1
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Pan Q, Darras H, Keller L. LncRNA gene ANTSR coordinates complementary sex determination in the Argentine ant. SCIENCE ADVANCES 2024; 10:eadp1532. [PMID: 38820161 DOI: 10.1126/sciadv.adp1532] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2024] [Accepted: 04/30/2024] [Indexed: 06/02/2024]
Abstract
Animals have evolved various sex determination systems. Here, we describe a newly found mechanism. A long noncoding RNA (lncRNA) transduces complementary sex determination (CSD) signal in the invasive Argentine ant. In this haplodiploid species, we identified a 5-kilobase hyper-polymorphic region underlying CSD: Heterozygous embryos become females, while homozygous and hemizygous embryos become males. Heterozygosity at the CSD locus correlates with higher expression of ANTSR, a gene that overlaps with the CSD locus and specifies an lncRNA transcript. ANTSR knockdown in CSD heterozygotes leads to male development. Comparative analyses indicated that, in Hymenoptera, ANTSR is an ancient yet rapidly evolving gene. This study reveals an lncRNA involved in genetic sex determination, alongside a previously unknown regulatory mechanism underlying sex determination based on complementarity among noncoding alleles.
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Affiliation(s)
- Qiaowei Pan
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
| | - Hugo Darras
- Institute of Organismic and Molecular Evolution, Johannes Gutenberg University, Mainz, Germany
| | - Laurent Keller
- Social Evolution Unit, Cornuit 8, BP 855, Chesières, Switzerland
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2
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Salzler HR, Vandadi V, Matera AG. Set2 and H3K36 regulate the Drosophila male X chromosome in a context-specific manner, independent from MSL complex spreading. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.03.592390. [PMID: 38766267 PMCID: PMC11100620 DOI: 10.1101/2024.05.03.592390] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2024]
Abstract
Dosage compensation in Drosophila involves upregulating male X-genes two-fold. This process is carried out by the MSL (male-specific lethal) complex, which binds high-affinity sites and spreads to surrounding genes. Current models of MSL spreading focus on interactions of MSL3 (male-specific lethal 3) with histone marks; in particular, Set2-dependent H3 lysine-36 trimethylation (H3K36me3). However, Set2 might affect DC via another target, or there could be redundancy between canonical H3.2 and variant H3.3 histones. Further, it is difficult to parse male-specific effects from those that are simply X-specific. To discriminate among these possibilities, we employed genomic approaches in H3K36 (residue) and Set2 (writer) mutants. The results confirm a role for Set2 in X-gene regulation, but show that expression trends in males are often mirrored in females. Instead of global male-specific reduction of X-genes in Set2/H3K36 mutants, the effects were heterogeneous. We identified cohorts of genes whose expression was significantly altered following loss of H3K36 or Set2, but the changes were in opposite directions, suggesting that H3K36me states have reciprocal functions. In contrast to H4K16R controls, analysis of combined H3.2K36R/H3.3K36R mutants neither showed consistent reduction in X-gene expression, nor any correlation with MSL3 binding. Examination of other developmental stages/tissues revealed additional layers of context-dependence. Our studies implicate BEAF-32 and other insulator proteins in Set2/H3K36-dependent regulation. Overall, the data are inconsistent with the prevailing model wherein H3K36me3 directly recruits the MSL complex. We propose that Set2 and H3K36 support DC indirectly, via processes that are utilized by MSL but common to both sexes.
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Affiliation(s)
- Harmony R. Salzler
- Integrative Program for Biological and Genome Sciences, University of North Carolina, Chapel Hill, NC, USA
| | - Vasudha Vandadi
- Integrative Program for Biological and Genome Sciences, University of North Carolina, Chapel Hill, NC, USA
| | - A. Gregory Matera
- Integrative Program for Biological and Genome Sciences, University of North Carolina, Chapel Hill, NC, USA
- Department of Genetics, University of North Carolina, Chapel Hill, NC, USA
- Department of Biology, University of North Carolina, Chapel Hill, NC, USA
- RNA Discovery and Lineberger Comprehensive Cancer Centers, University of North Carolina, Chapel Hill, NC, USA
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3
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Lee U, Li C, Langer CB, Svetec N, Zhao L. Comparative Single Cell Analysis of Transcriptional Bursting Reveals the Role of Genome Organization on de novo Transcript Origination. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.29.591771. [PMID: 38746255 PMCID: PMC11092510 DOI: 10.1101/2024.04.29.591771] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2024]
Abstract
Spermatogenesis is a key developmental process underlying the origination of newly evolved genes. However, rapid cell type-specific transcriptomic divergence of the Drosophila germline has posed a significant technical barrier for comparative single-cell RNA-sequencing (scRNA-Seq) studies. By quantifying a surprisingly strong correlation between species-and cell type-specific divergence in three closely related Drosophila species, we apply a simple statistical procedure to identify a core set of 198 genes that are highly predictive of cell type identity while remaining robust to species-specific differences that span over 25-30 million years of evolution. We then utilize cell type classifications based on the 198-gene set to show how transcriptional divergence in cell type increases throughout spermatogenic developmental time, contrasting with traditional hourglass models of whole-organism development. With these cross-species cell type classifications, we then investigate the influence of genome organization on the molecular evolution of spermatogenesis vis-a-vis transcriptional bursting. We first demonstrate how mechanistic control of pre-meiotic transcription is achieved by altering transcriptional burst size while post-meiotic control is exerted via altered bursting frequency. We then report how global differences in autosomal vs. X chromosomal transcription likely arise in a developmental stage preceding full testis organogenesis by showing evolutionarily conserved decreases in X-linked transcription bursting kinetics in all examined somatic and germline cell types. Finally, we provide evidence supporting the cultivator model of de novo gene origination by demonstrating how the appearance of newly evolved testis-specific transcripts potentially provides short-range regulation of the transcriptional bursting properties of neighboring genes during key stages of spermatogenesis.
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4
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Tikhonova E, Revel-Muroz A, Georgiev P, Maksimenko O. Interaction of MLE with CLAMP zinc finger is involved in proper MSL proteins binding to chromosomes in Drosophila. Open Biol 2024; 14:230270. [PMID: 38471568 DOI: 10.1098/rsob.230270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Accepted: 02/06/2024] [Indexed: 03/14/2024] Open
Abstract
The Drosophila male-specific lethal (MSL) complex binds to the male X chromosome to activate transcription. It comprises five proteins (MSL1, MSL2, MSL3, male absent on the first (MOF), and maleless (MLE)) and two long noncoding RNAs (lncRNAs; roX1 and roX2). The MLE helicase remodels the roX lncRNAs, enabling the lncRNA-mediated assembly of the Drosophila dosage compensation complex. MSL2 is expressed only in males and interacts with the N-terminal zinc finger of the transcription factor chromatin-linked adapter for MSL proteins (CLAMP), which is important for the specific recruitment of the MSL complex to the male X chromosome. Here, we found that MLE's unstructured C-terminal region interacts with the sixth zinc-finger domain of CLAMP. In vitro, 4-5 zinc fingers are critical for the specific DNA-binding of CLAMP with GA repeats, which constitute the core motif at the high affinity binding sites for MSL proteins. Deleting the CLAMP binding region in MLE decreases the association of MSL proteins with the male X chromosome and increases male lethality. These results suggest that interactions of unstructured regions in MSL2 and MLE with CLAMP zinc finger domains are important for the specific recruitment of the MSL complex to the male X chromosome.
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Affiliation(s)
- Evgeniya Tikhonova
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov Street, Moscow 119334, Russia
- Department of the Control of Genetic Processes, Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov Street, Moscow 119334, Russia
| | - Anastasia Revel-Muroz
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov Street, Moscow 119334, Russia
| | - Pavel Georgiev
- Department of the Control of Genetic Processes, Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov Street, Moscow 119334, Russia
| | - Oksana Maksimenko
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov Street, Moscow 119334, Russia
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5
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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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6
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Sun Y, Wiese M, Hmadi R, Karayol R, Seyfferth J, Martinez Greene JA, Erdogdu NU, Deboutte W, Arrigoni L, Holz H, Renschler G, Hirsch N, Foertsch A, Basilicata MF, Stehle T, Shvedunova M, Bella C, Pessoa Rodrigues C, Schwalb B, Cramer P, Manke T, Akhtar A. MSL2 ensures biallelic gene expression in mammals. Nature 2023; 624:173-181. [PMID: 38030723 PMCID: PMC10700137 DOI: 10.1038/s41586-023-06781-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2022] [Accepted: 10/24/2023] [Indexed: 12/01/2023]
Abstract
In diploid organisms, biallelic gene expression enables the production of adequate levels of mRNA1,2. This is essential for haploinsufficient genes, which require biallelic expression for optimal function to prevent the onset of developmental disorders1,3. Whether and how a biallelic or monoallelic state is determined in a cell-type-specific manner at individual loci remains unclear. MSL2 is known for dosage compensation of the male X chromosome in flies. Here we identify a role of MSL2 in regulating allelic expression in mammals. Allele-specific bulk and single-cell analyses in mouse neural progenitor cells revealed that, in addition to the targets showing biallelic downregulation, a class of genes transitions from biallelic to monoallelic expression after MSL2 loss. Many of these genes are haploinsufficient. In the absence of MSL2, one allele remains active, retaining active histone modifications and transcription factor binding, whereas the other allele is silenced, exhibiting loss of promoter-enhancer contacts and the acquisition of DNA methylation. Msl2-knockout mice show perinatal lethality and heterogeneous phenotypes during embryonic development, supporting a role for MSL2 in regulating gene dosage. The role of MSL2 in preserving biallelic expression of specific dosage-sensitive genes sets the stage for further investigation of other factors that are involved in allelic dosage compensation in mammalian cells, with considerable implications for human disease.
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Affiliation(s)
- Yidan Sun
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany
| | - Meike Wiese
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany
| | - Raed Hmadi
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany
| | - Remzi Karayol
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany
| | - Janine Seyfferth
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany
| | - Juan Alfonso Martinez Greene
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany
- Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Niyazi Umut Erdogdu
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany
- Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Ward Deboutte
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany
| | - Laura Arrigoni
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany
| | - Herbert Holz
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany
| | - Gina Renschler
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany
| | - Naama Hirsch
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany
| | - Arion Foertsch
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany
- Faculty of Biology, University of Freiburg, Freiburg, Germany
| | | | - Thomas Stehle
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany
| | - Maria Shvedunova
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany
| | - Chiara Bella
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany
| | | | - Bjoern Schwalb
- Max Planck Institute for Multidisciplinary Sciences, Goettingen, Germany
| | - Patrick Cramer
- Max Planck Institute for Multidisciplinary Sciences, Goettingen, Germany
| | - Thomas Manke
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany
| | - Asifa Akhtar
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany.
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7
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Kalita AI, Marois E, Kozielska M, Weissing FJ, Jaouen E, Möckel MM, Rühle F, Butter F, Basilicata MF, Keller Valsecchi CI. The sex-specific factor SOA controls dosage compensation in Anopheles mosquitoes. Nature 2023; 623:175-182. [PMID: 37769784 PMCID: PMC10620080 DOI: 10.1038/s41586-023-06641-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Accepted: 09/13/2023] [Indexed: 10/03/2023]
Abstract
The Anopheles mosquito is one of thousands of species in which sex differences play a central part in their biology, as only females need a blood meal to produce eggs. Sex differentiation is regulated by sex chromosomes, but their presence creates a dosage imbalance between males (XY) and females (XX). Dosage compensation (DC) can re-equilibrate the expression of sex chromosomal genes. However, because DC mechanisms have only been fully characterized in a few model organisms, key questions about its evolutionary diversity and functional necessity remain unresolved1. Here we report the discovery of a previously uncharacterized gene (sex chromosome activation (SOA)) as a master regulator of DC in the malaria mosquito Anopheles gambiae. Sex-specific alternative splicing prevents functional SOA protein expression in females. The male isoform encodes a DNA-binding protein that binds the promoters of active X chromosomal genes. Expressing male SOA is sufficient to induce DC in female cells. Male mosquitoes lacking SOA or female mosquitoes ectopically expressing the male isoform exhibit X chromosome misregulation, which is compatible with viability but causes developmental delay. Thus, our molecular analyses of a DC master regulator in a non-model organism elucidates the evolutionary steps that lead to the establishment of a chromosome-specific fine-tuning mechanism.
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Affiliation(s)
| | - Eric Marois
- INSERM U1257, CNRS UPR9022, Université de Strasbourg, Strasbourg, France
| | - Magdalena Kozielska
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, Netherlands
| | - Franz J Weissing
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, Netherlands
| | - Etienne Jaouen
- INSERM U1257, CNRS UPR9022, Université de Strasbourg, Strasbourg, France
| | | | - Frank Rühle
- Institute of Molecular Biology (IMB), Mainz, Germany
| | - Falk Butter
- Institute of Molecular Biology (IMB), Mainz, Germany
- Institute of Molecular Virology and Cell Biology, Friedrich Loeffler Institute, Greifswald, Germany
| | - M Felicia Basilicata
- Institute of Molecular Biology (IMB), Mainz, Germany
- Institute of Human Genetics, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
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8
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Eggers N, Gkountromichos F, Krause S, Campos-Sparr A, Becker P. Physical interaction between MSL2 and CLAMP assures direct cooperativity and prevents competition at composite binding sites. Nucleic Acids Res 2023; 51:9039-9054. [PMID: 37602401 PMCID: PMC10516644 DOI: 10.1093/nar/gkad680] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Revised: 07/13/2023] [Accepted: 08/09/2023] [Indexed: 08/22/2023] Open
Abstract
MSL2, the DNA-binding subunit of the Drosophila dosage compensation complex, cooperates with the ubiquitous protein CLAMP to bind MSL recognition elements (MREs) on the X chromosome. We explore the nature of the cooperative binding to these GA-rich, composite sequence elements in reconstituted naïve embryonic chromatin. We found that the cooperativity requires physical interaction between both proteins. Remarkably, disruption of this interaction does not lead to indirect, nucleosome-mediated cooperativity as expected, but to competition. The protein interaction apparently not only increases the affinity for composite binding sites, but also locks both proteins in a defined dimeric state that prevents competition. High Affinity Sites of MSL2 on the X chromosome contain variable numbers of MREs. We find that the cooperation between MSL2/CLAMP is not influenced by MRE clustering or arrangement, but happens largely at the level of individual MREs. The sites where MSL2/CLAMP bind strongly in vitro locate to all chromosomes and show little overlap to an expanded set of X-chromosomal MSL2 in vivo binding sites generated by CUT&RUN. Apparently, the intrinsic MSL2/CLAMP cooperativity is limited to a small selection of potential sites in vivo. This restriction must be due to components missing in our reconstitution, such as roX2 lncRNA.
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Affiliation(s)
- Nikolas Eggers
- Biomedical Center, Molecular Biology Division, LMU, Munich, Germany
| | | | - Silke Krause
- Biomedical Center, Molecular Biology Division, LMU, Munich, Germany
| | | | - Peter B Becker
- Biomedical Center, Molecular Biology Division, LMU, Munich, Germany
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9
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Schede HH, Natarajan P, Chakraborty AK, Shrinivas K. A model for organization and regulation of nuclear condensates by gene activity. Nat Commun 2023; 14:4152. [PMID: 37438363 DOI: 10.1038/s41467-023-39878-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Accepted: 07/03/2023] [Indexed: 07/14/2023] Open
Abstract
Condensation by phase separation has recently emerged as a mechanism underlying many nuclear compartments essential for cellular functions. Nuclear condensates enrich nucleic acids and proteins, localize to specific genomic regions, and often promote gene expression. How diverse properties of nuclear condensates are shaped by gene organization and activity is poorly understood. Here, we develop a physics-based model to interrogate how spatially-varying transcription activity impacts condensate properties and dynamics. Our model predicts that spatial clustering of active genes can enable precise localization and de novo nucleation of condensates. Strong clustering and high activity results in aspherical condensate morphologies. Condensates can flow towards distant gene clusters and competition between multiple clusters lead to stretched morphologies and activity-dependent repositioning. Overall, our model predicts and recapitulates morphological and dynamical features of diverse nuclear condensates and offers a unified mechanistic framework to study the interplay between non-equilibrium processes, spatially-varying transcription, and multicomponent condensates in cell biology.
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Affiliation(s)
- Halima H Schede
- School of Life Sciences, École Polytechnique Fédérale Lausanne, CH-1015, Lausanne, Switzerland
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Pradeep Natarajan
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Arup K Chakraborty
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
- Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, MA, USA
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA, USA
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Krishna Shrinivas
- NSF-Simons Center for Mathematical & Statistical Analysis of Biology, Harvard University, Cambridge, MA, USA.
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10
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Mattick JS, Amaral PP, Carninci P, Carpenter S, Chang HY, Chen LL, Chen R, Dean C, Dinger ME, Fitzgerald KA, Gingeras TR, Guttman M, Hirose T, Huarte M, Johnson R, Kanduri C, Kapranov P, Lawrence JB, Lee JT, Mendell JT, Mercer TR, Moore KJ, Nakagawa S, Rinn JL, Spector DL, Ulitsky I, Wan Y, Wilusz JE, Wu M. Long non-coding RNAs: definitions, functions, challenges and recommendations. Nat Rev Mol Cell Biol 2023; 24:430-447. [PMID: 36596869 PMCID: PMC10213152 DOI: 10.1038/s41580-022-00566-8] [Citation(s) in RCA: 323] [Impact Index Per Article: 323.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/16/2022] [Indexed: 01/05/2023]
Abstract
Genes specifying long non-coding RNAs (lncRNAs) occupy a large fraction of the genomes of complex organisms. The term 'lncRNAs' encompasses RNA polymerase I (Pol I), Pol II and Pol III transcribed RNAs, and RNAs from processed introns. The various functions of lncRNAs and their many isoforms and interleaved relationships with other genes make lncRNA classification and annotation difficult. Most lncRNAs evolve more rapidly than protein-coding sequences, are cell type specific and regulate many aspects of cell differentiation and development and other physiological processes. Many lncRNAs associate with chromatin-modifying complexes, are transcribed from enhancers and nucleate phase separation of nuclear condensates and domains, indicating an intimate link between lncRNA expression and the spatial control of gene expression during development. lncRNAs also have important roles in the cytoplasm and beyond, including in the regulation of translation, metabolism and signalling. lncRNAs often have a modular structure and are rich in repeats, which are increasingly being shown to be relevant to their function. In this Consensus Statement, we address the definition and nomenclature of lncRNAs and their conservation, expression, phenotypic visibility, structure and functions. We also discuss research challenges and provide recommendations to advance the understanding of the roles of lncRNAs in development, cell biology and disease.
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Affiliation(s)
- John S Mattick
- School of Biotechnology and Biomolecular Sciences, UNSW, Sydney, NSW, Australia.
- UNSW RNA Institute, UNSW, Sydney, NSW, Australia.
| | - Paulo P Amaral
- INSPER Institute of Education and Research, São Paulo, Brazil
| | - Piero Carninci
- RIKEN Center for Integrative Medical Sciences, Yokohama, Japan
- Human Technopole, Milan, Italy
| | - Susan Carpenter
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Cruz, Santa Cruz, CA, USA
| | - Howard Y Chang
- Center for Personal Dynamics Regulomes, Stanford University School of Medicine, Stanford, CA, USA
- Department of Dermatology, Stanford, CA, USA
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
- Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA, USA
| | - Ling-Ling Chen
- CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai, China
| | - Runsheng Chen
- Key Laboratory of RNA Biology, Center for Big Data Research in Health, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Caroline Dean
- John Innes Centre, Norwich Research Park, Norwich, UK
| | - Marcel E Dinger
- School of Biotechnology and Biomolecular Sciences, UNSW, Sydney, NSW, Australia
- UNSW RNA Institute, UNSW, Sydney, NSW, Australia
| | - Katherine A Fitzgerald
- Division of Innate Immunity, Department of Medicine, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | | | - Mitchell Guttman
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Tetsuro Hirose
- Graduate School of Frontier Biosciences, Osaka University, Osaka, Japan
| | - Maite Huarte
- Department of Gene Therapy and Regulation of Gene Expression, Center for Applied Medical Research, University of Navarra, Pamplona, Spain
- Institute of Health Research of Navarra, Pamplona, Spain
| | - Rory Johnson
- School of Biology and Environmental Science, University College Dublin, Dublin, Ireland
- Conway Institute for Biomolecular and Biomedical Research, University College Dublin, Dublin, Ireland
| | - Chandrasekhar Kanduri
- Department of Medical Biochemistry and Cell Biology, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Philipp Kapranov
- Institute of Genomics, School of Medicine, Huaqiao University, Xiamen, China
| | - Jeanne B Lawrence
- Department of Neurology, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Jeannie T Lee
- Department of Molecular Biology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
- Department of Genetics, Harvard Medical School, Boston, MA, USA
| | - Joshua T Mendell
- Howard Hughes Medical Institute, UT Southwestern Medical Center, Dallas, TX, USA
- Department of Molecular Biology, UT Southwestern Medical Center, Dallas, TX, USA
| | - Timothy R Mercer
- Australian Institute for Bioengineering and Nanotechnology, University of Queensland, Brisbane, QLD, Australia
| | - Kathryn J Moore
- Department of Medicine, New York University Grossman School of Medicine, New York, NY, USA
| | - Shinichi Nakagawa
- RNA Biology Laboratory, Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo, Japan
| | - John L Rinn
- Department of Biochemistry, University of Colorado Boulder, Boulder, CO, USA
- BioFrontiers Institute, University of Colorado Boulder, Boulder, CO, USA
- Howard Hughes Medical Institute, University of Colorado Boulder, Boulder, CO, USA
| | - David L Spector
- Cold Spring Harbour Laboratory, Cold Spring Harbour, NY, USA
| | - Igor Ulitsky
- Department of Biological Regulation, Weizmann Institute of Science, Rehovot, Israel
| | - Yue Wan
- Laboratory of RNA Genomics and Structure, Genome Institute of Singapore, A*STAR, Singapore, Singapore
- Department of Biochemistry, National University of Singapore, Singapore, Singapore
| | - Jeremy E Wilusz
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Therapeutic Innovation Center, Baylor College of Medicine, Houston, TX, USA
| | - Mian Wu
- Translational Research Institute, Henan Provincial People's Hospital, Academy of Medical Science, Zhengzhou University, Zhengzhou, China
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11
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Forbes Beadle L, Zhou H, Rattray M, Ashe HL. Modulation of transcription burst amplitude underpins dosage compensation in the Drosophila embryo. Cell Rep 2023; 42:112382. [PMID: 37060568 PMCID: PMC10283159 DOI: 10.1016/j.celrep.2023.112382] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Revised: 02/03/2023] [Accepted: 03/27/2023] [Indexed: 04/16/2023] Open
Abstract
Dosage compensation, the balancing of X-linked gene expression between sexes and to the autosomes, is critical to an organism's fitness and survival. In Drosophila, dosage compensation involves hypertranscription of the male X chromosome. Here, we use quantitative live imaging and modeling at single-cell resolution to study X chromosome dosage compensation in Drosophila. We show that the four X chromosome genes studied undergo transcriptional bursting in male and female embryos. Mechanistically, our data reveal that transcriptional upregulation of male X chromosome genes is primarily mediated by a higher RNA polymerase II initiation rate and burst amplitude across the expression domain. In contrast, burst frequency is spatially modulated in nuclei within the expression domain in response to different transcription factor concentrations to tune the transcriptional response. Together, these data show how the local and global regulation of distinct burst parameters can establish the complex transcriptional outputs underpinning developmental patterning.
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Affiliation(s)
- Lauren Forbes Beadle
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester M13 9PT, UK
| | - Hongpeng Zhou
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester M13 9PT, UK
| | - Magnus Rattray
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester M13 9PT, UK.
| | - Hilary L Ashe
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester M13 9PT, UK.
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12
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Ilık İA, Aktaş T. Nuclear speckles: dynamic hubs of gene expression regulation. FEBS J 2022; 289:7234-7245. [PMID: 34245118 DOI: 10.1111/febs.16117] [Citation(s) in RCA: 37] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Revised: 06/13/2021] [Accepted: 07/08/2021] [Indexed: 01/13/2023]
Abstract
Complex, multistep biochemical reactions that routinely take place in our cells require high concentrations of enzymes, substrates, and other structural components to proceed efficiently and typically require chemical environments that can inhibit other reactions in their immediate vicinity. Eukaryotic cells solve these problems by restricting such reactions into diffusion-restricted compartments within the cell called organelles that can be separated from their environment by a lipid membrane, or into membrane-less compartments that form through liquid-liquid phase separation (LLPS). One of the most easily noticeable and the earliest discovered organelle is the nucleus, which harbors the genetic material in cells where transcription by RNA polymerases produces most of the messenger RNAs and a plethora of noncoding RNAs, which in turn are required for translation of mRNAs in the cytoplasm. The interior of the nucleus is not a uniform soup of biomolecules and rather consists of a variety of membrane-less bodies, such as the nucleolus, nuclear speckles (NS), paraspeckles, Cajal bodies, histone locus bodies, and more. In this review, we will focus on NS with an emphasis on recent developments including our own findings about the formation of NS by two large IDR-rich proteins SON and SRRM2.
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Affiliation(s)
| | - Tuğçe Aktaş
- Max Planck Institute for Molecular Genetics, Berlin, Germany
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13
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Dosage Compensation in Drosophila: Its Canonical and Non-Canonical Mechanisms. Int J Mol Sci 2022; 23:ijms231810976. [PMID: 36142884 PMCID: PMC9506574 DOI: 10.3390/ijms231810976] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 09/16/2022] [Accepted: 09/17/2022] [Indexed: 11/17/2022] Open
Abstract
Dosage compensation equalizes gene expression in a single male X chromosome with that in the pairs of autosomes and female X chromosomes. In the fruit fly Drosophila, canonical dosage compensation is implemented by the male-specific lethal (MSL) complex functioning in all male somatic cells. This complex contains acetyl transferase males absent on the first (MOF), which performs H4K16 hyperacetylation specifically in the male X chromosome, thus facilitating transcription of the X-linked genes. However, accumulating evidence points to an existence of additional, non-canonical dosage compensation mechanisms operating in somatic and germline cells. In this review, we discuss current advances in the understanding of both canonical and non-canonical mechanisms of dosage compensation in Drosophila.
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14
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Arora R, Bodak M, Penouty L, Hackman C, Ciaudo C. Sequestration of
LINE
‐1 in cytosolic aggregates by
MOV10
restricts retrotransposition. EMBO Rep 2022; 23:e54458. [PMID: 35856394 PMCID: PMC9442310 DOI: 10.15252/embr.202154458] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Revised: 06/22/2022] [Accepted: 06/30/2022] [Indexed: 11/09/2022] Open
Affiliation(s)
- Rajika Arora
- Swiss Federal Institute of Technology Zurich IMHS, Chair of RNAi and Genome Integrity Zurich Switzerland
| | - Maxime Bodak
- Swiss Federal Institute of Technology Zurich IMHS, Chair of RNAi and Genome Integrity Zurich Switzerland
| | - Laura Penouty
- Swiss Federal Institute of Technology Zurich IMHS, Chair of RNAi and Genome Integrity Zurich Switzerland
| | - Cindy Hackman
- Swiss Federal Institute of Technology Zurich IMHS, Chair of RNAi and Genome Integrity Zurich Switzerland
| | - Constance Ciaudo
- Swiss Federal Institute of Technology Zurich IMHS, Chair of RNAi and Genome Integrity Zurich Switzerland
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15
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Ross CJ, Ulitsky I. Discovering functional motifs in long noncoding RNAs. WILEY INTERDISCIPLINARY REVIEWS. RNA 2022; 13:e1708. [PMID: 34981665 DOI: 10.1002/wrna.1708] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 11/19/2021] [Accepted: 12/04/2021] [Indexed: 12/27/2022]
Abstract
Long noncoding RNAs (lncRNAs) are products of pervasive transcription that closely resemble messenger RNAs on the molecular level, yet function through largely unknown modes of action. The current model is that the function of lncRNAs often relies on specific, typically short, conserved elements, connected by linkers in which specific sequences and/or structures are less important. This notion has fueled the development of both computational and experimental methods focused on the discovery of functional elements within lncRNA genes, based on diverse signals such as evolutionary conservation, predicted structural elements, or the ability to rescue loss-of-function phenotypes. In this review, we outline the main challenges that the different methods need to overcome, describe the recently developed approaches, and discuss their respective limitations. This article is categorized under: RNA Evolution and Genomics > Computational Analyses of RNA RNA Interactions with Proteins and Other Molecules > Protein-RNA Interactions: Functional Implications Regulatory RNAs/RNAi/Riboswitches > Regulatory RNAs.
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Affiliation(s)
- Caroline Jane Ross
- Biological Regulation and Molecular Neuroscience, Weizmann Institute of Science, Rehovot, Israel
| | - Igor Ulitsky
- Biological Regulation and Molecular Neuroscience, Weizmann Institute of Science, Rehovot, Israel
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16
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Tikhonova E, Mariasina S, Efimov S, Polshakov V, Maksimenko O, Georgiev P, Bonchuk A. Structural basis for interaction between CLAMP and MSL2 proteins involved in the specific recruitment of the dosage compensation complex in Drosophila. Nucleic Acids Res 2022; 50:6521-6531. [PMID: 35648444 PMCID: PMC9226498 DOI: 10.1093/nar/gkac455] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Revised: 04/26/2022] [Accepted: 05/30/2022] [Indexed: 12/02/2022] Open
Abstract
Transcriptional regulators select their targets from a large pool of similar genomic sites. The binding of the Drosophila dosage compensation complex (DCC) exclusively to the male X chromosome provides insight into binding site selectivity rules. Previous studies showed that the male-specific organizer of the complex, MSL2, and ubiquitous DNA-binding protein CLAMP directly interact and play an important role in the specificity of X chromosome binding. Here, we studied the highly specific interaction between the intrinsically disordered region of MSL2 and the N-terminal zinc-finger C2H2-type (C2H2) domain of CLAMP. We obtained the NMR structure of the CLAMP N-terminal C2H2 zinc finger, which has a classic C2H2 zinc-finger fold with a rather unusual distribution of residues typically used in DNA recognition. Substitutions of residues in this C2H2 domain had the same effect on the viability of males and females, suggesting that it plays a general role in CLAMP activity. The N-terminal C2H2 domain of CLAMP is highly conserved in insects. However, the MSL2 region involved in the interaction is conserved only within the Drosophila genus, suggesting that this interaction emerged during the evolution of a mechanism for the specific recruitment of the DCC on the male X chromosome in Drosophilidae.
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Affiliation(s)
- Evgeniya Tikhonova
- Department of the Control of Genetic Processes, Institute of Gene Biology, Moscow 119334, Russia
| | - Sofia Mariasina
- Center for Magnetic Tomography and Spectroscopy, Faculty of Fundamental Medicine, M.V. Lomonosov Moscow State University, Moscow 119991, Russia
| | - Sergey Efimov
- NMR Laboratory, Institute of Physics, Kazan Federal University, Kazan 420008, Russia
| | - Vladimir Polshakov
- Center for Magnetic Tomography and Spectroscopy, Faculty of Fundamental Medicine, M.V. Lomonosov Moscow State University, Moscow 119991, Russia
| | - Oksana Maksimenko
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Institute of Gene Biology, Moscow 119334, Russia
| | - Pavel Georgiev
- Department of the Control of Genetic Processes, Institute of Gene Biology, Moscow 119334, Russia
| | - Artem Bonchuk
- Department of the Control of Genetic Processes, Institute of Gene Biology, Moscow 119334, Russia.,Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Institute of Gene Biology, Moscow 119334, Russia
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17
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Tikhonova E, Mariasina S, Arkova O, Maksimenko O, Georgiev P, Bonchuk A. Dimerization Activity of a Disordered N-Terminal Domain from Drosophila CLAMP Protein. Int J Mol Sci 2022; 23:ijms23073862. [PMID: 35409222 PMCID: PMC8998743 DOI: 10.3390/ijms23073862] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 03/24/2022] [Accepted: 03/28/2022] [Indexed: 12/15/2022] Open
Abstract
In Drosophila melanogaster, CLAMP is an essential zinc-finger transcription factor that is involved in chromosome architecture and functions as an adaptor for the dosage compensation complex. Most of the known Drosophila architectural proteins have structural N-terminal homodimerization domains that facilitate distance interactions. Because CLAMP performs architectural functions, we tested its N-terminal region for the presence of a homodimerization domain. We used a yeast two-hybrid assay and biochemical studies to demonstrate that the adjacent N-terminal region between 46 and 86 amino acids is capable of forming homodimers. This region is conserved in CLAMP orthologs from most insects, except Hymenopterans. Biophysical techniques, including nuclear magnetic resonance (NMR) and small-angle X-ray scattering (SAXS), suggested that this domain lacks secondary structure and has features of intrinsically disordered regions despite the fact that the protein structure prediction algorithms suggested the presence of beta-sheets. The dimerization domain is essential for CLAMP functions in vivo because its deletion results in lethality. Thus, CLAMP is the second architectural protein after CTCF that contains an unstructured N-terminal dimerization domain.
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Affiliation(s)
- Evgeniya Tikhonova
- Department of the Control of Genetic Processes, Institute of Gene Biology, Russian Academy of Sciences, 119334 Moscow, Russia;
| | - Sofia Mariasina
- Center for Magnetic Tomography and Spectroscopy, Faculty of Fundamental Medicine, M.V. Lomonosov Moscow State University, 119991 Moscow, Russia;
| | - Olga Arkova
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Institute of Gene Biology, Russian Academy of Sciences, 119334 Moscow, Russia; (O.A.); (O.M.)
| | - Oksana Maksimenko
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Institute of Gene Biology, Russian Academy of Sciences, 119334 Moscow, Russia; (O.A.); (O.M.)
| | - Pavel Georgiev
- Department of the Control of Genetic Processes, Institute of Gene Biology, Russian Academy of Sciences, 119334 Moscow, Russia;
- Correspondence: (P.G.); (A.B.)
| | - Artem Bonchuk
- Department of the Control of Genetic Processes, Institute of Gene Biology, Russian Academy of Sciences, 119334 Moscow, Russia;
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Institute of Gene Biology, Russian Academy of Sciences, 119334 Moscow, Russia; (O.A.); (O.M.)
- Correspondence: (P.G.); (A.B.)
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18
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Cao H, Kapranov P. Methods to Analyze the Non-Coding RNA Interactome—Recent Advances and Challenges. Front Genet 2022; 13:857759. [PMID: 35368711 PMCID: PMC8969105 DOI: 10.3389/fgene.2022.857759] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Accepted: 02/15/2022] [Indexed: 12/03/2022] Open
Abstract
Most of the human genome is transcribed to generate a multitude of non-coding RNAs. However, while these transcripts have generated an immense amount of scientific interest, their biological function remains a subject of an intense debate. Understanding mechanisms of action of non-coding RNAs is a key to addressing the issue of biological relevance of these transcripts. Based on some well-understood non-coding RNAs that function inside the cell by interacting with other molecules, it is generally believed many other non-coding transcripts could also function in a similar fashion. Therefore, development of methods that can map RNA interactome is the key to understanding functionality of the extensive cellular non-coding transcriptome. Here, we review the vast progress that has been made in the past decade in technologies that can map RNA interactions with different sites in DNA, proteins or other RNA molecules; the general approaches used to validate the existence of novel interactions; and the challenges posed by interpreting the data obtained using the interactome mapping methods.
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19
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When Down Is Up: Heterochromatin, Nuclear Organization and X Upregulation. Cells 2021; 10:cells10123416. [PMID: 34943924 PMCID: PMC8700316 DOI: 10.3390/cells10123416] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Revised: 11/29/2021] [Accepted: 12/01/2021] [Indexed: 12/21/2022] Open
Abstract
Organisms with highly differentiated sex chromosomes face an imbalance in X-linked gene dosage. Male Drosophila solve this problem by increasing expression from virtually every gene on their single X chromosome, a process known as dosage compensation. This involves a ribonucleoprotein complex that is recruited to active, X-linked genes to remodel chromatin and increase expression. Interestingly, the male X chromosome is also enriched for several proteins associated with heterochromatin. Furthermore, the polytenized male X is selectively disrupted by the loss of factors involved in repression, silencing, heterochromatin formation or chromatin remodeling. Mutations in many of these factors preferentially reduce male survival or enhance the lethality of mutations that prevent normal recognition of the X chromosome. The involvement of primarily repressive factors in a process that elevates expression has long been puzzling. Interestingly, recent work suggests that the siRNA pathway, often associated with heterochromatin formation and repression, also helps the dosage compensation machinery identify the X chromosome. In light of this finding, we revisit the evidence that links nuclear organization and heterochromatin to regulation of the male X chromosome.
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20
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Birchler JA, Veitia RA. One Hundred Years of Gene Balance: How Stoichiometric Issues Affect Gene Expression, Genome Evolution, and Quantitative Traits. Cytogenet Genome Res 2021; 161:529-550. [PMID: 34814143 DOI: 10.1159/000519592] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Accepted: 09/13/2021] [Indexed: 11/19/2022] Open
Abstract
A century ago experiments with the flowering plant Datura stramonium and the fruit fly Drosophila melanogaster revealed that adding an extra chromosome to a karyotype was much more detrimental than adding a whole set of chromosomes. This phenomenon was referred to as gene balance and has been recapitulated across eukaryotic species. Here, we retrace some developments in this field. Molecular studies suggest that the basis of balance involves stoichiometric relationships of multi-component interactions. This concept has implication for the mechanisms controlling gene expression, genome evolution, sex chromosome evolution/dosage compensation, speciation mechanisms, and the underlying genetics of quantitative traits.
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Affiliation(s)
- James A Birchler
- Division of Biological Sciences, University of Missouri, Columbia, Missouri, USA
| | - Reiner A Veitia
- Université de Paris, Paris, France.,Institut Jacques Monod, Université de Paris/CNRS, Paris, France.,Institut de Biologie F. Jacob, Commissariat à l'Energie Atomique, Université Paris-Saclay, Fontenay aux Roses, France
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21
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Dasmeh P, Wagner A. Yeast Proteins may Reversibly Aggregate like Amphiphilic Molecules. J Mol Biol 2021; 434:167352. [PMID: 34774567 DOI: 10.1016/j.jmb.2021.167352] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Revised: 10/18/2021] [Accepted: 11/07/2021] [Indexed: 11/30/2022]
Abstract
More than a hundred proteins in yeast reversibly aggregate and phase-separate in response to various stressors, such as nutrient depletion and heat shock. We know little about the protein sequence and structural features behind this ability, which has not been characterized on a proteome-wide level. To identify the distinctive features of aggregation-prone protein regions, we apply machine learning algorithms to genome-scale limited proteolysis-mass spectrometry (LiP-MS) data from yeast proteins. LiP-MS data reveals that 96 proteins show significant structural changes upon heat shock. We find that in these proteins the propensity to phase separate cannot be solely driven by disordered regions, because their aggregation-prone regions (APRs) are not significantly disordered. Instead, the phase separation of these proteins requires contributions from both disordered and structured regions. APRs are significantly enriched in aliphatic residues and depleted in positively charged amino acids. Aggregator proteins with longer APRs show a greater propensity to aggregate, a relationship that can be explained by equilibrium statistical thermodynamics. Altogether, our observations suggest that proteome-wide reversible protein aggregation is mediated by sequence-encoded properties. We propose that aggregating proteins resemble supra-molecular amphiphiles, where APRs are the hydrophobic parts, and non-APRs are the hydrophilic parts.
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Affiliation(s)
- Pouria Dasmeh
- Institute for Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland; Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02139, USA; Swiss Institute of Bioinformatics (SIB), Switzerland.
| | - Andreas Wagner
- Institute for Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland; The Santa Fe Institute, Santa Fe, NM, USA; Swiss Institute of Bioinformatics (SIB), Switzerland; Stellenbosch Institute for Advanced Study (STIAS), Wallenberg Research Centre at Stellenbosch University, Stellenbosch 7600, South Africa.
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22
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Shared evolutionary trajectories of three independent neo-sex chromosomes in Drosophila. Genome Res 2021; 31:2069-2079. [PMID: 34675069 PMCID: PMC8559708 DOI: 10.1101/gr.275503.121] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Accepted: 07/22/2021] [Indexed: 11/25/2022]
Abstract
Dosage compensation (DC) on the X Chromosome counteracts the deleterious effects of gene loss on the Y Chromosome. However, DC is not efficient if the X Chromosome also degenerates. This indeed occurs in Drosophila miranda, in which both the neo-Y and the neo-X are under accelerated pseudogenization. To examine the generality of this pattern, we investigated the evolution of two additional neo-sex chromosomes that emerged independently in D. albomicans and D. americana and reanalyzed neo-sex chromosome evolution in D. miranda. Comparative genomic and transcriptomic analyses revealed that the pseudogenization rate on the neo-X is also accelerated in D. albomicans and D. americana although to a lesser extent than in D. miranda. In males, neo-X-linked genes whose neo-Y-linked homologs are pseudogenized tended to be up-regulated more than those whose neo-Y-linked homologs remain functional. Moreover, genes under strong functional constraint and genes highly expressed in the testis tended to remain functional on the neo-X and neo-Y, respectively. Focusing on the D. miranda and D. albomicans neo-sex chromosomes that emerged independently from the same autosome, we further found that the same genes tend to become pseudogenized in parallel on the neo-Y. These genes include Idgf6 and JhI-26, which may be unnecessary or even harmful in males. Our results indicate that neo-sex chromosomes in Drosophila share a common evolutionary trajectory after their emergence, which may prevent sex chromosomes from being an evolutionary dead end.
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23
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Lindehell H, Glotov A, Dorafshan E, Schwartz YB, Larsson J. The role of H3K36 methylation and associated methyltransferases in chromosome-specific gene regulation. SCIENCE ADVANCES 2021; 7:eabh4390. [PMID: 34597135 PMCID: PMC10938550 DOI: 10.1126/sciadv.abh4390] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Accepted: 08/11/2021] [Indexed: 06/13/2023]
Abstract
In Drosophila, two chromosomes require special mechanisms to balance their transcriptional output to the rest of the genome. These are the male-specific lethal complex targeting the male X chromosome and Painting of fourth targeting chromosome 4. Here, we explore the role of histone H3 methylated at lysine-36 (H3K36) and the associated methyltransferases—Set2, NSD, and Ash1—in these two chromosome-specific systems. We show that the loss of Set2 impairs the MSL complex–mediated dosage compensation; however, the effect is not recapitulated by H3K36 replacement and indicates an alternative target of Set2. Unexpectedly, balanced transcriptional output from the fourth chromosome requires intact H3K36 and depends on the additive functions of NSD and Ash1. We conclude that H3K36 methylation and the associated methyltransferases are important factors to balance transcriptional output of the male X chromosome and the fourth chromosome. Furthermore, our study highlights the pleiotropic effects of these enzymes.
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Affiliation(s)
- Henrik Lindehell
- Department of Molecular Biology, Umeå University, SE-90187 Umeå, Sweden
| | - Alexander Glotov
- Department of Molecular Biology, Umeå University, SE-90187 Umeå, Sweden
| | - Eshagh Dorafshan
- Department of Molecular Biology, Umeå University, SE-90187 Umeå, Sweden
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24
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Eggers N, Becker PB. Cell-free genomics reveal intrinsic, cooperative and competitive determinants of chromatin interactions. Nucleic Acids Res 2021; 49:7602-7617. [PMID: 34181732 PMCID: PMC8287947 DOI: 10.1093/nar/gkab558] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Revised: 06/08/2021] [Accepted: 06/21/2021] [Indexed: 11/13/2022] Open
Abstract
Metazoan transcription factors distinguish their response elements from a large excess of similar sequences. We explored underlying principles of DNA shape read-out and factor cooperativity in chromatin using a unique experimental system. We reconstituted chromatin on Drosophila genomes in extracts of preblastoderm embryos, mimicking the naïve state of the zygotic genome prior to developmental transcription activation. We then compared the intrinsic binding specificities of three recombinant transcription factors, alone and in combination, with GA-rich recognition sequences genome-wide. For MSL2, all functional elements reside on the X chromosome, allowing to distinguish physiological elements from non-functional 'decoy' sites. The physiological binding profile of MSL2 is approximated through interaction with other factors: cooperativity with CLAMP and competition with GAF, which sculpts the profile by occluding non-functional sites. An extended DNA shape signature is differentially read out in chromatin. Our results reveal novel aspects of target selection in a complex chromatin environment.
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Affiliation(s)
- Nikolas Eggers
- Biomedical Center, Molecular Biology Division, Ludwig-Maximilians-Universität, 82152 Planegg, Germany
| | - Peter B Becker
- Biomedical Center, Molecular Biology Division, Ludwig-Maximilians-Universität, 82152 Planegg, Germany
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25
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Nuclear compartmentalization as a mechanism of quantitative control of gene expression. Nat Rev Mol Cell Biol 2021; 22:653-670. [PMID: 34341548 DOI: 10.1038/s41580-021-00387-1] [Citation(s) in RCA: 111] [Impact Index Per Article: 37.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/28/2021] [Indexed: 01/08/2023]
Abstract
Gene regulation requires the dynamic coordination of hundreds of regulatory factors at precise genomic and RNA targets. Although many regulatory factors have specific affinity for their nucleic acid targets, molecular diffusion and affinity models alone cannot explain many of the quantitative features of gene regulation in the nucleus. One emerging explanation for these quantitative properties is that DNA, RNA and proteins organize within precise, 3D compartments in the nucleus to concentrate groups of functionally related molecules. Recently, nucleic acids and proteins involved in many important nuclear processes have been shown to engage in cooperative interactions, which lead to the formation of condensates that partition the nucleus. In this Review, we discuss an emerging perspective of gene regulation, which moves away from classic models of stoichiometric interactions towards an understanding of how spatial compartmentalization can lead to non-stoichiometric molecular interactions and non-linear regulatory behaviours. We describe key mechanisms of nuclear compartment formation, including emerging roles for non-coding RNAs in facilitating their formation, and discuss the functional role of nuclear compartments in transcription regulation, co-transcriptional and post-transcriptional RNA processing, and higher-order chromatin regulation. More generally, we discuss how compartmentalization may explain important quantitative aspects of gene regulation.
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26
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Keller Valsecchi CI, Marois E, Basilicata MF, Georgiev P, Akhtar A. Distinct mechanisms mediate X chromosome dosage compensation in Anopheles and Drosophila. Life Sci Alliance 2021; 4:4/9/e202000996. [PMID: 34266874 PMCID: PMC8321682 DOI: 10.26508/lsa.202000996] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Revised: 06/27/2021] [Accepted: 06/28/2021] [Indexed: 12/14/2022] Open
Abstract
CRISPR knockout of msl-2 and epigenome analyses in Anopheles reveal that X chromosome dosage compensation in mosquitos and Drosophila is achieved by two different molecular mechanisms. Sex chromosomes induce potentially deleterious gene expression imbalances that are frequently corrected by dosage compensation (DC). Three distinct molecular strategies to achieve DC have been previously described in nematodes, fruit flies, and mammals. Is this a consequence of distinct genomes, functional or ecological constraints, or random initial commitment to an evolutionary trajectory? Here, we study DC in the malaria mosquito Anopheles gambiae. The Anopheles and Drosophila X chromosomes evolved independently but share a high degree of homology. We find that Anopheles achieves DC by a mechanism distinct from the Drosophila MSL complex–histone H4 lysine 16 acetylation pathway. CRISPR knockout of Anopheles msl-2 leads to embryonic lethality in both sexes. Transcriptome analyses indicate that this phenotype is not a consequence of defective X chromosome DC. By immunofluorescence and ChIP, H4K16ac does not preferentially enrich on the male X. Instead, the mosquito MSL pathway regulates conserved developmental genes. We conclude that a novel mechanism confers X chromosome up-regulation in Anopheles. Our findings highlight the pluralism of gene-dosage buffering mechanisms even under similar genomic and functional constraints.
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Affiliation(s)
| | - Eric Marois
- Université de Strasbourg, Centre National de la Recherche Scientifique (CNRS) UPR9022, Inserm U1257, Strasbourg, France
| | - M Felicia Basilicata
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany.,Institute of Molecular Biology (IMB), Mainz, Germany
| | - Plamen Georgiev
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany
| | - Asifa Akhtar
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany
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Razin SV, Gavrilov AA. Non-coding RNAs in chromatin folding and nuclear organization. Cell Mol Life Sci 2021; 78:5489-5504. [PMID: 34117518 PMCID: PMC11072467 DOI: 10.1007/s00018-021-03876-w] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 04/24/2021] [Accepted: 06/05/2021] [Indexed: 12/19/2022]
Abstract
One of the most intriguing questions facing modern biology concerns how the genome directs the construction of cells, tissues, and whole organisms. It is tempting to suggest that the part of the genome that does not encode proteins contains architectural plans. We are still far from understanding how these plans work at the level of building tissues and the body as a whole. However, the results of recent studies demonstrate that at the cellular level, special non-coding RNAs serve as scaffolds for the construction of various intracellular structures. The term "architectural RNAs" was proposed to designate this subset of non-coding RNAs. In this review, we discuss the role of architectural RNAs in the construction of the cell nucleus and maintenance of the three-dimensional organization of the genome.
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Affiliation(s)
- Sergey V Razin
- Institute of Gene Biology, Russian Academy of Sciences, 119334, Moscow, Russia.
- Faculty of Biology, M. V. Lomonosov Moscow State University, 119234, Moscow, Russia.
| | - Alexey A Gavrilov
- Institute of Gene Biology, Russian Academy of Sciences, 119334, Moscow, Russia
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Institute of Gene Biology, Russian Academy of Sciences, 119334, Moscow, Russia
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28
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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: 6] [Impact Index Per Article: 2.0] [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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