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Webb JA, Farrow E, Cain B, Yuan Z, Yarawsky AE, Schoch E, Gagliani EK, Herr AB, Gebelein B, Kovall RA. Cooperative Gsx2-DNA Binding Requires DNA Bending and a Novel Gsx2 Homeodomain Interface. bioRxiv 2023:2023.12.08.570805. [PMID: 38106145 PMCID: PMC10723402 DOI: 10.1101/2023.12.08.570805] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2023]
Abstract
The conserved Gsx homeodomain (HD) transcription factors specify neural cell fates in animals from flies to mammals. Like many HD proteins, Gsx factors bind A/T-rich DNA sequences prompting the question - how do HD factors that bind similar DNA sequences in vitro regulate specific target genes in vivo? Prior studies revealed that Gsx factors bind DNA both as a monomer on individual A/T-rich sites and as a cooperative homodimer to two sites spaced precisely seven base pairs apart. However, the mechanistic basis for Gsx DNA binding and cooperativity are poorly understood. Here, we used biochemical, biophysical, structural, and modeling approaches to (1) show that Gsx factors are monomers in solution and require DNA for cooperative complex formation; (2) define the affinity and thermodynamic binding parameters of Gsx2/DNA interactions; (3) solve a high-resolution monomer/DNA structure that reveals Gsx2 induces a 20° bend in DNA; (4) identify a Gsx2 protein-protein interface required for cooperative DNA binding; and (5) determine that flexible spacer DNA sequences enhance Gsx2 cooperativity on dimer sites. Altogether, our results provide a mechanistic basis for understanding the protein and DNA structural determinants that underlie cooperative DNA binding by Gsx factors, thereby providing a deeper understanding of HD specificity.
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Affiliation(s)
- Jordan A. Webb
- Department of Molecular and Cellular Biosciences, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA
| | - Edward Farrow
- Graduate Program in Molecular and Developmental Biology, Cincinnati Children’s Hospital Research Foundation, Cincinnati, OH 45229, USA
- Medical-Scientist Training Program, University of Cincinnati College of Medicine, Cincinnati, OH 45229, USA
| | - Brittany Cain
- Division of Developmental Biology, Cincinnati Children’s Hospital Medical Center, 3333 Burnet Ave, MLC 7007, Cincinnati, OH 45229, USA
| | - Zhenyu Yuan
- Department of Molecular and Cellular Biosciences, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA
| | - Alexander E. Yarawsky
- Division of Immunobiology, Cincinnati Children’s Hospital Medical Center, 3333, Burnet Ave, Cincinnati, OH 45229, USA
| | - Emma Schoch
- Department of Medical Education, University of Cincinnati College of Medicine, Cincinnati, OH 45229, USA
| | - Ellen K. Gagliani
- Department of Chemistry, Xavier University, Cincinnati, OH 45207, USA
| | - Andrew B. Herr
- Division of Immunobiology, Cincinnati Children’s Hospital Medical Center, 3333, Burnet Ave, Cincinnati, OH 45229, USA
| | - Brian Gebelein
- Division of Developmental Biology, Cincinnati Children’s Hospital Medical Center, 3333 Burnet Ave, MLC 7007, Cincinnati, OH 45229, USA
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH 45229, USA
| | - Rhett A. Kovall
- Department of Molecular and Cellular Biosciences, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA
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2
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Diluvio G, Kelley TT, Lahiry M, Alvarez-Trotta A, Kolb EM, Shersher E, Astudillo L, Kovall RA, Schürer SC, Capobianco AJ. A novel chemical attack on Notch-mediated transcription by targeting the NACK ATPase. Mol Ther Oncolytics 2023; 28:307-320. [PMID: 36938545 PMCID: PMC10015116 DOI: 10.1016/j.omto.2023.02.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Accepted: 02/17/2023] [Indexed: 02/25/2023] Open
Abstract
Notch activation complex kinase (NACK) is a component of the Notch transcriptional machinery critical for the Notch-mediated tumorigenesis. However, the mechanism through which NACK regulates Notch-mediated transcription is not well understood. Here, we demonstrate that NACK binds and hydrolyzes ATP and that only ATP-bound NACK can bind to the Notch ternary complex (NTC). Considering this, we sought to identify inhibitors of this ATP-dependent function and, using computational pipelines, discovered the first small-molecule inhibitor of NACK, Z271-0326, that directly blocks the activity of Notch-mediated transcription and shows potent antineoplastic activity in PDX mouse models. In conclusion, we have discovered the first inhibitor that holds promise for the efficacious treatment of Notch-driven cancers by blocking the Notch activity downstream of the NTC.
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Affiliation(s)
- Giulia Diluvio
- Molecular Oncology Program, The DeWitt Daughtry Family Department of Surgery, Miller School of Medicine, University of Miami, Miami, FL 33136, USA
- Sylvester Comprehensive Cancer Center, Miller School of Medicine, University of Miami, Miami, FL 33136, USA
| | - Tanya T. Kelley
- Sylvester Comprehensive Cancer Center, Miller School of Medicine, University of Miami, Miami, FL 33136, USA
- Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Mohini Lahiry
- Molecular Oncology Program, The DeWitt Daughtry Family Department of Surgery, Miller School of Medicine, University of Miami, Miami, FL 33136, USA
- Sylvester Comprehensive Cancer Center, Miller School of Medicine, University of Miami, Miami, FL 33136, USA
| | - Annamil Alvarez-Trotta
- Molecular Oncology Program, The DeWitt Daughtry Family Department of Surgery, Miller School of Medicine, University of Miami, Miami, FL 33136, USA
- Sylvester Comprehensive Cancer Center, Miller School of Medicine, University of Miami, Miami, FL 33136, USA
| | - Ellen M. Kolb
- Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati, Cincinnati, OH 45267, USA
| | - Elena Shersher
- Molecular Oncology Program, The DeWitt Daughtry Family Department of Surgery, Miller School of Medicine, University of Miami, Miami, FL 33136, USA
- Sylvester Comprehensive Cancer Center, Miller School of Medicine, University of Miami, Miami, FL 33136, USA
- Cancer Epigenetics Program, Sylvester Comprehensive Cancer Center, Miller School of Medicine, University of Miami, Miami, FL 33136, USA
| | - Luisana Astudillo
- Molecular Oncology Program, The DeWitt Daughtry Family Department of Surgery, Miller School of Medicine, University of Miami, Miami, FL 33136, USA
- Sylvester Comprehensive Cancer Center, Miller School of Medicine, University of Miami, Miami, FL 33136, USA
| | - Rhett A. Kovall
- Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati, Cincinnati, OH 45267, USA
| | - Stephan C. Schürer
- Sylvester Comprehensive Cancer Center, Miller School of Medicine, University of Miami, Miami, FL 33136, USA
- Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, FL 33136, USA
- Corresponding author: Stephan C. Schürer, Miller School of Medicine, University of Miami, 1600 North West 10th Avenue, Miami, FL 33136, USA.
| | - Anthony J. Capobianco
- Molecular Oncology Program, The DeWitt Daughtry Family Department of Surgery, Miller School of Medicine, University of Miami, Miami, FL 33136, USA
- Sylvester Comprehensive Cancer Center, Miller School of Medicine, University of Miami, Miami, FL 33136, USA
- Corresponding author: Anthony J. Capobianco, Miller School of Medicine, University of Miami, 1600 North West 10th Avenue, Miami, FL 33136, USA.
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3
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Chandra H, Kovall RA, Yadav JS, Sun X. Host Immune Responses to Surface S-Layer Proteins (SLPs) of Clostridioides difficile. Microorganisms 2023; 11:380. [PMID: 36838345 PMCID: PMC9963625 DOI: 10.3390/microorganisms11020380] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2023] [Revised: 01/28/2023] [Accepted: 02/01/2023] [Indexed: 02/05/2023] Open
Abstract
Clostridioides difficile, a nosocomial pathogen, is an emerging gut pathobiont causing antibiotic-associated diarrhea. C. difficile infection involves gut colonization and disruption of the gut epithelial barrier, leading to the induction of inflammatory/immune responses. The expression of two major exotoxins, TcdA and TcdB is the major cause of C. difficile pathogenicity. Attachment of bacterial abundant cell wall proteins or surface S-layer proteins (SLPs) such as SlpA with host epithelial cells is critical for virulence. In addition to being toxins, these surface components have been shown to be highly immunogenic. Recent studies indicate that C. difficile SLPs play important roles in the adhesion of the bacteria to the intestinal epithelial cells, disruption of tight junctions, and modulation of the immune response of the host cells. These proteins might serve as new targets for vaccines and new therapeutic agents. This review summarizes our current understanding of the immunological role of SLPs in inducing host immunity and their use in the development of vaccines and novel therapeutics to combat C. difficile infection.
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Affiliation(s)
- Harish Chandra
- Department of Environmental Microbiology, School of Earth and Environmental Sciences, Babasaheb Bhimrao Ambedkar University, Lucknow 226025, UP, India
- Department of Molecular and Cellular Biosciences, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA
| | - Rhett A. Kovall
- Department of Molecular and Cellular Biosciences, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA
| | - Jagjit S. Yadav
- Department of Environmental and Public Health Sciences, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA
| | - Xingmin Sun
- Department of Molecular Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL 33612, USA
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4
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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5
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Gagliani EK, Gutzwiller LM, Kuang Y, Odaka Y, Hoffmeister P, Hauff S, Turkiewicz A, Harding-Theobald E, Dolph PJ, Borggrefe T, Oswald F, Gebelein B, Kovall RA. A Drosophila Su(H) model of Adams-Oliver Syndrome reveals cofactor titration as a mechanism underlying developmental defects. PLoS Genet 2022; 18:e1010335. [PMID: 35951645 PMCID: PMC9398005 DOI: 10.1371/journal.pgen.1010335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Revised: 08/23/2022] [Accepted: 07/11/2022] [Indexed: 12/02/2022] Open
Abstract
Notch signaling is a conserved pathway that converts extracellular receptor-ligand interactions into changes in gene expression via a single transcription factor (CBF1/RBPJ in mammals; Su(H) in Drosophila). In humans, RBPJ variants have been linked to Adams-Oliver syndrome (AOS), a rare autosomal dominant disorder characterized by scalp, cranium, and limb defects. Here, we found that a previously described Drosophila Su(H) allele encodes a missense mutation that alters an analogous residue found in an AOS-associated RBPJ variant. Importantly, genetic studies support a model that heterozygous Drosophila with the AOS-like Su(H) allele behave in an opposing manner to heterozygous flies with a Su(H) null allele, due to a dominant activity of sequestering either the Notch co-activator or the antagonistic Hairless co-repressor. Consistent with this model, AOS-like Su(H) and Rbpj variants have decreased DNA binding activity compared to wild type proteins, but these variants do not significantly alter protein binding to the Notch co-activator or the fly and mammalian co-repressors, respectively. Taken together, these data suggest a cofactor sequestration mechanism underlies AOS phenotypes associated with RBPJ variants, whereby the AOS-associated RBPJ allele encodes a protein with compromised DNA binding activity that retains cofactor binding, resulting in Notch target gene dysregulation. Adams-Oliver Syndrome (AOS) is a rare disease defined by missing skin/skull tissue, limb malformations, and cardiovascular abnormalities. Human genetic studies have revealed that ~40% of AOS patients inherit dominant mutations within specific genes in the Notch signaling pathway. Notch signaling is a highly conserved cell-to-cell communication pathway found in all metazoans and plays crucial roles during embryogenesis and tissue homeostasis in organisms from Drosophila (fruit-flies) to mammals. The Notch receptor converts cell-to-cell interactions into a Notch signal that enters the nucleus and activates target genes by binding to a highly conserved transcription factor. Here, we took advantage of the unexpected finding that a previously described dominant allele in the Drosophila Notch pathway transcription factor contains a missense variant in an analogous residue found in a family with AOS. Using this novel animal model of AOS along with biochemical DNA binding, protein-protein interaction, and transcriptional reporter assays, we found that this transcription factor variant selectively compromises DNA binding but not binding to the Notch signal nor binding to other proteins in the Notch pathway. Taken together with prior human genetic studies, these data suggest AOS phenotypes associated with variants in the Notch pathway transcription factor are caused by a dominant mechanism that sequesters the Notch signal, leading to Notch target gene dysregulation.
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Affiliation(s)
- Ellen K. Gagliani
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States of America
| | - Lisa M. Gutzwiller
- Division of Developmental Biology, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, United States of America
| | - Yi Kuang
- Graduate program in Molecular and Developmental Biology, Cincinnati Children’s Hospital Research Foundation, Cincinnati, Ohio, United States of America
| | - Yoshinobu Odaka
- Biology Department, University of Cincinnati Blue Ash College, Cincinnati, Ohio, United States of America
| | - Phillipp Hoffmeister
- University Medical Center Ulm, Center for Internal Medicine, Department of Internal Medicine, Ulm, Germany
| | - Stefanie Hauff
- University Medical Center Ulm, Center for Internal Medicine, Department of Internal Medicine, Ulm, Germany
| | | | - Emily Harding-Theobald
- Department of Biology, Dartmouth College, Hanover, New Hampshire, United States of America
| | - Patrick J. Dolph
- Department of Biology, Dartmouth College, Hanover, New Hampshire, United States of America
| | - Tilman Borggrefe
- Institute of Biochemistry, University of Giessen, Giessen, Germany
| | - Franz Oswald
- University Medical Center Ulm, Center for Internal Medicine, Department of Internal Medicine, Ulm, Germany
| | - Brian Gebelein
- Division of Developmental Biology, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, United States of America
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States of America
- * E-mail: (BG); (RAK)
| | - Rhett A. Kovall
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States of America
- * E-mail: (BG); (RAK)
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6
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Barreyro L, Sampson AM, Ishikawa C, Hueneman KM, Choi K, Pujato MA, Chutipongtanate S, Wyder M, Haffey WD, O'Brien E, Wunderlich M, Ramesh V, Kolb EM, Meydan C, Neelamraju Y, Bolanos LC, Christie S, Smith MA, Niederkorn M, Muto T, Kesari S, Garrett-Bakelman FE, Bartholdy B, Will B, Weirauch MT, Mulloy JC, Gul Z, Medlin S, Kovall RA, Melnick AM, Perentesis JP, Greis KD, Nurmemmedov E, Seibel WL, Starczynowski DT. Blocking UBE2N abrogates oncogenic immune signaling in acute myeloid leukemia. Sci Transl Med 2022; 14:eabb7695. [PMID: 35263148 DOI: 10.1126/scitranslmed.abb7695] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Dysregulation of innate immune signaling pathways is implicated in various hematologic malignancies. However, these pathways have not been systematically examined in acute myeloid leukemia (AML). We report that AML hematopoietic stem and progenitor cells (HSPCs) exhibit a high frequency of dysregulated innate immune-related and inflammatory pathways, referred to as oncogenic immune signaling states. Through gene expression analyses and functional studies in human AML cell lines and patient-derived samples, we found that the ubiquitin-conjugating enzyme UBE2N is required for leukemic cell function in vitro and in vivo by maintaining oncogenic immune signaling states. It is known that the enzyme function of UBE2N can be inhibited by interfering with thioester formation between ubiquitin and the active site. We performed in silico structure-based and cellular-based screens and identified two related small-molecule inhibitors UC-764864/65 that targeted UBE2N at its active site. Using these small-molecule inhibitors as chemical probes, we further revealed the therapeutic efficacy of interfering with UBE2N function. This resulted in the blocking of ubiquitination of innate immune- and inflammatory-related substrates in human AML cell lines. Inhibition of UBE2N function disrupted oncogenic immune signaling by promoting cell death of leukemic HSPCs while sparing normal HSPCs in vitro. Moreover, baseline oncogenic immune signaling states in leukemic cells derived from discrete subsets of patients with AML exhibited a selective dependency on UBE2N function in vitro and in vivo. Our study reveals that interfering with UBE2N abrogates leukemic HSPC function and underscores the dependency of AML cells on UBE2N-dependent oncogenic immune signaling states.
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Affiliation(s)
- Laura Barreyro
- Division of Experimental Hematology and Cancer Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Avery M Sampson
- Division of Experimental Hematology and Cancer Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Chiharu Ishikawa
- Division of Experimental Hematology and Cancer Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Kathleen M Hueneman
- Division of Experimental Hematology and Cancer Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Kwangmin Choi
- Division of Experimental Hematology and Cancer Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Mario A Pujato
- Center for Autoimmune Genetics and Etiology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Somchai Chutipongtanate
- Department of Cancer Biology, University of Cincinnati, Cincinnati, OH, USA.,Department of Pediatrics, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok, Thailand
| | - Michael Wyder
- Department of Cancer Biology, University of Cincinnati, Cincinnati, OH, USA
| | - Wendy D Haffey
- Department of Cancer Biology, University of Cincinnati, Cincinnati, OH, USA
| | - Eric O'Brien
- Division of Oncology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Mark Wunderlich
- Division of Experimental Hematology and Cancer Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Vighnesh Ramesh
- Division of Experimental Hematology and Cancer Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Ellen M Kolb
- Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - Cem Meydan
- Department of Physiology and Biophysics, Weill Cornell Medical College, New York, NY, USA
| | - Yaseswini Neelamraju
- Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, VA, USA
| | - Lyndsey C Bolanos
- Division of Experimental Hematology and Cancer Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Susanne Christie
- Division of Experimental Hematology and Cancer Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Molly A Smith
- Division of Experimental Hematology and Cancer Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.,Department of Cancer Biology, University of Cincinnati, Cincinnati, OH, USA
| | - Madeline Niederkorn
- Division of Experimental Hematology and Cancer Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.,Department of Cancer Biology, University of Cincinnati, Cincinnati, OH, USA
| | - Tomoya Muto
- Division of Experimental Hematology and Cancer Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Santosh Kesari
- Saint John's Cancer Institute at Providence St. John's Health Center, Santa Monica, CA, USA
| | - Francine E Garrett-Bakelman
- Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, VA, USA.,Department of Medicine, University of Virginia, Charlottesville, VA, USA.,Division of Hematology and Oncology, Weill Cornell Medicine, New York, NY, USA.,University of Virginia Cancer Center, Charlottesville, VA, USA
| | - Boris Bartholdy
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Britta Will
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Matthew T Weirauch
- Center for Autoimmune Genetics and Etiology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.,Division of Biomedical Informatics and Developmental Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.,Department of Pediatrics, University of Cincinnati, Cincinnati, OH, USA
| | - James C Mulloy
- Division of Experimental Hematology and Cancer Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.,Department of Pediatrics, University of Cincinnati, Cincinnati, OH, USA
| | - Zartash Gul
- Department of Internal Medicine, University of Cincinnati, Cincinnati, OH, USA
| | - Stephen Medlin
- Department of Internal Medicine, University of Cincinnati, Cincinnati, OH, USA
| | - Rhett A Kovall
- Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - Ari M Melnick
- Division of Hematology and Oncology, Weill Cornell Medicine, New York, NY, USA
| | - John P Perentesis
- Division of Oncology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Kenneth D Greis
- Department of Cancer Biology, University of Cincinnati, Cincinnati, OH, USA
| | - Elmar Nurmemmedov
- Saint John's Cancer Institute at Providence St. John's Health Center, Santa Monica, CA, USA
| | - William L Seibel
- Division of Oncology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Daniel T Starczynowski
- Division of Experimental Hematology and Cancer Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.,Department of Cancer Biology, University of Cincinnati, Cincinnati, OH, USA.,Department of Pediatrics, University of Cincinnati, Cincinnati, OH, USA
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7
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Bühler A, Gahr BM, Park DD, Bertozzi A, Boos A, Dalvoy M, Pott A, Oswald F, Kovall RA, Kühn B, Weidinger G, Rottbauer W, Just S. Histone deacetylase 1 controls cardiomyocyte proliferation during embryonic heart development and cardiac regeneration in zebrafish. PLoS Genet 2021; 17:e1009890. [PMID: 34723970 PMCID: PMC8584950 DOI: 10.1371/journal.pgen.1009890] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 11/11/2021] [Accepted: 10/18/2021] [Indexed: 12/20/2022] Open
Abstract
In contrast to mammals, the zebrafish maintains its cardiomyocyte proliferation capacity throughout adulthood. However, neither the molecular mechanisms that orchestrate the proliferation of cardiomyocytes during developmental heart growth nor in the context of regeneration in the adult are sufficiently defined yet. We identified in a forward genetic N-ethyl-N-nitrosourea (ENU) mutagenesis screen the recessive, embryonic-lethal zebrafish mutant baldrian (bal), which shows severely impaired developmental heart growth due to diminished cardiomyocyte proliferation. By positional cloning, we identified a missense mutation in the zebrafish histone deacetylase 1 (hdac1) gene leading to severe protein instability and the loss of Hdac1 function in vivo. Hdac1 inhibition significantly reduces cardiomyocyte proliferation, indicating a role of Hdac1 during developmental heart growth in zebrafish. To evaluate whether developmental and regenerative Hdac1-associated mechanisms of cardiomyocyte proliferation are conserved, we analyzed regenerative cardiomyocyte proliferation after Hdac1 inhibition at the wound border zone in cryoinjured adult zebrafish hearts and we found that Hdac1 is also essential to orchestrate regenerative cardiomyocyte proliferation in the adult vertebrate heart. In summary, our findings suggest an important and conserved role of Histone deacetylase 1 (Hdac1) in developmental and adult regenerative cardiomyocyte proliferation in the vertebrate heart. Heart disease is one of the most common causes of death in all developed countries. While zebrafish cardiomyocytes are able to proliferate throughout adulthood, mammalian cardiomyocytes lose this ability during early development, and therefore are not capable to replace and renew cardiomyocytes after injury. The underlying mechanisms of cardiomyocyte proliferation are still not completely resolved. Understanding how zebrafish cardiomyocytes preserve their proliferating state, would be a valuable information to foster cardiac regeneration, e.g. after myocardial infarction in patients. Knowledge of the signaling pathways that need to be activated, or deactivated in order to induce cardiomyocyte proliferation after acute or chronic injury will pave the way for the development of genetic and/or pharmacological treatment options. In an ENU-mutagenesis screen, we identified the zebrafish mutant baldrian, which shows reduced embryonic cardiomyocyte proliferation. As genetic cause of the observed phenotype, we identified a missense mutation in the hdac1 gene. By treatment of heart-injured adult fish with the HDAC1 inhibitor Mocetinostat, we were able to show a reduced rate of cardiomyocyte proliferation also in the adult zebrafish heart in vivo, suggesting a role of Hdac1 in embryonic heart growth and adult regenerative cardiomyocyte proliferation in zebrafish.
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Affiliation(s)
- Anja Bühler
- Molecular Cardiology, Department of Internal Medicine II, University of Ulm, Ulm, Germany
| | - Bernd M Gahr
- Molecular Cardiology, Department of Internal Medicine II, University of Ulm, Ulm, Germany
| | - Deung-Dae Park
- Molecular Cardiology, Department of Internal Medicine II, University of Ulm, Ulm, Germany
| | - Alberto Bertozzi
- Institute of Biochemistry and Molecular Biology, University of Ulm, Ulm, Germany
| | - Alena Boos
- Molecular Cardiology, Department of Internal Medicine II, University of Ulm, Ulm, Germany
| | - Mohankrishna Dalvoy
- Institute of Biochemistry and Molecular Biology, University of Ulm, Ulm, Germany
| | - Alexander Pott
- Molecular Cardiology, Department of Internal Medicine II, University of Ulm, Ulm, Germany.,Department of Internal Medicine II, University of Ulm, Ulm, Germany
| | - Franz Oswald
- Department of Internal Medicine I, University of Ulm, Ulm, Germany
| | - Rhett A Kovall
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States of America
| | - Bernhard Kühn
- Department of Pediatrics, University of Pittsburgh, and Richard King Mellon Institute for Pediatric Research and Division of Pediatric Cardiology, Children's Hospital of Pittsburgh of UPMC, Pittsburgh, Pennsylvania, United States of America
| | - Gilbert Weidinger
- Institute of Biochemistry and Molecular Biology, University of Ulm, Ulm, Germany
| | | | - Steffen Just
- Molecular Cardiology, Department of Internal Medicine II, University of Ulm, Ulm, Germany
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8
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Kuang Y, Pyo A, Eafergan N, Cain B, Gutzwiller LM, Axelrod O, Gagliani EK, Weirauch MT, Kopan R, Kovall RA, Sprinzak D, Gebelein B. Enhancers with cooperative Notch binding sites are more resistant to regulation by the Hairless co-repressor. PLoS Genet 2021; 17:e1009039. [PMID: 34559800 PMCID: PMC8494340 DOI: 10.1371/journal.pgen.1009039] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 10/06/2021] [Accepted: 09/08/2021] [Indexed: 11/21/2022] Open
Abstract
Notch signaling controls many developmental processes by regulating gene expression. Notch-dependent enhancers recruit activation complexes consisting of the Notch intracellular domain, the Cbf/Su(H)/Lag1 (CSL) transcription factor (TF), and the Mastermind co-factor via two types of DNA sites: monomeric CSL sites and cooperative dimer sites called Su(H) paired sites (SPS). Intriguingly, the CSL TF can also bind co-repressors to negatively regulate transcription via these same sites. Here, we tested how synthetic enhancers with monomeric CSL sites versus dimeric SPSs bind Drosophila Su(H) complexes in vitro and mediate transcriptional outcomes in vivo. Our findings reveal that while the Su(H)/Hairless co-repressor complex similarly binds SPS and CSL sites in an additive manner, the Notch activation complex binds SPSs, but not CSL sites, in a cooperative manner. Moreover, transgenic reporters with SPSs mediate stronger, more consistent transcription and are more resistant to increased Hairless co-repressor expression compared to reporters with the same number of CSL sites. These findings support a model in which SPS containing enhancers preferentially recruit cooperative Notch activation complexes over Hairless repression complexes to ensure consistent target gene activation. Cell signaling provides a basic means of communication during development. Many signaling pathways, including the Notch pathway, convert extracellular signals into changes in gene expression via transcription factors that bind specific DNA sequences. Importantly, the Notch pathway transcription factor can either form activating complexes upon Notch activation to stimulate gene expression or repression complexes with co-repressors to inhibit gene expression. Prior studies showed that the Notch activation complex binds DNA as either an independent complex on monomer binding sites or as two cooperative complexes (dimer) on paired binding sites. In this study, we used synthetic biology to examine how these two types of DNA sites impact the binding of Notch activation versus repression complexes and the output of Notch target gene expression. Our studies reveal that unlike the Notch activation complex, the repression complex does not cooperatively bind dimer sites. Moreover, our findings support the model that the enhanced stability of the Notch activation complex on dimer sites makes target genes with dimer sites less sensitive to the repression complex than target genes with only monomer sites. Thus, our studies reveal how target genes with different binding sites differ in sensitivity to the ratio of Notch activation to repression complexes.
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Affiliation(s)
- Yi Kuang
- Graduate Program in Molecular and Developmental Biology, Cincinnati Children’s Hospital Research Foundation, Cincinnati, Ohio, United States of America
| | - Anna Pyo
- Department of Biomedical Engineering, University of Cincinnati, Cincinnati, Ohio, United States of America
| | - Natanel Eafergan
- School of Neurobiology, Biochemistry and Biophysics, George S. Wise Faculty of Life Science, Tel Aviv University, Tel Aviv, Israel
| | - Brittany Cain
- Department of Biomedical Engineering, University of Cincinnati, Cincinnati, Ohio, United States of America
| | - Lisa M. Gutzwiller
- Division of Developmental Biology, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, United States of America
| | - Ofri Axelrod
- School of Neurobiology, Biochemistry and Biophysics, George S. Wise Faculty of Life Science, Tel Aviv University, Tel Aviv, Israel
| | - Ellen K. Gagliani
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States of America
| | - Matthew T. Weirauch
- Divisions of Biomedical Informatics and Developmental Biology, Center for Autoimmune Genomics and Etiology (CAGE), Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, United States of America
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States of America
| | - Raphael Kopan
- Division of Developmental Biology, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, United States of America
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States of America
| | - Rhett A. Kovall
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States of America
| | - David Sprinzak
- School of Neurobiology, Biochemistry and Biophysics, George S. Wise Faculty of Life Science, Tel Aviv University, Tel Aviv, Israel
| | - Brian Gebelein
- Division of Developmental Biology, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, United States of America
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States of America
- * E-mail:
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9
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Hassett DJ, Kovall RA, Schurr MJ, Kotagiri N, Kumari H, Satish L. The Bactericidal Tandem Drug, AB569: How to Eradicate Antibiotic-Resistant Biofilm Pseudomonas aeruginosa in Multiple Disease Settings Including Cystic Fibrosis, Burns/Wounds and Urinary Tract Infections. Front Microbiol 2021; 12:639362. [PMID: 34220733 PMCID: PMC8245851 DOI: 10.3389/fmicb.2021.639362] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Accepted: 04/07/2021] [Indexed: 11/13/2022] Open
Abstract
The life-threatening pandemic concerning multi-drug resistant (MDR) bacteria is an evolving problem involving increased hospitalizations, billions of dollars in medical costs and a remarkably high number of deaths. Bacterial pathogens have demonstrated the capacity for spontaneous or acquired antibiotic resistance and there is virtually no pool of organisms that have not evolved such potentially clinically catastrophic properties. Although many diseases are linked to such organisms, three include cystic fibrosis (CF), burn/blast wounds and urinary tract infections (UTIs), respectively. Thus, there is a critical need to develop novel, effective antimicrobials for the prevention and treatment of such problematic infections. One of the most formidable, naturally MDR bacterial pathogens is Pseudomonas aeruginosa (PA) that is particularly susceptible to nitric oxide (NO), a component of our innate immune response. This susceptibility sets the translational stage for the use of NO-based therapeutics during the aforementioned human infections. First, we discuss how such NO therapeutics may be able to target problematic infections in each of the aforementioned infectious scenarios. Second, we describe a recent discovery based on years of foundational information, a novel drug known as AB569. AB569 is capable of forming a "time release" of NO from S-nitrosothiols (RSNO). AB569, a bactericidal tandem consisting of acidified NaNO2 (A-NO2 -) and Na2-EDTA, is capable of killing all pathogens that are associated with the aforementioned disorders. Third, we described each disease state in brief, the known or predicted effects of AB569 on the viability of PA, its potential toxicity and highly remote possibility for resistance to develop. Finally, we conclude that AB569 can be a viable alternative or addition to conventional antibiotic regimens to treat such highly problematic MDR bacterial infections for civilian and military populations, as well as the economical burden that such organisms pose.
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Affiliation(s)
- Daniel J Hassett
- Department of Molecular Genetics, Biochemistry and Microbiology, Cincinnati, OH, United States
| | - Rhett A Kovall
- Department of Molecular Genetics, Biochemistry and Microbiology, Cincinnati, OH, United States
| | - Michael J Schurr
- Department of Immunology and Microbiology, University of Colorado Health Sciences, Denver, CO, United States
| | - Nalinikanth Kotagiri
- Division of Pharmacy, University of Colorado Health Sciences, Denver, CO, United States
| | - Harshita Kumari
- Division of Pharmacy, University of Colorado Health Sciences, Denver, CO, United States
| | - Latha Satish
- Department of Pathology and Laboratory Medicine, University of Cincinnati College of Medicine, Cincinnati, OH, United States.,Shriners Hospitals for Children-Cincinnati, Cincinnati, OH, United States
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10
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Landor SKJ, Santio NM, Eccleshall WB, Paramonov VM, Gagliani EK, Hall D, Jin SB, Dahlström KM, Salminen TA, Rivero-Müller A, Lendahl U, Kovall RA, Koskinen PJ, Sahlgren C. PIM-induced phosphorylation of Notch3 promotes breast cancer tumorigenicity in a CSL-independent fashion. J Biol Chem 2021; 296:100593. [PMID: 33775697 PMCID: PMC8100066 DOI: 10.1016/j.jbc.2021.100593] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Revised: 03/19/2021] [Accepted: 03/24/2021] [Indexed: 12/29/2022] Open
Abstract
Dysregulation of the developmentally important Notch signaling pathway is implicated in several types of cancer, including breast cancer. However, the specific roles and regulation of the four different Notch receptors have remained elusive. We have previously reported that the oncogenic PIM kinases phosphorylate Notch1 and Notch3. Phosphorylation of Notch1 within the second nuclear localization sequence of its intracellular domain (ICD) enhances its transcriptional activity and tumorigenicity. In this study, we analyzed Notch3 phosphorylation and its functional impact. Unexpectedly, we observed that the PIM target sites are not conserved between Notch1 and Notch3. Notch3 ICD (N3ICD) is phosphorylated within a domain, which is essential for formation of a transcriptionally active complex with the DNA-binding protein CSL. Through molecular modeling, X-ray crystallography, and isothermal titration calorimetry, we demonstrate that phosphorylation of N3ICD sterically hinders its interaction with CSL and thereby inhibits its CSL-dependent transcriptional activity. Surprisingly however, phosphorylated N3ICD still maintains tumorigenic potential in breast cancer cells under estrogenic conditions, which support PIM expression. Taken together, our data indicate that PIM kinases modulate the signaling output of different Notch paralogs by targeting distinct protein domains and thereby promote breast cancer tumorigenesis via both CSL-dependent and CSL-independent mechanisms.
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Affiliation(s)
- Sebastian K J Landor
- Faculty of Science and Engineering/Cell Biology, Åbo Akademi University, Turku, Finland; Turku Bioscience, University of Turku and Åbo Akademi University, Turku, Finland
| | - Niina M Santio
- Department of Biology, University of Turku, Turku, Finland
| | - William B Eccleshall
- Faculty of Science and Engineering/Cell Biology, Åbo Akademi University, Turku, Finland; Turku Bioscience, University of Turku and Åbo Akademi University, Turku, Finland; Department of Biology, University of Turku, Turku, Finland
| | - Valeriy M Paramonov
- Faculty of Science and Engineering/Cell Biology, Åbo Akademi University, Turku, Finland; Turku Bioscience, University of Turku and Åbo Akademi University, Turku, Finland; Institute of Biomedicine, Research Centre for Integrative Physiology and Pharmacology, University of Turku, Turku, Finland
| | - Ellen K Gagliani
- Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati, Ohio, USA
| | - Daniel Hall
- Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati, Ohio, USA
| | - Shao-Bo Jin
- Department of Cell and Molecular Biology, Karolinska Institute, Stockholm, Sweden
| | - Käthe M Dahlström
- Structural Bioinformatics Laboratory, Biochemistry, Faculty of Science and Engineering, Åbo Akademi, Turku, Finland
| | - Tiina A Salminen
- Structural Bioinformatics Laboratory, Biochemistry, Faculty of Science and Engineering, Åbo Akademi, Turku, Finland
| | - Adolfo Rivero-Müller
- Faculty of Science and Engineering/Cell Biology, Åbo Akademi University, Turku, Finland; Department of Biology, University of Turku, Turku, Finland
| | - Urban Lendahl
- Department of Cell and Molecular Biology, Karolinska Institute, Stockholm, Sweden
| | - Rhett A Kovall
- Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati, Ohio, USA
| | | | - Cecilia Sahlgren
- Faculty of Science and Engineering/Cell Biology, Åbo Akademi University, Turku, Finland; Turku Bioscience, University of Turku and Åbo Akademi University, Turku, Finland; Department of Biomedical Engineering, Institute for Complex Molecular Systems, Eindhoven University of Technology, Eindhoven, The Netherlands.
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11
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Kobia FM, Preusse K, Dai Q, Weaver N, Hass MR, Chaturvedi P, Stein SJ, Pear WS, Yuan Z, Kovall RA, Kuang Y, Eafergen N, Sprinzak D, Gebelein B, Brunskill EW, Kopan R. Notch dimerization and gene dosage are important for normal heart development, intestinal stem cell maintenance, and splenic marginal zone B-cell homeostasis during mite infestation. PLoS Biol 2020; 18:e3000850. [PMID: 33017398 PMCID: PMC7561103 DOI: 10.1371/journal.pbio.3000850] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Revised: 10/15/2020] [Accepted: 09/02/2020] [Indexed: 12/14/2022] Open
Abstract
Cooperative DNA binding is a key feature of transcriptional regulation. Here we examined the role of cooperativity in Notch signaling by CRISPR-mediated engineering of mice in which neither Notch1 nor Notch2 can homo- or heterodimerize, essential for cooperative binding to sequence-paired sites (SPS) located near many Notch-regulated genes. Although most known Notch-dependent phenotypes were unaffected in Notch1/2 dimer-deficient mice, a subset of tissues proved highly sensitive to loss of cooperativity. These phenotypes include heart development, compromised viability in combination with low gene dose, and the gut, developing ulcerative colitis in response to 1% dextran sulfate sodium (DSS). The most striking phenotypes-gender imbalance and splenic marginal zone B-cell lymphoma-emerged in combination with gene dose reduction or when challenged by chronic fur mite infestation. This study highlights the role of the environment in malignancy and colitis and is consistent with Notch-dependent anti-parasite immune responses being compromised in Notch dimer-deficient animals.
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Affiliation(s)
- Francis M. Kobia
- Division of Developmental Biology, Department of Pediatrics, University of Cincinnati College of Medicine and Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, United States of America
| | - Kristina Preusse
- Division of Developmental Biology, Department of Pediatrics, University of Cincinnati College of Medicine and Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, United States of America
| | - Quanhui Dai
- Division of Developmental Biology, Department of Pediatrics, University of Cincinnati College of Medicine and Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, United States of America
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, China
| | - Nicholas Weaver
- Immunology Graduate Program, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States of America
| | - Matthew R. Hass
- Division of Developmental Biology, Department of Pediatrics, University of Cincinnati College of Medicine and Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, United States of America
| | - Praneet Chaturvedi
- Division of Developmental Biology, Department of Pediatrics, University of Cincinnati College of Medicine and Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, United States of America
| | - Sarah J. Stein
- Department of Pathology and Laboratory Medicine, Abramson Family Cancer Research Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Warren S. Pear
- Department of Pathology and Laboratory Medicine, Abramson Family Cancer Research Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Zhenyu Yuan
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States of America
| | - Rhett A. Kovall
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States of America
| | - Yi Kuang
- Division of Developmental Biology, Department of Pediatrics, University of Cincinnati College of Medicine and Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, United States of America
| | - Natanel Eafergen
- School of Neurobiology, Biochemistry, and Biophysics, The George S. Wise Faculty of Life Sciences Tel Aviv University, Tel Aviv, Israel
| | - David Sprinzak
- School of Neurobiology, Biochemistry, and Biophysics, The George S. Wise Faculty of Life Sciences Tel Aviv University, Tel Aviv, Israel
| | - Brian Gebelein
- Division of Developmental Biology, Department of Pediatrics, University of Cincinnati College of Medicine and Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, United States of America
| | - Eric W. Brunskill
- Division of Developmental Biology, Department of Pediatrics, University of Cincinnati College of Medicine and Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, United States of America
| | - Raphael Kopan
- Division of Developmental Biology, Department of Pediatrics, University of Cincinnati College of Medicine and Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, United States of America
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12
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Kuang Y, Golan O, Preusse K, Cain B, Christensen CJ, Salomone J, Campbell I, Okwubido-Williams FV, Hass MR, Yuan Z, Eafergan N, Moberg KH, Kovall RA, Kopan R, Sprinzak D, Gebelein B. Enhancer architecture sensitizes cell specific responses to Notch gene dose via a bind and discard mechanism. eLife 2020; 9:53659. [PMID: 32297857 PMCID: PMC7213981 DOI: 10.7554/elife.53659] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Accepted: 04/15/2020] [Indexed: 11/13/2022] Open
Abstract
Notch pathway haploinsufficiency can cause severe developmental syndromes with highly variable penetrance. Currently, we have a limited mechanistic understanding of phenotype variability due to gene dosage. Here, we unexpectedly found that inserting an enhancer containing pioneer transcription factor sites coupled to Notch dimer sites can induce a subset of Notch haploinsufficiency phenotypes in Drosophila with wild type Notch gene dose. Using Drosophila genetics, we show that this enhancer induces Notch phenotypes in a Cdk8-dependent, transcription-independent manner. We further combined mathematical modeling with quantitative trait and expression analysis to build a model that describes how changes in Notch signal production versus degradation differentially impact cellular outcomes that require long versus short signal duration. Altogether, these findings support a 'bind and discard' mechanism in which enhancers with specific binding sites promote rapid Cdk8-dependent Notch turnover, and thereby reduce Notch-dependent transcription at other loci and sensitize tissues to gene dose based upon signal duration.
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Affiliation(s)
- Yi Kuang
- Graduate Program in Molecular and Developmental Biology, Cincinnati Children's Hospital Research Foundation, Cincinnati, United States
| | - Ohad Golan
- School of Neurobiology, Biochemistry and Biophysics, George S. Wise Faculty of Life Science, Tel Aviv University, Tel Aviv, Israel
| | - Kristina Preusse
- Division of Developmental Biology, Cincinnati Children's Hospital, Cincinnati, United States
| | - Brittany Cain
- Department of Biomedical Engineering, University of Cincinnati, Cincinnati, United States
| | - Collin J Christensen
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, Cincinnati, United States
| | - Joseph Salomone
- Graduate Program in Molecular and Developmental Biology, Cincinnati Children's Hospital Research Foundation, Cincinnati, United States.,Medical-Scientist Training Program, University of Cincinnati College of Medicine, Cincinnati, United States
| | - Ian Campbell
- Department of Biomedical Engineering, University of Cincinnati, Cincinnati, United States
| | | | - Matthew R Hass
- Division of Developmental Biology, Cincinnati Children's Hospital, Cincinnati, United States
| | - Zhenyu Yuan
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, Cincinnati, United States
| | - Nathanel Eafergan
- School of Neurobiology, Biochemistry and Biophysics, George S. Wise Faculty of Life Science, Tel Aviv University, Tel Aviv, Israel
| | - Kenneth H Moberg
- Department of Cell Biology, Emory University and Emory University School of Medicine, Atlanta, United States
| | - Rhett A Kovall
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, Cincinnati, United States
| | - Raphael Kopan
- Division of Developmental Biology, Cincinnati Children's Hospital, Cincinnati, United States.,Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, United States
| | - David Sprinzak
- School of Neurobiology, Biochemistry and Biophysics, George S. Wise Faculty of Life Science, Tel Aviv University, Tel Aviv, Israel
| | - Brian Gebelein
- Division of Developmental Biology, Cincinnati Children's Hospital, Cincinnati, United States.,Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, United States
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13
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Yuan Z, VanderWielen BD, Giaimo BD, Pan L, Collins CE, Turkiewicz A, Hein K, Oswald F, Borggrefe T, Kovall RA. Structural and Functional Studies of the RBPJ-SHARP Complex Reveal a Conserved Corepressor Binding Site. Cell Rep 2020; 26:845-854.e6. [PMID: 30673607 PMCID: PMC6352735 DOI: 10.1016/j.celrep.2018.12.097] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Revised: 11/05/2018] [Accepted: 12/21/2018] [Indexed: 11/28/2022] Open
Abstract
Notch is a conserved signaling pathway that is essential for metazoan development and homeostasis; dysregulated signaling underlies the pathophysiology of numerous human diseases. Receptor-ligand interactions result in gene expression changes, which are regulated by the transcription factor RBPJ. RBPJ forms a complex with the intracellular domain of the Notch receptor and the coactivator Mastermind to activate transcription, but it can also function as a repressor by interacting with corepressor proteins. Here, we determine the structure of RBPJ bound to the corepressor SHARP and DNA, revealing its mode of binding to RBPJ. We tested structure-based mutants in biophysical and biochemical-cellular as-says to characterize the role of RBPJ as a repressor, clearly demonstrating that RBPJ mutants deficient for SHARP binding are incapable of repressing transcription of genes responsive to Notch signaling in cells. Altogether, our structure-function studies provide significant insights into the repressor function of RBPJ. Yuan et al. determine the X-ray structure of the corepressor SHARP bound to RBPJ, the nuclear effector of the Notch pathway. The structure-function analysis provides insights into corepressor binding to RBPJ and how RBPJ functions as a repressor of transcription of Notch target genes.
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Affiliation(s)
- Zhenyu Yuan
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - Bradley D VanderWielen
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | | | - Leiling Pan
- Department of Internal Medicine I, Center for Internal Medicine, University Medical Center Ulm, 89081 Ulm, Germany
| | - Courtney E Collins
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | | | - Kerstin Hein
- Institute of Biochemistry, University of Giessen, Giessen, Germany
| | - Franz Oswald
- Department of Internal Medicine I, Center for Internal Medicine, University Medical Center Ulm, 89081 Ulm, Germany
| | - Tilman Borggrefe
- Institute of Biochemistry, University of Giessen, Giessen, Germany
| | - Rhett A Kovall
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, Cincinnati, OH, USA.
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14
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Thompson TB, Kovall RA. Structural biology: Gaining atomic level insight into the biological function of macromolecules. Exp Biol Med (Maywood) 2019; 244:1507-1509. [PMID: 31718278 DOI: 10.1177/1535370219887678] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- Thomas B Thompson
- Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati, OH 45267, USA
| | - Rhett A Kovall
- Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati, OH 45267, USA
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15
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Abstract
This mini review discusses the protein complexes comprised of the universal Notch signaling transcription factor, CSL (CBF1/Su(H)/Lag-1), and its activating or repressing transcriptional coregulation partners. Many of these complex structures have been solved crystallographically as well as undergoing extensive binding studies with wild-type and mutant variants. Notch signaling is critically important in a large variety of basic biological processes: cell proliferation, differentiation, cell cycle control to name a few. Aberrant Notch thus remains a coveted target for pharmaceutical intervention. To that end, we provide a molecular-level summary of the similarities and differences in the Notch coregulator complexes that ultimately govern these processes. We highlight a conserved binding motif that multiple superficially unrelated proteins have adopted to become involved in Notch target gene regulation. As CSL-interacting small molecules begin to be characterized, this review will provide insight to potential binding sites and differential complex disruption. Impact statement Proper Notch signaling regulation is informed by many distinct protein complexes involving a single nuclear effector. A decade of research into these protein complexes yields multiple crystal structures and a wealth of binding data to guide drug development for Notch-related diseases – cancer, cardiovascular, development disorders.
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Affiliation(s)
- Daniel P Hall
- Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA
| | - Rhett A Kovall
- Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA
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16
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Miesfeld JB, Moon MS, Riesenberg AN, Contreras AN, Kovall RA, Brown NL. Rbpj direct regulation of Atoh7 transcription in the embryonic mouse retina. Sci Rep 2018; 8:10195. [PMID: 29977079 PMCID: PMC6033939 DOI: 10.1038/s41598-018-28420-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Accepted: 06/22/2018] [Indexed: 12/24/2022] Open
Abstract
In vertebrate retinal progenitor cells, the proneural factor Atoh7 exhibits a dynamic tissue and cellular expression pattern. Although the resulting Atoh7 retinal lineage contains all seven major cell types, only retinal ganglion cells require Atoh7 for proper differentiation. Such specificity necessitates complex regulation of Atoh7 transcription during retina development. The Notch signaling pathway is an evolutionarily conserved suppressor of proneural bHLH factor expression. Previous in vivo mouse genetic studies established the cell autonomous suppression of Atoh7 transcription by Notch1, Rbpj and Hes1. Here we identify four CSL binding sites within the Atoh7 proximal regulatory region and demonstrate Rbpj protein interaction at these sequences by in vitro electromobility shift, calorimetry and luciferase assays and, in vivo via colocalization and chromatin immunoprecipitation. We found that Rbpj simultaneously represses Atoh7 transcription using both Notch-dependent and –independent pathways.
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Affiliation(s)
- Joel B Miesfeld
- Department of Cell Biology & Human Anatomy, University of California Davis School of Medicine, One Shields Avenue, Davis, CA, 95616, USA
| | - Myung-Soon Moon
- Department of Cell Biology & Human Anatomy, University of California Davis School of Medicine, One Shields Avenue, Davis, CA, 95616, USA.,Division of Developmental Biology, Cincinnati Children's Hospital Research Foundation, 3333 Burnet Avenue, Cincinnati, OH, 45229, USA
| | - Amy N Riesenberg
- Division of Developmental Biology, Cincinnati Children's Hospital Research Foundation, 3333 Burnet Avenue, Cincinnati, OH, 45229, USA
| | - Ashley N Contreras
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati School of Medicine, Cincinnati, OH, 45267, USA.,Department of Biology, University of Cincinnati Blue Ash College, Cincinnati, OH, 45236, USA
| | - Rhett A Kovall
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati School of Medicine, Cincinnati, OH, 45267, USA
| | - Nadean L Brown
- Department of Cell Biology & Human Anatomy, University of California Davis School of Medicine, One Shields Avenue, Davis, CA, 95616, USA. .,Division of Developmental Biology, Cincinnati Children's Hospital Research Foundation, 3333 Burnet Avenue, Cincinnati, OH, 45229, USA.
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17
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Xu T, Park SS, Giaimo BD, Hall D, Ferrante F, Ho DM, Hori K, Anhezini L, Ertl I, Bartkuhn M, Zhang H, Milon E, Ha K, Conlon KP, Kuick R, Govindarajoo B, Zhang Y, Sun Y, Dou Y, Basrur V, Elenitoba-Johnson KS, Nesvizhskii AI, Ceron J, Lee CY, Borggrefe T, Kovall RA, Rual JF. RBPJ/CBF1 interacts with L3MBTL3/MBT1 to promote repression of Notch signaling via histone demethylase KDM1A/LSD1. EMBO J 2017; 36:3232-3249. [PMID: 29030483 PMCID: PMC5666606 DOI: 10.15252/embj.201796525] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2017] [Revised: 08/31/2017] [Accepted: 09/12/2017] [Indexed: 12/21/2022] Open
Abstract
Notch signaling is an evolutionarily conserved signal transduction pathway that is essential for metazoan development. Upon ligand binding, the Notch intracellular domain (NOTCH ICD) translocates into the nucleus and forms a complex with the transcription factor RBPJ (also known as CBF1 or CSL) to activate expression of Notch target genes. In the absence of a Notch signal, RBPJ acts as a transcriptional repressor. Using a proteomic approach, we identified L3MBTL3 (also known as MBT1) as a novel RBPJ interactor. L3MBTL3 competes with NOTCH ICD for binding to RBPJ. In the absence of NOTCH ICD, RBPJ recruits L3MBTL3 and the histone demethylase KDM1A (also known as LSD1) to the enhancers of Notch target genes, leading to H3K4me2 demethylation and to transcriptional repression. Importantly, in vivo analyses of the homologs of RBPJ and L3MBTL3 in Drosophila melanogaster and Caenorhabditis elegans demonstrate that the functional link between RBPJ and L3MBTL3 is evolutionarily conserved, thus identifying L3MBTL3 as a universal modulator of Notch signaling in metazoans.
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Affiliation(s)
- Tao Xu
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Sung-Soo Park
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI, USA
| | | | - Daniel Hall
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | | | - Diana M Ho
- Department of Cell Biology, Harvard Medical School, Boston, MA, USA
| | - Kazuya Hori
- Department of Cell Biology, Harvard Medical School, Boston, MA, USA
| | - Lucas Anhezini
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA
| | - Iris Ertl
- Cancer and Human Molecular Genetics, Bellvitge Biomedical Research Institute, L'Hospitalet de Llobregat, Barcelona, Spain
| | - Marek Bartkuhn
- Institute for Genetics, University of Giessen, Giessen, Germany
| | - Honglai Zhang
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Eléna Milon
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Kimberly Ha
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Kevin P Conlon
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Rork Kuick
- Center for Cancer Biostatistics, School of Public Health, University of Michigan, Ann Arbor, MI, USA
| | - Brandon Govindarajoo
- Department of Computational Medicine & Bioinformatics, University of Michigan, Ann Arbor, MI, USA
| | - Yang Zhang
- Department of Computational Medicine & Bioinformatics, University of Michigan, Ann Arbor, MI, USA
| | - Yuqing Sun
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Yali Dou
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Venkatesha Basrur
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI, USA
| | | | - Alexey I Nesvizhskii
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI, USA.,Department of Computational Medicine & Bioinformatics, University of Michigan, Ann Arbor, MI, USA
| | - Julian Ceron
- Cancer and Human Molecular Genetics, Bellvitge Biomedical Research Institute, L'Hospitalet de Llobregat, Barcelona, Spain
| | - Cheng-Yu Lee
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA
| | - Tilman Borggrefe
- Institute of Biochemistry, University of Giessen, Giessen, Germany
| | - Rhett A Kovall
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - Jean-François Rual
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI, USA
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18
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Nagel AC, Auer JS, Schulz A, Pfannstiel J, Yuan Z, Collins CE, Kovall RA, Preiss A. Phosphorylation of Suppressor of Hairless impedes its DNA-binding activity. Sci Rep 2017; 7:11820. [PMID: 28928428 PMCID: PMC5605572 DOI: 10.1038/s41598-017-11952-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Accepted: 09/01/2017] [Indexed: 02/07/2023] Open
Abstract
Notch signalling activity governs cellular differentiation in higher metazoa, where Notch signals are transduced by the transcription factor CSL, called Suppressor of Hairless [Su(H)] in Drosophila. Su(H) operates as molecular switch on Notch target genes: within activator complexes, including intracellular Notch, or within repressor complexes, including the antagonist Hairless. Mass spectrometry identified phosphorylation on Serine 269 in Su(H), potentially serving as a point of cross-regulation by other signalling pathways. To address the biological significance, we generated phospho-deficient [Su(H)S269A] and phospho-mimetic [Su(H)S269D] variants: the latter displayed reduced transcriptional activity despite unaltered protein interactions with co-activators and -repressors. Based on the Su(H) structure, Ser269 phosphorylation may interfere with DNA-binding, which we confirmed by electro-mobility shift assay and isothermal titration calorimetry. Overexpression of Su(H)S269D during fly development demonstrated reduced transcriptional regulatory activity, similar to the previously reported DNA-binding defective mutant Su(H)R266H. As both are able to bind Hairless and Notch proteins, Su(H)S269D and Su(H)R266H provoked dominant negative effects upon overexpression. Our data imply that Ser269 phosphorylation impacts Notch signalling activity by inhibiting DNA-binding of Su(H), potentially affecting both activation and repression. Ser269 is highly conserved in vertebrate CSL homologues, opening the possibility of a general and novel mechanism of modulating Notch signalling activity.
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Affiliation(s)
- Anja C Nagel
- Institut für Genetik (240), University of Hohenheim, Garbenstr. 30, 70599, Stuttgart, Germany.
| | - Jasmin S Auer
- Institut für Genetik (240), University of Hohenheim, Garbenstr. 30, 70599, Stuttgart, Germany
| | - Adriana Schulz
- Institut für Genetik (240), University of Hohenheim, Garbenstr. 30, 70599, Stuttgart, Germany
| | - Jens Pfannstiel
- Core Facility Hohenheim, Mass Spectrometry Unit University of Hohenheim, 70599, Stuttgart, Germany
| | - Zhenyu Yuan
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States of America
| | - Courtney E Collins
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States of America
| | - Rhett A Kovall
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States of America
| | - Anette Preiss
- Institut für Genetik (240), University of Hohenheim, Garbenstr. 30, 70599, Stuttgart, Germany
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19
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Tabaja N, Yuan Z, Oswald F, Kovall RA. Structure-function analysis of RBP-J-interacting and tubulin-associated (RITA) reveals regions critical for repression of Notch target genes. J Biol Chem 2017; 292:10549-10563. [PMID: 28487372 DOI: 10.1074/jbc.m117.791707] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2017] [Revised: 05/04/2017] [Indexed: 11/06/2022] Open
Abstract
The Notch pathway is a cell-to-cell signaling mechanism that is essential for tissue development and maintenance, and aberrant Notch signaling has been implicated in various cancers, congenital defects, and cardiovascular diseases. Notch signaling activates the expression of target genes, which are regulated by the transcription factor CSL (CBF1/RBP-J, Su(H), Lag-1). CSL interacts with both transcriptional corepressor and coactivator proteins, functioning as both a repressor and activator, respectively. Although Notch activation complexes are relatively well understood at the structural level, less is known about how CSL interacts with corepressors. Recently, a new RBP-J (mammalian CSL ortholog)-interacting protein termed RITA has been identified and shown to export RBP-J out of the nucleus, thereby leading to the down-regulation of Notch target gene expression. However, the molecular details of RBP-J/RITA interactions are unclear. Here, using a combination of biochemical/cellular, structural, and biophysical techniques, we demonstrate that endogenous RBP-J and RITA proteins interact in cells, map the binding regions necessary for RBP-J·RITA complex formation, and determine the X-ray structure of the RBP-J·RITA complex bound to DNA. To validate the structure and glean more insights into function, we tested structure-based RBP-J and RITA mutants with biochemical/cellular assays and isothermal titration calorimetry. Whereas our structural and biophysical studies demonstrate that RITA binds RBP-J similarly to the RAM (RBP-J-associated molecule) domain of Notch, our biochemical and cellular assays suggest that RITA interacts with additional regions in RBP-J. Taken together, these results provide molecular insights into the mechanism of RITA-mediated regulation of Notch signaling, contributing to our understanding of how CSL functions as a transcriptional repressor of Notch target genes.
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Affiliation(s)
- Nassif Tabaja
- From the Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, Cincinnati, Ohio 45267 and
| | - Zhenyu Yuan
- From the Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, Cincinnati, Ohio 45267 and
| | - Franz Oswald
- the Department of Internal Medicine I, Center for Internal Medicine, University Medical Center Ulm, 89081 Ulm, Germany
| | - Rhett A Kovall
- From the Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, Cincinnati, Ohio 45267 and
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20
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Oswald F, Rodriguez P, Giaimo BD, Antonello ZA, Mira L, Mittler G, Thiel VN, Collins KJ, Tabaja N, Cizelsky W, Rothe M, Kühl SJ, Kühl M, Ferrante F, Hein K, Kovall RA, Dominguez M, Borggrefe T. A phospho-dependent mechanism involving NCoR and KMT2D controls a permissive chromatin state at Notch target genes. Nucleic Acids Res 2016; 44:4703-20. [PMID: 26912830 PMCID: PMC4889922 DOI: 10.1093/nar/gkw105] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2015] [Accepted: 02/11/2016] [Indexed: 01/24/2023] Open
Abstract
The transcriptional shift from repression to activation of target genes is crucial for the fidelity of Notch responses through incompletely understood mechanisms that likely involve chromatin-based control. To activate silenced genes, repressive chromatin marks are removed and active marks must be acquired. Histone H3 lysine-4 (H3K4) demethylases are key chromatin modifiers that establish the repressive chromatin state at Notch target genes. However, the counteracting histone methyltransferase required for the active chromatin state remained elusive. Here, we show that the RBP-J interacting factor SHARP is not only able to interact with the NCoR corepressor complex, but also with the H3K4 methyltransferase KMT2D coactivator complex. KMT2D and NCoR compete for the C-terminal SPOC-domain of SHARP. We reveal that the SPOC-domain exclusively binds to phosphorylated NCoR. The balance between NCoR and KMT2D binding is shifted upon mutating the phosphorylation sites of NCoR or upon inhibition of the NCoR kinase CK2β. Furthermore, we show that the homologs of SHARP and KMT2D in Drosophila also physically interact and control Notch-mediated functions in vivo. Together, our findings reveal how signaling can fine-tune a committed chromatin state by phosphorylation of a pivotal chromatin-modifier.
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Affiliation(s)
- Franz Oswald
- University Medical Center Ulm, Center for Internal Medicine, Department of Internal Medicine I, Albert-Einstein-Allee 23, 89081 Ulm, Germany
| | - Patrick Rodriguez
- Swiss Institute for Experimental Cancer Research, Lausanne, Switzerland
| | - Benedetto Daniele Giaimo
- Institute of Biochemistry, University of Giessen, Friedrichstrasse 24, 35392 Giessen, Germany Spemann Graduate School of Biology and Medicine (SGBM), Faculty of Biology, Albert Ludwigs University Freiburg, Germany
| | - Zeus A Antonello
- Instituto de Neurociencias, Consejo Superior de Investigaciones Cientificas-Universidad Miguel Hernández, Campus de Sant Joan, Alicante, Spain
| | - Laura Mira
- Instituto de Neurociencias, Consejo Superior de Investigaciones Cientificas-Universidad Miguel Hernández, Campus de Sant Joan, Alicante, Spain
| | - Gerhard Mittler
- Max-Planck-Institute of Immunobiology and Epigenetics, Stübeweg 51, 79108 Freiburg, Germany
| | - Verena N Thiel
- University Medical Center Ulm, Center for Internal Medicine, Department of Internal Medicine I, Albert-Einstein-Allee 23, 89081 Ulm, Germany
| | - Kelly J Collins
- Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati, Cincinnati, OH 45267, USA
| | - Nassif Tabaja
- Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati, Cincinnati, OH 45267, USA
| | - Wiebke Cizelsky
- Institute for Biochemistry and Molecular Biology, Ulm University, Albert-Einstein-Allee 11, 89081 Ulm, Germany International Graduate School in Molecular Medicine Ulm (IGradU), Ulm University, Albert-Einstein-Allee 11, 89081 Ulm, Germany
| | - Melanie Rothe
- Institute for Biochemistry and Molecular Biology, Ulm University, Albert-Einstein-Allee 11, 89081 Ulm, Germany International Graduate School in Molecular Medicine Ulm (IGradU), Ulm University, Albert-Einstein-Allee 11, 89081 Ulm, Germany
| | - Susanne J Kühl
- Institute for Biochemistry and Molecular Biology, Ulm University, Albert-Einstein-Allee 11, 89081 Ulm, Germany
| | - Michael Kühl
- Institute for Biochemistry and Molecular Biology, Ulm University, Albert-Einstein-Allee 11, 89081 Ulm, Germany
| | - Francesca Ferrante
- Institute of Biochemistry, University of Giessen, Friedrichstrasse 24, 35392 Giessen, Germany
| | - Kerstin Hein
- Institute of Biochemistry, University of Giessen, Friedrichstrasse 24, 35392 Giessen, Germany
| | - Rhett A Kovall
- Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati, Cincinnati, OH 45267, USA
| | - Maria Dominguez
- Instituto de Neurociencias, Consejo Superior de Investigaciones Cientificas-Universidad Miguel Hernández, Campus de Sant Joan, Alicante, Spain
| | - Tilman Borggrefe
- Institute of Biochemistry, University of Giessen, Friedrichstrasse 24, 35392 Giessen, Germany
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21
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Contreras AN, Yuan Z, Kovall RA. Thermodynamic binding analysis of Notch transcription complexes from Drosophila melanogaster. Protein Sci 2015; 24:812-22. [PMID: 25650119 DOI: 10.1002/pro.2652] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2014] [Revised: 01/26/2015] [Accepted: 01/27/2015] [Indexed: 12/22/2022]
Abstract
Notch is an intercellular signaling pathway that is highly conserved in metazoans and is essential for proper cellular specification during development and in the adult organism. Misregulated Notch signaling underlies or contributes to the pathogenesis of many human diseases, most notably cancer. Signaling through the Notch pathway ultimately results in changes in gene expression, which is regulated by the transcription factor CSL. Upon pathway activation, CSL forms a ternary complex with the intracellular domain of the Notch receptor (NICD) and the transcriptional coactivator Mastermind (MAM) that activates transcription from Notch target genes. While detailed in vitro studies have been conducted with mammalian and worm orthologous proteins, less is known regarding the molecular details of the Notch ternary complex in Drosophila. Here we thermodynamically characterize the assembly of the fly ternary complex using isothermal titration calorimetry. Our data reveal striking differences in the way the RAM (RBP-J associated molecule) and ANK (ankyrin) domains of NICD interact with CSL that is specific to the fly. Additional analysis using cross-species experiments suggest that these differences are primarily due to fly CSL, while experiments using point mutants show that the interface between fly CSL and ANK is likely similar to the mammalian and worm interface. Finally, we show that the binding of the fly RAM domain to CSL does not affect interactions of the corepressor Hairless with CSL. Taken together, our data suggest species-specific differences in ternary complex assembly that may be significant in understanding how CSL regulates transcription in different organisms.
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Affiliation(s)
- Ashley N Contreras
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati, Cincinnati, Ohio, 45267
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22
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Torella R, Li J, Kinrade E, Cerda-Moya G, Contreras AN, Foy R, Stojnic R, Glen RC, Kovall RA, Adryan B, Bray SJ. A combination of computational and experimental approaches identifies DNA sequence constraints associated with target site binding specificity of the transcription factor CSL. Nucleic Acids Res 2014; 42:10550-63. [PMID: 25114055 PMCID: PMC4176381 DOI: 10.1093/nar/gku730] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2014] [Revised: 07/29/2014] [Accepted: 07/29/2014] [Indexed: 12/27/2022] Open
Abstract
Regulation of transcription is fundamental to development and physiology, and occurs through binding of transcription factors to specific DNA sequences in the genome. CSL (CBF1/Suppressor of Hairless/LAG-1), a core component of the Notch signaling pathway, is one such transcription factor that acts in concert with co-activators or co-repressors to control the activity of associated target genes. One fundamental question is how CSL can recognize and select among different DNA sequences available in vivo and whether variations between selected sequences can influence its function. We have therefore investigated CSL-DNA recognition using computational approaches to analyze the energetics of CSL bound to different DNAs and tested the in silico predictions with in vitro and in vivo assays. Our results reveal novel aspects of CSL binding that may help explain the range of binding observed in vivo. In addition, using molecular dynamics simulations, we show that domain-domain correlations within CSL differ significantly depending on the DNA sequence bound, suggesting that different DNA sequences may directly influence CSL function. Taken together, our results, based on computational chemistry approaches, provide valuable insights into transcription factor-DNA binding, in this particular case increasing our understanding of CSL-DNA interactions and how these may impact on its transcriptional control.
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Affiliation(s)
- Rubben Torella
- Department of Chemistry, University of Cambridge, Cambridge, UK
| | - Jinghua Li
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, UK
| | - Eddie Kinrade
- Department of Genetics, University of Cambridge, Cambridge, UK Cambridge Systems Biology Centre, University of Cambridge, Cambridge, UK
| | - Gustavo Cerda-Moya
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, UK
| | - Ashley N Contreras
- University of Cincinnati College of Medicine, Department of Molecular Genetics, Biochemistry and Microbiology, 231 Albert Sabin Way CARE4836, Cincinnati, OH 45267-0524, USA
| | - Robert Foy
- Department of Genetics, University of Cambridge, Cambridge, UK Cambridge Systems Biology Centre, University of Cambridge, Cambridge, UK
| | - Robert Stojnic
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, UK Cambridge Systems Biology Centre, University of Cambridge, Cambridge, UK
| | - Robert C Glen
- Department of Chemistry, University of Cambridge, Cambridge, UK
| | - Rhett A Kovall
- University of Cincinnati College of Medicine, Department of Molecular Genetics, Biochemistry and Microbiology, 231 Albert Sabin Way CARE4836, Cincinnati, OH 45267-0524, USA
| | - Boris Adryan
- Department of Genetics, University of Cambridge, Cambridge, UK Cambridge Systems Biology Centre, University of Cambridge, Cambridge, UK
| | - Sarah J Bray
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, UK
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23
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Su S, Panmanee W, Wilson JJ, Mahtani HK, Li Q, VanderWielen BD, Makris TM, Rogers M, McDaniel C, Lipscomb JD, Irvin RT, Schurr MJ, Lancaster JR, Kovall RA, Hassett DJ. Catalase (KatA) plays a role in protection against anaerobic nitric oxide in Pseudomonas aeruginosa. PLoS One 2014; 9:e91813. [PMID: 24663218 PMCID: PMC3963858 DOI: 10.1371/journal.pone.0091813] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2013] [Accepted: 02/14/2014] [Indexed: 12/30/2022] Open
Abstract
Pseudomonas aeruginosa (PA) is a common bacterial pathogen, responsible for a high incidence of nosocomial and respiratory infections. KatA is the major catalase of PA that detoxifies hydrogen peroxide (H2O2), a reactive oxygen intermediate generated during aerobic respiration. Paradoxically, PA displays elevated KatA activity under anaerobic growth conditions where the substrate of KatA, H2O2, is not produced. The aim of the present study is to elucidate the mechanism underlying this phenomenon and define the role of KatA in PA during anaerobiosis using genetic, biochemical and biophysical approaches. We demonstrated that anaerobic wild-type PAO1 cells yielded higher levels of katA transcription and expression than aerobic cells, whereas a nitrite reductase mutant ΔnirS produced ∼50% the KatA activity of PAO1, suggesting that a basal NO level was required for the increased KatA activity. We also found that transcription of the katA gene was controlled, in part, by the master anaerobic regulator, ANR. A ΔkatA mutant and a mucoid mucA22 ΔkatA bacteria demonstrated increased sensitivity to acidified nitrite (an NO generator) in anaerobic planktonic and biofilm cultures. EPR spectra of anaerobic bacteria showed that levels of dinitrosyl iron complexes (DNIC), indicators of NO stress, were increased significantly in the ΔkatA mutant, and dramatically in a ΔnorCB mutant compared to basal levels of DNIC in PAO1 and ΔnirS mutant. Expression of KatA dramatically reduced the DNIC levels in ΔnorCB mutant. We further revealed direct NO-KatA interactions in vitro using EPR, optical spectroscopy and X-ray crystallography. KatA has a 5-coordinate high spin ferric heme that binds NO without prior reduction of the heme iron (Kd ∼6 μM). Collectively, we conclude that KatA is expressed to protect PA against NO generated during anaerobic respiration. We proposed that such protective effects of KatA may involve buffering of free NO when potentially toxic concentrations of NO are approached.
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Affiliation(s)
- Shengchang Su
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati, Cincinnati, Ohio, United States of America
| | - Warunya Panmanee
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati, Cincinnati, Ohio, United States of America
| | - Jeffrey J. Wilson
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati, Cincinnati, Ohio, United States of America
| | - Harry K. Mahtani
- Departments of Anesthesiology, Cell, Developmental and Integrative Biology, and Environmental Health Sciences, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Qian Li
- Departments of Anesthesiology, Cell, Developmental and Integrative Biology, and Environmental Health Sciences, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Bradley D. VanderWielen
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati, Cincinnati, Ohio, United States of America
| | - Thomas M. Makris
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, Minnesota, United States of America
| | - Melanie Rogers
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, Minnesota, United States of America
| | - Cameron McDaniel
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati, Cincinnati, Ohio, United States of America
| | - John D. Lipscomb
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, Minnesota, United States of America
| | - Randall T. Irvin
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta, Canada
| | - Michael J. Schurr
- Department of Microbiology, University of Colorado, Aurora, Colorado, United States of America
| | - Jack R. Lancaster
- Departments of Anesthesiology, Cell, Developmental and Integrative Biology, and Environmental Health Sciences, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
- Center for Free Radical Biology, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Rhett A. Kovall
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati, Cincinnati, Ohio, United States of America
| | - Daniel J. Hassett
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati, Cincinnati, Ohio, United States of America
- * E-mail:
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24
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Yuan Z, Friedmann DR, VanderWielen BD, Collins KJ, Kovall RA. Characterization of CSL (CBF-1, Su(H), Lag-1) mutants reveals differences in signaling mediated by Notch1 and Notch2. J Biol Chem 2012; 287:34904-34916. [PMID: 22915591 DOI: 10.1074/jbc.m112.403287] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Notch is a conserved signaling pathway that plays essential roles during embryonic development and postnatally in adult tissues; misregulated signaling results in human disease. Notch receptor-ligand interactions trigger cleavage of the Notch receptor and release of its intracellular domain (NICD) from the membrane. NICD localizes to the nucleus where it forms a transcriptionally active complex with the DNA-binding protein CSL and the coactivator Mastermind (MAM) to up-regulate transcription from Notch target genes. Previous studies have determined the structure of the CSL-NICD-MAM ternary complex and characterized mutations that affect complex assembly in functional assays. However, as CSL is expressed in all cell types, these studies have been limited to analyzing mutations in NICD and MAM. Here, we describe a novel set of cellular reagents to characterize how mutations in CSL affect its function as a transcriptional activator. Using retrovirally transduced embryonic fibroblasts from a CSL-null mouse, we generated cell lines that express either wild-type or mutant CSL molecules. We then analyzed these mutants for defects in Notch1- (NICD1) or Notch2 (NICD2)-mediated activation from two different transcriptional reporters (HES-1 or 4×CBS). Our results show that mutations targeted to the different domains of CSL display significant differences in their ability to adversely affect transcription from the two reporters. Additionally, a subset of CSL mutants is sensitive to whether NICD1 or NICD2 was used to activate the reporter. Taken together, these studies provide important molecular insights into how Notch transcription complexes assemble at different target genes and promoter arrangements in vivo.
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Affiliation(s)
- Zhenyu Yuan
- Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati, Cincinnati, Ohio 45267
| | | | - Bradley D VanderWielen
- Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati, Cincinnati, Ohio 45267
| | - Kelly J Collins
- Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati, Cincinnati, Ohio 45267
| | - Rhett A Kovall
- Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati, Cincinnati, Ohio 45267.
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25
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Kovall RA. In notch, one ANK repeat is not like the other. Structure 2012; 20:202-4. [PMID: 22325769 DOI: 10.1016/j.str.2012.01.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
In this issue of Structure, Choi et al. use hydrogen/deuterium exchange mass spectrometry to characterize a Notch transcription complex (NTC). When interpreted in the context of NTC X-ray structures, their findings reveal important molecular insights into the dynamics that underlie complex assembly.
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Affiliation(s)
- Rhett A Kovall
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA.
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Maier D, Kurth P, Schulz A, Russell A, Yuan Z, Gruber K, Kovall RA, Preiss A. Structural and functional analysis of the repressor complex in the Notch signaling pathway of Drosophila melanogaster. Mol Biol Cell 2011; 22:3242-52. [PMID: 21737682 PMCID: PMC3164469 DOI: 10.1091/mbc.e11-05-0420] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Despite high conservation of the Notch pathway, its repression appears diverse between organisms. In Drosophila, a high-affinity complex forms between the CSL orthologue Su(H) and Hairless, which is analyzed in great detail in vitro and in vivo. Drosophila Hairless is shown to bind CBF1 and inhibit Notch transcriptional output in mammalian cells. In metazoans, the highly conserved Notch pathway drives cellular specification. On receptor activation, the intracellular domain of Notch assembles a transcriptional activator complex that includes the DNA-binding protein CSL, a composite of human C-promoter binding factor 1, Suppressor of Hairless of Drosophila melanogaster [Su(H)], and lin-12 and Glp-1 phenotype of Caenorhabditis elegans. In the absence of ligand, CSL represses Notch target genes. However, despite the structural similarity of CSL orthologues, repression appears largely diverse between organisms. Here we analyze the Notch repressor complex in Drosophila, consisting of the fly CSL protein, Su(H), and the corepressor Hairless, which recruits general repressor proteins. We show that the C-terminal domain of Su(H) is necessary and sufficient for forming a high-affinity complex with Hairless. Mutations in Su(H) that affect interactions with Notch and Mastermind have no effect on Hairless binding. Nonetheless, we demonstrate that Notch and Hairless compete for CSL in vitro and in cell culture. In addition, we identify a site in Hairless that is crucial for binding Su(H) and subsequently show that this Hairless mutant is strongly impaired, failing to properly assemble the repressor complex in vivo. Finally, we demonstrate Hairless-mediated inhibition of Notch signaling in a cell culture assay, which hints at a potentially similar repression mechanism in mammals that might be exploited for therapeutic purposes.
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Affiliation(s)
- Dieter Maier
- Institut für Genetik, Universität Hohenheim, 70593 Stuttgart, Germany.
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VanderWielen BD, Yuan Z, Friedmann DR, Kovall RA. Transcriptional repression in the Notch pathway: thermodynamic characterization of CSL-MINT (Msx2-interacting nuclear target protein) complexes. J Biol Chem 2011; 286:14892-902. [PMID: 21372128 DOI: 10.1074/jbc.m110.181156] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The Notch pathway is a conserved cell-to-cell signaling mechanism that mediates cell fate decisions in metazoans. Canonical signaling results in changes in gene expression, which is regulated by the nuclear effector of the pathway CSL (CBF1/RBP-J, Su(H), Lag-1). CSL is a DNA binding protein that functions as either a repressor or an activator of transcription, depending upon whether it is complexed by transcriptional corepressor or coactivator proteins, respectively. In stark contrast to CSL-coactivator complexes, e.g. the transcriptionally active CSL-Notch-Mastermind ternary complex, the structure and function of CSL-corepressor complexes are poorly understood. The corepressor MINT (Msx2-interacting nuclear target protein) has been shown in vivo to antagonize Notch signaling and shown in vitro to biochemically interact with CSL; however, the molecular details of this interaction are only partially defined. Here, we provide a quantitative thermodynamic binding analysis of CSL-MINT complexes. Using isothermal titration calorimetry, we demonstrate that MINT forms a high affinity complex with CSL, and we also delineate the domains of MINT and CSL that are necessary and sufficient for complex formation. Moreover, we show in cultured cells that this region of MINT can inhibit Notch signaling in transcriptional reporter assays. Taken together, our results provide functional insights into how CSL is converted from a repressor to an activator of transcription.
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Affiliation(s)
- Bradley D VanderWielen
- Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati, Cincinnati, Ohio 45267, USA
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Bahassi EM, Yin M, Robbins SB, Li YQ, Conrady DG, Yuan Z, Kovall RA, Herr AB, Stambrook PJ. A human cancer-predisposing polymorphism in Cdc25A is embryonic lethal in the mouse and promotes ASK-1 mediated apoptosis. Cell Div 2011; 6:4. [PMID: 21310058 PMCID: PMC3048473 DOI: 10.1186/1747-1028-6-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2010] [Accepted: 02/10/2011] [Indexed: 11/24/2022] Open
Abstract
Background Failure to regulate the levels of Cdc25A phosphatase during the cell cycle or during a checkpoint response causes bypass of DNA damage and replication checkpoints resulting in genomic instability and cancer. During G1 and S and in cellular response to DNA damage, Cdc25A is targeted for degradation through the Skp1-cullin-β-TrCP (SCFβ-TrCP) complex. This complex binds to the Cdc25A DSG motif which contains serine residues at positions 82 and 88. Phosphorylation of one or both residues is necessary for the binding and degradation to occur. Results We now show that mutation of serine 88 to phenylalanine, which is a cancer-predisposing polymorphic variant in humans, leads to early embryonic lethality in mice. The mutant protein retains its phosphatase activity both in vitro and in cultured cells. It fails to interact with the apoptosis signal-regulating kinase 1 (ASK1), however, and therefore does not suppress ASK1-mediated apoptosis. Conclusions These data suggest that the DSG motif, in addition to its function in Cdc25A-mediated degradation, plays a role in cell survival during early embyogenesis through suppression of ASK1-mediated apoptosis.
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Affiliation(s)
- El Mustapha Bahassi
- Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati College of Medicine, Cincinnati, Ohio 45267, USA.
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Conrady DG, Flagler MJ, Friedmann DR, Vander Wielen BD, Kovall RA, Weiss AA, Herr AB. Molecular basis of differential B-pentamer stability of Shiga toxins 1 and 2. PLoS One 2010; 5:e15153. [PMID: 21203383 PMCID: PMC3010993 DOI: 10.1371/journal.pone.0015153] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2010] [Accepted: 10/25/2010] [Indexed: 11/18/2022] Open
Abstract
Escherichia coli strain O157:H7 is a major cause of food poisoning that can result in severe diarrhea and, in some cases, renal failure. The pathogenesis of E. coli O157:H7 is in large part due to the production of Shiga toxin (Stx), an AB(5) toxin that consists of a ribosomal RNA-cleaving A-subunit surrounded by a pentamer of receptor-binding B subunits. There are two major isoforms, Stx1 and Stx2, which differ dramatically in potency despite having 57% sequence identity. Animal studies and epidemiological studies show Stx2 is associated with more severe disease. Although the molecular basis of this difference is unknown, data suggest it is associated with the B-subunit. Mass spectrometry studies have suggested differential B-pentamer stability between Stx1 and Stx2. We have examined the relative stability of the B-pentamers in solution. Analytical ultracentrifugation using purified B-subunits demonstrates that Stx2B, the more deadly isoform, shows decreased pentamer stability compared to Stx1B (EC(50) = 2.3 µM vs. EC(50) = 0.043 µM for Stx1B). X-ray crystal structures of Stx1B and Stx2B identified a glutamine in Stx2 (versus leucine in Stx1) within the otherwise strongly hydrophobic interface between B-subunits. Interchanging these residues switches the stability phenotype of the B-pentamers of Stx1 and Stx2, as demonstrated by analytical ultracentrifugation and circular dichroism. These studies demonstrate a profound difference in stability of the B-pentamers in Stx1 and Stx2, illustrate the mechanistic basis for this differential stability, and provide novel reagents to test the basis for differential pathogenicity of these toxins.
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Affiliation(s)
- Deborah G. Conrady
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States of America
| | - Michael J. Flagler
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States of America
| | - David R. Friedmann
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States of America
| | - Bradley D. Vander Wielen
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States of America
| | - Rhett A. Kovall
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States of America
- * E-mail: (RAK); (AAW); (ABH)
| | - Alison A. Weiss
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States of America
- * E-mail: (RAK); (AAW); (ABH)
| | - Andrew B. Herr
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States of America
- * E-mail: (RAK); (AAW); (ABH)
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Abstract
The Notch pathway is an intercellular signaling mechanism that plays important roles in cell fates decisions throughout the developing and adult organism. Extracellular complexation of Notch receptors with ligands ultimately results in changes in gene expression, which is regulated by the nuclear effector of the pathway, CSL (C-promoter binding factor 1 (CBF-1), suppressor of hairless (Su(H)), lin-12 and glp-1 (Lag-1)). CSL is a DNA binding protein that is involved in both repression and activation of transcription from genes that are responsive to Notch signaling. One well-characterized Notch target gene is hairy and enhancer of split-1 (HES-1), which is regulated by a promoter element consisting of two CSL binding sites oriented in a head-to-head arrangement. Although previous studies have identified in vivo and consensus binding sites for CSL, and crystal structures of these complexes have been determined, to date, a quantitative description of the energetics that underlie CSL-DNA binding is unknown. Here, we provide a thermodynamic and structural analysis of the interaction between CSL and the two individual sites that comprise the HES-1 promoter element. Our comprehensive studies that analyze binding as a function of temperature, salt, and pH reveal moderate, but distinct, differences in the affinities of CSL for the two HES-1 binding sites. Similarly, our structural results indicate that overall CSL binds both DNA sites in a similar manner; however, minor changes are observed in both the conformation of CSL and DNA. Taken together, our results provide a quantitative and biophysical basis for understanding how CSL interacts with DNA sites in vivo.
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Affiliation(s)
- David R Friedmann
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, Cincinnati, Ohio 45267-0524, USA
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Abstract
Notch proteins are the receptors in a highly conserved signal transduction system used to communicate signals between cells that contact each other. Studies investigating structure-function relationships in Notch signaling have gained substantial momentum in recent years. Here, we summarize the current understanding of the molecular logic of Notch signal transduction, emphasizing structural and biochemical studies of Notch receptors, their ligands, and complexes of intracellular Notch proteins with their target transcription factors. Recent advances in the structure-based modulation of Notch-signaling activity are also discussed.
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Affiliation(s)
- Rhett A Kovall
- Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati, Cincinnati, OH, USA
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Abstract
The Notch pathway is a short-range signaling mechanism between neighboring cells that results in changes in gene expression. Extracellular interactions between Notch receptors and ligands trigger proteolytic cleavage of the receptor Notch. Following cleavage, the freed intracellular domain of Notch (NotchIC) moves from the cytoplasm to the nucleus, engaging the DNA-binding transcription factor CBF-1, Su(H), Lag-1 (CSL)--the nuclear effector of the pathway. NotchIC, together with the transcriptional coactivator Mastermind, form a ternary complex with CSL that activates transcription from genes that are responsive to Notch signaling. Illuminating the molecular details that underlie formation of the transcriptionally active CSL-NotchIC-Mastermind ternary complex is key for understanding how genes are turned on in response to a Notch signal. Recently, several studies using biophysical and computational methods have scrutinized how the CSL-NotchIC-Mastermind ternary complex forms and the role individual domains play in this process. These detailed analyses have provided a wealth of molecular insights into the assembly of a Notch pathway active transcription complex but have also raised several intriguing, yet confounding questions. This review will focus on the findings of these recent biophysical studies and provide speculative models that address these unanswered questions.
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Affiliation(s)
- R A Kovall
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, Cincinnati, OH 45267-0524, USA.
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Abstract
The Notch pathway is a conserved cell-to-cell signaling mechanism, in which extracellular signals are transduced into transcriptional outputs through the nuclear effector CSL. CSL is converted from a repressor to an activator through the formation of the CSL-NotchIC-Mastermind ternary complex. The RAM (RBP-J associated molecule) domain of NotchIC avidly interacts with CSL; however, its role in assembly of the CSL-NotchIC-Mastermind ternary complex is not understood. Here we provide a comprehensive thermodynamic, structural, and biochemical analysis of the RAM-CSL interaction for components from both mouse and worm. Our binding data show that RAM and CSL form a high affinity complex in the presence or absence of DNA. Our structural studies reveal a striking distal conformational change in CSL upon RAM binding, which creates a docking site for Mastermind to bind to the complex. Finally, we show that the addition of a RAM peptide in trans facilitates formation of the CSL-NotchIC-Mastermind ternary complex in vitro.
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Affiliation(s)
- David R Friedmann
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, Cincinnati, OH 45267-0524, USA
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Kovall RA. Structures of CSL, Notch and Mastermind proteins: piecing together an active transcription complex. Curr Opin Struct Biol 2006; 17:117-27. [PMID: 17157496 DOI: 10.1016/j.sbi.2006.11.004] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2006] [Revised: 10/18/2006] [Accepted: 11/27/2006] [Indexed: 01/05/2023]
Abstract
Notch signaling mediates communication between cells, and is essential for proper cell fate decisions in the developing embryo and the adult organism. Signaling initiates proteolytic release of the receptor Notch from the membrane, whereupon the intracellular portion of Notch (NotchIC) localizes to the nucleus and engages the DNA-binding transcription factor CSL. CSL is required for both repression and activation of Notch target genes, and is the focal point of a transcriptional switch, mediating interactions with transcriptional coregulators. Activation of transcription requires corepressor displacement from CSL by NotchIC and the recruitment of the transcriptional coactivator Mastermind to the complex. Several recently determined and exciting structures of CSL, NotchIC, and an active transcription complex composed of CSL, NotchIC and Mastermind have revealed new insights into transcriptional regulation in the Notch pathway.
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Affiliation(s)
- Rhett A Kovall
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, Cincinnati, OH 45267-0524, USA.
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Wilson JJ, Kovall RA. Crystal structure of the CSL-Notch-Mastermind ternary complex bound to DNA. Cell 2006; 124:985-96. [PMID: 16530045 DOI: 10.1016/j.cell.2006.01.035] [Citation(s) in RCA: 257] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2005] [Revised: 12/06/2005] [Accepted: 01/24/2006] [Indexed: 10/24/2022]
Abstract
Notch signaling mediates communication between cells and is essential for proper embryonic patterning and development. CSL is a DNA binding transcription factor that regulates transcription of Notch target genes by interacting with coregulators. Transcriptional activation requires the displacement of corepressors from CSL by the intracellular portion of the receptor Notch (NotchIC) and the recruitment of the coactivator protein Mastermind to the complex. Here we report the 3.1 A structure of the ternary complex formed by CSL, NotchIC, and Mastermind bound to DNA. As expected, the RAM domain of Notch interacts with the beta trefoil domain of CSL; however, the C-terminal domain of CSL has an unanticipated central role in the interface formed with the Notch ankyrin repeats and Mastermind. Ternary complex formation induces a substantial conformational change within CSL, suggesting a molecular mechanism for the conversion of CSL from a repressor to an activator.
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Affiliation(s)
- Jeffrey J Wilson
- Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA
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Kovall RA, Hendrickson WA. Crystal structure of the nuclear effector of Notch signaling, CSL, bound to DNA. EMBO J 2004; 23:3441-51. [PMID: 15297877 PMCID: PMC516623 DOI: 10.1038/sj.emboj.7600349] [Citation(s) in RCA: 117] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2004] [Accepted: 07/08/2004] [Indexed: 11/08/2022] Open
Abstract
Notch signaling is a conserved pathway of communication between neighboring cells that results in cell fate specification, and CSL is the universal transcriptional effector of Notch signaling. The Notch intracellular domain translocates to the nucleus after proteolytic release upon Notch extracellular engagement, and there it displaces corepressors from DNA-bound CSL and recruits activators of Notch target genes. Here we report the 2.85 A crystal structure of CSL with a target DNA. CSL comprises three structurally integrated domains: its amino (NTD)- and carboxy (CTD)-terminal domains are strikingly similar to those of Rel transcription factors, but a surprising beta-trefoil domain (BTD) is inserted between them. CSL-bound DNA is recognized specifically by conserved residues from NTD and BTD. A hydrophobic pocket on BTD is identified as the likely site of Notch interaction with CSL, which has functional implications for the mechanism of Notch signaling.
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Affiliation(s)
- Rhett A Kovall
- Department of Biochemistry and Molecular Biophysics, Howard Hughes Medical Institute, Columbia University, New York, NY, USA
| | - Wayne A Hendrickson
- Department of Biochemistry and Molecular Biophysics, Howard Hughes Medical Institute, Columbia University, New York, NY, USA
- Department of Biochemistry and Molecular Biophysics, Howard Hughes Medical Institute, Columbia University, New York, NY 10032, USA. Tel.: +1 212 305 3456; Fax: +1 212 305 7379; E-mail:
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Min KC, Kovall RA, Hendrickson WA. Crystal structure of human alpha-tocopherol transfer protein bound to its ligand: implications for ataxia with vitamin E deficiency. Proc Natl Acad Sci U S A 2003; 100:14713-8. [PMID: 14657365 PMCID: PMC299775 DOI: 10.1073/pnas.2136684100] [Citation(s) in RCA: 105] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Human alpha-tocopherol (alpha-T) transfer protein (ATTP) plays a central role in vitamin E homeostasis, preventing degradation of alpha-T by routing this lipophilic molecule for secretion by hepatocytes. Mutations in the gene encoding ATTP have been shown to cause a severe deficiency in alpha-T, which results in a progressive neurodegenerative spinocerebellar ataxia, known as ataxia with vitamin E deficiency (AVED). We have determined the high-resolution crystal structure of human ATTP with (2R,4'R,8'R)-alpha-T in the binding pocket. Surprisingly, the ligand is sequestered deep in the hydrophobic core of the protein, implicating a large structural rearrangement for the entry and release of alpha-T. A comparison to the structure of a related protein, Sec14p, crystallized without a bona fide ligand, shows a possibly relevant open conformation for this family of proteins. Furthermore, of the known mutations that cause AVED, one mutation, L183P, is located directly in the binding pocket. Finally, three mutations associated with AVED involve arginine residues that are grouped together on the surface of ATTP. We propose that this positively charged surface may serve to orient an interacting protein, which might function to regulate the release of alpha-T through an induced change in conformation of ATTP.
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Affiliation(s)
- K Christopher Min
- Howard Hughes Medical Institute and Department of Neurology, Columbia University, New York, NY 10032, USA
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Abstract
Type II restriction endonucleases are a paradigm for site-specific cleavage of DNA. Recent structural analyses, in particular in the presence of various divalent metals, have shed new insight into the mechanisms of catalysis. In addition, during this past year the crystal structure determinations of MutH, lambda-exonuclease and FokI have revealed that these proteins are also members of the same family.
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Affiliation(s)
- R A Kovall
- Institute of Molecular Biology, Howard Hughes Medical Institute, Department of Physics, 1229 University of Oregon, Eugene, OR 97403-1229, USA
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Kovall RA, Matthews BW. Structural, functional, and evolutionary relationships between lambda-exonuclease and the type II restriction endonucleases. Proc Natl Acad Sci U S A 1998; 95:7893-7. [PMID: 9653111 PMCID: PMC20900 DOI: 10.1073/pnas.95.14.7893] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
lambda-exonuclease participates in DNA recombination and repair. It binds a free end of double-stranded DNA and degrades one strand in the 5' to 3' direction. The primary sequence does not appear to be related to any other protein, but the crystal structure shows part of lambda-exonuclease to be similar to the type II restriction endonucleases PvuII and EcoRV. There is also a weaker correspondence with EcoRI, BamHI, and Cfr10I. The structure comparisons not only suggest that these enzymes all share a similar catalytic mechanism and a common structural ancestor but also provide strong evidence that the toroidal structure of lambda-exonuclease encircles its DNA substrate during hydrolysis.
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Affiliation(s)
- R A Kovall
- Institute of Molecular Biology, Howard Hughes Medical Institute and Department of Physics, University of Oregon, Eugene, OR 97403, USA
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