1
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Meyer-Nava S, Torres A, Zurita M, Valadez-Graham V. Molecular effects of dADD1 misexpression in chromatin organization and transcription. BMC Mol Cell Biol 2020; 21:17. [PMID: 32293240 PMCID: PMC7092677 DOI: 10.1186/s12860-020-00257-2] [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] [Received: 05/31/2019] [Accepted: 03/04/2020] [Indexed: 12/14/2022] Open
Abstract
Background dADD1 and dXNP proteins are the orthologs in Drosophila melanogaster of the ADD and SNF2 domains, respectively, of the ATRX vertebrate’s chromatin remodeler, they suppress position effect variegation phenotypes and participate in heterochromatin maintenance. Results We performed a search in human cancer databases and found that ATRX protein levels were elevated in more than 4.4% of the samples analyzed. Using the Drosophila model, we addressed the effects of over and under-expression of dADD1 proteins in polytene cells. Elevated levels of dADD1 in fly tissues caused different phenotypes, such as chromocenter disruption and loss of banding pattern at the chromosome arms. Analyses of the heterochromatin maintenance protein HP1a, the dXNP ATPase and the histone post-translational modification H3K9me3 revealed changes in their chromatin localization accompanied by mild transcriptional defects of genes embedded in heterochromatic regions. Furthermore, the expression of heterochromatin embedded genes in null dadd1 organisms is lower than in the wild-type conditions. Conclusion These data indicate that dADD1 overexpression induces chromatin changes, probably affecting the stoichiometry of HP1a containing complexes that lead to transcriptional and architectural changes. Our results place dADD1 proteins as important players in the maintenance of chromatin architecture and heterochromatic gene expression.
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Affiliation(s)
- Silvia Meyer-Nava
- Instituto de Biotecnología. Universidad Nacional Autónoma de México, Campus Morelos, Av. Universidad 2001, C.P, 62210, Cuernavaca, Morelos, Mexico
| | - Amada Torres
- Instituto de Biotecnología. Universidad Nacional Autónoma de México, Campus Morelos, Av. Universidad 2001, C.P, 62210, Cuernavaca, Morelos, Mexico
| | - Mario Zurita
- Instituto de Biotecnología. Universidad Nacional Autónoma de México, Campus Morelos, Av. Universidad 2001, C.P, 62210, Cuernavaca, Morelos, Mexico
| | - Viviana Valadez-Graham
- Instituto de Biotecnología. Universidad Nacional Autónoma de México, Campus Morelos, Av. Universidad 2001, C.P, 62210, Cuernavaca, Morelos, Mexico.
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2
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Palu RAS, Ong E, Stevens K, Chung S, Owings KG, Goodman AG, Chow CY. Natural Genetic Variation Screen in Drosophila Identifies Wnt Signaling, Mitochondrial Metabolism, and Redox Homeostasis Genes as Modifiers of Apoptosis. G3 (BETHESDA, MD.) 2019; 9:3995-4005. [PMID: 31570502 PMCID: PMC6893197 DOI: 10.1534/g3.119.400722] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Accepted: 09/26/2019] [Indexed: 12/22/2022]
Abstract
Apoptosis is the primary cause of degeneration in a number of neuronal, muscular, and metabolic disorders. These diseases are subject to a great deal of phenotypic heterogeneity in patient populations, primarily due to differences in genetic variation between individuals. This creates a barrier to effective diagnosis and treatment. Understanding how genetic variation influences apoptosis could lead to the development of new therapeutics and better personalized treatment approaches. In this study, we examine the impact of the natural genetic variation in the Drosophila Genetic Reference Panel (DGRP) on two models of apoptosis-induced retinal degeneration: overexpression of p53 or reaper (rpr). We identify a number of known apoptotic, neural, and developmental genes as candidate modifiers of degeneration. We also use Gene Set Enrichment Analysis (GSEA) to identify pathways that harbor genetic variation that impact these apoptosis models, including Wnt signaling, mitochondrial metabolism, and redox homeostasis. Finally, we demonstrate that many of these candidates have a functional effect on apoptosis and degeneration. These studies provide a number of avenues for modifying genes and pathways of apoptosis-related disease.
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Affiliation(s)
- Rebecca A S Palu
- Department of Human Genetics, University of Utah School of Medicine, Salt Lake City, UT 84112
| | - Elaine Ong
- Department of Human Genetics, University of Utah School of Medicine, Salt Lake City, UT 84112
| | - Kaitlyn Stevens
- Department of Human Genetics, University of Utah School of Medicine, Salt Lake City, UT 84112
| | - Shani Chung
- Department of Human Genetics, University of Utah School of Medicine, Salt Lake City, UT 84112
| | - Katie G Owings
- Department of Human Genetics, University of Utah School of Medicine, Salt Lake City, UT 84112
| | - Alan G Goodman
- School of Molecular Biosciences, and
- Paul G. Allen School for Global Animal Health, Washington State University College of Veterinary Medicine, Pullman, WA 99164
| | - Clement Y Chow
- Department of Human Genetics, University of Utah School of Medicine, Salt Lake City, UT 84112,
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3
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Abstract
Nucleotide excision repair (NER) is a highly conserved mechanism to remove helix-distorting DNA lesions. A major substrate for NER is DNA damage caused by environmental genotoxins, most notably ultraviolet radiation. Xeroderma pigmentosum, Cockayne syndrome and trichothiodystrophy are three human disorders caused by inherited defects in NER. The symptoms and severity of these diseases vary dramatically, ranging from profound developmental delay to cancer predisposition and accelerated ageing. All three syndromes include developmental abnormalities, indicating an important role for optimal transcription and for NER in protecting against spontaneous DNA damage during embryonic development. Here, we review the current knowledge on genes that function in NER that also affect embryonic development, in particular the development of a fully functional nervous system.
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Affiliation(s)
- Sofia J Araújo
- Department of Genetics, Microbiology and Statistics, Faculty of Biology, University of Barcelona, 08028 Barcelona, Spain.,Institute of Biomedicine, University of Barcelona (IBUB), Barcelona, Spain
| | - Isao Kuraoka
- Department of Chemistry, Faculty of Science, Fukuoka University, 8-19-1 Nanakuma, Jonan-ku, Fukuoka 814-0180, Japan
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4
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Cruz-Becerra G, Valerio-Cabrera S, Juárez M, Bucio-Mendez A, Zurita M. TFIIH localization is highly dynamic during zygotic genome activation in Drosophila, and its depletion causes catastrophic mitosis. J Cell Sci 2018; 131:jcs.211631. [PMID: 29643118 DOI: 10.1242/jcs.211631] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Accepted: 04/03/2018] [Indexed: 12/20/2022] Open
Abstract
In Drosophila, zygotic genome activation occurs in pre-blastoderm embryos during rapid mitotic divisions. How the transcription machinery is coordinated to achieve this goal in a very brief time span is still poorly understood. Transcription factor II H (TFIIH) is fundamental for transcription initiation by RNA polymerase II (RNAPII). Herein, we show the in vivo dynamics of TFIIH at the onset of transcription in Drosophila embryos. TFIIH shows an oscillatory behaviour between the nucleus and cytoplasm. TFIIH foci are observed from interphase to metaphase, and colocalize with those for RNAPII phosphorylated at serine 5 (RNAPIIS5P) at prophase, suggesting that transcription occurs during the first mitotic phases. Furthermore, embryos with defects in subunits of either the CAK or the core subcomplexes of TFIIH show catastrophic mitosis. Although, transcriptome analyses show altered expression of several maternal genes that participate in mitosis, the global level of RNAPIIS5P in TFIIH mutant embryos is similar to that in the wild type, therefore, a direct role for TFIIH in mitosis cannot be ruled out. These results provide important insights regarding the role of a basal transcription machinery component when the zygotic genome is activated.
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Affiliation(s)
- Grisel Cruz-Becerra
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología. Universidad Nacional Autónoma de México, Av Universidad 2001, Cuernavaca Morelos 62250, México
| | - Sarai Valerio-Cabrera
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología. Universidad Nacional Autónoma de México, Av Universidad 2001, Cuernavaca Morelos 62250, México
| | - Mandy Juárez
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología. Universidad Nacional Autónoma de México, Av Universidad 2001, Cuernavaca Morelos 62250, México
| | - Alyeri Bucio-Mendez
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología. Universidad Nacional Autónoma de México, Av Universidad 2001, Cuernavaca Morelos 62250, México
| | - Mario Zurita
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología. Universidad Nacional Autónoma de México, Av Universidad 2001, Cuernavaca Morelos 62250, México
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5
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Marelja Z, Leimkühler S, Missirlis F. Iron Sulfur and Molybdenum Cofactor Enzymes Regulate the Drosophila Life Cycle by Controlling Cell Metabolism. Front Physiol 2018; 9:50. [PMID: 29491838 PMCID: PMC5817353 DOI: 10.3389/fphys.2018.00050] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Accepted: 01/16/2018] [Indexed: 12/20/2022] Open
Abstract
Iron sulfur (Fe-S) clusters and the molybdenum cofactor (Moco) are present at enzyme sites, where the active metal facilitates electron transfer. Such enzyme systems are soluble in the mitochondrial matrix, cytosol and nucleus, or embedded in the inner mitochondrial membrane, but virtually absent from the cell secretory pathway. They are of ancient evolutionary origin supporting respiration, DNA replication, transcription, translation, the biosynthesis of steroids, heme, catabolism of purines, hydroxylation of xenobiotics, and cellular sulfur metabolism. Here, Fe-S cluster and Moco biosynthesis in Drosophila melanogaster is reviewed and the multiple biochemical and physiological functions of known Fe-S and Moco enzymes are described. We show that RNA interference of Mocs3 disrupts Moco biosynthesis and the circadian clock. Fe-S-dependent mitochondrial respiration is discussed in the context of germ line and somatic development, stem cell differentiation and aging. The subcellular compartmentalization of the Fe-S and Moco assembly machinery components and their connections to iron sensing mechanisms and intermediary metabolism are emphasized. A biochemically active Fe-S core complex of heterologously expressed fly Nfs1, Isd11, IscU, and human frataxin is presented. Based on the recent demonstration that copper displaces the Fe-S cluster of yeast and human ferredoxin, an explanation for why high dietary copper leads to cytoplasmic iron deficiency in flies is proposed. Another proposal that exosomes contribute to the transport of xanthine dehydrogenase from peripheral tissues to the eye pigment cells is put forward, where the Vps16a subunit of the HOPS complex may have a specialized role in concentrating this enzyme within pigment granules. Finally, we formulate a hypothesis that (i) mitochondrial superoxide mobilizes iron from the Fe-S clusters in aconitase and succinate dehydrogenase; (ii) increased iron transiently displaces manganese on superoxide dismutase, which may function as a mitochondrial iron sensor since it is inactivated by iron; (iii) with the Krebs cycle thus disrupted, citrate is exported to the cytosol for fatty acid synthesis, while succinyl-CoA and the iron are used for heme biosynthesis; (iv) as iron is used for heme biosynthesis its concentration in the matrix drops allowing for manganese to reactivate superoxide dismutase and Fe-S cluster biosynthesis to reestablish the Krebs cycle.
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Affiliation(s)
- Zvonimir Marelja
- Imagine Institute, Université Paris Descartes-Sorbonne Paris Cité, Paris, France
| | - Silke Leimkühler
- Department of Molecular Enzymology, Institute of Biochemistry and Biology, University of Potsdam, Potsdam, Germany
| | - Fanis Missirlis
- Departamento de Fisiología, Biofísica y Neurociencias, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Ciudad de México, Mexico
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6
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Mapping Second Chromosome Mutations to Defined Genomic Regions in Drosophila melanogaster. G3-GENES GENOMES GENETICS 2018; 8:9-16. [PMID: 29066472 PMCID: PMC5765369 DOI: 10.1534/g3.117.300289] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Hundreds of Drosophila melanogaster stocks are currently maintained at the Bloomington Drosophila Stock Center with mutations that have not been associated with sequence-defined genes. They have been preserved because they have interesting loss-of-function phenotypes. The experimental value of these mutations would be increased by tying them to specific genomic intervals so that geneticists can more easily associate them with annotated genes. Here, we report the mapping of 85 second chromosome complementation groups in the Bloomington collection to specific, small clusters of contiguous genes or individual genes in the sequenced genome. This information should prove valuable to Drosophila geneticists interested in processes associated with particular phenotypes and those searching for mutations affecting specific sequence-defined genes.
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7
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Herrera-Cruz M, Cruz G, Valadez-Graham V, Fregoso-Lomas M, Villicaña C, Vázquez M, Reynaud E, Zurita M. Physical and functional interactions between Drosophila homologue of Swc6/p18Hamlet subunit of the SWR1/SRCAP chromatin-remodeling complex with the DNA repair/transcription factor TFIIH. J Biol Chem 2012; 287:33567-80. [PMID: 22865882 DOI: 10.1074/jbc.m112.383505] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The multisubunit DNA repair and transcription factor TFIIH maintains an intricate cross-talk with different factors to achieve its functions. The p8 subunit of TFIIH maintains the basal levels of the complex by interacting with the p52 subunit. Here, we report that in Drosophila, the homolog of the p8 subunit (Dmp8) is encoded in a bicistronic transcript with the homolog of the Swc6/p18(Hamlet) subunit (Dmp18) of the SWR1/SRCAP chromatin remodeling complex. The SWR1 and SRCAP complexes catalyze the exchange of the canonical histone H2A with the H2AZ histone variant. In eukaryotic cells, bicistronic transcripts are not common, and in some cases, the two encoded proteins are functionally related. We found that Dmp18 physically interacts with the Dmp52 subunit of TFIIH and co-localizes with TFIIH in the chromatin. We also demonstrated that Dmp18 genetically interacts with Dmp8, suggesting that a cross-talk might exist between TFIIH and a component of a chromatin remodeler complex involved in histone exchange. Interestingly, our results also show that when the level of one of the two proteins is decreased and the other maintained, a specific defect in the fly is observed, suggesting that the organization of these two genes in a bicistronic locus has been selected during evolution to allow co-regulation of both genes.
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Affiliation(s)
- Mariana Herrera-Cruz
- Department of Developmental Genetics, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca Morelos, México
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8
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Reyes-Carmona S, Valadéz-Graham V, Aguilar-Fuentes J, Zurita M, León-Del-Río A. Trafficking and chromatin dynamics of holocarboxylase synthetase during development of Drosophila melanogaster. Mol Genet Metab 2011; 103:240-8. [PMID: 21463962 DOI: 10.1016/j.ymgme.2011.03.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/19/2011] [Revised: 03/05/2011] [Accepted: 03/05/2011] [Indexed: 11/26/2022]
Abstract
This work examines the cellular localization of holocarboxylase synthetase (HCS) and its association to chromatin during different stages of development of Drosophila melanogaster. While HCS is well known for its role in the attachment of biotin to biotin-dependent carboxylase, it also regulates the transcription of HCS and carboxylases genes by triggering a cGMP-dependent signal transduction cascade. Further, its presence in the nucleus of cells suggests additional regulatory roles, but the mechanism involved has remained elusive. In this study, we show in D. melanogaster that HCS migrates to the nucleus at the gastrulation stage. In polytene chromosomes, it is associated to heterochromatin bands where it co-localizes with histone 3 trimethylated at lysine 9 (H3K9met3) but not with the euchromatin mark histone 3 acetylated at lysine 9 (H3K9ac). Further, we demonstrate the association of HCS with the hsp70 promoter by immunofluorescence and chromatin immuno-precipitation (ChIP) of associated DNA sequences. We demonstrate the occupancy of HCS to the core promoter region of the transcriptionally inactive hsp70 gene. On heat-shock activation of the hsp70 promoter, HCS is displaced and the promoter region becomes enriched with the TFIIH subunits XPD and XPB and elongating RNA pol II, the latter also demonstrated using ChIP assays. We suggest that HCS may have a role in the repression of gene expression through a mechanism involving its trafficking to the nucleus and interaction with heterochromatic sites coincident with H3K9met3.
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Affiliation(s)
- Sandra Reyes-Carmona
- Departamento de Biología Molecular y Biotecnología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, México DF 04510, Mexico.
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9
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Palomera-Sanchez Z, Bucio-Mendez A, Valadez-Graham V, Reynaud E, Zurita M. Drosophila p53 is required to increase the levels of the dKDM4B demethylase after UV-induced DNA damage to demethylate histone H3 lysine 9. J Biol Chem 2010; 285:31370-9. [PMID: 20675387 DOI: 10.1074/jbc.m110.128462] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Chromatin undergoes a variety of changes in response to UV-induced DNA damage, including histone acetylation. In human and Drosophila cells, this response is affected by mutations in the tumor suppressor p53. In this work, we report that there is a global decrease in trimethylated Lys-9 in histone H3 (H3K9me3) in salivary gland cells in wild type flies in response to UV irradiation. In contrast, flies with mutations in the Dmp53 gene have reduced basal levels of H3K9me3, which are then increased after UV irradiation. The reduction of H3K9me3 in response to DNA damage occurs preferentially in heterochromatin. Our experiments demonstrate that UV irradiation enhances the levels of Lys-9 demethylase (dKDM4B) transcript and protein in wild type flies, but not in Dmp53 mutant flies. Dmp53 binds to a DNA element in the dKdm4B gene as a response to UV irradiation. Furthermore, heterozygous mutants for the dKdm4B gene are more sensitive to UV irradiation; they are deficient in the removal of cyclobutane-pyrimidine dimers, and the decrease of H3K9me3 levels following DNA damage is not observed in dKdm4B mutant flies. We propose that in response to UV irradiation, Dmp53 enhances the expression of the dKDM4B histone demethylase, which demethylates H3K9me3 preferentially in heterochromatin regions. This mechanism appears to be essential for the proper function of the nucleotide excision repair system.
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Affiliation(s)
- Zoraya Palomera-Sanchez
- Department of Developmental Genetics, Instituto de Biotecnología, Universidad Nacional Autónoma de México, AP 62250, Cuernavaca Morelos, México
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10
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Drosophila Xpd regulates Cdk7 localization, mitotic kinase activity, spindle dynamics, and chromosome segregation. PLoS Genet 2010; 6:e1000876. [PMID: 20300654 PMCID: PMC2837399 DOI: 10.1371/journal.pgen.1000876] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2009] [Accepted: 02/06/2010] [Indexed: 12/04/2022] Open
Abstract
The trimeric CAK complex functions in cell cycle control by phosphorylating and activating Cdks while TFIIH-linked CAK functions in transcription. CAK also associates into a tetramer with Xpd, and our analysis of young Drosophila embryos that do not require transcription now suggests a cell cycle function for this interaction. xpd is essential for the coordination and rapid progression of the mitotic divisions during the late nuclear division cycles. Lack of Xpd also causes defects in the dynamics of the mitotic spindle and chromosomal instability as seen in the failure to segregate chromosomes properly during ana- and telophase. These defects appear to be also nucleotide excision repair (NER)–independent. In the absence of Xpd, misrouted spindle microtubules attach to chromosomes of neighboring mitotic figures, removing them from their normal location and causing multipolar spindles and aneuploidy. Lack of Xpd also causes changes in the dynamics of subcellular and temporal distribution of the CAK component Cdk7 and local mitotic kinase activity. xpd thus functions normally to re-localize Cdk7(CAK) to different subcellular compartments, apparently removing it from its cell cycle substrate, the mitotic Cdk. This work proves that the multitask protein Xpd also plays an essential role in cell cycle regulation that appears to be independent of transcription or NER. Xpd dynamically localizes Cdk7/CAK to and away from subcellular substrates, thereby controlling local mitotic kinase activity. Possibly through this activity, xpd controls spindle dynamics and chromosome segregation in our model system. This novel role of xpd should also lead to new insights into the understanding of the neurological and cancer aspects of the human XPD disease phenotypes. Mutations in human xpd cause three different syndromes—XP (xeroderma pigmentosum), TTD (trichothiodystrophy), and CS (Cockayne syndrome)—and various different phenotypes, such as sun-induced hyperpigmentation of the skin, cutaneous abnormalities, neuronal degeneration, and developmental retardation. In addition, while some mutations cause a highly elevated cancer risk, others do not. The multitask protein Xpd functions in transcription, nucleotide excision repair (NER), and in cell cycle regulation. In a situation where transcription is not required and NER not induced, we specifically analyzed the cell cycle function of Xpd in Drosophila. In this situation Xpd locally controls the dynamic localization of Cdk7, the catalytic subunit of the Cdk activating kinase (CAK) to and away from its cellular targets, thereby regulating mitotic kinase activity and mitotic exit. Xpd also controls spindle dynamics to prevent formation of multipolar and promiscuous spindles and aneuploidy. Through multitask proteins like Xpd and Cdk7 cells regulate different cellular pathways in a coordinated fashion. In addition to the basic research relevance, the newly gained knowledge about the cell cycle function of Xpd and its control of spindle dynamics is also relevant for human xpd patients because it shows a possible pathway that could lead to highly increased cancer risk and neurological defects.
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11
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Fregoso M, Lainé JP, Aguilar-Fuentes J, Mocquet V, Reynaud E, Coin F, Egly JM, Zurita M. DNA repair and transcriptional deficiencies caused by mutations in the Drosophila p52 subunit of TFIIH generate developmental defects and chromosome fragility. Mol Cell Biol 2007; 27:3640-50. [PMID: 17339330 PMCID: PMC1899989 DOI: 10.1128/mcb.00030-07] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The transcription and DNA repair factor TFIIH is composed of 10 subunits. Mutations in the XPB, XPD, and p8 subunits are genetically linked to human diseases, including cancer. However, no reports of mutations in other TFIIH subunits have been reported in higher eukaryotes. Here, we analyze at genetic, molecular, and biochemical levels the Drosophila melanogaster p52 (DMP52) subunit of TFIIH. We found that DMP52 is encoded by the gene marionette in Drosophila and that a defective DMP52 produces UV light-sensitive flies and specific phenotypes during development: organisms are smaller than their wild-type siblings and present tumors and chromosomal instability. The human homologue of DMP52 partially rescues some of these phenotypes. Some of the defects observed in the fly caused by mutations in DMP52 generate trichothiodystrophy and cancer-like phenotypes. Biochemical analysis of DMP52 point mutations introduced in human p52 at positions homologous to those of defects in DMP52 destabilize the interaction between p52 and XPB, another TFIIH subunit, thus compromising the assembly of the complex. This study significantly extends the role of p52 in regulating XPB ATPase activity and, consequently, both its transcriptional and nucleotide excision repair functions.
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Affiliation(s)
- Mariana Fregoso
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, BP 163, 67404 Illkirch Cedex, C.U. de Strasbourg, France
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12
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Aguilar-Fuentes J, Valadez-Graham V, Reynaud E, Zurita M. TFIIH trafficking and its nuclear assembly during early Drosophila embryo development. J Cell Sci 2006; 119:3866-75. [PMID: 16940351 DOI: 10.1242/jcs.03150] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We present the first analysis of the dynamics of the transcription DNA-repair factor TFIIH at the onset of transcription in early Drosophila development. TFIIH is composed of ten polypeptides that are part of two complexes - the core and the CAK. We found that the TFIIH core is initially located in the cytoplasm of syncytial blastoderm embryos, and that after mitotic division ten and until the cellular blastoderm stage, the core moves from the cytoplasm to the nucleus. By contrast, the CAK complex is mostly cytoplasmic during cellularization and during gastrulation. However, both components are positioned at promoters of genes that are activated at transcription onset. Later in development, the CAK complex becomes mostly nuclear and co-localizes in most chromosomal regions with the TFIIH core, but not in all sites, suggesting that the CAK complex could have a TFIIH-independent role in transcription of some loci. We also demonstrate that even though the CAK and the core coexist in the early embryo cytoplasm, they do not interact until they are in the nucleus and suggest that the complete assembly of the ten subunits of TFIIH occurs in the nucleus at the mid-blastula transition. In addition, we present evidence that suggests that DNA helicase subunits XPB and XPD are assembled in the core when they are transported into the nucleus and are required for the onset of transcription.
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Affiliation(s)
- Javier Aguilar-Fuentes
- Department of Developmental Genetics and Molecular Physiology, Institute of Biotechnology, National Autonomous University of México, Av. Universidad 2001, Cuernavaca Morelos 62250, Mexico
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13
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Chmuzh EV, Shestakova LA, Volkova VS, Zakharov IK. Diversity of mechanisms and functions of enzyme systems of DNA repair in Drosophila melanogaster. RUSS J GENET+ 2006. [DOI: 10.1134/s1022795406040028] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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14
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Rebollar E, Valadez-Graham V, Vázquez M, Reynaud E, Zurita M. Role of the p53 homologue fromDrosophila melanogasterin the maintenance of histone H3 acetylation and response to UV-light irradiation. FEBS Lett 2006; 580:642-8. [PMID: 16412438 DOI: 10.1016/j.febslet.2005.12.083] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2005] [Revised: 12/20/2005] [Accepted: 12/27/2005] [Indexed: 01/01/2023]
Abstract
It has been demonstrated that the human tumor suppressor p53 has an important role in modulating histone modifications after UV light irradiation. In this work we explored if the p53 Drosophila homologue has a similar role. Taking advantage of the existence of polytene chromosomes in the salivary glands of third instar larvae, we analyzed K9 and K14 H3 acetylation patterns in situ after UV irradiation of wild-type and Dmp53 null flies. As in human cells, after UV damage there is an increase in H3 acetylation in wild-type organisms. In Dmp53 mutant flies, this response is significantly affected at the K9 position. These results are similar to those found in human p53 mutant tumor cells with one interesting difference, only the basal H3 acetylation of K14 is reduced in Dmp53 mutant flies, while the basal H3-K9 acetylation is not affected. This work shows, that the presence of Dmp53 is necessary to maintain normal H3-K14 acetylation levels in Drosophila chromatin and that the function of p53 to maintaining histone modifications, is conserved in Drosophila and humans.
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Affiliation(s)
- Eria Rebollar
- Department of Developmental Genetics and Molecular Physiology, Institute of Biotechnology, National University of México, Cuernavaca, Morelos 62250, Mexico
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15
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Spresser CR, Carlson KA. Drosophila melanogaster as a complementary system for studying HIV-1-related genes and proteins. J Neurosci Res 2005; 80:451-5. [PMID: 15795932 DOI: 10.1002/jnr.20460] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Human immunodeficiency virus type 1 (HIV-1) persists as a pandemic even though new information about the virus is being discovered on a daily basis. If the brain becomes infected, HIV-1 encephalitis or HIV-1-associated dementia may develop. There is much to be learned about the modes of action and mechanisms of genes and proteins, and their interactions that underlie HIV-1 infection. Drosophila melanogaster has been used successfully to study genes and proteins related to HIV-1 infection, including but not limited to the disturbance of antimicrobial responses by viral protein U and the identification of D. melanogaster analogs to the serine palmitoyltransferase 5 and 6 proteins that play a role in activation of transcription by the HIV-1 Tat protein in human cells. We believe that utilizing D. melanogaster as a complementary system for the study of genes and proteins related to HIV-1 infection will provide useful information that will lead to new studies designed to enhance our understanding of the mechanistic roles of these molecules. In the present study, we focus on the utilization of D. melanogaster as a complementary system for studying HIV-1 related genes and proteins, why this research should be extended, and why this complementary system is an important method for enhancing our understanding of the genetics involved in HIV-1 infection.
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Affiliation(s)
- Cole R Spresser
- Biology Department, University of Nebraska at Kearney, Kearney, Nebraska 68849, USA
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Lasko P. Diabetic flies? Using Drosophila melanogaster to understand the causes of monogenic and genetically complex diseases. Clin Genet 2002; 62:358-67. [PMID: 12431248 DOI: 10.1034/j.1399-0004.2002.620502.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Approximately three-quarters of human disease loci have counterparts in the fruit fly Drosophila melanogaster. This model organism is therefore extremely valuable for using to understand the role of these loci in normal development, and for unravelling genetic pathways in which these loci take part. Important advantages for Drosophila in such studies are its completed genome, the unparalleled collection of mutations already in existence, the relative ease in which new mutations can be generated, the existence of convenient techniques for inactivating or overexpressing genes in dispensable tissues that are easily observed and measured, and the ability to readily carry out second-site modifier genetics. Recent work in Drosophila on the insulin-signaling pathway, a pathway of profound clinical importance, is reviewed as an illustration of how such research can provide fundamental insights into the functions of this pathway in regulating growth and development. Moreover, Drosophila research is now identifying heretofore unknown regulators of insulin signaling, as well as indicating novel functions for this pathway in suppressing benign tumor formation and regulating life span.
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Affiliation(s)
- P Lasko
- Department of Biology, McGill University, Montréal, Québec, Canada.
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Merino C, Reynaud E, Vázquez M, Zurita M. DNA repair and transcriptional effects of mutations in TFIIH in Drosophila development. Mol Biol Cell 2002; 13:3246-56. [PMID: 12221129 PMCID: PMC124156 DOI: 10.1091/mbc.e02-02-0087] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Mutations in XPB and XPD TFIIH helicases have been related with three hereditary human disorders: xeroderma pigmentosum, Cockayne syndrome, and trichothiodystrophy. The dual role of TFIIH in DNA repair and transcription makes it difficult to discern which of the mutant TFIIH phenotypes is due to defects in any of these different processes. We used haywire (hay), the Drosophila XPB homolog, to dissect this problem. Our results show that when hay dosage is affected, the fly shows defects in structures that require high levels of transcription. We found a genetic interaction between hay and cdk7, and we propose that some of these phenotypes are due to transcriptional deficiencies. We also found more apoptotic cells in imaginal discs and in the CNS of hay mutant flies than in wild-type flies. Because this abnormal level of apoptosis was not detected in cdk7 flies, this phenotype could be related to defects in DNA repair. In addition the apoptosis induced by p53 Drosophila homolog (Dmp53) is suppressed in heterozygous hay flies.
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Affiliation(s)
- Carlos Merino
- Department of Genetics and Molecular Physiology, Institute of Biotechnology, Universidad Nacional Autónoma de México, Morelos 62250, México
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van Brabant AJ, Stan R, Ellis NA. DNA helicases, genomic instability, and human genetic disease. Annu Rev Genomics Hum Genet 2002; 1:409-59. [PMID: 11701636 DOI: 10.1146/annurev.genom.1.1.409] [Citation(s) in RCA: 203] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
DNA helicases are a highly conserved group of enzymes that unwind DNA. They function in all processes in which access to single-stranded DNA is required, including DNA replication, DNA repair and recombination, and transcription of RNA. Defects in helicases functioning in one or more of these processes can result in characteristic human genetic disorders in which genomic instability and predisposition to cancer are common features. So far, different helicase genes have been found mutated in six such disorders. Mutations in XPB and XPD can result in xeroderma pigmentosum, Cockayne syndrome, or trichothiodystrophy. Mutations in the RecQ-like genes BLM, WRN, and RECQL4 can result in Bloom syndrome, Werner syndrome, and Rothmund-Thomson syndrome, respectively. Because XPB and XPD function in both nucleotide excision repair and transcription initiation, the cellular phenotypes associated with a deficiency of each one of them include failure to repair mutagenic DNA lesions and defects in the recovery of RNA transcription after UV irradiation. The functions of the RecQ-like genes are unknown; however, a growing body of evidence points to a function in restarting DNA replication after the replication fork has become stalled. The genomic instability associated with mutations in the RecQ-like genes includes spontaneous chromosome instability and elevated mutation rates. Mouse models for nearly all of these entities have been developed, and these should help explain the widely different clinical features that are associated with helicase mutations.
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Affiliation(s)
- A J van Brabant
- Department of Human Genetics, Memorial Sloan-Kettering Cancer Center, New York, New York 10021, USA
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Larochelle S, Chen J, Knights R, Pandur J, Morcillo P, Erdjument-Bromage H, Tempst P, Suter B, Fisher RP. T-loop phosphorylation stabilizes the CDK7-cyclin H-MAT1 complex in vivo and regulates its CTD kinase activity. EMBO J 2001; 20:3749-59. [PMID: 11447116 PMCID: PMC125544 DOI: 10.1093/emboj/20.14.3749] [Citation(s) in RCA: 100] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Cyclin-dependent kinase (CDK)7-cyclin H, the CDK-activating kinase (CAK) and TFIIH-associated kinase in metazoans can be activated in vitro through T-loop phosphorylation or binding to the RING finger protein MAT1. Although the two mechanisms can operate independently, we show that in a physiological setting, MAT1 binding and T-loop phosphorylation cooperate to stabilize the CAK complex of Drosophila. CDK7 forms a stable complex with cyclin H and MAT1 in vivo only when phosphorylated on either one of two residues (Ser164 or Thr170) in its T-loop. Mutation of both phosphorylation sites causes temperature-dependent dissociation of CDK7 complexes and lethality. Furthermore, phosphorylation of Thr170 greatly stimulates the activity of the CDK7- cyclin H-MAT1 complex towards the C-terminal domain of RNA polymerase II without significantly affecting activity towards CDK2. Remarkably, the substrate-specific increase in activity caused by T-loop phosphorylation is due entirely to accelerated enzyme turnover. Thus phosphorylation on Thr170 could provide a mechanism to augment CTD phosphorylation by TFIIH-associated CDK7, and thereby regulate transcription.
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Affiliation(s)
- Stéphane Larochelle
- Cell Biology Program and Molecular Biology Program, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10021, USA and Department of Biology, McGill University, 1205 Dr Penfield Avenue, Montreal, PQ, Canada H3A 1B1 Corresponding author e-mail:
| | - Jian Chen
- Cell Biology Program and Molecular Biology Program, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10021, USA and Department of Biology, McGill University, 1205 Dr Penfield Avenue, Montreal, PQ, Canada H3A 1B1 Corresponding author e-mail:
| | - Ronald Knights
- Cell Biology Program and Molecular Biology Program, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10021, USA and Department of Biology, McGill University, 1205 Dr Penfield Avenue, Montreal, PQ, Canada H3A 1B1 Corresponding author e-mail:
| | - Judit Pandur
- Cell Biology Program and Molecular Biology Program, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10021, USA and Department of Biology, McGill University, 1205 Dr Penfield Avenue, Montreal, PQ, Canada H3A 1B1 Corresponding author e-mail:
| | - Patrick Morcillo
- Cell Biology Program and Molecular Biology Program, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10021, USA and Department of Biology, McGill University, 1205 Dr Penfield Avenue, Montreal, PQ, Canada H3A 1B1 Corresponding author e-mail:
| | - Hediye Erdjument-Bromage
- Cell Biology Program and Molecular Biology Program, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10021, USA and Department of Biology, McGill University, 1205 Dr Penfield Avenue, Montreal, PQ, Canada H3A 1B1 Corresponding author e-mail:
| | - Paul Tempst
- Cell Biology Program and Molecular Biology Program, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10021, USA and Department of Biology, McGill University, 1205 Dr Penfield Avenue, Montreal, PQ, Canada H3A 1B1 Corresponding author e-mail:
| | - Beat Suter
- Cell Biology Program and Molecular Biology Program, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10021, USA and Department of Biology, McGill University, 1205 Dr Penfield Avenue, Montreal, PQ, Canada H3A 1B1 Corresponding author e-mail:
| | - Robert P. Fisher
- Cell Biology Program and Molecular Biology Program, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10021, USA and Department of Biology, McGill University, 1205 Dr Penfield Avenue, Montreal, PQ, Canada H3A 1B1 Corresponding author e-mail:
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Sandoval MT, Zurita M. Increased UV light sensitivity in transgenic Drosophila expressing the antisense XPD homolog. ANTISENSE & NUCLEIC ACID DRUG DEVELOPMENT 2001; 11:125-8. [PMID: 11334141 DOI: 10.1089/108729001750171399] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The XPD gene is required for excision repair of UV-damaged DNA and is an important component of nucleotide excision repair (NER). Mutations in the XPD gene generate the cancer-prone syndrome xeroderma pigmentosum, Cockayne's syndrome, and trichothiodystrophy. XPD is a component of the TFIIH transcription factor, which is essential for RNA polymerase II elongation. In this work, we report the construction of transgenic flies overexpressing the antisense RNA of the Drosophila melanogaster XPD homolog (DmXPD). These flies show an increased sensitivity to UV radiation compared with the wild-type. This is an expected phenotype if the XPD function is affected and indicates that the antisense approach may be an alternative in the study of TFIIH functions in Drosophila.
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Affiliation(s)
- M T Sandoval
- Department of Genetics and Molecular Physiology, Institute of Biotechnology, Universidad Nacional Autónoma de México, Cuernavaca, Morelos
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21
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Affiliation(s)
- P Lasko
- Department of Biology, McGill University, Montréal, Québec, Canada H3A 1B1.
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