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Bravo‐Estupiñan DM, Aguilar‐Guerrero K, Quirós S, Acón M, Marín‐Müller C, Ibáñez‐Hernández M, Mora‐Rodríguez RA. Gene dosage compensation: Origins, criteria to identify compensated genes, and mechanisms including sensor loops as an emerging systems-level property in cancer. Cancer Med 2023; 12:22130-22155. [PMID: 37987212 PMCID: PMC10757140 DOI: 10.1002/cam4.6719] [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: 04/24/2023] [Revised: 10/31/2023] [Accepted: 11/07/2023] [Indexed: 11/22/2023] Open
Abstract
The gene dosage compensation hypothesis presents a mechanism through which the expression of certain genes is modulated to compensate for differences in the dose of genes when additional chromosomes are present. It is one of the means through which cancer cells actively cope with the potential damaging effects of aneuploidy, a hallmark of most cancers. Dosage compensation arises through several processes, including downregulation or overexpression of specific genes and the relocation of dosage-sensitive genes. In cancer, a majority of compensated genes are generally thought to be regulated at the translational or post-translational level, and include the basic components of a compensation loop, including sensors of gene dosage and modulators of gene expression. Post-translational regulation is mostly undertaken by a general degradation or aggregation of remaining protein subunits of macromolecular complexes. An increasingly important role has also been observed for transcriptional level regulation. This article reviews the process of targeted gene dosage compensation in cancer and other biological conditions, along with the mechanisms by which cells regulate specific genes to restore cellular homeostasis. These mechanisms represent potential targets for the inhibition of dosage compensation of specific genes in aneuploid cancers. This article critically examines the process of targeted gene dosage compensation in cancer and other biological contexts, alongside the criteria for identifying genes subject to dosage compensation and the intricate mechanisms by which cells orchestrate the regulation of specific genes to reinstate cellular homeostasis. Ultimately, our aim is to gain a comprehensive understanding of the intricate nature of a systems-level property. This property hinges upon the kinetic parameters of regulatory motifs, which we have termed "gene dosage sensor loops." These loops have the potential to operate at both the transcriptional and translational levels, thus emerging as promising candidates for the inhibition of dosage compensation in specific genes. Additionally, they represent novel and highly specific therapeutic targets in the context of aneuploid cancer.
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Affiliation(s)
- Diana M. Bravo‐Estupiñan
- CICICA, Centro de Investigación en Cirugía y Cáncer Research Center on Surgery and CancerUniversidad de Costa RicaSan JoséCosta Rica
- Programa de Doctorado en Ciencias, Sistema de Estudios de Posgrado (SEP)Universidad de Costa RicaSan JoséCosta Rica
- Laboratorio de Terapia Génica, Departamento de BioquímicaEscuela Nacional de Ciencias Biológicas del Instituto Politécnico NacionalCiudad de MéxicoMexico
- Speratum Biopharma, Inc.Centro Nacional de Innovación Biotecnológica Nacional (CENIBiot)San JoséCosta Rica
| | - Karol Aguilar‐Guerrero
- CICICA, Centro de Investigación en Cirugía y Cáncer Research Center on Surgery and CancerUniversidad de Costa RicaSan JoséCosta Rica
- Maestría académica en Microbiología, Programa de Posgrado en Microbiología, Parasitología, Química Clínica e InmunologíaUniversidad de Costa RicaSan JoséCosta Rica
| | - Steve Quirós
- CICICA, Centro de Investigación en Cirugía y Cáncer Research Center on Surgery and CancerUniversidad de Costa RicaSan JoséCosta Rica
- Laboratorio de Quimiosensibilidad tumoral (LQT), Centro de Investigación en enfermedades Tropicales (CIET), Facultad de MicrobiologíaUniversidad de Costa RicaSan JoséCosta Rica
| | - Man‐Sai Acón
- CICICA, Centro de Investigación en Cirugía y Cáncer Research Center on Surgery and CancerUniversidad de Costa RicaSan JoséCosta Rica
| | - Christian Marín‐Müller
- Speratum Biopharma, Inc.Centro Nacional de Innovación Biotecnológica Nacional (CENIBiot)San JoséCosta Rica
| | - Miguel Ibáñez‐Hernández
- Laboratorio de Terapia Génica, Departamento de BioquímicaEscuela Nacional de Ciencias Biológicas del Instituto Politécnico NacionalCiudad de MéxicoMexico
| | - Rodrigo A. Mora‐Rodríguez
- CICICA, Centro de Investigación en Cirugía y Cáncer Research Center on Surgery and CancerUniversidad de Costa RicaSan JoséCosta Rica
- Laboratorio de Quimiosensibilidad tumoral (LQT), Centro de Investigación en enfermedades Tropicales (CIET), Facultad de MicrobiologíaUniversidad de Costa RicaSan JoséCosta Rica
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2
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Hopkins BR, Angus-Henry A, Kim BY, Carlisle JA, Thompson A, Kopp A. Decoupled evolution of the Sex Peptide gene family and Sex Peptide Receptor in Drosophilidae. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.29.547128. [PMID: 37425821 PMCID: PMC10327216 DOI: 10.1101/2023.06.29.547128] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/11/2023]
Abstract
Across internally fertilising species, males transfer ejaculate proteins that trigger wide-ranging changes in female behaviour and physiology. Much theory has been developed to explore the drivers of ejaculate protein evolution. The accelerating availability of high-quality genomes now allows us to test how these proteins are evolving at fine taxonomic scales. Here, we use genomes from 264 species to chart the evolutionary history of Sex Peptide (SP), a potent regulator of female post-mating responses in Drosophila melanogaster. We infer that SP first evolved in the Drosophilinae subfamily and has followed markedly different evolutionary trajectories in different lineages. Outside of the Sophophora-Lordiphosa, SP exists largely as a single-copy gene with independent losses in several lineages. Within the Sophophora-Lordiphosa, the SP gene family has repeatedly and independently expanded. Up to seven copies, collectively displaying extensive sequence variation, are present in some species. Despite these changes, SP expression remains restricted to the male reproductive tract. Alongside, we document considerable interspecific variation in the presence and morphology of seminal microcarriers that, despite the critical role SP plays in microcarrier assembly in D. melanogaster, appear to be independent of changes in the presence/absence or sequence of SP. We end by providing evidence that SP's evolution is decoupled from that of its receptor, SPR, in which we detect no evidence of correlated diversifying selection. Collectively, our work describes the divergent evolutionary trajectories that a novel gene has taken following its origin and finds a surprisingly weak coevolutionary signal between a supposedly sexually antagonistic protein and its receptor.
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Affiliation(s)
- Ben R. Hopkins
- Department of Evolution and Ecology, University of California – Davis, CA, USA
| | - Aidan Angus-Henry
- Department of Evolution and Ecology, University of California – Davis, CA, USA
| | | | - Jolie A. Carlisle
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, USA
| | - Ammon Thompson
- Department of Evolution and Ecology, University of California – Davis, CA, USA
| | - Artyom Kopp
- Department of Evolution and Ecology, University of California – Davis, CA, USA
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3
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Villa R, Jagtap PKA, Thomae AW, Campos Sparr A, Forné I, Hennig J, Straub T, Becker PB. Divergent evolution toward sex chromosome-specific gene regulation in Drosophila. Genes Dev 2021; 35:1055-1070. [PMID: 34140353 PMCID: PMC8247607 DOI: 10.1101/gad.348411.121] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Accepted: 05/04/2021] [Indexed: 02/07/2023]
Abstract
The dosage compensation complex (DCC) of Drosophila identifies its X-chromosomal binding sites with exquisite selectivity. The principles that assure this vital targeting are known from the D. melanogaster model: DCC-intrinsic specificity of DNA binding, cooperativity with the CLAMP protein, and noncoding roX2 RNA transcribed from the X chromosome. We found that in D. virilis, a species separated from melanogaster by 40 million years of evolution, all principles are active but contribute differently to X specificity. In melanogaster, the DCC subunit MSL2 evolved intrinsic DNA-binding selectivity for rare PionX sites, which mark the X chromosome. In virilis, PionX motifs are abundant and not X-enriched. Accordingly, MSL2 lacks specific recognition. Here, roX2 RNA plays a more instructive role, counteracting a nonproductive interaction of CLAMP and modulating DCC binding selectivity. Remarkably, roX2 triggers a stable chromatin binding mode characteristic of DCC. Evidently, X-specific regulation is achieved by divergent evolution of protein, DNA, and RNA components.
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Affiliation(s)
- Raffaella Villa
- Molecular Biology Division, Biomedical Center, Ludwig-Maximilians-University Munich, 82152 Planegg-Martinsried, Germany
| | - Pravin Kumar Ankush Jagtap
- Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL), 69117 Heidelberg, Germany
| | - Andreas W Thomae
- Molecular Biology Division, Biomedical Center, Ludwig-Maximilians-University Munich, 82152 Planegg-Martinsried, Germany.,Core Facility Bioimaging, Biomedical Center, Ludwig-Maximilians-University Munich, 82152 Planegg-Martinsried, Germany
| | - Aline Campos Sparr
- Molecular Biology Division, Biomedical Center, Ludwig-Maximilians-University Munich, 82152 Planegg-Martinsried, Germany
| | - Ignasi Forné
- Protein Analysis Unit, Biomedical Center, Ludwig-Maximilians-University Munich, 82152 Planegg-Martinsried, Germany
| | - Janosch Hennig
- Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL), 69117 Heidelberg, Germany
| | - Tobias Straub
- Bioinformatics Unit, Biomedical Center, Ludwig-Maximilians-University Munich, 82152 Planegg-Martinsried, Germany
| | - Peter B Becker
- Molecular Biology Division, Biomedical Center, Ludwig-Maximilians-University Munich, 82152 Planegg-Martinsried, Germany
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4
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Albig C, Tikhonova E, Krause S, Maksimenko O, Regnard C, Becker PB. Factor cooperation for chromosome discrimination in Drosophila. Nucleic Acids Res 2019; 47:1706-1724. [PMID: 30541149 PMCID: PMC6393291 DOI: 10.1093/nar/gky1238] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Revised: 11/05/2018] [Accepted: 11/29/2018] [Indexed: 12/27/2022] Open
Abstract
Transcription regulators select their genomic binding sites from a large pool of similar, non-functional sequences. Although general principles that allow such discrimination are known, the complexity of DNA elements often precludes a prediction of functional sites. The process of dosage compensation in Drosophila allows exploring the rules underlying binding site selectivity. The male-specific-lethal (MSL) Dosage Compensation Complex (DCC) selectively binds to some 300 X chromosomal ‘High Affinity Sites’ (HAS) containing GA-rich ‘MSL recognition elements’ (MREs), but disregards thousands of other MRE sequences in the genome. The DNA-binding subunit MSL2 alone identifies a subset of MREs, but fails to recognize most MREs within HAS. The ‘Chromatin-linked adaptor for MSL proteins’ (CLAMP) also interacts with many MREs genome-wide and promotes DCC binding to HAS. Using genome-wide DNA-immunoprecipitation we describe extensive cooperativity between both factors, depending on the nature of the binding sites. These are explained by physical interaction between MSL2 and CLAMP. In vivo, both factors cooperate to compete with nucleosome formation at HAS. The male-specific MSL2 thus synergises with a ubiquitous GA-repeat binding protein for refined X/autosome discrimination.
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Affiliation(s)
- Christian Albig
- Molecular Biology Division, Biomedical Center, Faculty of Medicine and Center for Integrated Protein Science Munich (CIPSM), Ludwig-Maximilians-Universität Munich, 82151 Martinsried, Germany.,Graduate School for Quantitative Biosciences (QBM), Ludwig-Maximilians-Universität Munich, 81377 Munich, Germany
| | - Evgeniya Tikhonova
- Group of Molecular Organization of Genome, Department of the Control of Genetic Processes, Institute of Gene Biology, Russian Academy of Sciences, 119334 Moscow, Russia
| | - Silke Krause
- Molecular Biology Division, Biomedical Center, Faculty of Medicine and Center for Integrated Protein Science Munich (CIPSM), Ludwig-Maximilians-Universität Munich, 82151 Martinsried, Germany
| | - Oksana Maksimenko
- Group of Molecular Organization of Genome, Department of the Control of Genetic Processes, Institute of Gene Biology, Russian Academy of Sciences, 119334 Moscow, Russia
| | - Catherine Regnard
- Molecular Biology Division, Biomedical Center, Faculty of Medicine and Center for Integrated Protein Science Munich (CIPSM), Ludwig-Maximilians-Universität Munich, 82151 Martinsried, Germany
| | - Peter B Becker
- Molecular Biology Division, Biomedical Center, Faculty of Medicine and Center for Integrated Protein Science Munich (CIPSM), Ludwig-Maximilians-Universität Munich, 82151 Martinsried, Germany
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5
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Samata M, Akhtar A. Dosage Compensation of the X Chromosome: A Complex Epigenetic Assignment Involving Chromatin Regulators and Long Noncoding RNAs. Annu Rev Biochem 2018; 87:323-350. [PMID: 29668306 DOI: 10.1146/annurev-biochem-062917-011816] [Citation(s) in RCA: 73] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
X chromosome regulation represents a prime example of an epigenetic phenomenon where coordinated regulation of a whole chromosome is required. In flies, this is achieved by transcriptional upregulation of X chromosomal genes in males to equalize the gene dosage differences in females. Chromatin-bound proteins and long noncoding RNAs (lncRNAs) constituting a ribonucleoprotein complex known as the male-specific lethal (MSL) complex or the dosage compensation complex mediate this process. MSL complex members decorate the male X chromosome, and their absence leads to male lethality. The male X chromosome is also enriched with histone H4 lysine 16 acetylation (H4K16ac), indicating that the chromatin compaction status of the X chromosome also plays an important role in transcriptional activation. How the X chromosome is specifically targeted and how dosage compensation is mechanistically achieved are central questions for the field. Here, we review recent advances, which reveal a complex interplay among lncRNAs, the chromatin landscape, transcription, and chromosome conformation that fine-tune X chromosome gene expression.
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Affiliation(s)
- Maria Samata
- Department of Chromatin Regulation, Max Planck Institute of Immunobiology and Epigenetics, 79108 Freiburg im Breisgau, Germany; .,Faculty of Biology, University of Freiburg, 79104 Freiburg im Breisgau, Germany
| | - Asifa Akhtar
- Department of Chromatin Regulation, Max Planck Institute of Immunobiology and Epigenetics, 79108 Freiburg im Breisgau, Germany;
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6
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Abstract
Long non-coding RNAs (lncRNAs) are a diverse class of RNAs that engage in numerous biological processes across every branch of life. Although initially discovered as mRNA-like transcripts that do not encode proteins, recent studies have revealed features of lncRNAs that further distinguish them from mRNAs. In this Review, we describe special events in the lifetimes of lncRNAs - before, during and after transcription - and discuss how these events ultimately shape the unique characteristics and functional roles of lncRNAs.
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Affiliation(s)
- Jeffrey J Quinn
- Center for Personal Dynamic Regulomes, Stanford University School of Medicine, Stanford, California 94305, USA.,Department of Bioengineering, Stanford University School of Medicine and School of Engineering, Stanford, California 94305, USA
| | - Howard Y Chang
- Center for Personal Dynamic Regulomes, Stanford University School of Medicine, Stanford, California 94305, USA
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7
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Chen B, Zhang Y, Zhang X, Jia S, Chen S, Kang L. Genome-wide identification and developmental expression profiling of long noncoding RNAs during Drosophila metamorphosis. Sci Rep 2016; 6:23330. [PMID: 26996731 PMCID: PMC4800424 DOI: 10.1038/srep23330] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Accepted: 02/29/2016] [Indexed: 12/27/2022] Open
Abstract
An increasing number of long noncoding RNAs (lncRNAs) have been discovered with the recent advances in RNA-sequencing technologies. lncRNAs play key roles across diverse biological processes, and are involved in developmental regulation. However, knowledge about how the genome-wide expression of lncRNAs is developmentally regulated is still limited. We here performed a whole-genome identification of lncRNAs followed by a global expression profiling of these lncRNAs during development in Drosophila melanogaster. We combined bioinformatic prediction of lncRNAs with stringent filtering of protein-coding transcripts and experimental validation to define a high-confidence set of Drosophila lncRNAs. We identified 1,077 lncRNAs in the given transcriptomes that contain 43,967 transcripts; among these, 646 lncRNAs are novel. In vivo expression profiling of these lncRNAs in 27 developmental processes revealed that the expression of lncRNAs is highly temporally restricted relative to that of protein-coding genes. Remarkably, 21% and 42% lncRNAs were significantly upregulated at late embryonic and larval stage, the critical time for developmental transition. The results highlight the developmental specificity of lncRNA expression, and reflect the regulatory significance of a large subclass of lncRNAs for the onset of metamorphosis. The systematic annotation and expression analysis of lncRNAs during Drosophila development form the foundation for future functional exploration.
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Affiliation(s)
- Bing Chen
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Yi Zhang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China.,Department of Mathematics, Hebei University of Science and Technology/Hebei Laboratory of Pharmaceutical Molecular Chemistry, Shijiazhuang 050018, China
| | - Xia Zhang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China.,Beijing Institutes of Life Sciences, Chinese Academy of Sciences, Beijing 100101, China
| | - Shili Jia
- Department of Mathematics, Hebei University of Science and Technology/Hebei Laboratory of Pharmaceutical Molecular Chemistry, Shijiazhuang 050018, China
| | - Shuang Chen
- Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, China
| | - Le Kang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China.,Beijing Institutes of Life Sciences, Chinese Academy of Sciences, Beijing 100101, China
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8
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Primary Sex Determination in Drosophila melanogaster Does Not Rely on the Male-Specific Lethal Complex. Genetics 2015; 202:541-9. [PMID: 26614741 DOI: 10.1534/genetics.115.182931] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Accepted: 11/21/2015] [Indexed: 11/18/2022] Open
Abstract
It has been proposed that the Male Specific Lethal (MSL) complex is active in Drosophila melanogaster embryos of both sexes prior to the maternal-to-zygotic transition. Elevated gene expression from the two X chromosomes of female embryos is proposed to facilitate the stable establishment of Sex-lethal (Sxl) expression, which determines sex and represses further activity of the MSL complex, leaving it active only in males. Important supporting data included female-lethal genetic interactions between the seven msl genes and either Sxl or scute and sisterlessA, two of the X-signal elements (XSE) that regulate early Sxl expression. Here I report contrary findings that there are no female-lethal genetic interactions between the msl genes and Sxl or its XSE regulators. Fly stocks containing the msl3(1) allele were found to exhibit a maternal-effect interaction with Sxl, scute, and sisterlessA mutations, but genetic complementation experiments showed that msl3 is neither necessary nor sufficient for the female-lethal interactions, which appear to be due to an unidentified maternal regulator of Sxl. Published data cited as evidence for an early function of the MSL complex in females, including a maternal effect of msl2, have been reevaluated and found not to support a maternal, or other effect, of the MSL complex in sex determination. These findings suggest that the MSL complex is not involved in primary sex determination or in X chromosome dosage compensation prior to the maternal-to-zygotic transition.
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9
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LAKHOTIA SUBHASHC. Divergent actions of long noncoding RNAs on X-chromosome remodelling in mammals and Drosophila achieve the same end result: dosage compensation. J Genet 2015; 94:575-84. [DOI: 10.1007/s12041-015-0566-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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10
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Soruco MML, Larschan E. A new player in X identification: the CLAMP protein is a key factor in Drosophila dosage compensation. Chromosome Res 2014; 22:505-15. [PMID: 25102930 DOI: 10.1007/s10577-014-9438-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2014] [Revised: 06/29/2014] [Accepted: 07/22/2014] [Indexed: 10/24/2022]
Abstract
Dosage compensation adjusts the expression levels of genes on one or both targeted sex chromosomes in heterogametic species. This process results in the normalized transcriptional output of important and essential gene families encoded on multiple chromosomes. The mechanisms of dosage compensation have been studied in many model organisms, including Drosophila melanogaster (fly), Caenorhabditis elegans (worm), and Mus musculus (mouse). Although the mechanisms of dosage compensations differ among these species, all of these processes rely on the initial discrimination of the X chromosome from autosomes. Recently, a new paradigm for how the X chromosome is targeted for regulation was identified in Drosophila. This mechanism involves a newly identified zinc finger protein, CLAMP. Here, we review important factors involved in dosage compensation across species with special focus on the fly. Understanding how the newly identified CLAMP protein is involved in X targeting in the fly could provide key insights into how the X chromosome is initially identified across species.
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Affiliation(s)
- Marcela M L Soruco
- Department of Molecular Biology, Cellular Biology and Biochemistry, Brown University, Providence, RI, 02912, USA
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11
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Maenner S, Müller M, Fröhlich J, Langer D, Becker PB. ATP-dependent roX RNA remodeling by the helicase maleless enables specific association of MSL proteins. Mol Cell 2013; 51:174-84. [PMID: 23870143 DOI: 10.1016/j.molcel.2013.06.011] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2013] [Revised: 04/19/2013] [Accepted: 06/14/2013] [Indexed: 12/22/2022]
Abstract
Dosage compensation in Drosophila involves a global activation of genes on the male X chromosome. The activating complex (MSL-DCC) consists of male-specific-lethal (MSL) proteins and two long, noncoding roX RNAs. The roX RNAs are essential for X-chromosomal targeting, but their contributions to MSL-DCC structure and function are enigmatic. Conceivably, the RNA helicase MLE, itself an MSL subunit, is actively involved in incorporating roX into functional DCC. We determined the secondary structure of roX2 and mapped specific interaction sites for MLE in vitro. Upon addition of ATP, MLE disrupted a functionally important stem loop in roX2. This RNA remodeling enhanced specific ATP-dependent association of MSL2, the core subunit of the MSL-DCC, providing a link between roX and MSL subunits. Probing the conformation of roX in vivo revealed a remodeled stem loop in chromatin-bound roX2. The active remodeling of a stable secondary structure by MLE may constitute a rate-limiting step for MSL-DCC assembly.
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Affiliation(s)
- Sylvain Maenner
- Adolf-Butenandt-Institute and Center for Integrated Protein Science, Ludwig-Maximilians-University, D-80336 Munich, Germany
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12
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Soruco MML, Chery J, Bishop EP, Siggers T, Tolstorukov MY, Leydon AR, Sugden AU, Goebel K, Feng J, Xia P, Vedenko A, Bulyk ML, Park PJ, Larschan E. The CLAMP protein links the MSL complex to the X chromosome during Drosophila dosage compensation. Genes Dev 2013; 27:1551-6. [PMID: 23873939 DOI: 10.1101/gad.214585.113] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The Drosophila male-specific lethal (MSL) dosage compensation complex increases transcript levels on the single male X chromosome to equal the transcript levels in XX females. However, it is not known how the MSL complex is linked to its DNA recognition elements, the critical first step in dosage compensation. Here, we demonstrate that a previously uncharacterized zinc finger protein, CLAMP (chromatin-linked adaptor for MSL proteins), functions as the first link between the MSL complex and the X chromosome. CLAMP directly binds to the MSL complex DNA recognition elements and is required for the recruitment of the MSL complex. The discovery of CLAMP identifies a key factor required for the chromosome-specific targeting of dosage compensation, providing new insights into how subnuclear domains of coordinate gene regulation are formed within metazoan genomes.
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Affiliation(s)
- Marcela M L Soruco
- Department of Molecular Biology, Cellular Biology, and Biochemistry, Brown University, Providence, Rhode Island 02912, USA
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13
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Lim CK, Kelley RL. The Drosophila over compensating males gene genetically inhibits dosage compensation in males. PLoS One 2013; 8:e60450. [PMID: 23565249 PMCID: PMC3615101 DOI: 10.1371/journal.pone.0060450] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2013] [Accepted: 02/25/2013] [Indexed: 11/29/2022] Open
Abstract
Male Drosophila are monosomic for the X chromosome, but survive due to dosage compensation. They use the Male Specific Lethal (MSL) complex composed of noncoding roX RNA and histone modifying enzymes to hypertranscribe most genes along the X ∼1.6–1.8 fold relative to each female allele. It is not known how the MSL complex achieves this precise adjustment to a large and diverse set of target genes. We carried out a genetic screen searching for novel factors that regulate dosage compensation in flies. This strategy generated thirty alleles in a previously uncharacterized gene, over compensating males (ocm) that antagonizes some aspect of MSL activity. The mutations were initially recovered because they derepressed an MSL-dependent eye color reporter. Null ocm mutations are lethal to both sexes early in development revealing an essential function. Combinations of hypomorphic ocm alleles display a male specific lethality similar to mutations in the classic msl genes, but ocm males die due to excessive, rather than lack of dosage compensation. Males that die due to very low MSL activity can be partially rescued by ocm mutations. Likewise, males that would die from ocm mutations can be rescued by reducing the dose of various msl and roX genes. ocm encodes a large nuclear protein that shares a novel cysteine rich motif with known transcription factors.
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Affiliation(s)
- Chiat Koo Lim
- Program in Developmental Biology, Baylor College of Medicine, Houston, TX, USA.
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14
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Villa R, Forné I, Müller M, Imhof A, Straub T, Becker P. MSL2 Combines Sensor and Effector Functions in Homeostatic Control of the Drosophila Dosage Compensation Machinery. Mol Cell 2012; 48:647-54. [DOI: 10.1016/j.molcel.2012.09.012] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2012] [Revised: 08/02/2012] [Accepted: 09/11/2012] [Indexed: 01/28/2023]
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