1
|
Krasnov AN, Evdokimova AA, Mazina MY, Erokhin M, Chetverina D, Vorobyeva NE. Coregulators Reside within Drosophila Ecdysone-Inducible Loci before and after Ecdysone Treatment. Int J Mol Sci 2023; 24:11844. [PMID: 37511602 PMCID: PMC10380596 DOI: 10.3390/ijms241411844] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Revised: 07/19/2023] [Accepted: 07/21/2023] [Indexed: 07/30/2023] Open
Abstract
Ecdysone signaling in Drosophila remains a popular model for investigating the mechanisms of steroid action in eukaryotes. The ecdysone receptor EcR can effectively bind ecdysone-response elements with or without the presence of a hormone. For years, EcR enhancers were thought to respond to ecdysone via recruiting coactivator complexes, which replace corepressors and stimulate transcription. However, the exact mechanism of transcription activation by ecdysone remains unclear. Here, we present experimental data on 11 various coregulators at ecdysone-responsive loci of Drosophila S2 cells. We describe the regulatory elements where coregulators reside within these loci and assess changes in their binding levels following 20-hydroxyecdysone treatment. In the current study, we detected the presence of some coregulators at the TSSs (active and inactive) and boundaries marked with CP190 rather than enhancers of the ecdysone-responsive loci where EcR binds. We observed minor changes in the coregulators' binding level. Most were present at inducible loci before and after 20-hydroxyecdysone treatment. Our findings suggest that: (1) coregulators can activate a particular TSS operating from some distal region (which could be an enhancer, boundary regulatory region, or inactive TSS); (2) coregulators are not recruited after 20-hydroxyecdysone treatment to the responsive loci; rather, their functional activity changes (shown as an increase in H3K27 acetylation marks generated by CBP/p300/Nejire acetyltransferase). Taken together, our findings imply that the 20-hydroxyecdysone signal enhances the functional activity of coregulators rather than promoting their binding to regulatory regions during the ecdysone response.
Collapse
Affiliation(s)
- Aleksey N Krasnov
- Institute of Gene Biology, Russian Academy of Sciences, 119334 Moscow, Russia
| | | | - Marina Yu Mazina
- Institute of Gene Biology, Russian Academy of Sciences, 119334 Moscow, Russia
| | - Maksim Erokhin
- Institute of Gene Biology, Russian Academy of Sciences, 119334 Moscow, Russia
| | - Darya Chetverina
- Institute of Gene Biology, Russian Academy of Sciences, 119334 Moscow, Russia
| | - Nadezhda E Vorobyeva
- 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
| |
Collapse
|
2
|
Transcriptional Activation of Ecdysone-Responsive Genes Requires H3K27 Acetylation at Enhancers. Int J Mol Sci 2022; 23:ijms231810791. [PMID: 36142704 PMCID: PMC9502983 DOI: 10.3390/ijms231810791] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2022] [Revised: 09/05/2022] [Accepted: 09/09/2022] [Indexed: 11/23/2022] Open
Abstract
The steroid hormone ecdysone regulates insect development via its nuclear receptor (the EcR protein), which functions as a ligand-dependent transcription factor. The EcR regulates target gene expression by binding to ecdysone response elements (EcREs) in their promoter or enhancer regions. Its role in epigenetic regulation and, particularly, in histone acetylation remains to be clarified. Here, we analyzed the dynamics of histone acetylation and demonstrated that the acetylation of histone H3 on lysine 27 (H3K27) at enhancers was required for the transcriptional activation of ecdysone-responsive genes. Western blotting and ChIP-qPCR revealed that ecdysone altered the acetylation of H3K27. For E75B and Hr4, ecdysone-responsive genes, enhancer activity, and transcription required the histone acetyltransferase activity of the CBP. EcR binding was critical in inducing enhancer activity and H3K27 acetylation. The CREB-binding protein (CBP) HAT domain catalyzed H3K27 acetylation and CBP coactivation with EcR, independent of the presence of ecdysone. Increased H3K27 acetylation promoted chromatin accessibility, with the EcR and CBP mediating a local chromatin opening in response to ecdysone. Hence, epigenetic mechanisms, including the modification of acetylation and chromatin accessibility, controlled ecdysone-dependent gene transcription.
Collapse
|
3
|
Cho Y, Kim G, Park J. Mitochondrial aconitase 1 regulates age-related memory impairment via autophagy/mitophagy-mediated neural plasticity in middle-aged flies. Aging Cell 2021; 20:e13520. [PMID: 34799973 PMCID: PMC8672789 DOI: 10.1111/acel.13520] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Revised: 10/06/2021] [Accepted: 11/03/2021] [Indexed: 01/24/2023] Open
Abstract
Age‐related memory impairment (AMI) occurs in many species, including humans. The underlying mechanisms are not fully understood. In wild‐type Drosophila (w1118), AMI appears in the form of a decrease in learning (3‐min memory) from middle age (30 days after eclosion [DAE]). We performed in vivo, DNA microarray, and behavioral screen studies to identify genes controlling both lifespan and AMI and selected mitochondrial Acon1 (mAcon1). mAcon1 expression in the head of w1118 decreased with age. Neuronal overexpression of mAcon1 extended its lifespan and improved AMI. Neuronal or mushroom body expression of mAcon1 regulated the learning of young (10 DAE) and middle‐aged flies. Interestingly, acetyl‐CoA and citrate levels increased in the heads of middle‐aged and neuronal mAcon1 knockdown flies. Acetyl‐CoA, as a cellular energy sensor, is related to autophagy. Autophagy activity and efficacy determined by the positive and negative changes in the expression levels of Atg8a‐II and p62 were proportional to the expression level of mAcon1. Levels of the presynaptic active zone scaffold protein Bruchpilot were inversely proportional to neuronal mAcon1 levels in the whole brain. Furthermore, mAcon1 overexpression in Kenyon cells induced mitophagy labeled with mt‐Keima and improved learning ability. Both processes were blocked by pink1 knockdown. Taken together, our results imply that the regulation of learning and AMI by mAcon1 occurs via autophagy/mitophagy‐mediated neural plasticity.
Collapse
Affiliation(s)
- Yun‐Ho Cho
- Department of Physiology Korea University College of Medicine Seoul Republic of Korea
| | - Gye‐Hyeong Kim
- Department of Physiology Korea University College of Medicine Seoul Republic of Korea
| | - Joong‐Jean Park
- Department of Physiology Korea University College of Medicine Seoul Republic of Korea
| |
Collapse
|
4
|
Jugder BE, Kamareddine L, Watnick PI. Microbiota-derived acetate activates intestinal innate immunity via the Tip60 histone acetyltransferase complex. Immunity 2021; 54:1683-1697.e3. [PMID: 34107298 DOI: 10.1016/j.immuni.2021.05.017] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Revised: 04/05/2021] [Accepted: 05/24/2021] [Indexed: 02/06/2023]
Abstract
Microbe-derived acetate activates the Drosophila immunodeficiency (IMD) pathway in a subset of enteroendocrine cells (EECs) of the anterior midgut. In these cells, the IMD pathway co-regulates expression of antimicrobial and enteroendocrine peptides including tachykinin, a repressor of intestinal lipid synthesis. To determine whether acetate acts on a cell surface pattern recognition receptor or an intracellular target, we asked whether acetate import was essential for IMD signaling. Mutagenesis and RNA interference revealed that the putative monocarboxylic acid transporter Tarag was essential for enhancement of IMD signaling by dietary acetate. Interference with histone deacetylation in EECs augmented transcription of genes regulated by the steroid hormone ecdysone including IMD targets. Reduced expression of the histone acetyltransferase Tip60 decreased IMD signaling and blocked rescue by dietary acetate and other sources of intracellular acetyl-CoA. Thus, microbe-derived acetate induces chromatin remodeling within enteroendocrine cells, co-regulating host metabolism and intestinal innate immunity via a Tip60-steroid hormone axis that is conserved in mammals.
Collapse
Affiliation(s)
- Bat-Erdene Jugder
- Division of Infectious Diseases, Boston Children's Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA
| | - Layla Kamareddine
- Department of Biomedical Sciences, College of Health Sciences, QU Health, Qatar University, Doha, Qatar; Biomedical Research Center, Qatar University, Doha, Qatar; Biomedical and Pharmaceutical Research Unit, QU Health, Qatar University, Doha, Qatar
| | - Paula I Watnick
- Division of Infectious Diseases, Boston Children's Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA.
| |
Collapse
|
5
|
Palli SR. Epigenetic regulation of post-embryonic development. CURRENT OPINION IN INSECT SCIENCE 2021; 43:63-69. [PMID: 33068783 PMCID: PMC8044252 DOI: 10.1016/j.cois.2020.09.011] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 09/09/2020] [Accepted: 09/18/2020] [Indexed: 05/02/2023]
Abstract
Modifications to DNA and core histones influence chromatin organization and expression of the genome. DNA methylation plays a significant role in the regulation of multiple biological processes that regulate behavior and caste differentiation in social insects. Histone modifications play significant roles in the regulation of development and reproduction in other insects. Genes coding for acetyltransferases, deacetylases, methyltransferases, and demethylases that modify core histones have been identified in genomes of multiple insects. Studies on the function and mechanisms of action of some of these enzymes uncovered their contribution to post-embryonic development. The results from studies on epigenetic modifiers could help in the identification of inhibitors of epigenetic modifiers that could be developed to control pests and disease vectors.
Collapse
Affiliation(s)
- Subba Reddy Palli
- Department of Entomology, College of Agriculture, Food and Environment, University of Kentucky, S225 Ag. Science N, Lexington, KY 40546, United States.
| |
Collapse
|
6
|
Abstract
Phenotypic plasticity describes the ability of a given genotype to produce different phenotypes in response to distinct environmental conditions. It has major implications in agronomy, animal husbandry and medicine and is also thought to facilitate evolution. Phenotypic plasticity is widely observed in the wild. It is only relatively recently that the mechanisms involved in phenotypic plasticity have been analysed. Thanks to laboratory experiments we understand better how environmental conditions are involved in phenotypic variations. This article introduces major concepts from the phenotypic plasticity field, presents briefly mechanisms involved in phenotypic plasticity and discusses the links between phenotypic plasticity and evolution.
Collapse
Affiliation(s)
- Jean-Michel Gibert
- Sorbonne Université, Centre National de la Recherche Scientifique (CNRS), UMR7622, Institut de Biologie Paris Seine, Laboratoire de Biologie du Développement (IBPS-LBD), 75005 Paris, France
| |
Collapse
|
7
|
George S, Palli SR. Histone Deacetylase 11 Knockdown Blocks Larval Development and Metamorphosis in the Red Flour Beetle, Tribolium castaneum. Front Genet 2020; 11:683. [PMID: 32719718 PMCID: PMC7348043 DOI: 10.3389/fgene.2020.00683] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Accepted: 06/04/2020] [Indexed: 12/31/2022] Open
Abstract
Post-translational modifications (PTM) such as methylation, acetylation, phosphorylation, and ubiquitination of histones and other proteins regulate expression of genes. The acetylation levels of these proteins are determined by the balance of expression of histone acetyltransferase (HATs) and histone deacetylases (HDACs). We recently reported that class I HDACs (HDAC1 and HDAC3) play important roles in juvenile hormone (JH) suppression of metamorphosis in the red flour beetle, Tribolium castaneum. Here, we report on the function of a single class IV HDAC member, HDAC11. Injection of dsRNA targeting T. castaneum HDAC11 gene into newly molted last instar larvae induced knockdown of the target gene and arrested larval development and prevented metamorphosis into the pupal stage. Dark melanized areas were detected in larvae that showed developmental arrest and mortality. Developmental expression studies showed an increase in HDAC11 mRNA levels beginning at the end of the penultimate larval stage. These higher levels were maintained during the final instar larval and pupal stages. A JH analog, hydroprene, suppressed HDAC11 expression in the larvae. Sequencing of RNA isolated from control and dsHDAC11 injected larvae identified several differentially expressed genes, including those involved in JH action, ecdysone response, and melanization. The acetylation levels of core histones showed an increase in TcA cells exposed to dsHDAC11. Also, an increase in histone H3 acetylation, specifically H3K9, H3K18 and H3K27, were detected in HDAC11 knockdown larvae. These studies report the function of HDAC11 in insects other than Drosophila for the first time and show that HDAC11 influences the acetylation levels of histones and expression of multiple genes involved in T. castaneum larval development.
Collapse
Affiliation(s)
- Smitha George
- Department of Entomology, University of Kentucky, Lexington, KY, United States
| | - Subba Reddy Palli
- Department of Entomology, University of Kentucky, Lexington, KY, United States
| |
Collapse
|
8
|
George S, Palli SR. Histone deacetylase 3 is required for development and metamorphosis in the red flour beetle, Tribolium castaneum. BMC Genomics 2020; 21:420. [PMID: 32571203 PMCID: PMC7310253 DOI: 10.1186/s12864-020-06840-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Accepted: 06/16/2020] [Indexed: 12/31/2022] Open
Abstract
Background Hormones are chemical communication signaling molecules released into the body fluids to stimulate target cells of multicellular organisms. We recently showed that histone deacetylase 1 (HDAC1) plays an important role in juvenile hormone (JH) suppression of metamorphosis in the red flour beetle, Tribolium castaneum. Here, we investigated the function of another class I HDAC member, HDAC3, and show that it is required for the normal development of T. castaneum. Results RNA interference-mediated knockdown of the HDAC3 gene affected development resulting in abnormally folded wings in pupae and adults. JH analog, hydroprene, suppressed the expression of HDAC3 in T. castaneum larvae. The knockdown of HDAC3 during the final instar larval stage resulted in an increase in the expression of genes coding for proteins involved in JH action. Sequencing of RNA isolated from larvae injected with dsRNA targeting malE (E. coli gene, control) or HDAC3 followed by differential gene expression analysis identified 148 and 741 differentially expressed genes based on the P-value < 0.01 and four-fold difference, and the P-value < 0.05 and two-fold difference, respectively. Several genes, including those coding for myosin-I heavy chain (Myosin 22), Shaven, and nuclear receptor corepressor 1 were identified as differentially expressed genes in HDAC3 knockdown larvae. An increase in histone H3 acetylation, specifically H3K9, H3K18, and H3K27, was detected in HDAC3 knockdown insects. Conclusion Overall, these data suggest that HDAC3 affects the acetylation levels of histones and influences the expression of genes coding for proteins involved in the regulation of growth, development, and metamorphosis.
Collapse
Affiliation(s)
- Smitha George
- Department of Entomology, University of Kentucky, Lexington, KY, 40546, USA
| | - Subba Reddy Palli
- Department of Entomology, University of Kentucky, Lexington, KY, 40546, USA.
| |
Collapse
|
9
|
Lyu H, Xu G, Chen P, Song Q, Feng Q, Yi Y, Zheng S. 20-Hydroxyecdysone receptor-activated Bombyx mori CCAAT/enhancer-binding protein gamma regulates the expression of BmCBP and subsequent histone H3 lysine 27 acetylation in Bo. mori. INSECT MOLECULAR BIOLOGY 2020; 29:256-270. [PMID: 31840914 DOI: 10.1111/imb.12630] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Revised: 11/09/2019] [Accepted: 12/06/2019] [Indexed: 06/10/2023]
Abstract
Cyclic adenosine monophosphate (cAMP) response element binding protein (CREB)-binding protein (CBP or CREBBP) plays important roles in regulating gene transcription and animal development. However, the process by which CBP is up-regulated to impact insect development is unknown. In this study, the regulatory mechanism of Bombyx mori CBP (BmCBP) expression induced by 20-hydroxyecdysone (20E) was investigated. In the Bo. mori cell line, DZNU-Bm-12, 20E enhanced BmCBP transcription and histone H3K27 acetylation. BmCBP RNA interference (RNAi) resulted in decreased histone H3K27 acetylation. Additionally, the luciferase activity analysis revealed that the transcription factor, Bo. mori CCAAT/enhancer-binding protein gamma (BmC/EBPg), activated BmCBP transcription, which was suppressed by BmC/EBPg RNAi and promoted by BmC/EBPg overexpression. Electrophoretic mobility shift assay and chromatin immunoprecipitation results demonstrated that BmC/EBPg could bind to the C/EBP cis-regulatory elements in two positions of the BmCBP promoter. Moreover, BmC/EBPg transcription was enhanced by the 20E receptor (BmEcR), which bound to the BmC/EBPg promoter. BmEcR RNAi significantly inhibited the transcriptional levels of BmC/EBPg and BmCBP in the presence of 20E. Furthermore, the BmEcR-BmC/EBPg pathway regulated the acetylation levels of histone H3K27. Altogether, these results indicate that BmEcR enhances the expression of BmC/EBPg, which binds to the BmCBP promoter, activates BmCBP expression and leads to histone H3K27 acetylation.
Collapse
Affiliation(s)
- H Lyu
- Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied Technology, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou, China
- Guangzhou Key Laboratory of Insect Development Regulation and Applied Research, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou, China
| | - G Xu
- Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied Technology, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou, China
- Guangzhou Key Laboratory of Insect Development Regulation and Applied Research, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou, China
| | - P Chen
- Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied Technology, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou, China
- Guangzhou Key Laboratory of Insect Development Regulation and Applied Research, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou, China
| | - Q Song
- Division of Plant Sciences, College of Agriculture, Food and Natural Resources, University of Missouri, Columbia, MO, USA
| | - Q Feng
- Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied Technology, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou, China
- Guangzhou Key Laboratory of Insect Development Regulation and Applied Research, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou, China
| | - Y Yi
- Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied Technology, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou, China
- Guangzhou Key Laboratory of Insect Development Regulation and Applied Research, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou, China
| | - S Zheng
- Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied Technology, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou, China
- Guangzhou Key Laboratory of Insect Development Regulation and Applied Research, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou, China
| |
Collapse
|
10
|
Histone deacetylase 1 suppresses Krüppel homolog 1 gene expression and influences juvenile hormone action in Tribolium castaneum. Proc Natl Acad Sci U S A 2019; 116:17759-17764. [PMID: 31439816 PMCID: PMC6731676 DOI: 10.1073/pnas.1909554116] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Juvenile hormone (JH) regulates many processes in insects, and JH mimics are used to control them. However, not much is known about the epigenetic regulation of JH action. Histone deacetylases (HDACs) are known to modulate hormone action. We identified 12 HDACs and analyzed their function in Tribolium castaneum. RNA interference-mediated knockdown of HDAC genes showed that HDAC1 plays critical roles in the regulation of growth and development by suppressing the expression of many genes, including those involved in JH action. Expression of the HDAC1 gene is suppressed by JH, resulting in an increase in acetylation levels of histones, which promotes expression of JH response genes. SIN3:HDAC1 multiprotein complexes suppress the expression of JH response genes in the absence of JH. Posttranslational modifications, including acetylation and deacetylation of histones and other proteins, modulate hormone action. In Tribolium castaneum TcA cells, Trichostatin A, a histone deacetylase (HDAC) inhibitor, mimics juvenile hormone (JH) in inducing JH response genes (e.g., Kr-h1), suggesting that HDACs may be involved in JH action. To test this hypothesis, we identified genes coding for HDACs in T. castaneum and studied their function. Knockdown of 12 HDAC genes showed variable phenotypes; the most severe phenotype was detected in insects injected with double-stranded RNA targeting HDAC1 (dsHDAC1). The dsHDAC1-injected insects showed arrested growth and development and eventually died. Application of JH analogs hydroprene to T. castaneum larvae and JH III to TcA cells suppressed HDAC1 expression. Sequencing of RNA isolated from control and dsHDAC1-injected larvae identified 1,720 differentially expressed genes, of which 1,664 were up-regulated in dsHDAC1-treated insects. The acetylation levels of core histones were increased in TcA cells exposed to dsHDAC1 or JH III. ChIP assays performed using histone H2BK5ac antibodies showed an increase in acetylation in the Kr-h1 promoter region of cells exposed to JH III or dsHDAC1. Overexpression or knockdown of HDAC1, SIN3, or both resulted in a decrease or increase in Kr-h1 mRNA levels and its promoter activity, respectively. Overexpression of the JH receptor Methoprene tolerant (Met) was unable to induce Kr-h1 in the presence of HDAC1 or SIN3. These data suggest that epigenetic modifications influence JH action by modulating acetylation levels of histones and by affecting the recruitment of proteins involved in the regulation of JH response genes.
Collapse
|
11
|
Mazina MY, Vorobyeva NE. Mechanisms of transcriptional regulation of ecdysone response. Vavilovskii Zhurnal Genet Selektsii 2019. [DOI: 10.18699/vj19.484] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
The mechanisms of ecdysone-dependent expression have been studied for many decades. Initially, the activation of individual genes under the influence of ecdysone was studied on the model of polythene chromosomes from salivary glands of Drosophila melanogaster. These works helped to investigate the many aspects of the Drosophila development. They also revealed plenty of valuable information regarding the fundamental mechanisms controlling the genes’ work. Many years ago, a model describing the process of gene activation by ecdysone, named after the author – Ashburner model – was proposed. This model is still considered an excellent description of the ecdysone cascade, which is implemented in the salivary glands during the formation of the Drosophila pupa. However, these days there is an opinion that the response of cells to the hormone ecdysone can develop with significant differences, depending on the type of cells. The same genes can be activated or repressed under the influence of ecdysone in different tissues. Likely, certain DNA-binding transcription factors that are involved in the ecdysonedependent response together with the EcR/Usp heterodimer are responsible for cell-type specificity. A number of transcriptional regulators involved in the ecdysone response have been described. Among them are several complexes responsible for chromatin remodeling and modification. It has been shown by various methods that ecdysone-dependent activation/repression of gene transcription develops with significant structural changes of chromatin on regulatory elements. The description of the molecular mechanism of this process, in particular, the role of individual proteins in it, as well as structural interactions between various regulatory elements is a matter of the future. This review is aimed to discuss the available information regarding the main regulators that interact with the ecdysone receptor. We provide a brief description of the regulator’s participation in the ecdysone response and links to the corresponding study. We also discuss general aspects of the mechanism of ecdysone-dependent regulation and highlight the most promising points for further research.
Collapse
Affiliation(s)
- M. Yu. Mazina
- Institute of Gene Biology, RAS, Group of transcriptional complexes dynamics
| | - N. E. Vorobyeva
- Institute of Gene Biology, RAS, Group of transcriptional complexes dynamics
| |
Collapse
|
12
|
Histone acetyltransferase CBP-related H3K23 acetylation contributes to courtship learning in Drosophila. BMC DEVELOPMENTAL BIOLOGY 2018; 18:20. [PMID: 30458702 PMCID: PMC6247617 DOI: 10.1186/s12861-018-0179-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Accepted: 11/05/2018] [Indexed: 12/16/2022]
Abstract
Background Histone modifications are critical in regulating neuronal processes. However, the impacts of individual histone modifications on learning and memory are elusive. Here, we investigated the contributions of histone H3 lysine modifications to learning and memory in Drosophila by using histone lysine-to-alanine mutants. Results Behavioural analysis indicated that compared to the H3WT group, mutants overexpressing H3K23A displayed impaired courtship learning. Chromatin immunoprecipitation analysis of H3K23A mutants showed that H3K23 acetylation (H3K23ac) levels were decreased on learning-related genes. Knockdown of CREB-binding protein (CBP) decreased H3K23ac levels, attenuated the expression of learning-related genes, led to a courtship learning defect and altered development of the mushroom bodies. A decline in courtship learning ability was observed in both larvae and adult treatments with ICG-001. Furthermore, treatment of Drosophila overexpressing mutated H3K23A with a CBP inhibitor did not aggravate the learning defect. Conclusions H3K23ac, catalysed by the acetyltransferases dCBP, contributes to Drosophila learning, likely by controlling the expression of specific genes. This is a novel epigenetic regulatory mechanism underlying neuronal behaviours. Electronic supplementary material The online version of this article (10.1186/s12861-018-0179-z) contains supplementary material, which is available to authorized users.
Collapse
|
13
|
Prud'homme SM, Renault D, David JP, Reynaud S. Multiscale Approach to Deciphering the Molecular Mechanisms Involved in the Direct and Intergenerational Effect of Ibuprofen on Mosquito Aedes aegypti. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:7937-7950. [PMID: 29874051 DOI: 10.1021/acs.est.8b00988] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The anti-inflammatory ibuprofen is a ubiquitous surface water contaminant. However, the chronic impact of this pharmaceutical on aquatic invertebrate populations remains poorly understood. In model insect Aedes aegypti, we investigated the intergenerational consequences of parental chronic exposure to an environmentally relevant concentration of ibuprofen. While exposed individuals did not show any phenotypic changes, their progeny showed accelerated development and an increased tolerance to starvation. In order to understand the mechanistic processes underpinning the direct and intergenerational impacts of ibuprofen, we combined transcriptomic, metabolomics, and hormone kinetics studies at several life stages in exposed individuals and their progeny. This integrative approach revealed moderate transcriptional changes in exposed larvae consistent with the pharmacological mode of action of ibuprofen. Parental exposure led to lower levels of several polar metabolites in progeny eggs and to major transcriptional changes in the following larval stage. These transcriptional changes, most likely driven by changes in the expression of numerous transcription factors and epigenetic regulators, led to ecdysone signaling and stress response potentiation. Overall, the present study illustrates the complexity of the molecular basis of the intergenerational pollutant response in insects and the importance of considering the entire life cycle of exposed organisms and of their progeny in order to fully understand the mode of action of pollutants and their impact on ecosystems.
Collapse
Affiliation(s)
- Sophie M Prud'homme
- Univ. Grenoble-Alpes, Univ. Savoie Mont Blanc, CNRS, LECA , 38000 Grenoble , France
| | - David Renault
- Université de Rennes 1, UMR CNRS 6553 Ecobio, Campus de Beaulieu, 263 Avenue du Gal Leclerc, CS 74205 , 35042 Rennes Cedex, France
- Institut Universitaire de France , 1 rue Descartes , 75231 Paris Cedex 05, France
| | - Jean-Philippe David
- Univ. Grenoble-Alpes, Univ. Savoie Mont Blanc, CNRS, LECA , 38000 Grenoble , France
| | - Stéphane Reynaud
- Univ. Grenoble-Alpes, Univ. Savoie Mont Blanc, CNRS, LECA , 38000 Grenoble , France
| |
Collapse
|
14
|
CREB-binding protein plays key roles in juvenile hormone action in the red flour beetle, Tribolium Castaneum. Sci Rep 2018; 8:1426. [PMID: 29362416 PMCID: PMC5780420 DOI: 10.1038/s41598-018-19667-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Accepted: 01/05/2018] [Indexed: 12/23/2022] Open
Abstract
Juvenile hormones (JH) and ecdysteroids regulate many biological and metabolic processes. CREB-binding protein (CBP) is a transcriptional co-regulator with histone acetyltransferase (HAT) activity. Therefore, CBP is involved in activation of many transcription factors that regulate expression of genes associated with postembryonic development in insects. However, the function of CBP in JH action in insects is not well understood. Hence, we studied the role of CBP in JH action in the red flour beetle, Tribolium castaneum and the Tribolium cell line. CBP knockdown caused a decrease in JH induction of genes, Kr-h1, 4EBP and G13402 in T. castaneum larvae, adults and TcA cells whereas, Trichostatin A [TSA, a histone deacetylase (HDAC) inhibitor] induced the expression of these JH-response genes. Western blot analysis with specific antibodies revealed the requirement of CBP for the acetylation of H3K18 and H3K27 in both T. castaneum and TcA cells. Chromatin immunoprecipitation (Chip) assays showed the importance of CBP-mediated acetylation of H3K27 for JH induction of Kr-h1, 4EBP, and G13402 in TcA cells. These data suggest that CBP plays an important role in JH action in the model insect, T.castaneum.
Collapse
|
15
|
Roy A, George S, Palli SR. Multiple functions of CREB-binding protein during postembryonic development: identification of target genes. BMC Genomics 2017; 18:996. [PMID: 29284404 PMCID: PMC5747157 DOI: 10.1186/s12864-017-4373-3] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Accepted: 12/08/2017] [Indexed: 11/25/2022] Open
Abstract
Background Juvenile hormones (JH) and ecdysteroids control postembryonic development in insects. They serve as valuable targets for pest management. Hence, understanding the molecular mechanisms of their action is of crucial importance. CREB-binding protein (CBP) is a universal transcriptional co-regulator. It controls the expression of several genes including those from hormone signaling pathways through co-activation of many transcription factors. However, the role of CBP during postembryonic development in insects is not well understood. Therefore, we have studied the role of CBP in postembryonic development in Tribolium, a model coleopteran insect. Results CBP is ubiquitously expressed in the red flour beetle, Tribolium castaneum. RNA interference (RNAi) mediated knockdown of CBP resulted in a decrease in JH induction of Kr-h1 gene expression in Tribolium larvae and led to a block in their development. Moreover, the injection of CBP double-stranded RNA (dsRNA) showed lethal phenotypes within 8 days of injection. RNA-seq and subsequent differential gene expression analysis identified CBP target genes in Tribolium. Knockdown of CBP caused a decrease in the expression of 1306 genes coding for transcription factors and other proteins associated with growth and development. Depletion of CBP impaired the expression of several JH response genes (e.g., Kr-h1, Hairy, early trypsin) and ecdysone response genes (EcR, E74, E75, and broad complex). Further, GO enrichment analyses of the downregulated genes showed enrichment in different functions including developmental processes, pigmentation, anatomical structure development, regulation of biological and cellular processes, etc. Conclusion These data suggest diverse but crucial roles for CBP during postembryonic development in the coleopteran model insect, Tribolium. It can serve as a target for RNAi mediated pest management of this stored product pest. Electronic supplementary material The online version of this article (10.1186/s12864-017-4373-3) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Amit Roy
- Department of Entomology, College of Agriculture, University of Kentucky, Lexington, KY, 40546, USA.,Present address, Faculty of Forestry and Wood Sciences, EXTEMIT-K, Czech University of Life Sciences, Kamýcká 1176, Prague 6, 165 21, Suchdol, Czech Republic
| | - Smitha George
- Department of Entomology, College of Agriculture, University of Kentucky, Lexington, KY, 40546, USA
| | - Subba Reddy Palli
- Department of Entomology, College of Agriculture, University of Kentucky, Lexington, KY, 40546, USA.
| |
Collapse
|
16
|
Histone H3 lysine 23 acetylation is associated with oncogene TRIM24 expression and a poor prognosis in breast cancer. Tumour Biol 2016; 37:14803-14812. [PMID: 27638829 DOI: 10.1007/s13277-016-5344-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Accepted: 09/06/2016] [Indexed: 12/22/2022] Open
Abstract
Acetylated H3 lysine 23 (H3K23ac) is a specific histone post-translational modification recognized by oncoprotein TRIM24. However, it is not clear whether H3K23ac levels are correlated with TRIM24 expression and what role H3K23ac may have in cancer. In this study, we collected breast carcinoma samples from 121 patients and conducted immunohistochemistry to determine the levels of TRIM24 and H3K23ac in breast cancer. Our results demonstrated that TRIM24 expression is positively correlated with H3K23ac levels, and high levels of both TRIM24 and H3K23ac predict shorter overall survival of breast cancer patients. We also showed that both TRIM24 and H3K23ac are higher in HER2-positive patients, and their levels were positively correlated with HER2 levels in breast cancer. Moreover, TRIM24 expression is associated with estrogen receptor (ER) and progesterone receptor (PR) statuses in both our cohort and The Cancer Genome Atlas (TCGA) breast carcinoma. In summary, our results revealed an important role of TRIM24 and H3K23ac in breast cancer and provided further evidence that TRIM24 small-molecule inhibitors may benefit ER- and PR-negative or HER2-positive breast cancer patients.
Collapse
|
17
|
Abstract
Steroid hormones induce cascades of gene activation and repression with transformative effects on cell fate . Steroid transduction plays a major role in the development and physiology of nearly all metazoan species, and in the progression of the most common forms of cancer. Despite the paramount importance of steroids in developmental and translational biology, a complete map of transcriptional response has not been developed for any hormone . In the case of 20-hydroxyecdysone (ecdysone) in Drosophila melanogaster, these trajectories range from apoptosis to immortalization. We mapped the ecdysone transduction network in a cohort of 41 cell lines, the largest such atlas yet assembled. We found that the early transcriptional response mirrors the distinctiveness of physiological origins: genes respond in restricted patterns, conditional on the expression levels of dozens of transcription factors. Only a small cohort of genes is constitutively modulated independent of initial cell state. Ecdysone-responsive genes tend to organize into directional same-stranded units, with consecutive genes induced from the same strand. Here, we identify half of the ecdysone receptor heterodimer as the primary rate-limiting step in the response, and find that initial receptor isoform levels modulate the activated cohort of target transcription factors. This atlas of steroid response reveals organizing principles of gene regulation by a model type II nuclear receptor and lays the foundation for comprehensive and predictive understanding of the ecdysone transduction network in the fruit fly.
Collapse
|
18
|
Fernandez-Nicolas A, Belles X. CREB-binding protein contributes to the regulation of endocrine and developmental pathways in insect hemimetabolan pre-metamorphosis. Biochim Biophys Acta Gen Subj 2015; 1860:508-15. [PMID: 26706852 DOI: 10.1016/j.bbagen.2015.12.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Revised: 11/10/2015] [Accepted: 12/11/2015] [Indexed: 10/22/2022]
Abstract
BACKGROUND CREB-binding protein (CBP) is a promiscuous transcriptional co-regulator. In insects, CBP has been studied in the fly Drosophila melanogaster, where it is known as Nejire. Studies in D. melanogaster have revealed that Nejire is involved in the regulation of many pathways during embryo development, especially in anterior/posterior polarity, through Hedgehog and Wingless signaling, and in dorsal/ventral patterning, through TGF-ß signaling. Regarding post-embryonic development, Nejire influences histone acetyl transferase activity on the ecdysone signaling pathway. METHODS AND RESULTS Functional genomics studies using RNAi have shown that CBP contributes to the regulation of feeding and ecdysis during the pre-metamorphic nymphal instar of the cockroach Blattella germanica and is involved in TGF-ß, ecdysone, and MEKRE93 pathways, contributing to the activation of Kr-h1 and E93 expression. In D. melanogaster, Nejire's involvement in the ecdysone pathway in pre-metamorphic stages is conserved, whereas the TGF-ß pathway has only been described in the embryo. CBP role in ecdysis pathway and in the activation of Kr-h1 and E93 expression is described here for the first time. CONCLUSIONS Studies in D. melanogaster may have been suggestive that CBP functions in insects are concentrated in the embryo. Results obtained in B. germanica indicate, however, that CBP have diverse and important functions in post-embryonic development and metamorphosis, especially regarding endocrine signaling. GENERAL SIGNIFICANCE Further research into a higher diversity of models will probably reveal that the multiple post-embryonic roles of CBP observed in B. germanica are general in insects.
Collapse
Affiliation(s)
- Ana Fernandez-Nicolas
- Institut de Biologia Evolutiva (CSIC-UPF), Passeig Marítim de la Barceloneta 37, 08003 Barcelona, Spain
| | - Xavier Belles
- Institut de Biologia Evolutiva (CSIC-UPF), Passeig Marítim de la Barceloneta 37, 08003 Barcelona, Spain.
| |
Collapse
|
19
|
Philip P, Boija A, Vaid R, Churcher AM, Meyers DJ, Cole PA, Mannervik M, Stenberg P. CBP binding outside of promoters and enhancers in Drosophila melanogaster. Epigenetics Chromatin 2015; 8:48. [PMID: 26604986 PMCID: PMC4657240 DOI: 10.1186/s13072-015-0042-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Accepted: 11/09/2015] [Indexed: 01/23/2023] Open
Abstract
BACKGROUND CREB-binding protein (CBP, also known as nejire) is a transcriptional co-activator that is conserved in metazoans. CBP plays an important role in embryonic development and cell differentiation and mutations in CBP can lead to various diseases in humans. In addition, CBP and the related p300 protein have successfully been used to predict enhancers in both humans and flies when they occur with monomethylation of histone H3 on lysine 4 (H3K4me1). RESULTS Here, we compare CBP chromatin immunoprecipitation sequencing data from Drosophila S2 cells with modENCODE data and show that CBP is bound at genomic sites with a wide range of functions. As expected, we find that CBP is bound at active promoters and enhancers. In addition, we find that the strongest CBP sites in the genome are found at Polycomb response elements embedded in histone H3 lysine 27 trimethylated (H3K27me3) chromatin, where they correlate with binding of the Pho repressive complex. Interestingly, we find that CBP also binds to most insulators in the genome. At a subset of these, CBP may regulate insulating activity, measured as the ability to prevent repressive H3K27 methylation from spreading into adjacent chromatin. CONCLUSIONS We conclude that CBP could be involved in a much wider range of functions than has previously been appreciated, including Polycomb repression and insulator activity. In addition, we discuss the possibility that a common role for CBP at all functional elements may be to regulate interactions between distant chromosomal regions and speculate that CBP is controlling higher order chromatin organization.
Collapse
Affiliation(s)
- Philge Philip
- Department of Molecular Biology, Umeå University, 901 87 Umeå, Sweden ; Computational Life Science Cluster (CLiC), Umeå University, 901 87 Umeå, Sweden ; Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad, Telangana 500007 India
| | - Ann Boija
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, 106 91 Stockholm, Sweden
| | - Roshan Vaid
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, 106 91 Stockholm, Sweden
| | | | - David J Meyers
- Department Pharmacology and Molecular Sciences, The Johns Hopkins University School of Medicine, 725 North Wolfe Street, Baltimore, MD 21205 USA
| | - Philip A Cole
- Department Pharmacology and Molecular Sciences, The Johns Hopkins University School of Medicine, 725 North Wolfe Street, Baltimore, MD 21205 USA
| | - Mattias Mannervik
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, 106 91 Stockholm, Sweden
| | - Per Stenberg
- Department of Molecular Biology, Umeå University, 901 87 Umeå, Sweden ; Computational Life Science Cluster (CLiC), Umeå University, 901 87 Umeå, Sweden ; Division of CBRN Security and Defence, FOI-Swedish Defence Research Agency, Umeå, Sweden
| |
Collapse
|
20
|
Nishiyama A, Yamaguchi L, Nakanishi M. Regulation of maintenance DNA methylation via histone ubiquitylation. J Biochem 2015; 159:9-15. [PMID: 26590302 DOI: 10.1093/jb/mvv113] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Accepted: 10/07/2015] [Indexed: 11/13/2022] Open
Abstract
DNA methylation is one of the most stable but dynamically regulated epigenetic marks that act as determinants of cell fates during embryonic development through regulation of various forms of gene expression. DNA methylation patterns must be faithfully propagated throughout successive cell divisions in order to maintain cell-specific function. We have recently demonstrated that Uhrf1-dependent ubiquitylation of histone H3 at lysine 23 is critical for Dnmt1 recruitment to DNA replication sites, which catalyzes the conversion of hemi-methylated DNA to fully methylated DNA. In this review, we provide an overview of recent progress in understanding the mechanism underlying maintenance DNA methylation.
Collapse
Affiliation(s)
- Atsuya Nishiyama
- Department of Cell Biology, Graduate School of Medical Sciences, Nagoya City University, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya 467-8601, Japan
| | - Luna Yamaguchi
- Department of Cell Biology, Graduate School of Medical Sciences, Nagoya City University, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya 467-8601, Japan
| | - Makoto Nakanishi
- Department of Cell Biology, Graduate School of Medical Sciences, Nagoya City University, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya 467-8601, Japan
| |
Collapse
|
21
|
Huang F, Paulson A, Dutta A, Venkatesh S, Smolle M, Abmayr SM, Workman JL. Histone acetyltransferase Enok regulates oocyte polarization by promoting expression of the actin nucleation factor spire. Genes Dev 2015; 28:2750-63. [PMID: 25512562 PMCID: PMC4265678 DOI: 10.1101/gad.249730.114] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
KAT6 histone acetyltransferases (HATs) are highly conserved in eukaryotes and have been shown to play important roles in transcriptional regulation. Here, we demonstrate that the Drosophila KAT6 Enok acetylates histone H3 Lys 23 (H3K23) in vitro and in vivo. Mutants lacking functional Enok exhibited defects in the localization of Oskar (Osk) to the posterior end of the oocyte, resulting in loss of germline formation and abdominal segments in the embryo. RNA sequencing (RNA-seq) analysis revealed that spire (spir) and maelstrom (mael), both required for the posterior localization of Osk in the oocyte, were down-regulated in enok mutants. Chromatin immunoprecipitation showed that Enok is localized to and acetylates H3K23 at the spir and mael genes. Furthermore, Gal4-driven expression of spir in the germline can largely rescue the defective Osk localization in enok mutant ovaries. Our results suggest that the Enok-mediated H3K23 acetylation (H3K23Ac) promotes the expression of spir, providing a specific mechanism linking oocyte polarization to histone modification.
Collapse
Affiliation(s)
- Fu Huang
- Stowers Institute for Medical Research, Kansas City, Missouri 64110, USA
| | - Ariel Paulson
- Stowers Institute for Medical Research, Kansas City, Missouri 64110, USA
| | - Arnob Dutta
- Stowers Institute for Medical Research, Kansas City, Missouri 64110, USA
| | | | - Michaela Smolle
- Stowers Institute for Medical Research, Kansas City, Missouri 64110, USA
| | - Susan M Abmayr
- Stowers Institute for Medical Research, Kansas City, Missouri 64110, USA; Department of Anatomy and Cell Biology, University of Kansas Medical Center, Kansas City, Kansas 66160, USA
| | - Jerry L Workman
- Stowers Institute for Medical Research, Kansas City, Missouri 64110, USA;
| |
Collapse
|
22
|
López Y, Vandenbon A, Nakai K. A set of structural features defines the cis-regulatory modules of antenna-expressed genes in Drosophila melanogaster. PLoS One 2014; 9:e104342. [PMID: 25153327 PMCID: PMC4143197 DOI: 10.1371/journal.pone.0104342] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2014] [Accepted: 07/13/2014] [Indexed: 11/18/2022] Open
Abstract
Unraveling the biological information within the regulatory region (RR) of genes has become one of the major focuses of current genomic research. It has been hypothesized that RRs of co-expressed genes share similar architecture, but to the best of our knowledge, no studies have simultaneously examined multiple structural features, such as positioning of cis-regulatory elements relative to transcription start sites and to each other, and the order and orientation of regulatory motifs, to accurately describe overall cis-regulatory structure. In our work we present an improved computational method that builds a feature collection based on all of these structural features. We demonstrate the utility of this approach by modeling the cis-regulatory modules of antenna-expressed genes in Drosophila melanogaster. Six potential antenna-related motifs were predicted initially, including three that appeared to be novel. A feature set was created with the predicted motifs, where a correlation-based filter was used to remove irrelevant features, and a genetic algorithm was designed to optimize the feature set. Finally, a set of eight highly informative structural features was obtained for the RRs of antenna-expressed genes, achieving an area under the curve of 0.841. We used these features to score all D. melanogaster RRs for potentially unknown antenna-expressed genes sharing a similar regulatory structure. Validation of our predictions with an independent RNA sequencing dataset showed that 76.7% of genes with high scoring RRs were expressed in antenna. In addition, we found that the structural features we identified are highly conserved in RRs of orthologs in other Drosophila sibling species. This approach to identify tissue-specific regulatory structures showed comparable performance to previous approaches, but also uncovered additional interesting features because it also considered the order and orientation of motifs.
Collapse
Affiliation(s)
- Yosvany López
- Department of Computational Biology, Graduate School of Frontier Sciences, The University of Tokyo, Chiba, Japan
- Human Genome Center, The Institute of Medical Science, The University of Tokyo, Tokyo, Japan
| | - Alexis Vandenbon
- Immunology Frontier Research Center, Osaka University, Osaka, Japan
| | - Kenta Nakai
- Human Genome Center, The Institute of Medical Science, The University of Tokyo, Tokyo, Japan
- * E-mail:
| |
Collapse
|