1
|
Chen Y, Li H, Yi TC, Shen J, Zhang J. Notch Signaling in Insect Development: A Simple Pathway with Diverse Functions. Int J Mol Sci 2023; 24:14028. [PMID: 37762331 PMCID: PMC10530718 DOI: 10.3390/ijms241814028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 09/05/2023] [Accepted: 09/06/2023] [Indexed: 09/29/2023] Open
Abstract
Notch signaling is an evolutionarily conserved pathway which functions between adjacent cells to establish their distinct identities. Despite operating in a simple mechanism, Notch signaling plays remarkably diverse roles in development to regulate cell fate determination, organ growth and tissue patterning. While initially discovered and characterized in the model insect Drosophila melanogaster, recent studies across various insect species have revealed the broad involvement of Notch signaling in shaping insect tissues. This review focuses on providing a comprehensive picture regarding the roles of the Notch pathway in insect development. The roles of Notch in the formation and patterning of the insect embryo, wing, leg, ovary and several specific structures, as well as in physiological responses, are summarized. These results are discussed within the developmental context, aiming to deepen our understanding of the diversified functions of the Notch signaling pathway in different insect species.
Collapse
Affiliation(s)
- Yao Chen
- Department of Plant Biosecurity and MOA Key Laboratory of Surveillance and Management for Plant Quarantine Pests, College of Plant Protection, China Agricultural University, Beijing 100193, China; (Y.C.)
| | - Haomiao Li
- Department of Plant Biosecurity and MOA Key Laboratory of Surveillance and Management for Plant Quarantine Pests, College of Plant Protection, China Agricultural University, Beijing 100193, China; (Y.C.)
| | - Tian-Ci Yi
- Guizhou Provincial Key Laboratory for Agricultural Pest Management of Mountainous Regions, Institute of Entomology, Guizhou University, Guiyang 550025, China
| | - Jie Shen
- Department of Plant Biosecurity and MOA Key Laboratory of Surveillance and Management for Plant Quarantine Pests, College of Plant Protection, China Agricultural University, Beijing 100193, China; (Y.C.)
| | - Junzheng Zhang
- Department of Plant Biosecurity and MOA Key Laboratory of Surveillance and Management for Plant Quarantine Pests, College of Plant Protection, China Agricultural University, Beijing 100193, China; (Y.C.)
| |
Collapse
|
2
|
Protein kinase CK2 phosphorylates a conserved motif in the Notch effector E(spl)-Mγ. Mol Cell Biochem 2022; 478:781-790. [PMID: 36087252 DOI: 10.1007/s11010-022-04539-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Accepted: 08/08/2022] [Indexed: 11/27/2022]
Abstract
Across metazoan animals, the effects of Notch signaling are mediated via the Enhancer of Split (E(spl)/HES) basic Helix-Loop-Helix-Orange (bHLH-O) repressors. Although these repressors are generally conserved, their sequence diversity is, in large part, restricted to the C-terminal domain (CtD), which separates the Orange (O) domain from the penultimate WRPW tetrapeptide motif that binds the obligate co-repressor Groucho. While the kinases CK2 and MAPK target the CtD and regulate Drosophila E(spl)-M8 and mammalian HES6, the generality of this regulation to other E(spl)/HES repressors has remained unknown. To determine the broader impact of phosphorylation on this large family of repressors, we conducted bioinformatics, evolutionary, and biochemical analyses. Our studies identify E(spl)-Mγ as a new target of native CK2 purified from Drosophila embryos, reveal that phosphorylation is specific to CK2 and independent of the regulatory CK2-β subunit, and identify that the site of phosphorylation is juxtaposed to the WRPW motif, a feature unique to and conserved in the Mγ homologues over 50 × 106 years of Drosophila evolution. Thus, a preponderance of E(spl) homologues (four out of seven total) in Drosophila are targets for CK2, and the distinct positioning of the CK2 and MAPK sites raises the prospect that phosphorylation underlies functional diversity of bHLH-O proteins.
Collapse
|
3
|
Pourquié O. A brief history of the segmentation clock. Dev Biol 2022; 485:24-36. [DOI: 10.1016/j.ydbio.2022.02.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Accepted: 02/23/2022] [Indexed: 11/16/2022]
|
4
|
He X, Wu F, Zhang L, Li L, Zhang G. Comparative and evolutionary analyses reveal conservation and divergence of the notch pathway in lophotrochozoa. Sci Rep 2021; 11:11378. [PMID: 34059772 PMCID: PMC8166818 DOI: 10.1038/s41598-021-90800-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Accepted: 05/17/2021] [Indexed: 01/03/2023] Open
Abstract
Lophotrochozoan species exhibit wide morphological diversity; however, the molecular basis underlying this diversity remains unclear. Here, we explored the evolution of Notch pathway genes across 37 metazoan species via phylogenetic and molecular evolutionary studies with emphasis on the lophotrochozoans. We displayed the components of Notch pathway in metazoans and found that Delta and Hes/Hey-related genes, as well as their functional domains, are duplicated in lophotrochozoans. Comparative transcriptomics analyses allow us to pinpoint sequence divergence of multigene families in the Notch signalling pathway. We identified the duplication mechanism of a mollusc-specific gene, Delta2, and found it displayed complementary expression throughout development. Furthermore, we found the functional diversification not only in expanded genes in the Notch pathway (Delta and Hes/Hey-related genes), but also in evolutionary conservative genes (Notch, Presenilin, and Su(H)). Together, this comprehensive study demonstrates conservation and divergence within the Notch pathway, reveals evolutionary relationships among metazoans, and provides evidence for the occurrence of developmental diversity in lophotrochozoans, as well as a basis for future gene function studies.
Collapse
Affiliation(s)
- Xin He
- CAS and Shandong Province Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China
- Laboratory for Marine Biology and Biotechnology, Pilot National Laboratory for Marine Science and Technology, Qingdao, 266237, China
- University of Chinese Academy of Sciences, Beijing, 100039, China
- The Innovation of Seed Design, Chinese Academy of Sciences, Wuhan, 430072, China
| | - Fucun Wu
- CAS and Shandong Province Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China.
- Laboratory for Marine Biology and Biotechnology, Pilot National Laboratory for Marine Science and Technology, Qingdao, 266237, China.
- National and Local Joint Engineering Laboratory of Ecological Mariculture, Qingdao, 266071, China.
- The Innovation of Seed Design, Chinese Academy of Sciences, Wuhan, 430072, China.
| | - Linlin Zhang
- CAS and Shandong Province Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China.
- Laboratory for Marine Biology and Biotechnology, Pilot National Laboratory for Marine Science and Technology, Qingdao, 266237, China.
- National and Local Joint Engineering Laboratory of Ecological Mariculture, Qingdao, 266071, China.
| | - Li Li
- CAS and Shandong Province Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China
- Laboratory for Marine Fisheries Science and Food Production Processes, Pilot National Laboratory for Marine Science and Technology, Qingdao, 266237, China
- National and Local Joint Engineering Laboratory of Ecological Mariculture, Qingdao, 266071, China
| | - Guofan Zhang
- CAS and Shandong Province Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China
- Laboratory for Marine Biology and Biotechnology, Pilot National Laboratory for Marine Science and Technology, Qingdao, 266237, China
- National and Local Joint Engineering Laboratory of Ecological Mariculture, Qingdao, 266071, China
| |
Collapse
|
5
|
Nagel AC, Maier D, Scharpf J, Ketelhut M, Preiss A. Limited Availability of General Co-Repressors Uncovered in an Overexpression Context during Wing Venation in Drosophila melanogaster. Genes (Basel) 2020; 11:genes11101141. [PMID: 32998295 PMCID: PMC7601384 DOI: 10.3390/genes11101141] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 09/17/2020] [Accepted: 09/25/2020] [Indexed: 12/31/2022] Open
Abstract
Cell fate is determined by the coordinated activity of different pathways, including the conserved Notch pathway. Activation of Notch results in the transcription of Notch targets that are otherwise silenced by repressor complexes. In Drosophila, the repressor complex comprises the transcription factor Suppressor of Hairless (Su(H)) bound to the Notch antagonist Hairless (H) and the general co-repressors Groucho (Gro) and C-terminal binding protein (CtBP). The latter two are shared by different repressors from numerous pathways, raising the possibility that they are rate-limiting. We noted that the overexpression during wing development of H mutants HdNT and HLD compromised in Su(H)-binding induced ectopic veins. On the basis of the role of H as Notch antagonist, overexpression of Su(H)-binding defective H isoforms should be without consequence, implying different mechanisms but repression of Notch signaling activity. Perhaps excess H protein curbs general co-repressor availability. Supporting this model, nearly normal wings developed upon overexpression of H mutant isoforms that bound neither Su(H) nor co-repressor Gro and CtBP. Excessive H protein appeared to sequester general co-repressors, resulting in specific vein defects, indicating their limited availability during wing vein development. In conclusion, interpretation of overexpression phenotypes requires careful consideration of possible dominant negative effects from interception of limiting factors.
Collapse
|
6
|
Wang Y, Wang GD, He QL, Luo ZP, Yang L, Yao Q, Chen KP. Phylogenetic analysis of achaete–scute complex genes in metazoans. Mol Genet Genomics 2020; 295:591-606. [DOI: 10.1007/s00438-020-01648-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Accepted: 01/13/2020] [Indexed: 11/30/2022]
|
7
|
Schweisguth F, Corson F. Self-Organization in Pattern Formation. Dev Cell 2020; 49:659-677. [PMID: 31163171 DOI: 10.1016/j.devcel.2019.05.019] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2018] [Revised: 02/16/2019] [Accepted: 05/07/2019] [Indexed: 12/19/2022]
Abstract
Self-organization is pervasive in development, from symmetry breaking in the early embryo to tissue patterning and morphogenesis. For a few model systems, the underlying molecular and cellular processes are now sufficiently characterized that mathematical models can be confronted with experiments, to explore the dynamics of pattern formation. Here, we review selected systems, ranging from cyanobacteria to mammals, where different forms of cell-cell communication, acting alone or together with positional cues, drive the patterning of cell fates, highlighting the insights that even very simple models can provide as well as the challenges on the path to a predictive understanding of development.
Collapse
Affiliation(s)
- François Schweisguth
- Institut Pasteur, Department of Developmental and Stem Cell Biology F-75015 Paris, France; CNRS, UMR 3738 F-75015 Paris, France.
| | - Francis Corson
- Laboratoire de Physique de l'Ecole Normale Supérieure, CNRS, Sorbonne Université, Université Paris Diderot 75005 Paris, France.
| |
Collapse
|
8
|
Gahr BM, Brändle F, Zimmermann M, Nagel AC. An RBPJ- Drosophila Model Reveals Dependence of RBPJ Protein Stability on the Formation of Transcription-Regulator Complexes. Cells 2019; 8:cells8101252. [PMID: 31615108 PMCID: PMC6829621 DOI: 10.3390/cells8101252] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Revised: 10/07/2019] [Accepted: 10/10/2019] [Indexed: 01/07/2023] Open
Abstract
Notch signaling activity governs widespread cellular differentiation in higher animals, including humans, and is involved in several congenital diseases and different forms of cancer. Notch signals are mediated by the transcriptional regulator RBPJ in a complex with activated Notch (NICD). Analysis of Notch pathway regulation in humans is hampered by a partial redundancy of the four Notch receptor copies, yet RBPJ is solitary, allowing its study in model systems. In Drosophila melanogaster, the RBPJ orthologue is encoded by Suppressor of Hairless [Su(H)]. Using genome engineering, we replaced Su(H) by murine RBPJ in order to study its function in the fly. In fact, RBPJ largely substitutes for Su(H)’s function, yet subtle phenotypes reflect increased Notch signaling activity. Accordingly, the binding of RBPJ to Hairless (H) protein, the general Notch antagonist in Drosophila, was considerably reduced compared to that of Su(H). An H-binding defective RBPJLLL mutant matched the respective Su(H)LLL allele: homozygotes were lethal due to extensive Notch hyperactivity. Moreover, RBPJLLL protein accumulated at lower levels than wild type RBPJ, except in the presence of NICD. Apparently, RBPJ protein stability depends on protein complex formation with either H or NICD, similar to Su(H), demonstrating that the murine homologue underlies the same regulatory mechanisms as Su(H) in Drosophila. These results underscore the importance of regulating the availability of RBPJ protein to correctly mediate Notch signaling activity in the fly.
Collapse
Affiliation(s)
- Bernd M. Gahr
- Institute of Genetics (240), University of Hohenheim, Garbenstr. 30, 70599 Stuttgart, Germany; (B.M.G.); (F.B.); (M.Z.)
- Present address: Molecular Cardiology, Department of Internal Medicine II, University of Ulm, Albert-Einstein-Allee 23, 89081 Ulm, Germany
| | - Franziska Brändle
- Institute of Genetics (240), University of Hohenheim, Garbenstr. 30, 70599 Stuttgart, Germany; (B.M.G.); (F.B.); (M.Z.)
| | - Mirjam Zimmermann
- Institute of Genetics (240), University of Hohenheim, Garbenstr. 30, 70599 Stuttgart, Germany; (B.M.G.); (F.B.); (M.Z.)
| | - Anja C. Nagel
- Institute of Genetics (240), University of Hohenheim, Garbenstr. 30, 70599 Stuttgart, Germany; (B.M.G.); (F.B.); (M.Z.)
- Correspondence: ; Tel.: +49-711-45922210
| |
Collapse
|
9
|
Korzelius J, Azami S, Ronnen-Oron T, Koch P, Baldauf M, Meier E, Rodriguez-Fernandez IA, Groth M, Sousa-Victor P, Jasper H. The WT1-like transcription factor Klumpfuss maintains lineage commitment of enterocyte progenitors in the Drosophila intestine. Nat Commun 2019; 10:4123. [PMID: 31511511 PMCID: PMC6739418 DOI: 10.1038/s41467-019-12003-0] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Accepted: 08/09/2019] [Indexed: 01/01/2023] Open
Abstract
In adult epithelial stem cell lineages, the precise differentiation of daughter cells is critical to maintain tissue homeostasis. Notch signaling controls the choice between absorptive and entero-endocrine cell differentiation in both the mammalian small intestine and the Drosophila midgut, yet how Notch promotes lineage restriction remains unclear. Here, we describe a role for the transcription factor Klumpfuss (Klu) in restricting the fate of enteroblasts (EBs) in the Drosophila intestine. Klu is induced in Notch-positive EBs and its activity restricts cell fate towards the enterocyte (EC) lineage. Transcriptomics and DamID profiling show that Klu suppresses enteroendocrine (EE) fate by repressing the action of the proneural gene Scute, which is essential for EE differentiation. Loss of Klu results in differentiation of EBs into EE cells. Our findings provide mechanistic insight into how lineage commitment in progenitor cell differentiation can be ensured downstream of initial specification cues. Notch signaling mediates intestinal enteroblast specification in Drosophila but the molecular mechanism as to how this is regulated is unclear. Here, the authors show that the transcription factor Klumpfuss ensures enteroblast commitment through repression of enteroendocrine cell fate downstream of Notch.
Collapse
Affiliation(s)
- Jerome Korzelius
- Leibniz Institute on Aging-Fritz Lipmann Institute (FLI), Jena, Germany. .,Max-Planck-Institute for Biology of Aging, Cologne, Germany.
| | - Sina Azami
- Leibniz Institute on Aging-Fritz Lipmann Institute (FLI), Jena, Germany.,Max-Planck-Institute for Biology of Aging, Cologne, Germany
| | - Tal Ronnen-Oron
- Buck Institute for Research on Aging, 8001 Redwood Boulevard, Novato, CA, 94945-1400, USA
| | - Philipp Koch
- Leibniz Institute on Aging-Fritz Lipmann Institute (FLI), Jena, Germany
| | - Maik Baldauf
- Leibniz Institute on Aging-Fritz Lipmann Institute (FLI), Jena, Germany
| | - Elke Meier
- Leibniz Institute on Aging-Fritz Lipmann Institute (FLI), Jena, Germany
| | | | - Marco Groth
- Leibniz Institute on Aging-Fritz Lipmann Institute (FLI), Jena, Germany
| | - Pedro Sousa-Victor
- Buck Institute for Research on Aging, 8001 Redwood Boulevard, Novato, CA, 94945-1400, USA
| | - Heinrich Jasper
- Leibniz Institute on Aging-Fritz Lipmann Institute (FLI), Jena, Germany. .,Buck Institute for Research on Aging, 8001 Redwood Boulevard, Novato, CA, 94945-1400, USA. .,Immunology Discovery, Genentech, Inc., 1 DNA Way, South San Francisco, CA, 94080, USA.
| |
Collapse
|
10
|
Couturier L, Mazouni K, Corson F, Schweisguth F. Regulation of Notch output dynamics via specific E(spl)-HLH factors during bristle patterning in Drosophila. Nat Commun 2019; 10:3486. [PMID: 31375669 PMCID: PMC6677740 DOI: 10.1038/s41467-019-11477-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Accepted: 07/03/2019] [Indexed: 12/13/2022] Open
Abstract
The stereotyped arrangement of sensory bristles on the adult fly thorax arises from a self-organized process, in which inhibitory Notch signaling both delimits proneural stripes and singles out sensory organ precursor cells (SOPs). A dynamic balance between proneural factors and Enhancer of split-HLH (E(spl)-HLH) Notch targets underlies patterning, but how this is regulated is unclear. Here, were identify two classes of E(spl)-HLH factors, whose expression both precedes and delimits proneural activity, and is dependent on proneural activity and required for proper SOP spacing within the stripes, respectively. These two classes are partially redundant, since a member of the second class, that is normally cross-repressed by members of the first class, can functionally compensate for their absence. The regulation of specific E(spl)-HLH genes by proneural factors amplifies the response to Notch as SOPs are being selected, contributing to patterning dynamics in the notum, and likely operates in other developmental contexts. The patterning of sensory bristles on the dorsal thorax of flies is regulated by two transcription factor families but the dynamics of this regulation is unclear. Here, the authors visualize seven E(spl)-HLH proteins, showing their regulated expression promotes mutual inhibition by Notch during notum patterning.
Collapse
Affiliation(s)
- Lydie Couturier
- Department of Developmental and Stem Cell Biology, Institut Pasteur, 75015, Paris, France.,CNRS, UMR3738, 75015, Paris, France
| | - Khalil Mazouni
- Department of Developmental and Stem Cell Biology, Institut Pasteur, 75015, Paris, France.,CNRS, UMR3738, 75015, Paris, France
| | - Francis Corson
- Laboratoire de Physique de l'Ecole Normale Supérieure, CNRS, Sorbonne Université, Université Paris Diderot, 75005, Paris, France
| | - François Schweisguth
- Department of Developmental and Stem Cell Biology, Institut Pasteur, 75015, Paris, France. .,CNRS, UMR3738, 75015, Paris, France.
| |
Collapse
|
11
|
Piwko P, Vitsaki I, Livadaras I, Delidakis C. The Role of Insulators in Transgene Transvection in Drosophila. Genetics 2019; 212:489-508. [PMID: 30948430 PMCID: PMC6553826 DOI: 10.1534/genetics.119.302165] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Accepted: 04/02/2019] [Indexed: 12/19/2022] Open
Abstract
Transvection is the phenomenon where a transcriptional enhancer activates a promoter located on the homologous chromosome. It has been amply documented in Drosophila where homologs are closely paired in most, if not all, somatic nuclei, but it has been known to rarely occur in mammals as well. We have taken advantage of site-directed transgenesis to insert reporter constructs into the same genetic locus in Drosophila and have evaluated their ability to engage in transvection by testing many heterozygous combinations. We find that transvection requires the presence of an insulator element on both homologs. Homotypic trans-interactions between four different insulators can support transvection: the gypsy insulator (GI), Wari, Fab-8 and 1A2; GI and Fab-8 are more effective than Wari or 1A2 We show that, in the presence of insulators, transvection displays the characteristics that have been previously described: it requires homolog pairing, but can happen at any of several loci in the genome; a solitary enhancer confronted with an enhancerless reporter is sufficient to drive transcription; it is weaker than the action of the same enhancer-promoter pair in cis, and it is further suppressed by cis-promoter competition. Though necessary, the presence of homotypic insulators is not sufficient for transvection; their position, number and orientation matters. A single GI adjacent to both enhancer and promoter is the optimal configuration. The identity of enhancers and promoters in the vicinity of a trans-interacting insulator pair is also important, indicative of complex insulator-enhancer-promoter interactions.
Collapse
Affiliation(s)
- Pawel Piwko
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology Hellas, Heraklion 70013, Crete, Greece
- Department of Biology, University of Crete, Heraklion 70013, Crete, Greece
| | - Ilektra Vitsaki
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology Hellas, Heraklion 70013, Crete, Greece
- Department of Biology, University of Crete, Heraklion 70013, Crete, Greece
| | - Ioannis Livadaras
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology Hellas, Heraklion 70013, Crete, Greece
| | - Christos Delidakis
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology Hellas, Heraklion 70013, Crete, Greece
- Department of Biology, University of Crete, Heraklion 70013, Crete, Greece
| |
Collapse
|
12
|
Mieszczanek J, van Tienen LM, Ibrahim AEK, Winton DJ, Bienz M. Bcl9 and Pygo synergise downstream of Apc to effect intestinal neoplasia in FAP mouse models. Nat Commun 2019; 10:724. [PMID: 30760710 PMCID: PMC6374407 DOI: 10.1038/s41467-018-08164-z] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Accepted: 12/19/2018] [Indexed: 01/03/2023] Open
Abstract
Bcl9 and Pygo are Wnt enhanceosome components that effect β-catenin-dependent transcription. Whether they mediate β-catenin-dependent neoplasia is unclear. Here we assess their roles in intestinal tumourigenesis initiated by Apc loss-of-function (ApcMin), or by Apc1322T encoding a partially-functional Apc truncation commonly found in colorectal carcinomas. Intestinal deletion of Bcl9 extends disease-free survival in both models, and essentially cures Apc1322T mice of their neoplasia. Loss-of-Bcl9 synergises with loss-of-Pygo to shift gene expression within Apc-mutant adenomas from stem cell-like to differentiation along Notch-regulated secretory lineages. Bcl9 loss also promotes tumour retention in ApcMin mice, apparently via relocating nuclear β-catenin to the cell surface, but this undesirable effect is not seen in Apc1322T mice whose Apc truncation retains partial function in regulating β-catenin. Our results demonstrate a key role of the Wnt enhanceosome in β-catenin-dependent intestinal tumourigenesis and reveal the potential of BCL9 as a therapeutic target during early stages of colorectal cancer.
Collapse
Affiliation(s)
- Juliusz Mieszczanek
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Francis Crick Avenue, Cambridge, CB2 0QH, UK
| | - Laurens M van Tienen
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Francis Crick Avenue, Cambridge, CB2 0QH, UK
| | - Ashraf E K Ibrahim
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Francis Crick Avenue, Cambridge, CB2 0QH, UK
| | - Douglas J Winton
- Cancer Research UK Cambridge Institute, University of Cambridge, Li Ka Shing Centre,, Robinson Way, Cambridge, CB2 0RE, UK
| | - Mariann Bienz
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Francis Crick Avenue, Cambridge, CB2 0QH, UK.
| |
Collapse
|
13
|
Xu M, Xiang Y, Liu X, Bai B, Chen R, Liu L, Li M. Long noncoding RNA SMRG regulates Drosophila macrochaetes by antagonizing scute through E(spl)mβ. RNA Biol 2018; 16:42-53. [PMID: 30526271 DOI: 10.1080/15476286.2018.1556148] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
It is obvious that the majority of cellular transcripts are long noncoding RNAs (lncRNAs). Although studies suggested that lncRNAs participate in many biological processes through diverse mechanisms, however, little is known about their effects on epidermal mechanoreceptors. Here, we identified one novel Drosophila lncRNA, Scutellar Macrochaetes Regulatory Gene (SMRG), which regulates scutellar macrochaetes that act as mechanoreceptors by antagonizing the proneural gene scute (sc), through the repressor Enhancer-of-split mβ (E(spl)mβ). SMRG deficiency induced supernumerary scutellar macrochaetes and simultaneously a high sc RNA level in the adult thorax. Genetically, sc overexpression enhanced this supernumerary phenotype, while heterozygous sc mutant rescued this phenotype, both of which were mediated by E(spl)mβ. At the molecular level, SMRG recruited E(spl)mβ to the sc promoter region, which in turn suppressed sc expression. Our work presents a novel function of lncRNA and offers insights into the molecular mechanism underlying mechanoreceptor development.
Collapse
Affiliation(s)
- Mengbo Xu
- a State Key Laboratory of Brain and Cognitive Science , Institute of Biophysics, Chinese Academy of Sciences , Beijing , China
| | - Yuanhang Xiang
- a State Key Laboratory of Brain and Cognitive Science , Institute of Biophysics, Chinese Academy of Sciences , Beijing , China.,b College of Life Sciences , University of Chinese Academy of Sciences , Beijing , China
| | - Xiaojun Liu
- c State Key Laboratory of Medical Molecular Biology , Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences & School of Basic Medicine Peking Union Medical College , Beijing , China
| | - Baoyan Bai
- d Key Laboratory of Noncoding RNA , Institute of Biophysics, Chinese Academy of Sciences , Beijing , China
| | - Runsheng Chen
- d Key Laboratory of Noncoding RNA , Institute of Biophysics, Chinese Academy of Sciences , Beijing , China
| | - Li Liu
- a State Key Laboratory of Brain and Cognitive Science , Institute of Biophysics, Chinese Academy of Sciences , Beijing , China.,b College of Life Sciences , University of Chinese Academy of Sciences , Beijing , China.,e Key Laboratory of Mental Health , Chinese Academy of Sciences , Beijing , China
| | - Meixia Li
- a State Key Laboratory of Brain and Cognitive Science , Institute of Biophysics, Chinese Academy of Sciences , Beijing , China.,b College of Life Sciences , University of Chinese Academy of Sciences , Beijing , China
| |
Collapse
|
14
|
Salazar JL, Yamamoto S. Integration of Drosophila and Human Genetics to Understand Notch Signaling Related Diseases. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1066:141-185. [PMID: 30030826 PMCID: PMC6233323 DOI: 10.1007/978-3-319-89512-3_8] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Notch signaling research dates back to more than one hundred years, beginning with the identification of the Notch mutant in the fruit fly Drosophila melanogaster. Since then, research on Notch and related genes in flies has laid the foundation of what we now know as the Notch signaling pathway. In the 1990s, basic biological and biochemical studies of Notch signaling components in mammalian systems, as well as identification of rare mutations in Notch signaling pathway genes in human patients with rare Mendelian diseases or cancer, increased the significance of this pathway in human biology and medicine. In the 21st century, Drosophila and other genetic model organisms continue to play a leading role in understanding basic Notch biology. Furthermore, these model organisms can be used in a translational manner to study underlying mechanisms of Notch-related human diseases and to investigate the function of novel disease associated genes and variants. In this chapter, we first briefly review the major contributions of Drosophila to Notch signaling research, discussing the similarities and differences between the fly and human pathways. Next, we introduce several biological contexts in Drosophila in which Notch signaling has been extensively characterized. Finally, we discuss a number of genetic diseases caused by mutations in genes in the Notch signaling pathway in humans and we expand on how Drosophila can be used to study rare genetic variants associated with these and novel disorders. By combining modern genomics and state-of-the art technologies, Drosophila research is continuing to reveal exciting biology that sheds light onto mechanisms of disease.
Collapse
Affiliation(s)
- Jose L Salazar
- Department of Molecular and Human Genetics, Baylor College of Medicine (BCM), Houston, TX, USA
| | - Shinya Yamamoto
- Department of Molecular and Human Genetics, Baylor College of Medicine (BCM), Houston, TX, USA.
- Program in Developmental Biology, BCM, Houston, TX, USA.
- Department of Neuroscience, BCM, Houston, TX, USA.
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA.
| |
Collapse
|
15
|
The Biology of SUMO-Targeted Ubiquitin Ligases in Drosophila Development, Immunity, and Cancer. J Dev Biol 2018; 6:jdb6010002. [PMID: 29615551 PMCID: PMC5875560 DOI: 10.3390/jdb6010002] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Revised: 12/27/2017] [Accepted: 12/27/2017] [Indexed: 12/12/2022] Open
Abstract
The ubiquitin and SUMO (small ubiquitin-like modifier) pathways modify proteins that in turn regulate diverse cellular processes, embryonic development, and adult tissue physiology. These pathways were originally discovered biochemically in vitro, leading to a long-standing challenge of elucidating both the molecular cross-talk between these pathways and their biological importance. Recent discoveries in Drosophila established that ubiquitin and SUMO pathways are interconnected via evolutionally conserved SUMO-targeted ubiquitin ligase (STUbL) proteins. STUbL are RING ubiquitin ligases that recognize SUMOylated substrates and catalyze their ubiquitination, and include Degringolade (Dgrn) in Drosophila and RNF4 and RNF111 in humans. STUbL are essential for early development of both the fly and mouse embryos. In the fly embryo, Dgrn regulates early cell cycle progression, sex determination, zygotic gene transcription, segmentation, and neurogenesis, among other processes. In the fly adult, Dgrn is required for systemic immune response to pathogens and intestinal stem cell regeneration upon infection. These functions of Dgrn are highly conserved in humans, where RNF4-dependent ubiquitination potentiates key oncoproteins, thereby accelerating tumorigenesis. Here, we review the lessons learned to date in Drosophila and highlight their relevance to cancer biology.
Collapse
|
16
|
Siebel C, Lendahl U. Notch Signaling in Development, Tissue Homeostasis, and Disease. Physiol Rev 2017; 97:1235-1294. [PMID: 28794168 DOI: 10.1152/physrev.00005.2017] [Citation(s) in RCA: 577] [Impact Index Per Article: 82.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Revised: 05/19/2017] [Accepted: 05/26/2017] [Indexed: 02/07/2023] Open
Abstract
Notch signaling is an evolutionarily highly conserved signaling mechanism, but in contrast to signaling pathways such as Wnt, Sonic Hedgehog, and BMP/TGF-β, Notch signaling occurs via cell-cell communication, where transmembrane ligands on one cell activate transmembrane receptors on a juxtaposed cell. Originally discovered through mutations in Drosophila more than 100 yr ago, and with the first Notch gene cloned more than 30 yr ago, we are still gaining new insights into the broad effects of Notch signaling in organisms across the metazoan spectrum and its requirement for normal development of most organs in the body. In this review, we provide an overview of the Notch signaling mechanism at the molecular level and discuss how the pathway, which is architecturally quite simple, is able to engage in the control of cell fates in a broad variety of cell types. We discuss the current understanding of how Notch signaling can become derailed, either by direct mutations or by aberrant regulation, and the expanding spectrum of diseases and cancers that is a consequence of Notch dysregulation. Finally, we explore the emerging field of Notch in the control of tissue homeostasis, with examples from skin, liver, lung, intestine, and the vasculature.
Collapse
Affiliation(s)
- Chris Siebel
- Department of Discovery Oncology, Genentech Inc., DNA Way, South San Francisco, California; and Department of Cell and Molecular Biology, Karolinska Institute, Stockholm, Sweden
| | - Urban Lendahl
- Department of Discovery Oncology, Genentech Inc., DNA Way, South San Francisco, California; and Department of Cell and Molecular Biology, Karolinska Institute, Stockholm, Sweden
| |
Collapse
|
17
|
Praxenthaler H, Nagel AC, Schulz A, Zimmermann M, Meier M, Schmid H, Preiss A, Maier D. Hairless-binding deficient Suppressor of Hairless alleles reveal Su(H) protein levels are dependent on complex formation with Hairless. PLoS Genet 2017; 13:e1006774. [PMID: 28475577 PMCID: PMC5438185 DOI: 10.1371/journal.pgen.1006774] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Revised: 05/19/2017] [Accepted: 04/21/2017] [Indexed: 11/19/2022] Open
Abstract
Cell fate choices during metazoan development are driven by the highly conserved Notch signalling pathway. Notch receptor activation results in release of the Notch intracellular domain (NICD) that acts as transcriptional co-activator of the DNA-binding protein CSL. In the absence of signal, a repressor complex consisting of CSL bound to co-repressors silences Notch target genes. The Drosophila repressor complex contains the fly CSL orthologue Suppressor of Hairless [Su(H)] and Hairless (H). The Su(H)-H crystal structure revealed a large conformational change within Su(H) upon H binding, precluding interactions with NICD. Based on the structure, several sites in Su(H) and H were determined to specifically engage in complex formation. In particular, three mutations in Su(H) were identified that affect interactions with the repressor H but not the activator NICD. To analyse the effects these mutants have on normal fly development, we introduced these mutations into the native Su(H) locus by genome engineering. We show that the three H-binding deficient Su(H) alleles behave similarly. As these mutants lack the ability to form the repressor complex, Notch signalling activity is strongly increased in homozygotes, comparable to a complete loss of H activity. Unexpectedly, we find that the abundance of the three mutant Su(H) protein variants is altered, as is that of wild type Su(H) protein in the absence of H protein. In the presence of NICD, however, Su(H) mutant protein persists. Apparently, Su(H) protein levels depend on the interactions with H as well as with NICD. Based on these results, we propose that in vivo levels of Su(H) protein are stabilised by interactions with transcription-regulator complexes.
Collapse
Affiliation(s)
- Heiko Praxenthaler
- Institute of Genetics (240), University of Hohenheim, Stuttgart, Germany
| | - Anja C. Nagel
- Institute of Genetics (240), University of Hohenheim, Stuttgart, Germany
| | - Adriana Schulz
- Institute of Genetics (240), University of Hohenheim, Stuttgart, Germany
| | - Mirjam Zimmermann
- Institute of Genetics (240), University of Hohenheim, Stuttgart, Germany
| | - Markus Meier
- Institute of Genetics (240), University of Hohenheim, Stuttgart, Germany
| | - Hannes Schmid
- Institute of Genetics (240), University of Hohenheim, Stuttgart, Germany
| | - Anette Preiss
- Institute of Genetics (240), University of Hohenheim, Stuttgart, Germany
| | - Dieter Maier
- Institute of Genetics (240), University of Hohenheim, Stuttgart, Germany
- * E-mail:
| |
Collapse
|
18
|
Yang CP, Fu CC, Sugino K, Liu Z, Ren Q, Liu LY, Yao X, Lee LP, Lee T. Transcriptomes of lineage-specific Drosophila neuroblasts profiled by genetic targeting and robotic sorting. Development 2015; 143:411-21. [PMID: 26700685 DOI: 10.1242/dev.129163] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Accepted: 12/11/2015] [Indexed: 12/21/2022]
Abstract
A brain consists of numerous distinct neurons arising from a limited number of progenitors, called neuroblasts in Drosophila. Each neuroblast produces a specific neuronal lineage. To unravel the transcriptional networks that underlie the development of distinct neuroblast lineages, we marked and isolated lineage-specific neuroblasts for RNA sequencing. We labeled particular neuroblasts throughout neurogenesis by activating a conditional neuroblast driver in specific lineages using various intersection strategies. The targeted neuroblasts were efficiently recovered using a custom-built device for robotic single-cell picking. Transcriptome analysis of mushroom body, antennal lobe and type II neuroblasts compared with non-selective neuroblasts, neurons and glia revealed a rich repertoire of transcription factors expressed among neuroblasts in diverse patterns. Besides transcription factors that are likely to be pan-neuroblast, many transcription factors exist that are selectively enriched or repressed in certain neuroblasts. The unique combinations of transcription factors present in different neuroblasts may govern the diverse lineage-specific neuron fates.
Collapse
Affiliation(s)
- Ching-Po Yang
- Howard Hughes Medical Institute, Janelia Research Campus, 19700 Helix Drive, Ashburn, VA 20147, USA
| | - Chi-Cheng Fu
- Howard Hughes Medical Institute, Janelia Research Campus, 19700 Helix Drive, Ashburn, VA 20147, USA Departments of Bioengineering, Electrical Engineering and Computer Science, and Biophysics Graduate Program, University of California, Berkeley, CA 94720, USA
| | - Ken Sugino
- Howard Hughes Medical Institute, Janelia Research Campus, 19700 Helix Drive, Ashburn, VA 20147, USA
| | - Zhiyong Liu
- Howard Hughes Medical Institute, Janelia Research Campus, 19700 Helix Drive, Ashburn, VA 20147, USA
| | - Qingzhong Ren
- Howard Hughes Medical Institute, Janelia Research Campus, 19700 Helix Drive, Ashburn, VA 20147, USA
| | - Ling-Yu Liu
- Howard Hughes Medical Institute, Janelia Research Campus, 19700 Helix Drive, Ashburn, VA 20147, USA
| | - Xiaohao Yao
- Howard Hughes Medical Institute, Janelia Research Campus, 19700 Helix Drive, Ashburn, VA 20147, USA
| | - Luke P Lee
- Departments of Bioengineering, Electrical Engineering and Computer Science, and Biophysics Graduate Program, University of California, Berkeley, CA 94720, USA
| | - Tzumin Lee
- Howard Hughes Medical Institute, Janelia Research Campus, 19700 Helix Drive, Ashburn, VA 20147, USA
| |
Collapse
|
19
|
Dearden PK. Origin and evolution of the enhancer of split complex. BMC Genomics 2015; 16:712. [PMID: 26384649 PMCID: PMC4575448 DOI: 10.1186/s12864-015-1926-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Accepted: 09/12/2015] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND The Enhancer of split complex is an unusual gene complex found in Arthropod genomes. Where known this complex of genes is often regulated by Notch cell signalling and is critically important for neurogenesis. The Enhancer of split complex is made up of two different classes of genes, basic helix-loop-helix-orange domain transcription factors and bearded class genes. The association of these genes has been detected in the genomes of insects and crustaceans. RESULTS Tracing the evolution of the Enhancer of split complex in recently sequenced Arthropod genomes indicates that enhancer of split basic helix-loop-helix orange domain genes arose before the common ancestor of insects and Crustacea, and before the formation of the complex. Throughout insect and crustacean evolution, a four-gene cluster has been present with lineage specific gene losses and duplications. The complex can be found in the vast majority of genomes, but appears to be missing from the genomes of chalcid wasps, raising questions as to how they carry out neurogenesis in the absence of these crucial genes. CONCLUSIONS The enhancer of split complex arose in the common ancestor of Crustacea and insects, probably through the linkage of a basic helix-loop-helix orange domain gene and a bearded class gene. The complex has been maintained, with variations, throughout insect and crustacean evolution indicating some function of the complex, such as coordinate regulation, may maintain its structure through evolutionary time.
Collapse
Affiliation(s)
- Peter K Dearden
- Genetics Otago and Gravida (National Centre for Growth and Development), Biochemistry Department, University of Otago, Dunedin, Aotearoa, New Zealand.
| |
Collapse
|
20
|
Matsumoto H, Ueno C, Nakamura Y, Kinjoh T, Ito Y, Shimura S, Noda H, Imanishi S, Mita K, Fujiwara H, Hiruma K, Shinoda T, Kamimura M. Identification of two juvenile hormone inducible transcription factors from the silkworm, Bombyx mori. JOURNAL OF INSECT PHYSIOLOGY 2015; 80:31-41. [PMID: 25770979 DOI: 10.1016/j.jinsphys.2015.02.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2014] [Revised: 01/30/2015] [Accepted: 02/13/2015] [Indexed: 06/04/2023]
Abstract
Juvenile hormone (JH) regulates many physiological processes in insects. However, the signal cascades in which JH is active have not yet been fully elucidated, particularly in comparison to another major hormone ecdysteroid. Here we identified two JH inducible transcription factors as candidate components of JH signaling pathways in the silkworm, Bombyx mori. DNA microarray analysis showed that expression of two transcription factor genes, E75 and Enhancer of split mβ (E(spl)mβ), was induced by juvenile hormone I (JH I) in NIAS-Bm-aff3 cells. Real time RT-PCR analysis confirmed that expression of four E75 isoforms (E75A, E75B, E75C and E75D) and E(spl)mβ was 3-8 times greater after JH I addition. Addition of the protein synthesis inhibitor cycloheximide did not suppress JH-induced expression of the genes, indicating that they were directly induced by JH. JH-induced expression of E75 and E(spl)mβ was also observed in four other B. mori cell lines and in larval hemocytes of final instar larvae. Notably, E75A expression was induced very strongly in larval hemocytes by topical application of the JH analog fenoxycarb; the level of induced expression was comparable to that produced by feeding larvae with 20-hydroxyecdysone. These results suggest that E75 and E(spl)mβ are general and direct target genes of JH and that the transcription factors encoded by these genes play important roles in JH signaling.
Collapse
Affiliation(s)
- Hitoshi Matsumoto
- National Institute of Agrobiological Sciences, Tsukuba, Ibaraki, Japan
| | - Chihiro Ueno
- National Institute of Agrobiological Sciences, Tsukuba, Ibaraki, Japan
| | - Yuki Nakamura
- National Institute of Agrobiological Sciences, Tsukuba, Ibaraki, Japan
| | - Terunori Kinjoh
- National Institute of Agrobiological Sciences, Tsukuba, Ibaraki, Japan; Faculty of Agriculture and Life Sciences, Hirosaki University, Hirosaki, Aomori, Japan
| | - Yuka Ito
- National Institute of Agrobiological Sciences, Tsukuba, Ibaraki, Japan
| | - Sachiko Shimura
- National Institute of Agrobiological Sciences, Tsukuba, Ibaraki, Japan
| | - Hiroaki Noda
- National Institute of Agrobiological Sciences, Tsukuba, Ibaraki, Japan
| | - Shigeo Imanishi
- National Institute of Agrobiological Sciences, Tsukuba, Ibaraki, Japan
| | - Kazuei Mita
- National Institute of Agrobiological Sciences, Tsukuba, Ibaraki, Japan
| | - Haruhiko Fujiwara
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba, Japan
| | - Kiyoshi Hiruma
- Faculty of Agriculture and Life Sciences, Hirosaki University, Hirosaki, Aomori, Japan
| | - Tetsuro Shinoda
- National Institute of Agrobiological Sciences, Tsukuba, Ibaraki, Japan
| | - Manabu Kamimura
- National Institute of Agrobiological Sciences, Tsukuba, Ibaraki, Japan.
| |
Collapse
|
21
|
Fiedler M, Graeb M, Mieszczanek J, Rutherford TJ, Johnson CM, Bienz M. An ancient Pygo-dependent Wnt enhanceosome integrated by Chip/LDB-SSDP. eLife 2015; 4:e09073. [PMID: 26312500 PMCID: PMC4571689 DOI: 10.7554/elife.09073] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Accepted: 08/26/2015] [Indexed: 12/15/2022] Open
Abstract
TCF/LEF factors are ancient context-dependent enhancer-binding proteins that are activated by β-catenin following Wnt signaling. They control embryonic development and adult stem cell compartments, and their dysregulation often causes cancer. β-catenin-dependent transcription relies on the NPF motif of Pygo proteins. Here, we use a proteomics approach to discover the Chip/LDB-SSDP (ChiLS) complex as the ligand specifically binding to NPF. ChiLS also recognizes NPF motifs in other nuclear factors including Runt/RUNX2 and Drosophila ARID1, and binds to Groucho/TLE. Studies of Wnt-responsive dTCF enhancers in the Drosophila embryonic midgut indicate how these factors interact to form the Wnt enhanceosome, primed for Wnt responses by Pygo. Together with previous evidence, our study indicates that ChiLS confers context-dependence on TCF/LEF by integrating multiple inputs from lineage and signal-responsive factors, including enhanceosome switch-off by Notch. Its pivotal function in embryos and stem cells explain why its integrity is crucial in the avoidance of cancer.
Collapse
Affiliation(s)
- Marc Fiedler
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge, United Kingdom
| | - Michael Graeb
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge, United Kingdom
| | - Juliusz Mieszczanek
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge, United Kingdom
| | - Trevor J Rutherford
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge, United Kingdom
| | - Christopher M Johnson
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge, United Kingdom
| | - Mariann Bienz
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge, United Kingdom
| |
Collapse
|
22
|
Kiparaki M, Zarifi I, Delidakis C. bHLH proteins involved in Drosophila neurogenesis are mutually regulated at the level of stability. Nucleic Acids Res 2015; 43:2543-59. [PMID: 25694512 PMCID: PMC4357701 DOI: 10.1093/nar/gkv083] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Proneural bHLH activators are expressed in all neuroectodermal regions prefiguring events of central and peripheral neurogenesis. Drosophila Sc is a prototypical proneural activator that heterodimerizes with the E-protein Daughterless (Da) and is antagonized by, among others, the E(spl) repressors. We determined parameters that regulate Sc stability in Drosophila S2 cells. We found that Sc is a very labile phosphoprotein and its turnover takes place via at least three proteasome-dependent mechanisms. (i) When Sc is in excess of Da, its degradation is promoted via its transactivation domain (TAD). (ii) In a DNA-bound Da/Sc heterodimer, Sc degradation is promoted via an SPTSS phosphorylation motif and the AD1 TAD of Da; Da is spared in the process. (iii) When E(spl)m7 is expressed, it complexes with Sc or Da/Sc and promotes their degradation in a manner that requires the corepressor Groucho and the Sc SPTSS motif. Da/Sc reciprocally promotes E(spl)m7 degradation. Since E(spl)m7 is a direct target of Notch, the mutual destabilization of Sc and E(spl) may contribute in part to the highly conserved anti-neural activity of Notch. Sc variants lacking the SPTSS motif are dramatically stabilized and are hyperactive in transgenic flies. Our results propose a novel mechanism of regulation of neurogenesis, involving the stability of key players in the process.
Collapse
Affiliation(s)
- Marianthi Kiparaki
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology Hellas, and Department of Biology, University of Crete, 70013 Heraklion, Crete, Greece
| | - Ioanna Zarifi
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology Hellas, and Department of Biology, University of Crete, 70013 Heraklion, Crete, Greece
| | - Christos Delidakis
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology Hellas, and Department of Biology, University of Crete, 70013 Heraklion, Crete, Greece
| |
Collapse
|