitate chromosome alignment and segregation. The proteins that comprise the kinetochore in the protozoan parasite Trypanosoma brucei are divergent from yeast and mammals and comprise an inner kinetochore complex composed of 24 distinct proteins (KKT1 to KKT23, KKT25) that include four protein kinases, CLK1 (KKT10), CLK2 (KKT19), KKT2, and KKT3. We recently reported the identification of a specific trypanocidal inhibitor of T. brucei CLK1, an amidobenzimidazole, AB1. We now show that chemical inhibition of CLK1 with AB1 impairs inner kinetochore recruitment and compromises cell cycle progression, leading to cell death. Here, we show that KKT2 is a substrate for CLK1 and identify phosphorylation of S508 by CLK1 to be essential for KKT2 function and for kinetochore assembly. Additionally, KKT2 protein kinase activity is required for parasite proliferation but not for assembly of the inner kinetochore complex. We also show that chemical inhibition of the aurora kinase AUK1 does not affect CLK1 phosphorylation of KKT2, indicating that AUK1 and CLK1 are in separate regulatory pathways. We propose that CLK1 is part of a divergent signaling cascade that controls kinetochore function via phosphorylation of the inner kinetochore protein kinase KKT2. IMPORTANCE In eukaryotic cells, kinetochores are large protein complexes that link chromosomes to dynamic microtubule tips, ensuring proper segregation and genomic stability during cell division. Several proteins tightly coordinate kinetochore functions, including the protein kinase aurora kinase B. The kinetochore has diverse evolutionary roots. For example, trypanosomatids, single-cell parasitic protozoa that cause several neglected tropical diseases, possess a unique repertoire of kinetochore components whose regulation during the cell cycle remains unclear. Here, we shed light on trypanosomatid kinetochore biology by showing that the protein kinase CLK1 coordinates the assembly of the inner kinetochore by phosphorylating one of its components, KKT2, allowing the timely spatial recruitment of the rest of the kinetochore proteins and posterior attachment to microtubules in a process that is aurora kinase B independent.
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Affiliation(s)
- Manuel Saldivia
- York Biomedical Research Institute, Department of Biology, University of York, Heslington, United Kingdom
- Novartis Institute for Tropical Diseases, Emeryville, California, USA
| | - Adam J. M. Wollman
- York Biomedical Research Institute, Department of Biology, University of York, Heslington, United Kingdom
- York Biomedical Research Institute, Department of Physics, University of York, Heslington, United Kingdom
| | - Juliana B. T. Carnielli
- York Biomedical Research Institute, Department of Biology, University of York, Heslington, United Kingdom
| | - Nathaniel G. Jones
- York Biomedical Research Institute, Department of Biology, University of York, Heslington, United Kingdom
| | - Mark C. Leake
- York Biomedical Research Institute, Department of Biology, University of York, Heslington, United Kingdom
- York Biomedical Research Institute, Department of Physics, University of York, Heslington, United Kingdom
| | - Christopher Bower-Lepts
- York Biomedical Research Institute, Department of Biology, University of York, Heslington, United Kingdom
| | | | - Jeremy C. Mottram
- York Biomedical Research Institute, Department of Biology, University of York, Heslington, United Kingdom
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16
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Gonçalves CS, Catta-Preta CMC, Repolês B, Mottram JC, De Souza W, Machado CR, Motta MCM. Importance of Angomonas deanei KAP4 for kDNA arrangement, cell division and maintenance of the host-bacterium relationship. Sci Rep 2021; 11:9210. [PMID: 33911164 PMCID: PMC8080567 DOI: 10.1038/s41598-021-88685-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2020] [Accepted: 04/13/2021] [Indexed: 11/29/2022] Open
Abstract
Angomonas deanei coevolves in a mutualistic relationship with a symbiotic bacterium that divides in synchronicity with other host cell structures. Trypanosomatid mitochondrial DNA is contained in the kinetoplast and is composed of thousands of interlocked DNA circles (kDNA). The arrangement of kDNA is related to the presence of histone-like proteins, known as KAPs (kinetoplast-associated proteins), that neutralize the negatively charged kDNA, thereby affecting the activity of mitochondrial enzymes involved in replication, transcription and repair. In this study, CRISPR-Cas9 was used to delete both alleles of the A. deanei KAP4 gene. Gene-deficient mutants exhibited high compaction of the kDNA network and displayed atypical phenotypes, such as the appearance of a filamentous symbionts, cells containing two nuclei and one kinetoplast, and division blocks. Treatment with cisplatin and UV showed that Δkap4 null mutants were not more sensitive to DNA damage and repair than wild-type cells. Notably, lesions caused by these genotoxic agents in the mitochondrial DNA could be repaired, suggesting that the kDNA in the kinetoplast of trypanosomatids has unique repair mechanisms. Taken together, our data indicate that although KAP4 is not an essential protein, it plays important roles in kDNA arrangement and replication, as well as in the maintenance of symbiosis.
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Affiliation(s)
- Camila Silva Gonçalves
- Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, IBCCF, CCS, UFRJ, Cidade Universitária, Rio de Janeiro, RJ, CEP 21941-590, Brazil
- Centro Nacional de Biologia Estrutural e Bioimagem, Rio de Janeiro, RJ, Brazil
| | | | - Bruno Repolês
- Laboratório de Genética Bioquímica, Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Jeremy C Mottram
- Department of Biology, York Biomedical Research Institute, University of York, Wentworth Way, Heslington, York, YO10 5DD, UK
| | - Wanderley De Souza
- Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, IBCCF, CCS, UFRJ, Cidade Universitária, Rio de Janeiro, RJ, CEP 21941-590, Brazil
- Centro Nacional de Biologia Estrutural e Bioimagem, Rio de Janeiro, RJ, Brazil
| | - Carlos Renato Machado
- Laboratório de Genética Bioquímica, Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.
| | - Maria Cristina M Motta
- Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, IBCCF, CCS, UFRJ, Cidade Universitária, Rio de Janeiro, RJ, CEP 21941-590, Brazil.
- Centro Nacional de Biologia Estrutural e Bioimagem, Rio de Janeiro, RJ, Brazil.
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17
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Gogl G, Tugaeva KV, Eberling P, Kostmann C, Trave G, Sluchanko NN. Hierarchized phosphotarget binding by the seven human 14-3-3 isoforms. Nat Commun 2021; 12:1677. [PMID: 33723253 PMCID: PMC7961048 DOI: 10.1038/s41467-021-21908-8] [Citation(s) in RCA: 52] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Accepted: 02/17/2021] [Indexed: 02/07/2023] Open
Abstract
The seven 14-3-3 isoforms are highly abundant human proteins encoded by similar yet distinct genes. 14-3-3 proteins recognize phosphorylated motifs within numerous human and viral proteins. Here, we analyze by X-ray crystallography, fluorescence polarization, mutagenesis and fusicoccin-mediated modulation the structural basis and druggability of 14-3-3 binding to four E6 oncoproteins of tumorigenic human papillomaviruses. 14-3-3 isoforms bind variant and mutated phospho-motifs of E6 and unrelated protein RSK1 with different affinities, albeit following an ordered affinity ranking with conserved relative KD ratios. Remarkably, 14-3-3 isoforms obey the same hierarchy when binding to most of their established targets, as supported by literature and a recent human complexome map. This knowledge allows predicting proportions of 14-3-3 isoforms engaged with phosphoproteins in various tissues. Notwithstanding their individual functions, cellular concentrations of 14-3-3 may be collectively adjusted to buffer the strongest phosphorylation outbursts, explaining their expression variations in different tissues and tumors.
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Affiliation(s)
- Gergo Gogl
- Equipe Labellisee Ligue 2015, Department of Integrated Structural Biology, Institut de Genetique et de Biologie Moleculaire et Cellulaire (IGBMC), INSERM U1258/CNRS UMR 7104/Universite de Strasbourg, Illkirch, France.
| | - Kristina V Tugaeva
- A.N. Bach Institute of Biochemistry, Federal Research Center of Biotechnology of the Russian Academy of Sciences, Moscow, Russia
| | - Pascal Eberling
- Equipe Labellisee Ligue 2015, Department of Integrated Structural Biology, Institut de Genetique et de Biologie Moleculaire et Cellulaire (IGBMC), INSERM U1258/CNRS UMR 7104/Universite de Strasbourg, Illkirch, France
| | - Camille Kostmann
- Equipe Labellisee Ligue 2015, Department of Integrated Structural Biology, Institut de Genetique et de Biologie Moleculaire et Cellulaire (IGBMC), INSERM U1258/CNRS UMR 7104/Universite de Strasbourg, Illkirch, France
| | - Gilles Trave
- Equipe Labellisee Ligue 2015, Department of Integrated Structural Biology, Institut de Genetique et de Biologie Moleculaire et Cellulaire (IGBMC), INSERM U1258/CNRS UMR 7104/Universite de Strasbourg, Illkirch, France.
| | - Nikolai N Sluchanko
- A.N. Bach Institute of Biochemistry, Federal Research Center of Biotechnology of the Russian Academy of Sciences, Moscow, Russia.
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18
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An T, Hu H, Li Z. The kinetoplastid-specific phosphatase KPP1 attenuates PLK activity to facilitate flagellum inheritance in Trypanosoma brucei. Sci Signal 2021; 14:14/669/eabc6435. [PMID: 33563698 DOI: 10.1126/scisignal.abc6435] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Trypanosoma brucei, an important human parasite, has a flagellum that controls cell motility, morphogenesis, proliferation, and cell-cell communication. Inheritance of the newly assembled flagellum during the cell cycle requires the Polo-like kinase homolog TbPLK and the kinetoplastid-specific protein phosphatase KPP1, although whether TbPLK acts on KPP1 or vice versa has been unclear. Here, we showed that dephosphorylation of TbPLK on Thr125 by KPP1 maintained low TbPLK activity in the flagellum-associated hook complex structure, thereby ensuring proper flagellum positioning and attachment. This dephosphorylation event required the recognition of phosphorylated Thr198 in the activation loop of TbPLK by the N-terminal Plus3 domain of KPP1 and the dephosphorylation of phosphorylated Thr125 in TbPLK by the C-terminal catalytic domain of KPP1. Dephosphorylation of TbPLK by KPP1 prevented hyperphosphorylation of the hook complex protein TbCentrin2, thereby allowing timely dephosphorylation of phosphorylated TbCentrin2 for hook complex duplication and flagellum positioning and attachment. Thus, KPP1 attenuates TbPLK activity by dephosphorylating TbPLK to facilitate flagellum inheritance.
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Affiliation(s)
- Tai An
- Department of Microbiology and Molecular Genetics, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Huiqing Hu
- Department of Microbiology and Molecular Genetics, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Ziyin Li
- Department of Microbiology and Molecular Genetics, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX 77030, USA.
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19
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Cayla M, Matthews KR, Ivens AC. A global analysis of low-complexity regions in the Trypanosoma brucei proteome reveals enrichment in the C-terminus of nucleic acid binding proteins providing potential targets of phosphorylation. Wellcome Open Res 2020; 5:219. [PMID: 33274300 PMCID: PMC7682498 DOI: 10.12688/wellcomeopenres.16286.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/04/2020] [Indexed: 11/29/2022] Open
Abstract
Background: Low-complexity regions (LCRs) on proteins have attracted increasing attention recently due to their role in the assembly of membraneless organelles or granules by liquid-liquid phase separation. Several examples of such granules have been shown to sequester RNA and proteins in an inactive state, providing an important mechanism for dynamic post-transcriptional gene regulation. In trypanosome parasites, post-transcriptional control overwhelmingly dominates gene regulation due to the organisation of their genome into polycistronic transcription units. The purpose of the current study was to generate a substantially more comprehensive genome-wide survey of LCRs on trypanosome proteins than currently available . Methods: Using the Shannon's entropy method, provided in the R package 'entropy', we identified LCRs in the proteome of Trypanosoma brucei. Our analysis predicts LCRs and their positional enrichment in distinct protein cohorts and superimposes on this a range of post-translational modifications derived from available experimental datasets. Results: We have identified 8162 LCRs present on 4914 proteins, representing 42% of the proteome, placing Trypanosoma brucei among the eukaryotes with the highest percentage of LCRs . Our results highlight the enrichment of LCRs in the C-terminal region of predicted nucleic acid binding proteins, these acting as favoured sites for potential phosphorylation. Phosphorylation represents 51% of the post-translational modifications present on LCRs compared to 16% on the rest of the proteome. Conclusions: The post-translational modifications of LCRs, and in particular phosphorylation events, could contribute to post-transcriptional gene expression control and the dynamics of protein targeting to membraneless organelles in kinetoplastid parasites.
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Affiliation(s)
- Mathieu Cayla
- Centre for Immunity, Infection and Evolution, Institute for Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh, Scotland, EH9 3JT, UK
| | - Keith R. Matthews
- Centre for Immunity, Infection and Evolution, Institute for Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh, Scotland, EH9 3JT, UK
| | - Alasdair C. Ivens
- Centre for Immunity, Infection and Evolution, Institute for Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh, Scotland, EH9 3JT, UK
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20
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Kurasawa Y, An T, Li Z. Polo-like kinase in trypanosomes: an odd member out of the Polo family. Open Biol 2020; 10:200189. [PMID: 33050792 PMCID: PMC7653357 DOI: 10.1098/rsob.200189] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Accepted: 09/17/2020] [Indexed: 12/12/2022] Open
Abstract
Polo-like kinases (Plks) are evolutionarily conserved serine/threonine protein kinases playing crucial roles during multiple stages of mitosis and cytokinesis in yeast and animals. Plks are characterized by a unique Polo-box domain, which plays regulatory roles in controlling Plk activation, interacting with substrates and targeting Plk to specific subcellular locations. Plk activity and protein abundance are subject to temporal and spatial control through transcription, phosphorylation and proteolysis. In the early branching protists, Plk orthologues are present in some taxa, such as kinetoplastids and Giardia, but are lost in apicomplexans, such as Plasmodium. Works from characterizing a Plk orthologue in Trypanosoma brucei, a kinetoplastid protozoan, discover its essential roles in regulating the inheritance of flagellum-associated cytoskeleton and the initiation of cytokinesis, but not any stage of mitosis. These studies reveal evolutionarily conserved and species-specific features in the control of Plk activation, substrate recognition and protein abundance, and suggest the divergence of Plk function and regulation for specialized needs in this flagellated unicellular eukaryote.
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Affiliation(s)
| | | | - Ziyin Li
- Department of Microbiology and Molecular Genetics, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
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21
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Cayla M, Matthews KR, Ivens AC. A global analysis of low-complexity regions in the Trypanosoma brucei proteome reveals enrichment in the C-terminus of nucleic acid binding proteins providing potential targets of phosphorylation. Wellcome Open Res 2020; 5:219. [PMID: 33274300 PMCID: PMC7682498 DOI: 10.12688/wellcomeopenres.16286.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/11/2020] [Indexed: 03/31/2024] Open
Abstract
Background: Low-complexity regions (LCRs) on proteins have attracted increasing attention recently due to their role in the assembly of membraneless organelles or granules by liquid-liquid phase separation. Several examples of such granules have been shown to sequester RNA and proteins in an inactive state, providing an important mechanism for dynamic post-transcriptional gene regulation. In trypanosome parasites, post-transcriptional control overwhelmingly dominates gene regulation due to the organisation of their genome into polycistronic transcription units. The purpose of the current study was to generate a substantially more comprehensive genome-wide survey of LCRs on trypanosome proteins than currently available . Methods: Using the Shannon's entropy method, provided in the R package 'entropy', we identified LCRs in the proteome of Trypanosoma brucei. Our analysis predicts LCRs and their positional enrichment in distinct protein cohorts and superimposes on this a range of post-translational modifications derived from available experimental datasets. Results: Our results highlight the enrichment of LCRs in the C-terminal region of predicted nucleic acid binding proteins, these acting as favoured sites for potential phosphorylation. Conclusions: The post-translational modifications of LCRs, and in particular the phosphorylation events, could contribute to post-transcriptional gene expression control and the dynamics of protein targeting to membraneless organelles in kinetoplastid parasites.
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Affiliation(s)
- Mathieu Cayla
- Centre for Immunity, Infection and Evolution, Institute for Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh, Scotland, EH9 3JT, UK
| | - Keith R. Matthews
- Centre for Immunity, Infection and Evolution, Institute for Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh, Scotland, EH9 3JT, UK
| | - Alasdair C. Ivens
- Centre for Immunity, Infection and Evolution, Institute for Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh, Scotland, EH9 3JT, UK
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22
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Bajak K, Leiss K, Clayton C, Erben E. A potential role for a novel ZC3H5 complex in regulating mRNA translation in Trypanosoma brucei. J Biol Chem 2020; 295:14291-14304. [PMID: 32763974 DOI: 10.1074/jbc.ra120.014346] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 07/29/2020] [Indexed: 11/06/2022] Open
Abstract
In Trypanosoma brucei and related kinetoplastids, gene expression regulation occurs mostly posttranscriptionally. Consequently, RNA-binding proteins play a critical role in the regulation of mRNA and protein abundance. Yet, the roles of many RNA-binding proteins are not understood. Our previous research identified the RNA-binding protein ZC3H5 as possibly involved in gene repression, but its role in controlling gene expression was unknown. We here show that ZC3H5 is an essential cytoplasmic RNA-binding protein. RNAi targeting ZC3H5 causes accumulation of precytokinetic cells followed by rapid cell death. Affinity purification and pairwise yeast two-hybrid analysis suggest that ZC3H5 forms a complex with three other proteins, encoded by genes Tb927.11.4900, Tb927.8.1500, and Tb927.7.3040. RNA immunoprecipitation revealed that ZC3H5 is preferentially associated with poorly translated, low-stability mRNAs, the 5'-untranslated regions and coding regions of which are enriched in the motif (U/A)UAG(U/A). As previously found in high-throughput analyses, artificial tethering of ZC3H5 to a reporter mRNA or other complex components repressed reporter expression. However, depletion of ZC3H5 in vivo caused only very minor decreases in a few targets, marked increases in the abundances of very stable mRNAs, an increase in monosomes at the expense of large polysomes, and appearance of "halfmer" disomes containing two 80S subunits and one 40S subunit. We speculate that the ZC3H5 complex might be implicated in quality control during the translation of suboptimal open reading frames.
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Affiliation(s)
- Kathrin Bajak
- Zentrum für Molekulare Biologie der Universität Heidelberg (ZMBH), Heidelberg, Germany.,Deutsches Krebsforschungszentrum (DKFZ), Heidelberg, Germany
| | - Kevin Leiss
- Zentrum für Molekulare Biologie der Universität Heidelberg (ZMBH), Heidelberg, Germany
| | - Christine Clayton
- Zentrum für Molekulare Biologie der Universität Heidelberg (ZMBH), Heidelberg, Germany
| | - Esteban Erben
- Deutsches Krebsforschungszentrum (DKFZ), Heidelberg, Germany
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23
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Faktorová D, Kaur B, Valach M, Graf L, Benz C, Burger G, Lukeš J. Targeted integration by homologous recombination enables in situ tagging and replacement of genes in the marine microeukaryote Diplonema papillatum. Environ Microbiol 2020; 22:3660-3670. [PMID: 32548939 DOI: 10.1111/1462-2920.15130] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2020] [Revised: 06/07/2020] [Accepted: 06/13/2020] [Indexed: 12/17/2022]
Abstract
Diplonemids are a group of highly diverse and abundant marine microeukaryotes that belong to the phylum Euglenozoa and form a sister clade to the well-studied, mostly parasitic kinetoplastids. Very little is known about the biology of diplonemids, as few species have been formally described and just one, Diplonema papillatum, has been studied to a decent extent at the molecular level. Following up on our previous results showing stable but random integration of delivered extraneous DNA, we demonstrate here homologous recombination in D. papillatum. Targeting various constructs to the intended position in the nuclear genome was successful when 5' and 3' homologous regions longer than 1 kbp were used, achieving N-terminal tagging with mCherry and gene replacement of α- and β-tubulins. For more convenient genetic manipulation, we designed a modular plasmid, pDP002, which bears a protein-A tag and used it to generate and express a C-terminally tagged mitoribosomal protein. Lastly, we developed an improved transformation protocol for broader applicability across laboratories. Our robust methodology allows the replacement, integration as well as endogenous tagging of D. papillatum genes, thus opening the door to functional studies in this species and establishing a basic toolkit for reverse genetics of diplonemids in general.
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Affiliation(s)
- Drahomíra Faktorová
- Czech Academy of Sciences, Institute of Parasitology, Biology Centre, Czech Republic.,Faculty of Sciences, University of South Bohemia, Cˇeské Budějovice (Budweis), Czech Republic
| | - Binnypreet Kaur
- Czech Academy of Sciences, Institute of Parasitology, Biology Centre, Czech Republic.,Faculty of Sciences, University of South Bohemia, Cˇeské Budějovice (Budweis), Czech Republic
| | - Matus Valach
- Department of Biochemistry and Robert-Cedergren Centre for Bioinformatics and Genomics, Université de Montréal, Montreal, Canada
| | - Lena Graf
- Faculty of Sciences, University of South Bohemia, Cˇeské Budějovice (Budweis), Czech Republic.,Present address: Johannes Kepler University, Linz, Austria
| | - Corinna Benz
- Czech Academy of Sciences, Institute of Parasitology, Biology Centre, Czech Republic
| | - Gertraud Burger
- Department of Biochemistry and Robert-Cedergren Centre for Bioinformatics and Genomics, Université de Montréal, Montreal, Canada
| | - Julius Lukeš
- Czech Academy of Sciences, Institute of Parasitology, Biology Centre, Czech Republic.,Faculty of Sciences, University of South Bohemia, Cˇeské Budějovice (Budweis), Czech Republic
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Roles of the Pumilio domain protein PUF3 in Trypanosoma brucei growth and differentiation. Parasitology 2020; 147:1171-1183. [PMID: 32513341 DOI: 10.1017/s003118202000092x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Trypanosomes strongly rely on post-transcriptional mechanisms to control gene expression. Several Opisthokont Pumilio domain proteins are known to suppress expression when bound to mRNAs. The Trypanosoma brucei Pumilio domain protein PUF3 is a cytosolic mRNA-binding protein that suppresses expression when tethered to a reporter mRNA. RNA-binding studies showed that PUF3 preferentially binds to mRNAs with a classical Pumilio-domain recognition motif, UGUA[U/C]AUU. RNA-interference-mediated reduction of PUF3 in bloodstream forms caused a minor growth defect, but the transcriptome was not affected. Depletion of PUF3 also slightly delayed differentiation to the procyclic form. However, both PUF3 genes could be deleted in cultured bloodstream- and procyclic-form trypanosomes. Procyclic forms without PUF3 also grew somewhat slower than wild-type, but ectopic expression of C-terminally tagged PUF3 impaired their viability. PUF3 was not required for RBP10-induced differentiation of procyclic forms to bloodstream forms. Mass spectrometry revealed no PUF3 binding partners that might explain its suppressive activity. We conclude that PUF3 may have a role in fine-tuning gene expression. Since PUF3 is conserved in all Kinetoplastids, including those that do not infect vertebrates, we suggest that it might confer advantages within the invertebrate host.
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Ooi CP, Benz C, Urbaniak MD. Phosphoproteomic analysis of mammalian infective Trypanosoma brucei subjected to heat shock suggests atypical mechanisms for thermotolerance. J Proteomics 2020; 219:103735. [PMID: 32198071 DOI: 10.1016/j.jprot.2020.103735] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Revised: 02/11/2020] [Accepted: 03/10/2020] [Indexed: 10/24/2022]
Abstract
The symptoms of African sleeping sickness, caused by the parasite Trypanosoma brucei, can include periods of fever as high as 41 °C which triggers a heat shock response in the parasite. To capture events involved in sensing and responding to heat shock in the mammalian infective form we have conducted a SILAC-based quantitative proteomic and phosphoproteomic analysis of T. brucei cells treated at 41 °C for 1h. Our analysis identified 193 heat shock responsive phosphorylation sites with an average of 5-fold change in abundance, but only 20 heat shock responsive proteins with average of 1.5-fold change. These data indicate that protein abundance does not rapidly respond (≤1 h) to heat shock, and that the changes observed in phosphorylation site abundance are larger and more widespread. The heat shock responsive phosphorylation sites showed enrichment of RNA binding proteins with putative roles in heat shock response included P-body / stress granules and the eukaryotic translation initiation 4F complex. The ZC3H11-MKT1 complex, which stabilises mRNAs of thermotolerance proteins, appears to represent a key signal integration node in the heat shock response. SIGNIFICANCE: We report the first quantitative study of changes in protein and phosphorylation site abundance in response to heat shock in the clinically relevant form of the human parasite Trypanosoma brucei. The identification of heat shock responsive phosphorylation sites on proteins with putative roles in thermotolerance including the ZC3H11-MKT1 complex provides evidence of the role dynamic phosphorylation of RNA binding proteins in co-ordinating heat shock. Temperature changes in the host are a major physiological challenge to parasites and factors conferring tolerance to heat shock constitute overlooked virulence factors. A better understanding of these virulence factors will pave the way for the development of novel drug therapies which selectively target T. brucei.
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Affiliation(s)
- Cher P Ooi
- Department of Life Sciences, Sir Alexander Fleming Building, Imperial College London, South Kensington, London SW7 2AZ, UK.
| | - Corinna Benz
- Biomedical and Life Sciences, Faculty of Health and Medicine, Lancaster University, Lancaster LA1 4YG, UK
| | - Michael D Urbaniak
- Biomedical and Life Sciences, Faculty of Health and Medicine, Lancaster University, Lancaster LA1 4YG, UK.
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Ishii M, Akiyoshi B. Characterization of unconventional kinetochore kinases KKT10 and KKT19 in Trypanosoma brucei. J Cell Sci 2020; 133:jcs240978. [PMID: 32184264 PMCID: PMC7197874 DOI: 10.1242/jcs.240978] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Accepted: 03/02/2020] [Indexed: 12/23/2022] Open
Abstract
The kinetochore is a macromolecular protein complex that drives chromosome segregation in eukaryotes. Unlike most eukaryotes that have canonical kinetochore proteins, evolutionarily divergent kinetoplastids, such as Trypanosoma brucei, have unconventional kinetochore proteins. T. brucei also lacks a canonical spindle checkpoint system, and it therefore remains unknown how mitotic progression is regulated in this organism. Here, we characterized, in the procyclic form of T. brucei, two paralogous kinetochore proteins with a CLK-like kinase domain, KKT10 and KKT19, which localize at kinetochores in metaphase but disappear at the onset of anaphase. We found that these proteins are functionally redundant. Double knockdown of KKT10 and KKT19 led to a significant delay in the metaphase to anaphase transition. We also found that phosphorylation of two kinetochore proteins, KKT4 and KKT7, depended on KKT10 and KKT19 in vivo Finally, we showed that the N-terminal part of KKT7 directly interacts with KKT10 and that kinetochore localization of KKT10 depends not only on KKT7 but also on the KKT8 complex. Our results reveal that kinetochore localization of KKT10 and KKT19 is tightly controlled to regulate the metaphase to anaphase transition in T. bruceiThis article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Midori Ishii
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
| | - Bungo Akiyoshi
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
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