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Fenelon KD, Borad P, Rout B, Malidarreh PB, Nasr MS, Luber JM, Koromila T. Su(H) Modulates Enhancer Transcriptional Bursting in Prelude to Gastrulation. Cells 2024; 13:1759. [PMID: 39513866 PMCID: PMC11545809 DOI: 10.3390/cells13211759] [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: 09/17/2024] [Revised: 10/09/2024] [Accepted: 10/16/2024] [Indexed: 11/16/2024] Open
Abstract
Transcriptional regulation, orchestrated by the interplay between transcription factors (TFs) and enhancers, governs gene expression dynamics crucial for cellular processes. While gross qualitative fluctuations in transcription factor-dependent gene expression patterning have a long history of characterization, the roles of these factors in the nuclei retaining expression in the presence or absence of these factors are now observable using modern techniques. Our study investigates the impact of Suppressor of Hairless (Su(H)), a broadly expressed transcription factor, on enhancer-driven transcriptional modulation using Drosophila early embryos as a model system. Building upon previous findings, we employ super-resolution microscopy to dissect Su(H)'s influence on sog-Distal (sogD) enhancer activity specifically in nuclei with preserved sogD-driven expression in the absence of Su(H) binding. We demonstrate that Su(H) occupancy perturbations alter expression levels and bursting dynamics. Notably, Su(H) absence during embryonic development exhibits region-specific effects, inhibiting expression dorsally and stabilizing expression ventrally, implying a nuanced role in enhancer regulation. Our findings shed light on the intricate mechanisms that govern transcriptional dynamics and suggest a critical patterning role for Notch/Hairless signaling in sog expression as embryos transition to gastrulation.
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Affiliation(s)
- Kelli D. Fenelon
- Department of Biology, University of Texas at Arlington, Arlington, TX 76010, USA; (K.D.F.); (P.B.)
| | - Priyanshi Borad
- Department of Biology, University of Texas at Arlington, Arlington, TX 76010, USA; (K.D.F.); (P.B.)
| | - Biraaj Rout
- Department of Computer Science, University of Texas at Arlington, Arlington, TX 76010, USA; (B.R.); (P.B.M.); (J.M.L.)
| | - Parisa Boodaghi Malidarreh
- Department of Computer Science, University of Texas at Arlington, Arlington, TX 76010, USA; (B.R.); (P.B.M.); (J.M.L.)
| | - Mohammad Sadegh Nasr
- Department of Computer Science, University of Texas at Arlington, Arlington, TX 76010, USA; (B.R.); (P.B.M.); (J.M.L.)
| | - Jacob M. Luber
- Department of Computer Science, University of Texas at Arlington, Arlington, TX 76010, USA; (B.R.); (P.B.M.); (J.M.L.)
- Multi-Interprofessional Center for Health Informatics, University of Texas at Arlington, Arlington, TX 76010, USA
| | - Theodora Koromila
- Department of Biology, University of Texas at Arlington, Arlington, TX 76010, USA; (K.D.F.); (P.B.)
- School of Biology, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
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2
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Epigenetic regulation of Neuregulin 1 promotes breast cancer progression associated to hyperglycemia. Nat Commun 2023; 14:439. [PMID: 36707514 PMCID: PMC9883495 DOI: 10.1038/s41467-023-36179-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Accepted: 01/18/2023] [Indexed: 01/28/2023] Open
Abstract
Hyperglycemia is a risk factor for breast cancer-related morbidity and mortality. Hyperglycemia induces Neuregulin 1 (Nrg1) overexpression in breast cancer, which subsequently promotes tumor progression. However, molecular mechanisms underlying hyperglycemia-induced Nrg1 overexpression remain poorly understood. Here, we show that hyperglycemia causes active histone modifications at the Nrg1 enhancer, forming enhanceosome complexes where recombination signal binding protein for immunoglobulin kappa J region (RBPJ), E1A binding protein p300 (P300), and SET domain containing 1 A (SETD1A) are recruited to upregulate Nrg1 expression. Deletions in RBPJ-binding sites causes hyperglycemia-controlled Nrg1 levels to be downregulated, resulting in decreased tumor growth in vitro and in vivo. Mice with modest-temporary hyperglycemia, induced by low-dose short-exposure streptozotocin, display accelerated tumor growth and lapatinib resistance, whereas combining lapatinib with N-[N-(3,5-difluorophenacetyl)-l-alanyl]-S42 phenylglycine t-butyl ester (DAPT) ameliorates tumor growth under these modest hyperglycemic conditions by inhibiting NOTCH and EGFR superfamilies. NOTCH activity is correlated with NRG1 levels, and high NRG1 levels predicts poor outcomes, particularly in HER2-positive breast cancer patients. Our findings highlight the hyperglycemia-linked epigenetic modulation of NRG1 as a potential therapeutic strategy for treating breast cancer patients with diabetes.
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Maier D, Bauer M, Boger M, Sanchez Jimenez A, Yuan Z, Fechner J, Scharpf J, Kovall RA, Preiss A, Nagel AC. Genetic and Molecular Interactions between HΔCT, a Novel Allele of the Notch Antagonist Hairless, and the Histone Chaperone Asf1 in Drosophila melanogaster. Genes (Basel) 2023; 14:205. [PMID: 36672946 PMCID: PMC9858708 DOI: 10.3390/genes14010205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 01/03/2023] [Accepted: 01/09/2023] [Indexed: 01/15/2023] Open
Abstract
Cellular differentiation relies on the highly conserved Notch signaling pathway. Notch activity induces gene expression changes that are highly sensitive to chromatin landscape. We address Notch gene regulation using Drosophila as a model, focusing on the genetic and molecular interactions between the Notch antagonist Hairless and the histone chaperone Asf1. Earlier work implied that Asf1 promotes the silencing of Notch target genes via Hairless (H). Here, we generate a novel HΔCT allele by genome engineering. Phenotypically, HΔCT behaves as a Hairless gain of function allele in several developmental contexts, indicating that the conserved CT domain of H has an attenuator role under native biological contexts. Using several independent methods to assay protein-protein interactions, we define the sequences of the CT domain that are involved in Hairless-Asf1 binding. Based on previous models, where Asf1 promotes Notch repression via Hairless, a loss of Asf1 binding should reduce Hairless repressive activity. However, tissue-specific Asf1 overexpression phenotypes are increased, not rescued, in the HΔCT background. Counterintuitively, Hairless protein binding mitigates the repressive activity of Asf1 in the context of eye development. These findings highlight the complex connections of Notch repressors and chromatin modulators during Notch target-gene regulation and open the avenue for further investigations.
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Affiliation(s)
- Dieter Maier
- Institute of Biology, Genetics Department 190g, University of Hohenheim, Garbenstr. 30, D-70599 Stuttgart, Germany
| | - Milena Bauer
- Institute of Biology, Genetics Department 190g, University of Hohenheim, Garbenstr. 30, D-70599 Stuttgart, Germany
- Biozentrum, University of Basel, Spitalstrasse 41, CH-4056 Basel, Switzerland
| | - Mike Boger
- Institute of Biology, Genetics Department 190g, University of Hohenheim, Garbenstr. 30, D-70599 Stuttgart, Germany
- European Center for Angioscience, Medical Faculty Mannheim, Heidelberg University, Ludolf-Krehl-Straße 13–17, D-68167 Mannheim, Germany
| | - Anna Sanchez Jimenez
- Institute of Biology, Genetics Department 190g, University of Hohenheim, Garbenstr. 30, D-70599 Stuttgart, Germany
| | - Zhenyu Yuan
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, Medical Sciences Building 2201, Albert Sabin Way, Cincinnati, OH 45267, USA
| | - Johannes Fechner
- Institute of Biology, Genetics Department 190g, University of Hohenheim, Garbenstr. 30, D-70599 Stuttgart, Germany
- Institute of Biomedical Genetics (IBMG), University of Stuttgart, Allmandring 31, D-70569 Stuttgart, Germany
| | - Janika Scharpf
- Institute of Biology, Genetics Department 190g, University of Hohenheim, Garbenstr. 30, D-70599 Stuttgart, Germany
| | - Rhett A. Kovall
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, Medical Sciences Building 2201, Albert Sabin Way, Cincinnati, OH 45267, USA
| | - Anette Preiss
- Institute of Biology, Genetics Department 190g, University of Hohenheim, Garbenstr. 30, D-70599 Stuttgart, Germany
| | - Anja C. Nagel
- Institute of Biology, Genetics Department 190g, University of Hohenheim, Garbenstr. 30, D-70599 Stuttgart, Germany
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4
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Rahman S, Lan X, Terranova C, El-Kholdi R, Yilmaz OH, Cheng CW. Epigenetic and Transcriptional Dynamics of Notch Program in Intestinal Differentiation. Methods Mol Biol 2023; 2650:77-88. [PMID: 37310625 DOI: 10.1007/978-1-0716-3076-1_7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The equilibrium between stem cell self-renewal and differentiation followed by proper lineage specification of progenitor cells is considered imperative for maintaining intestinal homeostasis. In the hierarchical model, intestinal differentiation is defined by the stepwise acquisition of lineage-specific mature cell features, where Notch signaling and lateral inhibition instructively regulate the cell-fate decisions. Recent studies reveal a broadly permissive intestinal chromatin underlies the lineage plasticity and adaptation to diet mediated by Notch transcriptional program. Here, we review the conventional understanding of Notch programming in intestinal differentiation and describe how new data from epigenetic and transcriptional analyses may refine or revise the current view. We provide instructions on sample preparation and data analysis and explain how to use ChIP-seq and scRNA-seq in combination of lineage tracing assay to determine the dynamics of Notch program and intestinal differentiation in the context of dietary and metabolic regulation of cell-fate decisions.
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Affiliation(s)
- Shahadat Rahman
- Columbia Stem Cell Initiative, Columbia University Irving Medical Center, New York, NY, USA
| | - Xi Lan
- Koch Institute for Integrative Cancer Research, MIT, Cambridge, MA, USA
| | - Christopher Terranova
- Genomic Medicine Department, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Rayan El-Kholdi
- Columbia Stem Cell Initiative, Columbia University Irving Medical Center, New York, NY, USA
- ESPCI Paris, Université PSL, Paris, France
| | - Omer H Yilmaz
- Koch Institute for Integrative Cancer Research, MIT, Cambridge, MA, USA
| | - Chia-Wei Cheng
- Columbia Stem Cell Initiative, Columbia University Irving Medical Center, New York, NY, USA.
- Koch Institute for Integrative Cancer Research, MIT, Cambridge, MA, USA.
- Department of Genetics and Development, Columbia University Irving Medical Center, New York, NY, USA.
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Ho MT, Lu J, Vazquez-Pianzola P, Suter B. α-Phenylalanyl tRNA synthetase competes with Notch signaling through its N-terminal domain. PLoS Genet 2022; 18:e1010185. [PMID: 35486661 PMCID: PMC9094542 DOI: 10.1371/journal.pgen.1010185] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2021] [Revised: 05/11/2022] [Accepted: 04/04/2022] [Indexed: 02/07/2023] Open
Abstract
The alpha subunit of the cytoplasmic Phenylalanyl tRNA synthetase (α-PheRS, FARSA in humans) displays cell growth and proliferation activities and its elevated levels can induce cell fate changes and tumor-like phenotypes that are neither dependent on the canonical function of charging tRNAPhe with phenylalanine nor on stimulating general translation. In intestinal stem cells of Drosophila midguts, α-PheRS levels are naturally slightly elevated and human FARSA mRNA levels are elevated in multiple cancers. In the Drosophila midgut model, elevated α-PheRS levels caused the accumulation of many additional proliferating cells resembling intestinal stem cells (ISCs) and enteroblasts (EBs). This phenotype partially resembles the tumor-like phenotype described as Notch RNAi phenotype for the same cells. Genetic interactions between α-PheRS and Notch suggest that their activities neutralize each other and that elevated α-PheRS levels attenuate Notch signaling when Notch induces differentiation into enterocytes, type II neuroblast stem cell proliferation, or transcription of a Notch reporter. These non-canonical functions all map to the N-terminal part of α-PheRS which accumulates naturally in the intestine. This truncated version of α-PheRS (α-S) also localizes to nuclei and displays weak sequence similarity to the Notch intracellular domain (NICD), suggesting that α-S might compete with the NICD for binding to a common target. Supporting this hypothesis, the tryptophan (W) residue reported to be key for the interaction between the NICD and the Su(H) BTD domain is not only conserved in α-PheRS and α-S, but also essential for attenuating Notch signaling. Aminoacyl tRNA synthetases charge tRNAs with their cognate amino acid to ensure proper decoding of the genetic code during translation. Independent of its aminoacylation function, the alpha subunit of Drosophila cytoplasmic Phenylalanyl tRNA synthetase (α-PheRS, FARSA in humans) has an additional activity that promotes growth and proliferation. Here we describe that elevated α-PheRS levels also induce cell fate changes and tumorous phenotypes in Drosophila midguts. Excessive proliferating cells with stem and progenitor cell characteristics accumulate and the composition of the terminally differentiated cells changes, too. This phenotype together with observed genetic interactions between α-PheRS and Notch levels show that α-PheRS counteracts Notch signaling in many different tissues and developmental stages. This novel activity of α-PheRS maps to its N-terminal part, which is naturally produced. The fragment contains a DNA binding domain, translocates into nuclei, and displays essential similarities to a Notch domain that binds to the downstream transcription factor. This suggests that it might be competing with Notch for binding to a common target. Not only because Notch plays important roles in many tumors, but also because FARSA mRNA levels are considerably upregulated in many tumors, this novel activity deserves more attention for cancer research.
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Affiliation(s)
- Manh Tin Ho
- Institute of Cell Biology, University of Bern, Bern, Switzerland
| | - Jiongming Lu
- Institute of Cell Biology, University of Bern, Bern, Switzerland
| | | | - Beat Suter
- Institute of Cell Biology, University of Bern, Bern, Switzerland
- * E-mail:
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6
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Huang Z, Yang M. Molecular Network of Colorectal Cancer and Current Therapeutic Options. Front Oncol 2022; 12:852927. [PMID: 35463300 PMCID: PMC9018988 DOI: 10.3389/fonc.2022.852927] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Accepted: 03/11/2022] [Indexed: 12/24/2022] Open
Abstract
Colorectal cancer (CRC), a leading cause of cancer-related mortalities globally, results from the accumulation of multiple genetic and epigenetic alterations in the normal colonic and rectum epithelium, leading to the progression from colorectal adenomas to invasive carcinomas. Almost half of CRC patients will develop metastases in the course of the disease and most patients with metastatic CRC are incurable. Particularly, the 5-year survival rate of patients with stage 4 CRC at diagnosis is less than 10%. Although genetic understanding of these CRC tumors and paired metastases has led to major advances in elucidating early driver genes responsible for carcinogenesis and metastasis, the pathophysiological contribution of transcriptional and epigenetic aberrations in this malignancy which influence many central signaling pathways have attracted attention recently. Therefore, treatments that could affect several different molecular pathways may have pivotal implications for their efficacy. In this review, we summarize our current knowledge on the molecular network of CRC, including cellular signaling pathways, CRC microenvironment modulation, epigenetic changes, and CRC biomarkers for diagnosis and predictive/prognostic use. We also provide an overview of opportunities for the treatment and prevention strategies in this field.
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Affiliation(s)
- Zhe Huang
- The Department of 11 General Surgery, Minimally Invasive Colorectal Hernia Unit, Shengjing Hospital of China Medical University, Shenyang, China
| | - Mingli Yang
- The Department of 3Oncology, Gastrointestinal Cancer Unit, Shengjing Hospital of China Medical University, Shenyang, China
- *Correspondence: Mingli Yang,
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7
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Nagel AC, Müller D, Zimmermann M, Preiss A. The Membrane-Bound Notch Regulator Mnr Supports Notch Cleavage and Signaling Activity in Drosophila melanogaster. Biomolecules 2021; 11:1672. [PMID: 34827670 PMCID: PMC8615698 DOI: 10.3390/biom11111672] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Revised: 10/28/2021] [Accepted: 11/04/2021] [Indexed: 11/17/2022] Open
Abstract
The Notch signaling pathway is pivotal to cellular differentiation. Activation of this pathway involves proteolysis of the Notch receptor and the release of the biologically active Notch intracellular domain, acting as a transcriptional co-activator of Notch target genes. While the regulation of Notch signaling dynamics at the level of ligand-receptor interaction, endocytosis, and transcriptional regulation has been well studied, little is known about factors influencing Notch cleavage. We identified EP555 as a suppressor of the Notch antagonist Hairless (H). EP555 drives expression of CG32521 encoding membrane-bound proteins, which we accordingly rename membrane-bound Notch regulator (mnr). Within the signal-receiving cell, upregulation of Mnr stimulates Notch receptor activation, whereas a knockdown reduces it, without apparent influence on ligand-receptor interaction. We provide evidence that Mnr plays a role in γ-secretase-mediated intramembrane cleavage of the Notch receptor. As revealed by a fly-eye-based reporter system, γ-secretase activity is stimulated by the overexpression of Mnr, and is inhibited by its knockdown. We conclude that Mnr proteins support Notch signaling activity by fostering the cleavage of the Notch receptor. With Mnr, we identified a membrane-bound factor directly augmenting Notch intra-membrane processing, thereby acting as a positive regulator of Notch signaling activity.
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Affiliation(s)
- Anja C. Nagel
- Department of General Genetics 190g, University of Hohenheim, Garbenstr. 30, 70599 Stuttgart, Germany; (D.M.); (M.Z.); (A.P.)
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8
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Frankenreiter L, Gahr BM, Schmid H, Zimmermann M, Deichsel S, Hoffmeister P, Turkiewicz A, Borggrefe T, Oswald F, Nagel AC. Phospho-Site Mutations in Transcription Factor Suppressor of Hairless Impact Notch Signaling Activity During Hematopoiesis in Drosophila. Front Cell Dev Biol 2021; 9:658820. [PMID: 33937259 PMCID: PMC8079769 DOI: 10.3389/fcell.2021.658820] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 03/25/2021] [Indexed: 11/13/2022] Open
Abstract
The highly conserved Notch signaling pathway controls a multitude of developmental processes including hematopoiesis. Here, we provide evidence for a novel mechanism of tissue-specific Notch regulation involving phosphorylation of CSL transcription factors within the DNA-binding domain. Earlier we found that a phospho-mimetic mutation of the Drosophila CSL ortholog Suppressor of Hairless [Su(H)] at Ser269 impedes DNA-binding. By genome-engineering, we now introduced phospho-specific Su(H) mutants at the endogenous Su(H) locus, encoding either a phospho-deficient [Su(H) S269A ] or a phospho-mimetic [Su(H) S269D ] isoform. Su(H) S269D mutants were defective of Notch activity in all analyzed tissues, consistent with impaired DNA-binding. In contrast, the phospho-deficient Su(H) S269A mutant did not generally augment Notch activity, but rather specifically in several aspects of blood cell development. Unexpectedly, this process was independent of the corepressor Hairless acting otherwise as a general Notch antagonist in Drosophila. This finding is in agreement with a novel mode of Notch regulation by posttranslational modification of Su(H) in the context of hematopoiesis. Importantly, our studies of the mammalian CSL ortholog (RBPJ/CBF1) emphasize a potential conservation of this regulatory mechanism: phospho-mimetic RBPJ S221D was dysfunctional in both the fly as well as two human cell culture models, whereas phospho-deficient RBPJ S221A rather gained activity during fly hematopoiesis. Thus, dynamic phosphorylation of CSL-proteins within the DNA-binding domain provides a novel means to fine-tune Notch signal transduction in a context-dependent manner.
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Affiliation(s)
- Lisa Frankenreiter
- Department of General Genetics (190g), Institute of Biology (190), University of Hohenheim, Stuttgart, Germany
| | - Bernd M Gahr
- Department of General Genetics (190g), Institute of Biology (190), University of Hohenheim, Stuttgart, Germany
| | - Hannes Schmid
- Department of General Genetics (190g), Institute of Biology (190), University of Hohenheim, Stuttgart, Germany
| | - Mirjam Zimmermann
- Department of General Genetics (190g), Institute of Biology (190), University of Hohenheim, Stuttgart, Germany
| | - Sebastian Deichsel
- Department of General Genetics (190g), Institute of Biology (190), University of Hohenheim, Stuttgart, Germany
| | - Philipp Hoffmeister
- Department of Internal Medicine 1, Center for Internal Medicine, University Medical Center Ulm, Ulm, Germany
| | | | - Tilman Borggrefe
- Institute of Biochemistry, Justus-Liebig University of Giessen, Giessen, Germany
| | - Franz Oswald
- Department of Internal Medicine 1, Center for Internal Medicine, University Medical Center Ulm, Ulm, Germany
| | - Anja C Nagel
- Department of General Genetics (190g), Institute of Biology (190), University of Hohenheim, Stuttgart, Germany
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9
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Wolf DB, Maier D, Nagel AC. Nucleo-cytoplasmic shuttling of murine RBPJ by Hairless protein matches that of Su(H) protein in the model system Drosophila melanogaster. Hereditas 2021; 158:11. [PMID: 33775255 PMCID: PMC8006372 DOI: 10.1186/s41065-021-00175-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Accepted: 03/15/2021] [Indexed: 11/16/2022] Open
Abstract
Abstract CSL transcription factors are central to signal transduction in the highly conserved Notch signaling pathway. CSL acts as a molecular switch: depending on the cofactors recruited, CSL induces either activation or repression of Notch target genes. Unexpectedly, CSL depends on its cofactors for nuclear entry, despite its role as gene regulator. In Drosophila, the CSL homologue Suppressor of Hairless (Su(H)), recruits Hairless (H) for repressor complex assembly, and eventually for nuclear import. We recently found that Su(H) is subjected to a dynamic nucleo-cytoplasmic shuttling, thereby strictly following H subcellular distribution. Hence, regulation of nuclear availability of Su(H) by H may represent a new layer of control of Notch signaling activity. Here we extended this work on the murine CSL homologue RBPJ. Using a ‘murinized’ fly model bearing RBPJwt in place of Su(H) at the endogenous locus we demonstrate that RBPJ protein likewise follows H subcellular distribution. For example, overexpression of a H*NLS3 protein variant defective of nuclear import resulted in a cytosolic localization of RBPJ protein, whereas the overexpression of a H*NES protein variant defective in the nuclear export signal caused the accumulation of RBPJ protein in the nucleus. Evidently, RBPJ is exported from the nucleus as well. Overall these data demonstrate that in our fly model, RBPJ is subjected to H-mediated nucleo-cytoplasmic shuttling as is Su(H). These data raise the possibility that nuclear availability of mammalian CSL proteins is likewise restricted by cofactors, and may hence present a more general mode of regulating Notch signaling activity. Graphical abstract ![]()
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Affiliation(s)
- Dorina B Wolf
- Department of General Genetics (190g), University of Hohenheim, Garbenstr. 30, 70599, Stuttgart, Germany
| | - Dieter Maier
- Department of General Genetics (190g), University of Hohenheim, Garbenstr. 30, 70599, Stuttgart, Germany
| | - Anja C Nagel
- Department of General Genetics (190g), University of Hohenheim, Garbenstr. 30, 70599, Stuttgart, Germany.
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10
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Maier D. Membrane-Anchored Hairless Protein Restrains Notch Signaling Activity. Genes (Basel) 2020; 11:genes11111315. [PMID: 33171957 PMCID: PMC7694644 DOI: 10.3390/genes11111315] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Revised: 11/03/2020] [Accepted: 11/04/2020] [Indexed: 11/16/2022] Open
Abstract
The Notch signaling pathway governs cell-to-cell communication in higher eukaryotes. In Drosophila, after cleavage of the transmembrane receptor Notch, the intracellular domain of Notch (ICN) binds to the transducer Suppressor of Hairless (Su(H)) and shuttles into the nucleus to activate Notch target genes. Similarly, the Notch antagonist Hairless transfers Su(H) into the nucleus to repress Notch target genes. With the aim to prevent Su(H) nuclear translocation, Hairless was fused to a transmembrane domain to anchor the protein at membranes. Indeed, endogenous Su(H) co-localized with membrane-anchored Hairless, demonstrating their binding in the cytoplasm. Moreover, adult phenotypes uncovered a loss of Notch activity, in support of membrane-anchored Hairless sequestering Su(H) in the cytosol. A combined overexpression of membrane-anchored Hairless with Su(H) lead to tissue proliferation, which is in contrast to the observed apoptosis after ectopic co-overexpression of the wild-type genes, indicating a shift to a gain of Notch activity. A mixed response, general de-repression of Notch signaling output, plus inhibition at places of highest Notch activity, perhaps reflects Su(H)’s role as activator and repressor, supported by results obtained with the Hairless-binding deficient Su(H)LLL mutant, inducing activation only. Overall, the results strengthen the idea of Su(H) and Hairless complex formation within the cytosolic compartment.
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Affiliation(s)
- Dieter Maier
- Deptartment of General Genetics 190g, University of Hohenheim, Garbenstr. 30, 70599 Stuttgart, Germany
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11
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Nagel AC, Maier D, Scharpf J, Ketelhut M, Preiss A. Limited Availability of General Co-Repressors Uncovered in an Overexpression Context during Wing Venation in Drosophila melanogaster. Genes (Basel) 2020; 11:genes11101141. [PMID: 32998295 PMCID: PMC7601384 DOI: 10.3390/genes11101141] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 09/17/2020] [Accepted: 09/25/2020] [Indexed: 12/31/2022] Open
Abstract
Cell fate is determined by the coordinated activity of different pathways, including the conserved Notch pathway. Activation of Notch results in the transcription of Notch targets that are otherwise silenced by repressor complexes. In Drosophila, the repressor complex comprises the transcription factor Suppressor of Hairless (Su(H)) bound to the Notch antagonist Hairless (H) and the general co-repressors Groucho (Gro) and C-terminal binding protein (CtBP). The latter two are shared by different repressors from numerous pathways, raising the possibility that they are rate-limiting. We noted that the overexpression during wing development of H mutants HdNT and HLD compromised in Su(H)-binding induced ectopic veins. On the basis of the role of H as Notch antagonist, overexpression of Su(H)-binding defective H isoforms should be without consequence, implying different mechanisms but repression of Notch signaling activity. Perhaps excess H protein curbs general co-repressor availability. Supporting this model, nearly normal wings developed upon overexpression of H mutant isoforms that bound neither Su(H) nor co-repressor Gro and CtBP. Excessive H protein appeared to sequester general co-repressors, resulting in specific vein defects, indicating their limited availability during wing vein development. In conclusion, interpretation of overexpression phenotypes requires careful consideration of possible dominant negative effects from interception of limiting factors.
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12
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Arifuzzaman S, Khatun MR, Khatun R. Emerging of lysine demethylases (KDMs): From pathophysiological insights to novel therapeutic opportunities. Biomed Pharmacother 2020; 129:110392. [PMID: 32574968 DOI: 10.1016/j.biopha.2020.110392] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Revised: 06/06/2020] [Accepted: 06/09/2020] [Indexed: 12/12/2022] Open
Abstract
In recent years, there have been remarkable scientific advancements in the understanding of lysine demethylases (KDMs) because of their demethylation of diverse substrates, including nucleic acids and proteins. Novel structural architectures, physiological roles in the gene expression regulation, and ability to modify protein functions made KDMs the topic of interest in biomedical research. These structural diversities allow them to exert their function either alone or in complex with numerous other bio-macromolecules. Impressive number of studies have demonstrated that KDMs are localized dynamically across the cellular and tissue microenvironment. Their dysregulation is often associated with human diseases, such as cancer, immune disorders, neurological disorders, and developmental abnormalities. Advancements in the knowledge of the underlying biochemistry and disease associations have led to the development of a series of modulators and technical compounds. Given the distinct biophysical and biochemical properties of KDMs, in this review we have focused on advances related to the structure, function, disease association, and therapeutic targeting of KDMs highlighting improvements in both the specificity and efficacy of KDM modulation.
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Affiliation(s)
- Sarder Arifuzzaman
- Department of Pharmacy, Jahangirnagar University, Dhaka-1342, Bangladesh; Everest Pharmaceuticals Ltd., Dhaka-1208, Bangladesh.
| | - Mst Reshma Khatun
- Department of Pharmacy, Jahangirnagar University, Dhaka-1342, Bangladesh
| | - Rabeya Khatun
- Department of Pediatrics, TMSS Medical College and Rafatullah Community Hospital, Gokul, Bogura, 5800, Bangladesh
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13
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Epigenetic Regulation of Notch Signaling During Drosophila Development. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1218:59-75. [PMID: 32060871 DOI: 10.1007/978-3-030-34436-8_4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Notch signaling exerts multiple important functions in various developmental processes, including cell differentiation and cell proliferation, while mis-regulation of this pathway results in a variety of complex diseases, such as cancer and developmental defects. The simplicity of the Notch pathway in Drosophila melanogaster, in combination with the availability of powerful genetics, makes this an attractive model for studying the fundamental mechanisms of how Notch signaling is regulated and how it functions in various cellular contexts. Recently, increasing evidence for epigenetic control of Notch signaling reveals the intimate link between epigenetic regulators and Notch signaling pathway. In this chapter, we summarize the research advances of Notch and CAF-1 in Drosophila development and the epigenetic regulation mechanisms of Notch signaling activity by CAF-1 as well as other epigenetic modification machineries, which enables Notch to orchestrate different biological inputs and outputs in specific cellular contexts.
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14
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Koveitypour Z, Panahi F, Vakilian M, Peymani M, Seyed Forootan F, Nasr Esfahani MH, Ghaedi K. Signaling pathways involved in colorectal cancer progression. Cell Biosci 2019; 9:97. [PMID: 31827763 PMCID: PMC6889432 DOI: 10.1186/s13578-019-0361-4] [Citation(s) in RCA: 243] [Impact Index Per Article: 40.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Accepted: 11/22/2019] [Indexed: 02/07/2023] Open
Abstract
Colorectal cancer (CRC) is the fourth leading cause of the worldwide cancer mortality. Different molecular mechanisms have been attributed to the development and progress of CRC. In this review, we will focus on the mitogen-activated protein kinase (MAPK) cascades downstream of the epidermal growth factor receptor (EGFR), Notch, PI3K/AKT pathway, transforming growth factor-β (TGF-β), and Wnt signaling pathways. Various mutations in the components of these signaling pathways have been linked to the development of CRC. Accordingly, numerous efforts have been carried out to target the signaling pathways to develop novel therapeutic approaches. Herein, we review the signaling pathways involved in the incidence and progression of CRC, and the strategies for the therapy targeting components of signaling pathways in CRC.
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Affiliation(s)
- Zahra Koveitypour
- Department of Modern Biology, ACECR Institute of Higher Education (Isfahan Branch), Isfahan, Iran
| | - Farnoush Panahi
- Department of Modern Biology, ACECR Institute of Higher Education (Isfahan Branch), Isfahan, Iran
| | - Mehrdad Vakilian
- 6Department of Cell Regeneration and Advanced Therapies, Andalusian Center for Molecular Biology and Regenerative Medicine (CABIMER), University of Pablo de Olavide-University of Seville-CSIC, Seville, Spain.,7Department of Cellular Biology, Genetics and Physiology, Faculty of Science, University of Malaga (UMA), Malaga, Spain
| | - Maryam Peymani
- Department of Biology, Faculty of Basic Sciences, Shahrekord Branch, Islamic Azad University, P.O. Box: 88137-33395, Shahrekord, Iran.,4Department of Cellular Biotechnology, Cell Science Research Center, Royan Institute for Biotechnology, ACECR, P.O. Box: 816513-1378, Isfahan, Iran
| | - Farzad Seyed Forootan
- 4Department of Cellular Biotechnology, Cell Science Research Center, Royan Institute for Biotechnology, ACECR, P.O. Box: 816513-1378, Isfahan, Iran.,Legal Medicine Research Center, Legal Medicine Organization, Tehran, Iran
| | - Mohammad Hossein Nasr Esfahani
- 4Department of Cellular Biotechnology, Cell Science Research Center, Royan Institute for Biotechnology, ACECR, P.O. Box: 816513-1378, Isfahan, Iran
| | - Kamran Ghaedi
- 3Department of Cell and Molecular Biology and Microbiology, Faculty of Biological Science and Technology, University of Isfahan, Isfahan, Iran.,4Department of Cellular Biotechnology, Cell Science Research Center, Royan Institute for Biotechnology, ACECR, P.O. Box: 816513-1378, Isfahan, Iran
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15
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Gahr BM, Brändle F, Zimmermann M, Nagel AC. An RBPJ- Drosophila Model Reveals Dependence of RBPJ Protein Stability on the Formation of Transcription-Regulator Complexes. Cells 2019; 8:cells8101252. [PMID: 31615108 PMCID: PMC6829621 DOI: 10.3390/cells8101252] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Revised: 10/07/2019] [Accepted: 10/10/2019] [Indexed: 01/07/2023] Open
Abstract
Notch signaling activity governs widespread cellular differentiation in higher animals, including humans, and is involved in several congenital diseases and different forms of cancer. Notch signals are mediated by the transcriptional regulator RBPJ in a complex with activated Notch (NICD). Analysis of Notch pathway regulation in humans is hampered by a partial redundancy of the four Notch receptor copies, yet RBPJ is solitary, allowing its study in model systems. In Drosophila melanogaster, the RBPJ orthologue is encoded by Suppressor of Hairless [Su(H)]. Using genome engineering, we replaced Su(H) by murine RBPJ in order to study its function in the fly. In fact, RBPJ largely substitutes for Su(H)’s function, yet subtle phenotypes reflect increased Notch signaling activity. Accordingly, the binding of RBPJ to Hairless (H) protein, the general Notch antagonist in Drosophila, was considerably reduced compared to that of Su(H). An H-binding defective RBPJLLL mutant matched the respective Su(H)LLL allele: homozygotes were lethal due to extensive Notch hyperactivity. Moreover, RBPJLLL protein accumulated at lower levels than wild type RBPJ, except in the presence of NICD. Apparently, RBPJ protein stability depends on protein complex formation with either H or NICD, similar to Su(H), demonstrating that the murine homologue underlies the same regulatory mechanisms as Su(H) in Drosophila. These results underscore the importance of regulating the availability of RBPJ protein to correctly mediate Notch signaling activity in the fly.
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Affiliation(s)
- Bernd M. Gahr
- Institute of Genetics (240), University of Hohenheim, Garbenstr. 30, 70599 Stuttgart, Germany; (B.M.G.); (F.B.); (M.Z.)
- Present address: Molecular Cardiology, Department of Internal Medicine II, University of Ulm, Albert-Einstein-Allee 23, 89081 Ulm, Germany
| | - Franziska Brändle
- Institute of Genetics (240), University of Hohenheim, Garbenstr. 30, 70599 Stuttgart, Germany; (B.M.G.); (F.B.); (M.Z.)
| | - Mirjam Zimmermann
- Institute of Genetics (240), University of Hohenheim, Garbenstr. 30, 70599 Stuttgart, Germany; (B.M.G.); (F.B.); (M.Z.)
| | - Anja C. Nagel
- Institute of Genetics (240), University of Hohenheim, Garbenstr. 30, 70599 Stuttgart, Germany; (B.M.G.); (F.B.); (M.Z.)
- Correspondence: ; Tel.: +49-711-45922210
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16
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Maier D. The evolution of transcriptional repressors in the Notch signaling pathway: a computational analysis. Hereditas 2019; 156:5. [PMID: 30679936 PMCID: PMC6337844 DOI: 10.1186/s41065-019-0081-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Accepted: 01/09/2019] [Indexed: 11/18/2022] Open
Abstract
Background The Notch signaling pathway governs the specification of different cell types in flies, nematodes and vertebrates alike. Principal components of the pathway that activate Notch target genes are highly conserved throughout the animal kingdom. Despite the impact on development and disease, repression mechanisms are less well studied. Repressors are known from arthropods and vertebrates that differ strikingly by mode of action: whereas Drosophila Hairless assembles repressor complexes with CSL transcription factors, competition between activator and repressors occurs in vertebrates (for example SHARP/MINT and KyoT2). This divergence raises questions on the evolution: Are there common ancestors throughout the animal kingdom? Results Available genome databases representing all animal clades were searched for homologues of Hairless, SHARP and KyoT2. The most distant species with convincing Hairless orthologs belong to Myriapoda, indicating its emergence after the Mandibulata-Chelicarata radiation about 500 million years ago. SHARP shares motifs with SPEN and SPENITO proteins, present throughout the animal kingdom. The CSL interacting domain of SHARP, however, is specific to vertebrates separated by roughly 600 million years of evolution. KyoT2 bears a C-terminal CSL interaction domain (CID), present only in placental mammals but highly diverged already in marsupials, suggesting introduction roughly 100 million years ago. Based on the LIM-domains that characterize KyoT2, homologues can be found in Drosophila melanogaster (Limpet) and Hydra vulgaris (Prickle 3 like). These lack the CID of KyoT2, however, contain a PET and additional LIM domains. Conservation of intron/exon boundaries underscores the phylogenetic relationship between KyoT2, Limpet and Prickle. Most strikingly, Limpet and Prickle proteins carry a tetra-peptide motif resembling that of several CSL interactors. Overall, KyoT2 may have evolved from prickle and Limpet to a Notch repressor in mammals. Conclusions Notch repressors appear to be specific to either chordates or arthropods. Orthologues of experimentally validated repressors were not found outside the phylogenetic group they have been originally identified. However, the data provide a hypothesis on the evolution of mammalian KyoT2 from Prickle like ancestors. The finding of a potential CSL interacting domain in Prickle homologues points to a novel, very ancestral CSL interactor present in the entire animal kingdom. Electronic supplementary material The online version of this article (10.1186/s41065-019-0081-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Dieter Maier
- Institute of Genetics (240), University of Hohenheim, Garbenstr. 30, 70599 Stuttgart, Germany
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17
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Smylla TK, Meier M, Preiss A, Maier D. The Notch repressor complex in Drosophila: in vivo analysis of Hairless mutants using overexpression experiments. Dev Genes Evol 2019; 229:13-24. [PMID: 30612166 DOI: 10.1007/s00427-018-00624-2] [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: 09/14/2018] [Accepted: 12/17/2018] [Indexed: 10/27/2022]
Abstract
During development of higher animals, the Notch signalling pathway governs cell type specification by mediating appropriate gene expression responses. In the absence of signalling, Notch target genes are silenced by repressor complexes. In the model organism Drosophila melanogaster, the repressor complex includes the transcription factor Suppressor of Hairless [Su(H)] and Hairless (H) plus general co-repressors. Recent crystal structure analysis of the Drosophila Notch repressor revealed details of the Su(H)-H complex. They were confirmed by mutational analyses of either protein; however, only Su(H) mutants have been further studied in vivo. Here, we analyse three H variants predicted to affect Su(H) binding. To this end, amino acid replacements Phenylalanine 237, Leucines 245 and 247, as well as Tryptophan 258 to Alanine were introduced into the H protein. A cell-based reporter assay indicates substantial loss of Su(H) binding to the respective mutant proteins HFA, HLLAA and HWA. For in vivo analysis, UAS-lines HFA, HLLAA and HWA were generated to allow spatially restricted overexpression. In these assays, all three mutants resembled the HLD control, shown before to lack Su(H) binding, indicating a strong reduction of H activity. For example, the H variants were impaired in wing margin formation, but unexpectedly induced ectopic wing venation. Concurrent overexpression with Su(H), however, suggests that all mutant H protein isoforms are still able to bind Su(H) in vivo. We conclude that a weakening of the cohesion in the H-Su(H) repressor complex is sufficient for disrupting its in vivo functionality.
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Affiliation(s)
- Thomas K Smylla
- Institut für Genetik, Universität Hohenheim, Garbenstr. 30, 70599, Stuttgart, Germany
| | - Markus Meier
- Institut für Genetik, Universität Hohenheim, Garbenstr. 30, 70599, Stuttgart, Germany
| | - Anette Preiss
- Institut für Genetik, Universität Hohenheim, Garbenstr. 30, 70599, Stuttgart, Germany
| | - Dieter Maier
- Institut für Genetik, Universität Hohenheim, Garbenstr. 30, 70599, Stuttgart, Germany.
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18
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Singh A, Paul MS, Dutta D, Mutsuddi M, Mukherjee A. Regulation of notch signaling by a chromatin modeling protein Hat-trick. Development 2019; 146:dev.170837. [DOI: 10.1242/dev.170837] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2018] [Accepted: 05/16/2019] [Indexed: 01/08/2023]
Abstract
Notch signaling plays pleiotropic role in astounding variety of cellular processes including cell fate determination, differentiation, proliferation and apoptosis. The increasingly complex regulatory mechanisms of Notch signaling account for the multitude of functions exhibited by Notch during development. We identified Hat-trick (Htk), a DNA binding protein, as an interacting partner of Notch-ICD in a yeast two-hybrid screen and their physical interaction was further validated by co-immunoprecipitation experiments. htk genetically interacts with Notch pathway components in trans-heterozygous combinations. Loss of htk function in htk mutant somatic clones showed down-regulation of Notch targets, whereas over-expression of htk caused ectopic expression of Notch target, without affecting the level of Notch protein. Immunocytochemical analysis has demonstrated that Htk co-localizes with over-expressed Notch-ICD in the same nuclear compartment. We have shown here that Htk cooperates with Notch-ICD and Suppressor of Hairless to form activation complex and binds to the regulatory sequences of Notch downstream targets, Enhancer of Split complex genes to direct their expression. Taken together, our results suggest a novel mode of regulation of Notch signaling by a chromatin modeling protein Htk.
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Affiliation(s)
- Ankita Singh
- Department of Molecular and Human Genetics, Institute of Science, Banaras Hindu University, Varanasi-221005, Uttar Pradesh, India
| | - Maimuna S. Paul
- Department of Molecular and Human Genetics, Institute of Science, Banaras Hindu University, Varanasi-221005, Uttar Pradesh, India
| | - Debdeep Dutta
- Department of Molecular and Human Genetics, Institute of Science, Banaras Hindu University, Varanasi-221005, Uttar Pradesh, India
| | - Mousumi Mutsuddi
- Department of Molecular and Human Genetics, Institute of Science, Banaras Hindu University, Varanasi-221005, Uttar Pradesh, India
| | - Ashim Mukherjee
- Department of Molecular and Human Genetics, Institute of Science, Banaras Hindu University, Varanasi-221005, Uttar Pradesh, India
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19
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Petruccelli E, Feyder M, Ledru N, Jaques Y, Anderson E, Kaun KR. Alcohol Activates Scabrous-Notch to Influence Associated Memories. Neuron 2018; 100:1209-1223.e4. [PMID: 30482693 DOI: 10.1016/j.neuron.2018.10.005] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Revised: 08/17/2018] [Accepted: 10/02/2018] [Indexed: 12/17/2022]
Abstract
Drugs of abuse, like alcohol, modulate gene expression in reward circuits and consequently alter behavior. However, the in vivo cellular mechanisms through which alcohol induces lasting transcriptional changes are unclear. We show that Drosophila Notch/Su(H) signaling and the secreted fibrinogen-related protein Scabrous in mushroom body (MB) memory circuitry are important for the enduring preference of cues associated with alcohol's rewarding properties. Alcohol exposure affects Notch responsivity in the adult MB and alters Su(H) targeting at the dopamine-2-like receptor (Dop2R). Alcohol cue training also caused lasting changes to the MB nuclear transcriptome, including changes in the alternative splicing of Dop2R and newly implicated transcripts like Stat92E. Together, our data suggest that alcohol-induced activation of the highly conserved Notch pathway and accompanying transcriptional responses in memory circuitry contribute to addiction. Ultimately, this provides mechanistic insight into the etiology and pathophysiology of alcohol use disorder.
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Affiliation(s)
- Emily Petruccelli
- Department of Neuroscience, Brown University, Providence, RI 02912, USA
| | - Michael Feyder
- Department of Neuroscience, Brown University, Providence, RI 02912, USA
| | - Nicolas Ledru
- Department of Neuroscience, Brown University, Providence, RI 02912, USA
| | - Yanabah Jaques
- Department of Neuroscience, Brown University, Providence, RI 02912, USA
| | - Edward Anderson
- Department of Neuroscience, Brown University, Providence, RI 02912, USA
| | - Karla R Kaun
- Department of Neuroscience, Brown University, Providence, RI 02912, USA.
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20
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Kim GS, Park HS, Lee YC. OPTHiS Identifies the Molecular Basis of the Direct Interaction between CSL and SMRT Corepressor. Mol Cells 2018; 41:842-852. [PMID: 30157580 PMCID: PMC6182220 DOI: 10.14348/molcells.2018.0196] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Revised: 06/18/2018] [Accepted: 07/19/2018] [Indexed: 01/17/2023] Open
Abstract
Notch signaling is an evolutionarily conserved pathway and involves in the regulation of various cellular and developmental processes. Ligand binding releases the intracellular domain of Notch receptor (NICD), which interacts with DNA-bound CSL [CBF1/Su(H)/Lag-1] to activate transcription of target genes. In the absence of NICD binding, CSL down-regulates target gene expression through the recruitment of various corepressor proteins including SMRT/NCoR (silencing mediator of retinoid and thyroid receptors/nuclear receptor corepressor), SHARP (SMRT/HDAC1-associated repressor protein), and KyoT2. Structural and functional studies revealed the molecular basis of these interactions, in which NICD coactivator and corepressor proteins competitively bind to β-trefoil domain (BTD) of CSL using a conserved ϕWϕP motif (ϕ denotes any hydrophobic residues). To date, there are conflicting ideas regarding the molecular mechanism of SMRT-mediated repression of CSL as to whether CSL-SMRT interaction is direct or indirect (via the bridge factor SHARP). To solve this issue, we mapped the CSL-binding region of SMRT and employed a 'one- plus two-hybrid system' to obtain CSL interaction-defective mutants for this region. We identified the CSL-interaction module of SMRT (CIMS; amino acid 1816-1846) as the molecular determinant of its direct interaction with CSL. Notably, CIMS contains a canonical ϕWϕP sequence (APIWRP, amino acids 1832-1837) and directly interacts with CSL-BTD in a mode similar to other BTD-binding corepressors. Finally, we showed that CSL-interaction motif, rather than SHARP-interaction motif, of SMRT is involved in transcriptional repression of NICD in a cell-based assay. These results strongly suggest that SMRT participates in CSL-mediated repression via direct binding to CSL.
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Affiliation(s)
- Gwang Sik Kim
- School of Biological Sciences and Technology, Chonnam National University, Gwangju 61186,
Korea
| | - Hee-Sae Park
- School of Biological Sciences and Technology, Chonnam National University, Gwangju 61186,
Korea
| | - Young Chul Lee
- School of Biological Sciences and Technology, Chonnam National University, Gwangju 61186,
Korea
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21
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Wang Z, Lyu J, Wang F, Miao C, Nan Z, Zhang J, Xi Y, Zhou Q, Yang X, Ge W. The histone deacetylase HDAC1 positively regulates Notch signaling during Drosophila wing development. Biol Open 2018; 7:bio.029637. [PMID: 29437043 PMCID: PMC5861358 DOI: 10.1242/bio.029637] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
The Notch signaling pathway is highly conserved across different animal species and plays crucial roles in development and physiology. Regulation of Notch signaling occurs at multiple levels in different tissues and cell types. Here, we show that the histone deacetylase HDAC1 acts as a positive regulator of Notch signaling during Drosophila wing development. Depletion of HDAC1 causes wing notches on the margin of adult wing. Consistently, the expression of Notch target genes is reduced in the absence of HDAC1 during wing margin formation. We further provide evidence that HDAC1 acts upstream of Notch activation. Mechanistically, we show that HDAC1 regulates Notch protein levels by promoting Notch transcription. Consistent with this, the HDAC1-associated transcriptional co-repressor Atrophin (Atro) is also required for transcriptional activation of Notch in the wing disc. In summary, our results demonstrate that HDAC1 positively regulates Notch signaling and reveal a previously unidentified function of HDAC1 in Notch signaling.
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Affiliation(s)
- Zehua Wang
- Division of Human Reproduction and Developmental Genetics, The Women's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China.,Institute of Genetics and Department of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China.,College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Jialan Lyu
- Division of Human Reproduction and Developmental Genetics, The Women's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China.,Institute of Genetics and Department of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Fang Wang
- College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Chen Miao
- Division of Human Reproduction and Developmental Genetics, The Women's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China.,Institute of Genetics and Department of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Zi Nan
- College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Jiayu Zhang
- Life Sciences Institute, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Yongmei Xi
- Division of Human Reproduction and Developmental Genetics, The Women's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China.,Institute of Genetics and Department of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Qi Zhou
- Life Sciences Institute, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Xiaohang Yang
- Division of Human Reproduction and Developmental Genetics, The Women's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China.,Institute of Genetics and Department of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Wanzhong Ge
- Division of Human Reproduction and Developmental Genetics, The Women's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China .,Institute of Genetics and Department of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
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22
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Salazar JL, Yamamoto S. Integration of Drosophila and Human Genetics to Understand Notch Signaling Related Diseases. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1066:141-185. [PMID: 30030826 PMCID: PMC6233323 DOI: 10.1007/978-3-319-89512-3_8] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Notch signaling research dates back to more than one hundred years, beginning with the identification of the Notch mutant in the fruit fly Drosophila melanogaster. Since then, research on Notch and related genes in flies has laid the foundation of what we now know as the Notch signaling pathway. In the 1990s, basic biological and biochemical studies of Notch signaling components in mammalian systems, as well as identification of rare mutations in Notch signaling pathway genes in human patients with rare Mendelian diseases or cancer, increased the significance of this pathway in human biology and medicine. In the 21st century, Drosophila and other genetic model organisms continue to play a leading role in understanding basic Notch biology. Furthermore, these model organisms can be used in a translational manner to study underlying mechanisms of Notch-related human diseases and to investigate the function of novel disease associated genes and variants. In this chapter, we first briefly review the major contributions of Drosophila to Notch signaling research, discussing the similarities and differences between the fly and human pathways. Next, we introduce several biological contexts in Drosophila in which Notch signaling has been extensively characterized. Finally, we discuss a number of genetic diseases caused by mutations in genes in the Notch signaling pathway in humans and we expand on how Drosophila can be used to study rare genetic variants associated with these and novel disorders. By combining modern genomics and state-of-the art technologies, Drosophila research is continuing to reveal exciting biology that sheds light onto mechanisms of disease.
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Affiliation(s)
- Jose L Salazar
- Department of Molecular and Human Genetics, Baylor College of Medicine (BCM), Houston, TX, USA
| | - Shinya Yamamoto
- Department of Molecular and Human Genetics, Baylor College of Medicine (BCM), Houston, TX, USA.
- Program in Developmental Biology, BCM, Houston, TX, USA.
- Department of Neuroscience, BCM, Houston, TX, USA.
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA.
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23
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Molecular mechanism underlying juvenile hormone-mediated repression of precocious larval-adult metamorphosis. Proc Natl Acad Sci U S A 2017; 114:1057-1062. [PMID: 28096379 DOI: 10.1073/pnas.1615423114] [Citation(s) in RCA: 117] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Juvenile hormone (JH) represses precocious metamorphosis of larval to pupal and adult transitions in holometabolous insects. The early JH-inducible gene Krüppel homolog 1 (Kr-h1) plays a key role in the repression of metamorphosis as a mediator of JH action. Previous studies demonstrated that Kr-h1 inhibits precocious larval-pupal transition in immature larva via direct transcriptional repression of the pupal specifier Broad-Complex (BR-C). JH was recently reported to repress the adult specifier gene Ecdysone-induced protein 93F (E93); however, its mechanism of action remains unclear. Here, we found that JH suppressed ecdysone-inducible E93 expression in the epidermis of the silkworm Bombyx mori and in a B. mori cell line. Reporter assays in the cell line revealed that the JH-dependent suppression was mediated by Kr-h1. Genome-wide ChIP-seq analysis identified a consensus Kr-h1 binding site (KBS, 14 bp) located in the E93 promoter region, and EMSA confirmed that Kr-h1 directly binds to the KBS. Moreover, we identified a C-terminal conserved domain in Kr-h1 essential for the transcriptional repression of E93 Based on these results, we propose a mechanism in which JH-inducible Kr-h1 directly binds to the KBS site upstream of the E93 locus to repress its transcription in a cell-autonomous manner, thereby preventing larva from bypassing the pupal stage and progressing to precocious adult development. These findings help to elucidate the molecular mechanisms regulating the metamorphic genetic network, including the functional significance of Kr-h1, BR-C, and E93 in holometabolous insect metamorphosis.
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