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Mondragón-Rosas F, Florencio-Martínez LE, Villa-Delavequia GS, Manning-Cela RG, Carrero JC, Nepomuceno-Mejía T, Martínez-Calvillo S. Characterization of Tau95 led to the identification of a four-subunit TFIIIC complex in trypanosomatid parasites. Appl Microbiol Biotechnol 2024; 108:109. [PMID: 38204130 PMCID: PMC10781861 DOI: 10.1007/s00253-023-12903-8] [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: 07/05/2023] [Revised: 09/20/2023] [Accepted: 09/30/2023] [Indexed: 01/12/2024]
Abstract
RNA polymerase III (RNAP III) synthetizes small essential non-coding RNA molecules such as tRNAs and 5S rRNA. In yeast and vertebrates, RNAP III needs general transcription factors TFIIIA, TFIIIB, and TFIIIC to initiate transcription. TFIIIC, composed of six subunits, binds to internal promoter elements in RNAP III-dependent genes. Limited information is available about RNAP III transcription in the trypanosomatid protozoa Trypanosoma brucei and Leishmania major, which diverged early from the eukaryotic lineage. Analyses of the first published draft of the trypanosomatid genome sequences failed to recognize orthologs of any of the TFIIIC subunits, suggesting that this transcription factor is absent in these parasites. However, a putative TFIIIC subunit was recently annotated in the databases. Here we characterize this subunit in T. brucei and L. major and demonstrate that it corresponds to Tau95. In silico analyses showed that both proteins possess the typical Tau95 sequences: the DNA binding region and the dimerization domain. As anticipated for a transcription factor, Tau95 localized to the nucleus in insect forms of both parasites. Chromatin immunoprecipitation (ChIP) assays demonstrated that Tau95 binds to tRNA and U2 snRNA genes in T. brucei. Remarkably, by performing tandem affinity purifications we identified orthologs of TFIIIC subunits Tau55, Tau131, and Tau138 in T. brucei and L. major. Thus, contrary to what was assumed, trypanosomatid parasites do possess a TFIIIC complex. Other putative interacting partners of Tau95 were identified in T. brucei and L. major. KEY POINTS: • A four-subunit TFIIIC complex is present in T. brucei and L. major • TbTau95 associates with tRNA and U2 snRNA genes • Putative interacting partners of Tau95 might include some RNAP II regulators.
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Affiliation(s)
- Fabiola Mondragón-Rosas
- Facultad de Estudios Superiores Iztacala, Unidad de Biomedicina, Universidad Nacional Autónoma de México, Av. de los Barrios 1, Col. Los Reyes Iztacala, Tlalnepantla, Edo. de México, CP 54090, México
| | - Luis E Florencio-Martínez
- Facultad de Estudios Superiores Iztacala, Unidad de Biomedicina, Universidad Nacional Autónoma de México, Av. de los Barrios 1, Col. Los Reyes Iztacala, Tlalnepantla, Edo. de México, CP 54090, México
| | - Gino S Villa-Delavequia
- Facultad de Estudios Superiores Iztacala, Unidad de Biomedicina, Universidad Nacional Autónoma de México, Av. de los Barrios 1, Col. Los Reyes Iztacala, Tlalnepantla, Edo. de México, CP 54090, México
| | - Rebeca G Manning-Cela
- Departamento de Biomedicina Molecular, Centro de Investigación y de Estudios Avanzados del IPN, Av. IPN 2508, Ciudad de Mexico, CP 07360, México
| | - Julio C Carrero
- Departamento de Inmunología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Ciudad de Mexico, 04510, México
| | - Tomás Nepomuceno-Mejía
- Facultad de Estudios Superiores Iztacala, Unidad de Biomedicina, Universidad Nacional Autónoma de México, Av. de los Barrios 1, Col. Los Reyes Iztacala, Tlalnepantla, Edo. de México, CP 54090, México
| | - Santiago Martínez-Calvillo
- Facultad de Estudios Superiores Iztacala, Unidad de Biomedicina, Universidad Nacional Autónoma de México, Av. de los Barrios 1, Col. Los Reyes Iztacala, Tlalnepantla, Edo. de México, CP 54090, México.
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2
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Gaona-López C, Vazquez-Jimenez LK, Gonzalez-Gonzalez A, Delgado-Maldonado T, Ortiz-Pérez E, Nogueda-Torres B, Moreno-Rodríguez A, Vázquez K, Saavedra E, Rivera G. Advances in Protozoan Epigenetic Targets and Their Inhibitors for the Development of New Potential Drugs. Pharmaceuticals (Basel) 2023; 16:ph16040543. [PMID: 37111300 PMCID: PMC10143871 DOI: 10.3390/ph16040543] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Revised: 03/29/2023] [Accepted: 03/31/2023] [Indexed: 04/29/2023] Open
Abstract
Protozoan parasite diseases cause significant mortality and morbidity worldwide. Factors such as climate change, extreme poverty, migration, and a lack of life opportunities lead to the propagation of diseases classified as tropical or non-endemic. Although there are several drugs to combat parasitic diseases, strains resistant to routinely used drugs have been reported. In addition, many first-line drugs have adverse effects ranging from mild to severe, including potential carcinogenic effects. Therefore, new lead compounds are needed to combat these parasites. Although little has been studied regarding the epigenetic mechanisms in lower eukaryotes, it is believed that epigenetics plays an essential role in vital aspects of the organism, from controlling the life cycle to the expression of genes involved in pathogenicity. Therefore, using epigenetic targets to combat these parasites is foreseen as an area with great potential for development. This review summarizes the main known epigenetic mechanisms and their potential as therapeutics for a group of medically important protozoal parasites. Different epigenetic mechanisms are discussed, highlighting those that can be used for drug repositioning, such as histone post-translational modifications (HPTMs). Exclusive parasite targets are also emphasized, including the base J and DNA 6 mA. These two categories have the greatest potential for developing drugs to treat or eradicate these diseases.
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Affiliation(s)
- Carlos Gaona-López
- Laboratorio de Biotecnología Farmacéutica, Centro de Biotecnología Genómica, Instituto Politécnico Nacional, Reynosa 88710, Mexico
| | - Lenci K Vazquez-Jimenez
- Laboratorio de Biotecnología Farmacéutica, Centro de Biotecnología Genómica, Instituto Politécnico Nacional, Reynosa 88710, Mexico
| | - Alonzo Gonzalez-Gonzalez
- Laboratorio de Biotecnología Farmacéutica, Centro de Biotecnología Genómica, Instituto Politécnico Nacional, Reynosa 88710, Mexico
| | - Timoteo Delgado-Maldonado
- Laboratorio de Biotecnología Farmacéutica, Centro de Biotecnología Genómica, Instituto Politécnico Nacional, Reynosa 88710, Mexico
| | - Eyrá Ortiz-Pérez
- Laboratorio de Biotecnología Farmacéutica, Centro de Biotecnología Genómica, Instituto Politécnico Nacional, Reynosa 88710, Mexico
| | - Benjamín Nogueda-Torres
- Departamento de Parasitología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Mexico City 11340, Mexico
| | - Adriana Moreno-Rodríguez
- Laboratorio de Estudios Epidemiológicos, Clínicos, Diseños Experimentales e Investigación, Facultad de Ciencias Químicas, Universidad Autónoma "Benito Juárez" de Oaxaca, Avenida Universidad S/N, Ex Hacienda Cinco Señores, Oaxaca 68120, Mexico
| | - Karina Vázquez
- Facultad de Medicina Veterinaria y Zootecnia, Universidad Autónoma de Nuevo León, Francisco Villa 20, General Escobedo 66054, Mexico
| | - Emma Saavedra
- Departamento de Bioquímica, Instituto Nacional de Cardiología Ignacio Chávez, Mexico City 14080, Mexico
| | - Gildardo Rivera
- Laboratorio de Biotecnología Farmacéutica, Centro de Biotecnología Genómica, Instituto Politécnico Nacional, Reynosa 88710, Mexico
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Kamran M, Bhattacharjee R, Das S, Mukherjee S, Ali N. The paradigm of intracellular parasite survival and drug resistance in leishmanial parasite through genome plasticity and epigenetics: Perception and future perspective. Front Cell Infect Microbiol 2023; 13:1001973. [PMID: 36814446 PMCID: PMC9939536 DOI: 10.3389/fcimb.2023.1001973] [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: 07/24/2022] [Accepted: 01/16/2023] [Indexed: 02/09/2023] Open
Abstract
Leishmania is an intracellular, zoonotic, kinetoplastid eukaryote with more than 1.2 million cases all over the world. The leishmanial chromosomes are divided into polymorphic chromosomal ends, conserved central domains, and antigen-encoding genes found in telomere-proximal regions. The genome flexibility of chromosomal ends of the leishmanial parasite is known to cause drug resistance and intracellular survival through the evasion of host defense mechanisms. Therefore, in this review, we discuss the plasticity of Leishmania genome organization which is the primary cause of drug resistance and parasite survival. Moreover, we have not only elucidated the causes of such genome plasticity which includes aneuploidy, epigenetic factors, copy number variation (CNV), and post-translation modification (PTM) but also highlighted their impact on drug resistance and parasite survival.
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Affiliation(s)
| | | | - Sonali Das
- Infectious Diseases and Immunology Division, Indian Institute of Chemical Biology, Kolkata, West Bengal, India
| | - Sohitri Mukherjee
- Infectious Diseases and Immunology Division, Indian Institute of Chemical Biology, Kolkata, West Bengal, India
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Tallant C, Bamborough P, Chung CW, Gamo FJ, Kirkpatrick R, Larminie C, Martín J, Prinjha R, Rioja I, Simola DF, Gabarró R, Calderón F. Expanding Bromodomain Targeting into Neglected Parasitic Diseases. ACS Infect Dis 2021; 7:2953-2958. [PMID: 34612618 DOI: 10.1021/acsinfecdis.1c00387] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
This Perspective discusses the published data and recent developments in the research area of bromodomains in parasitic protozoa. Further work is needed to evaluate the tractability of this target class in the context of infectious diseases and launch drug discovery campaigns to identify and develop antiparasite drugs that can offer differentiated mechanisms of action.
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Affiliation(s)
- Cynthia Tallant
- Global Health R&D, GlaxoSmithKline, c/ Severo Ochoa 2, 28760 Tres Cantos, Spain
| | - Paul Bamborough
- Molecular Design, GlaxoSmithKline, Gunnels Wood Road, Stevenage, Hertfordshire SG1 2NY, United Kingdom
| | - Chun-wa Chung
- Protein, Cellular and Structural Sciences, GlaxoSmithKline, Gunnels Wood Road, Stevenage, Hertfordshire SG1 2NY, United Kingdom
| | | | - Robert Kirkpatrick
- GlaxoSmithKline R&D, 1250 S. Collegeville Rd., Collegeville, Pennsylvania 19426, United States
| | - Chris Larminie
- Human Genetics, GlaxoSmithKline, Gunnels Wood Road, Stevenage, Hertfordshire SG1 2NY, United Kingdom
| | - Julio Martín
- Global Health R&D, GlaxoSmithKline, c/ Severo Ochoa 2, 28760 Tres Cantos, Spain
| | - Rab Prinjha
- Immunology Research Unit, Research, R&D GlaxoSmithKline, Gunnels Wood Road, Stevenage, Hertfordshire SG1 2NY, United Kingdom
| | - Inmaculada Rioja
- Immunology Research Unit, Research, R&D GlaxoSmithKline, Gunnels Wood Road, Stevenage, Hertfordshire SG1 2NY, United Kingdom
| | - Daniel F. Simola
- Human Genetics and Computational Biology, GlaxoSmithKline, 1250 S. Collegeville Rd., Collegeville, Pennsylvania 19426, United States
| | - Raquel Gabarró
- Global Health R&D, GlaxoSmithKline, c/ Severo Ochoa 2, 28760 Tres Cantos, Spain
| | - Félix Calderón
- Global Health R&D, GlaxoSmithKline, c/ Severo Ochoa 2, 28760 Tres Cantos, Spain
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Abstract
Leishmania donovani is a parasitic protist that causes the lethal Kala-azar fever in India and East Africa. Gene expression in Leishmania is regulated by gene copy number variation and inducible translation while RNA synthesis initiates at a small number of sites per chromosome and proceeds through polycistronic transcription units, precluding a gene-specific regulation (C. Clayton and M. Shapira, Mol Biochem Parasitol 156:93–101, 2007, https://doi.org/10.1016/j.molbiopara.2007.07.007). Here, we analyze the dynamics of chromatin structure in both life cycle stages of the parasite and find evidence for an additional, epigenetic gene regulation pathway in this early branching eukaryote. The assay for transposase-accessible chromatin using sequencing (ATAC-seq) analysis (J. D. Buenrostro, P. G. Giresi, L. C. Zaba, H. Y. Chang, and W. J. Greenleaf, Nat Methods 10:1213–1218, 2013, https://doi.org/10.1038/nmeth.2688) predominantly shows euchromatin at transcription start regions in fast-growing promastigotes, but mostly heterochromatin in the slowly proliferating amastigotes, the mammalian stage, reflecting a previously shown increase of histone synthesis in the latter stage. IMPORTANCELeishmania parasites are important pathogens with a global impact and cause poverty-related illness and death. They are devoid of classic cis- and trans-acting transcription regulators but use regulated translation and gene copy number variations to adapt to hosts and environments. In this work, we show that transcription start regions present as open euchromatin in fast-growing insect stages but as less-accessible heterochromatin in the slowly proliferating amastigote stage, indicating an epigenetic control of gene accessibility in this early branching eukaryotic pathogen. This finding should stimulate renewed interest in the control of RNA synthesis in Leishmania and related parasites.
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Role of chromatin modulation in the establishment of protozoan parasite infection for developing targeted chemotherapeutics. THE NUCLEUS 2021. [DOI: 10.1007/s13237-021-00356-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
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Participation of TFIIIB Subunit Brf1 in Transcription Regulation in the Human Pathogen Leishmania major. Genes (Basel) 2021; 12:genes12020280. [PMID: 33669344 PMCID: PMC7920299 DOI: 10.3390/genes12020280] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Revised: 02/02/2021] [Accepted: 02/11/2021] [Indexed: 12/24/2022] Open
Abstract
In yeast and higher eukaryotes, transcription factor TFIIIB is required for accurate initiation of transcription by RNA Polymerase III (Pol III), which synthesizes transfer RNAs (tRNAs), 5S ribosomal RNA (rRNA), and other essential RNA molecules. TFIIIB is composed of three subunits: B double prime 1 (Bdp1), TATA-binding protein (TBP), and TFIIB-related factor 1 (Brf1). Here, we report the molecular characterization of Brf1 in Leishmania major (LmBrf1), a parasitic protozoan that shows distinctive transcription characteristics, including the apparent absence of Pol III general transcription factors TFIIIA and TFIIIC. Although single-knockout parasites of LmBrf1 were obtained, attempts to generate LmBrf1-null mutants were unsuccessful, which suggests that LmBrf1 is essential in promastigotes of L. major. Notably, Northern blot analyses showed that the half-lives of the messenger RNAs (mRNAs) from LmBrf1 and other components of the Pol III transcription machinery (Bdp1 and Pol III subunit RPC1) are very similar (~40 min). Stabilization of these transcripts was observed in stationary-phase parasites. Chromatin immunoprecipitation (ChIP) experiments showed that LmBrf1 binds to tRNA, small nuclear RNA (snRNA), and 5S rRNA genes. Unexpectedly, the results also indicated that LmBrf1 associates to the promoter region of the 18S rRNA genes and to three Pol II-dependent regions here analyzed. Tandem affinity purification and mass spectrometry analyses allowed the identification of a putative TFIIIC subunit. Moreover, several proteins involved in transcription by all three RNA polymerases co-purified with the tagged version of LmBrf1.
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8
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Histone Modifications and Other Facets of Epigenetic Regulation in Trypanosomatids: Leaving Their Mark. mBio 2020; 11:mBio.01079-20. [PMID: 32873754 PMCID: PMC7468196 DOI: 10.1128/mbio.01079-20] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Histone posttranslational modifications (PTMs) modulate several eukaryotic cellular processes, including transcription, replication, and repair. Vast arrays of modifications have been identified in conventional eukaryotes over the last 20 to 25 years. While initial studies uncovered these primarily on histone tails, multiple modifications were subsequently found on the central globular domains as well. Histones are evolutionarily conserved across eukaryotes, and a large number of their PTMs and the functional relevance of these PTMs are largely conserved. Histone posttranslational modifications (PTMs) modulate several eukaryotic cellular processes, including transcription, replication, and repair. Vast arrays of modifications have been identified in conventional eukaryotes over the last 20 to 25 years. While initial studies uncovered these primarily on histone tails, multiple modifications were subsequently found on the central globular domains as well. Histones are evolutionarily conserved across eukaryotes, and a large number of their PTMs and the functional relevance of these PTMs are largely conserved. Trypanosomatids, however, are early diverging eukaryotes. Although possessing all four canonical histones as well as several variants, their sequences diverge from those of other eukaryotes, particularly in the tails. Consequently, the modifications they carry also vary. Initial analyses almost 15 years ago suggested that trypanosomatids possessed a smaller collection of histone modifications. However, exhaustive high resolution mass spectrometry analyses in the last few years have overturned this belief, and it is now evident that the “histone code” proposed by Allis and coworkers in the early years of this century is as complex in these organisms as in other eukaryotes. Trypanosomatids cause several diseases, and the members of this group of organisms have varied lifestyles, evolving diverse mechanisms to evade the host immune system, some of which have been found to be principally controlled by epigenetic mechanisms. This minireview aims to acquaint the reader with the impact of histone PTMs on trypanosomatid cellular processes, as well as other facets of trypanosomatid epigenetic regulation, including the influence of three-dimensional (3D) genome architecture, and discusses avenues for future investigations.
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de Oliveira França A, de Oliveira Ramos Pereira L, Ortiz Tanaka TS, Pereira de Oliveira M, Cavalheiros Dorval ME. Viability of Leishmania in blood donors: A tangible possibility of transfusion transmission. JOURNAL OF MICROBIOLOGY, IMMUNOLOGY, AND INFECTION = WEI MIAN YU GAN RAN ZA ZHI 2019; 53:176-178. [PMID: 31427110 DOI: 10.1016/j.jmii.2019.06.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Revised: 04/05/2019] [Accepted: 06/20/2019] [Indexed: 01/09/2023]
Abstract
Asymptomatic individuals apparently able for blood donation, could be infected with Leishmania imposing risks for immunologically vulnerable recipients. Reverse transcribed conventional PCR targeting the 28S ribosomal subunit was conducted, in order to confirm the viability of the parasite in blood donors positive for Leishmania infection.
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Affiliation(s)
- Adriana de Oliveira França
- Laboratory of Clinical Parasitology, Graduate Program in Infectious and Parasitic Diseases, Universidade Federal de Mato Grosso do Sul, Campo Grande, MS, Brazil.
| | - Luiza de Oliveira Ramos Pereira
- Interdisciplinary Laboratory of Medical Research (LIPMed), Laboratory of Leishmaniasis Research, Instituto Oswaldo Cruz, Rio de Janeiro, RJ, Brazil
| | - Tayana Serpa Ortiz Tanaka
- Graduate Program in Infectious and Parasitic Diseases, Universidade Federal de Mato Grosso do Sul, Campo Grande, MS, Brazil
| | - Márcia Pereira de Oliveira
- Interdisciplinary Laboratory of Medical Research (LIPMed), Instituto Oswaldo Cruz, Rio de Janeiro, RJ, Brazil
| | - Maria Elizabeth Cavalheiros Dorval
- Laboratory of Clinical Parasitology, Graduate Program in Infectious and Parasitic Diseases, Universidade Federal de Mato Grosso do Sul, Campo Grande, MS, Brazil
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Martínez-Calvillo S, Florencio-Martínez LE, Nepomuceno-Mejía T. Nucleolar Structure and Function in Trypanosomatid Protozoa. Cells 2019; 8:cells8050421. [PMID: 31071985 PMCID: PMC6562600 DOI: 10.3390/cells8050421] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Revised: 04/26/2019] [Accepted: 04/28/2019] [Indexed: 12/12/2022] Open
Abstract
The nucleolus is the conspicuous nuclear body where ribosomal RNA genes are transcribed by RNA polymerase I, pre-ribosomal RNA is processed, and ribosomal subunits are assembled. Other important functions have been attributed to the nucleolus over the years. Here we review the current knowledge about the structure and function of the nucleolus in the trypanosomatid parasites Trypanosoma brucei, Trypanosoma cruzi and Leishmania ssp., which represent one of the earliest branching lineages among the eukaryotes. These protozoan parasites present a single nucleolus that is preserved throughout the closed nuclear division, and that seems to lack fibrillar centers. Trypanosomatids possess a relatively low number of rRNA genes, which encode rRNA molecules that contain large expansion segments, including several that are trypanosomatid-specific. Notably, the large subunit rRNA (28S-type) is fragmented into two large and four small rRNA species. Hence, compared to other organisms, the rRNA primary transcript requires additional processing steps in trypanosomatids. Accordingly, this group of parasites contains the highest number ever reported of snoRNAs that participate in rRNA processing. The number of modified rRNA nucleotides in trypanosomatids is also higher than in other organisms. Regarding the structure and biogenesis of the ribosomes, recent cryo-electron microscopy analyses have revealed several trypanosomatid-specific features that are discussed here. Additional functions of the nucleolus in trypanosomatids are also reviewed.
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Affiliation(s)
- Santiago Martínez-Calvillo
- Unidad de Biomedicina, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Av. de los Barrios 1, Col. Los Reyes Iztacala, Tlalnepantla CP 54090, Estado de México, Mexico.
| | - Luis E Florencio-Martínez
- Unidad de Biomedicina, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Av. de los Barrios 1, Col. Los Reyes Iztacala, Tlalnepantla CP 54090, Estado de México, Mexico.
| | - Tomás Nepomuceno-Mejía
- Unidad de Biomedicina, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Av. de los Barrios 1, Col. Los Reyes Iztacala, Tlalnepantla CP 54090, Estado de México, Mexico.
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Román-Carraro FC, Florencio-Martínez LE, Romero-Meza G, Nepomuceno-Mejía T, Carrero JC, Arroyo R, Ortega-López J, Manning-Cela RG, Martínez-Calvillo S. TFIIIB Subunit Bdp1 Participates in RNA Polymerase III Transcription in the Protozoan Parasite Leishmania major. BIOMED RESEARCH INTERNATIONAL 2019; 2019:1425281. [PMID: 31058184 PMCID: PMC6463643 DOI: 10.1155/2019/1425281] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/01/2018] [Accepted: 03/13/2019] [Indexed: 01/03/2023]
Abstract
Leishmania major, a protozoan parasite that diverged early from the main eukaryotic lineage, exhibits unusual mechanisms of gene expression. Little is known in this organism about the transcription factors involved in the synthesis of tRNA, 5S rRNA, and snRNAs, transcribed by RNA Polymerase III (Pol III). Here we identify and characterize the TFIIIB subunit Bdp1 in L. major (LmBdp1). Bdp1 plays key roles in Pol III transcription initiation in other organisms, as it participates in Pol III recruitment and promoter opening. In silico analysis showed that LmBdp1 contains the typical extended SANT domain as well as other Bdp1 conserved regions. Nevertheless, LmBdp1 also displays distinctive features, including the presence of only one aromatic residue in the N-linker region. We were not able to produce null mutants of LmBdp1 by homologous recombination, as the obtained double replacement cell line contained an extra copy of LmBdp1, indicating that LmBdp1 is essential for the viability of L. major promastigotes. Notably, the mutant cell line showed reduced levels of the LmBdp1 protein, and its growth was significantly decreased in relation to wild-type cells. Nuclear run-on assays demonstrated that Pol III transcription was affected in the mutant cell line, and ChIP experiments showed that LmBdp1 binds to 5S rRNA, tRNA, and snRNA genes. Thus, our results indicate that LmBdp1 is an essential protein required for Pol III transcription in L. major.
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Affiliation(s)
- Fiordaliso C. Román-Carraro
- Unidad de Biomedicina, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Av. de Los Barrios 1, Col. Los Reyes Iztacala, Tlalnepantla, Estado de México, CP 54090, Mexico
| | - Luis E. Florencio-Martínez
- Unidad de Biomedicina, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Av. de Los Barrios 1, Col. Los Reyes Iztacala, Tlalnepantla, Estado de México, CP 54090, Mexico
| | - Gabriela Romero-Meza
- Unidad de Biomedicina, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Av. de Los Barrios 1, Col. Los Reyes Iztacala, Tlalnepantla, Estado de México, CP 54090, Mexico
| | - Tomás Nepomuceno-Mejía
- Unidad de Biomedicina, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Av. de Los Barrios 1, Col. Los Reyes Iztacala, Tlalnepantla, Estado de México, CP 54090, Mexico
| | - Julio C. Carrero
- Departamento de Inmunología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Ciudad de México, CP 04510, Mexico
| | - Rossana Arroyo
- Departamento de Infectómica y Patogénesis Molecular, Centro de Investigación y de Estudios Avanzados del IPN, Av. IPN 2508, Ciudad de México, CP 07360, Mexico
| | - Jaime Ortega-López
- Departamento de Biotecnología y Bioingeniería, Centro de Investigación y de Estudios Avanzados del IPN, Av. IPN 2508, Ciudad de México, CP 07360, Mexico
| | - Rebeca G. Manning-Cela
- Departamento de Biomedicina Molecular, Centro de Investigación y de Estudios Avanzados del IPN, Av. IPN 2508, Ciudad de México, CP 07360, Mexico
| | - Santiago Martínez-Calvillo
- Unidad de Biomedicina, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Av. de Los Barrios 1, Col. Los Reyes Iztacala, Tlalnepantla, Estado de México, CP 54090, Mexico
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12
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Afrin F, Khan I, Hemeg HA. Leishmania-Host Interactions-An Epigenetic Paradigm. Front Immunol 2019; 10:492. [PMID: 30967861 PMCID: PMC6438953 DOI: 10.3389/fimmu.2019.00492] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2018] [Accepted: 02/25/2019] [Indexed: 12/17/2022] Open
Abstract
Leishmaniasis is one of the major neglected tropical diseases, for which no vaccines exist. Chemotherapy is hampered by limited efficacy coupled with development of resistance and other side effects. Leishmania parasites elude the host defensive mechanisms by modulating their surface proteins as well as dampening the host's immune responses. The parasites use the conventional RNA polymerases peculiarly under different environmental cues or pressures such as the host's milieu or the drugs. The mechanisms that restructure post-translational modifications are poorly understood but altered epigenetic histone modifications are believed to be instrumental in influencing the chromatin remodeling in the parasite. Interestingly, the parasite also modulates gene expression of the hosts, thereby hijacking or dampening the host immune response. Epigenetic factor such as DNA methylation of cytosine residues has been incriminated in silencing of macrophage-specific genes responsible for defense against these parasites. Although there is dearth of information regarding the epigenetic alterations-mediated pathogenesis in these parasites and the host, the unique epigenetic marks may represent targets for potential anti-leishmanial drug candidates. This review circumscribes the epigenetic changes during Leishmania infection, and the epigenetic modifications they enforce upon the host cells to ensure a safe haven. The non-coding micro RNAs as post-transcriptional regulators and correlates of wound healing and toll-like receptor signaling, as well as prognostic biomarkers of therapeutic failure and healing time are also explored. Finally, we highlight the recent advances on how the epigenetic perturbations may impact leishmaniasis vaccine development as biomarkers of safety and immunogenicity.
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Affiliation(s)
- Farhat Afrin
- Department of Medical Laboratory Technology, Faculty of Applied Medical Sciences, Taibah University, Madina, Saudi Arabia
| | - Inbesat Khan
- Rajiv Gandhi Technical University, Bhopal, India
| | - Hassan A Hemeg
- Department of Medical Laboratory Technology, Faculty of Applied Medical Sciences, Taibah University, Madina, Saudi Arabia
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Abstract
The nucleolus as site of ribosome biogenesis holds a pivotal role in cell metabolism. It is composed of ribosomal DNA (rDNA), which is present as tandem arrays located in nucleolus organizer regions (NORs). In interphase cells, rDNA can be found inside and adjacent to nucleoli and the location is indicative for transcriptional activity of ribosomal genes-inactive rDNA (outside) versus active one (inside). Moreover, the nucleolus itself acts as a spatial organizer of non-nucleolar chromatin. Microscopy-based approaches offer the possibility to explore the spatially distinct localization of the different DNA populations in relation to the nucleolar structure. Recent technical developments in microscopy and preparatory methods may further our understanding of the functional architecture of nucleoli. This review will attempt to summarize the current understanding of mammalian nucleolar chromatin organization as seen from a microscopist's perspective.
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Affiliation(s)
- Christian Schöfer
- Division of Cell and Developmental Biology, Center for Anatomy and Cell Biology, Medical University of Vienna, Schwarzspanierstr. 17, 1090, Vienna, Austria.
| | - Klara Weipoltshammer
- Division of Cell and Developmental Biology, Center for Anatomy and Cell Biology, Medical University of Vienna, Schwarzspanierstr. 17, 1090, Vienna, Austria
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Martínez-Calvillo S, Romero-Meza G, Vizuet-de-Rueda JC, Florencio-Martínez LE, Manning-Cela R, Nepomuceno-Mejía T. Epigenetic Regulation of Transcription in Trypanosomatid Protozoa. Curr Genomics 2018; 19:140-149. [PMID: 29491742 PMCID: PMC5814962 DOI: 10.2174/1389202918666170911163517] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Revised: 02/13/2017] [Accepted: 04/18/2017] [Indexed: 12/15/2022] Open
Abstract
The Trypanosomatid family includes flagellated parasites that cause fatal human diseases. Remarkably, protein-coding genes in these organisms are positioned in long tandem arrays that are transcribed polycistronically. However, the knowledge about regulation of transcription initiation and termination in trypanosomatids is scarce. The importance of epigenetic regulation in these processes has become evident in the last years, as distinctive histone modifications and histone variants have been found in transcription initiation and termination regions. Moreover, multiple chromatin-related proteins have been identified and characterized in trypanosomatids, including histone-modifying enzymes, effector complexes, chromatin-remodelling enzymes and histone chaperones. Notably, base J, a modified thymine residue present in the nuclear DNA of trypanosomatids, has been implicated in transcriptional regulation. Here we review the current knowledge on epigenetic control of transcription by all three RNA polymerases in this group of early-diverged eukaryotes.
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Affiliation(s)
- Santiago Martínez-Calvillo
- Unidad de Biomedicina, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México. Av. de los Barrios 1, Col. Los Reyes Iztacala, Tlalnepantla, Edo. de México, CP 54090, México
| | - Gabriela Romero-Meza
- Unidad de Biomedicina, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México. Av. de los Barrios 1, Col. Los Reyes Iztacala, Tlalnepantla, Edo. de México, CP 54090, México
| | - Juan C. Vizuet-de-Rueda
- Unidad de Biomedicina, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México. Av. de los Barrios 1, Col. Los Reyes Iztacala, Tlalnepantla, Edo. de México, CP 54090, México
| | - Luis E. Florencio-Martínez
- Unidad de Biomedicina, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México. Av. de los Barrios 1, Col. Los Reyes Iztacala, Tlalnepantla, Edo. de México, CP 54090, México
| | - Rebeca Manning-Cela
- Departamento de Biomedicina Molecular, Centro de Investigación y de Estudios Avanzados del IPN, Av. IPN 2508, México, D.F., CP 07360, México
| | - Tomás Nepomuceno-Mejía
- Unidad de Biomedicina, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México. Av. de los Barrios 1, Col. Los Reyes Iztacala, Tlalnepantla, Edo. de México, CP 54090, México
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15
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Romero-Meza G, Vélez-Ramírez DE, Florencio-Martínez LE, Román-Carraro FC, Manning-Cela R, Hernández-Rivas R, Martínez-Calvillo S. Maf1 is a negative regulator of transcription in Trypanosoma brucei. Mol Microbiol 2016; 103:452-468. [PMID: 27802583 DOI: 10.1111/mmi.13568] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/26/2016] [Indexed: 11/29/2022]
Abstract
RNA polymerase III (Pol III) produces small RNA molecules that play essential roles in mRNA processing and translation. Maf1, originally described as a negative regulator of Pol III transcription, has been studied from yeast to human. Here we characterized Maf1 in the parasitic protozoa Trypanosoma brucei (TbMaf1), representing the first report to analyse Maf1 in an early-diverged eukaryote. While Maf1 is generally encoded by a single-copy gene, the T. brucei genome contains two almost identical TbMaf1 genes. The TbMaf1 protein has the three conserved sequences and is predicted to fold into a globular structure. Unlike in yeast, TbMaf1 localizes to the nucleus in procyclic forms of T. brucei under normal growth conditions. Cell lines that either downregulate or overexpress TbMaf1 were generated, and growth curve analysis with them suggested that TbMaf1 participates in the regulation of cell growth of T. brucei. Nuclear run-on and chromatin immunoprecipitation analyses demonstrated that TbMaf1 represses Pol III transcription of tRNA and U2 snRNA genes by associating with their promoters. Interestingly, 5S rRNA levels do not change after TbMaf1 ablation or overexpression. Notably, our data also revealed that TbMaf1 regulates Pol I transcription of procyclin gene and Pol II transcription of SL RNA genes.
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Affiliation(s)
- Gabriela Romero-Meza
- Unidad de Biomedicina, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Av. De los Barrios 1, Col. Los Reyes Iztacala, Tlalnepantla, Edo. de México, CP, 54090, México.,Departamento de Biomedicina Molecular, Centro de Investigación y de Estudios Avanzados del IPN, Apartado Postal 14-740, México, DF, 07360, México
| | - Daniel E Vélez-Ramírez
- Unidad de Biomedicina, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Av. De los Barrios 1, Col. Los Reyes Iztacala, Tlalnepantla, Edo. de México, CP, 54090, México
| | - Luis E Florencio-Martínez
- Unidad de Biomedicina, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Av. De los Barrios 1, Col. Los Reyes Iztacala, Tlalnepantla, Edo. de México, CP, 54090, México
| | - Fiordaliso C Román-Carraro
- Unidad de Biomedicina, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Av. De los Barrios 1, Col. Los Reyes Iztacala, Tlalnepantla, Edo. de México, CP, 54090, México
| | - Rebeca Manning-Cela
- Departamento de Biomedicina Molecular, Centro de Investigación y de Estudios Avanzados del IPN, Apartado Postal 14-740, México, DF, 07360, México
| | - Rosaura Hernández-Rivas
- Departamento de Biomedicina Molecular, Centro de Investigación y de Estudios Avanzados del IPN, Apartado Postal 14-740, México, DF, 07360, México
| | - Santiago Martínez-Calvillo
- Unidad de Biomedicina, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Av. De los Barrios 1, Col. Los Reyes Iztacala, Tlalnepantla, Edo. de México, CP, 54090, México
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