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Hwangbo DS, Biteau B, Rath S, Kim J, Jasper H. Control of apoptosis by Drosophila DCAF12. Dev Biol 2016; 413:50-9. [PMID: 26972874 DOI: 10.1016/j.ydbio.2016.03.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Revised: 01/08/2016] [Accepted: 03/05/2016] [Indexed: 11/30/2022]
Abstract
Regulated Apoptosis (Programmed Cell Death, PCD) maintains tissue homeostasis in adults, and ensures proper growth and morphogenesis of tissues during development of metazoans. Accordingly, defects in cellular processes triggering or executing apoptotic programs have been implicated in a variety of degenerative and neoplastic diseases. Here, we report the identification of DCAF12, an evolutionary conserved member of the WD40-motif repeat family of proteins, as a new regulator of apoptosis in Drosophila. We find that DCAF12 is required for Diap1 cleavage in response to pro-apoptotic signals, and is thus necessary and sufficient for RHG (Reaper, Hid, and Grim)-mediated apoptosis. Loss of DCAF12 perturbs the elimination of supernumerary or proliferation-impaired cells during development, and enhances tumor growth induced by loss of neoplastic tumor suppressors, highlighting the wide requirement for DCAF12 in PCD.
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Affiliation(s)
- Dae-Sung Hwangbo
- Department of Biology, University of Rochester, River Campus Box 270211, Rochester, NY 14627, USA; Department of Biomedical Genetics, University of Rochester School of Medicine and Dentistry, 601 Elmwood Avenue, Rochester, NY 14642, USA
| | - Benoit Biteau
- Department of Biomedical Genetics, University of Rochester School of Medicine and Dentistry, 601 Elmwood Avenue, Rochester, NY 14642, USA
| | - Sneha Rath
- Department of Biology, University of Rochester, River Campus Box 270211, Rochester, NY 14627, USA
| | - Jihyun Kim
- Buck Institute for Research on Aging, 8001 Redwood Boulevard, Novato, CA 94945-1400, USA
| | - Heinrich Jasper
- Department of Biology, University of Rochester, River Campus Box 270211, Rochester, NY 14627, USA; Buck Institute for Research on Aging, 8001 Redwood Boulevard, Novato, CA 94945-1400, USA.
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Hu Z, Holzschuh J, Driever W. Loss of DDB1 Leads to Transcriptional p53 Pathway Activation in Proliferating Cells, Cell Cycle Deregulation, and Apoptosis in Zebrafish Embryos. PLoS One 2015. [PMID: 26225764 PMCID: PMC4520591 DOI: 10.1371/journal.pone.0134299] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
DNA damage-binding protein 1 (DDB1) is a large subunit of the heterodimeric DDB complex that recognizes DNA lesions and initiates the nucleotide excision repair process. DDB1 is also a component of the CUL4 E3 ligase complex involved in a broad spectrum of cellular processes by targeted ubiquitination of key regulators. Functions of DDB1 in development have been addressed in several model organisms, however, are not fully understood so far. Here we report an ENU induced mutant ddb1 allele (ddb1m863) identified in zebrafish (Danio rerio), and analyze its effects on development. Zebrafish ddb1 is expressed broadly, both maternally and zygotically, with enhanced expression in proliferation zones. The (ddb1m863 mutant allele affects the splice acceptor site of exon 20, causing a splicing defect that results in truncation of the 1140 amino acid protein after residue 800, lacking part of the β-propeller domain BPC and the C-terminal helical domain CTD. ddb1m863 zygotic mutant embryos have a pleiotropic phenotype, including smaller and abnormally shaped brain, head skeleton, eyes, jaw, and branchial arches, as well as reduced dopaminergic neuron groups. However, early forming tissues develop normally in zygotic ddb1m863 mutant embryos, which may be due to maternal rescue. In ddb1m863 mutant embryos, pcna-expressing proliferating cell populations were reduced, concurrent with increased apoptosis. We also observed a concomitant strong up-regulation of transcripts of the tumor suppressor p53 (tp53) and the cell cycle inhibitor cdkn1a (p21a/bCIP1/WAF1) in proliferating tissues. In addition, transcription of cyclin genes ccna2 and ccnd1 was deregulated in ddb1m863 mutants. Reduction of p53 activity by anti-sense morpholinos alleviated the apoptotic phenotype in ddb1m863 mutants. These results imply that Ddb1 may be involved in maintaining proper cell cycle progression and viability of dividing cells during development through transcriptional mechanisms regulating genes involved in cell cycle control and cell survival.
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Affiliation(s)
- Zhilian Hu
- Developmental Biology, Institute Biology I, Faculty of Biology, Albert-Ludwigs-University Freiburg, Hauptstrasse 1, 79104, Freiburg, Germany; Department of Pediatrics and Communicable Diseases, University of Michigan, Ann Arbor, MI, 48109-5646, United States of America
| | - Jochen Holzschuh
- Developmental Biology, Institute Biology I, Faculty of Biology, Albert-Ludwigs-University Freiburg, Hauptstrasse 1, 79104, Freiburg, Germany
| | - Wolfgang Driever
- Developmental Biology, Institute Biology I, Faculty of Biology, Albert-Ludwigs-University Freiburg, Hauptstrasse 1, 79104, Freiburg, Germany; BIOSS-Centre for Biological Signalling Studies, Albert-Ludwigs-University Freiburg, Schänzlestrasse 18, 79104, Freiburg, Germany
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Sakaguchi K, Ishibashi T, Uchiyama Y, Iwabata K. The multi-replication protein A (RPA) system--a new perspective. FEBS J 2009; 276:943-63. [PMID: 19154342 DOI: 10.1111/j.1742-4658.2008.06841.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Replication protein A (RPA) complex has been shown, using both in vivo and in vitro approaches, to be required for most aspects of eukaryotic DNA metabolism: replication, repair, telomere maintenance and homologous recombination. Here, we review recent data concerning the function and biological importance of the multi-RPA complex. There are distinct complexes of RPA found in the biological kingdoms, although for a long time only one type of RPA complex was believed to be present in eukaryotes. Each complex probably serves a different role. In higher plants, three distinct large and medium subunits are present, but only one species of the smallest subunit. Each of these protein subunits forms stable complexes with their respective partners. They are paralogs as complex. Humans possess two paralogs and one analog of RPA. The multi-RPA system can be regarded as universal in eukaryotes. Among eukaryotic kingdoms, paralogs, orthologs, analogs and heterologs of many DNA synthesis-related factors, including RPA, are ubiquitous. Convergent evolution seems to be ubiquitous in these processes. Using recent findings, we review the composition and biological functions of RPA complexes.
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Affiliation(s)
- Kengo Sakaguchi
- Department of Applied Biological Science, Tokyo University of Science, Chiba, Japan.
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Jin LH, Shim J, Yoon JS, Kim B, Kim J, Kim-Ha J, Kim YJ. Identification and functional analysis of antifungal immune response genes in Drosophila. PLoS Pathog 2008; 4:e1000168. [PMID: 18833296 PMCID: PMC2542415 DOI: 10.1371/journal.ppat.1000168] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2008] [Accepted: 09/08/2008] [Indexed: 11/18/2022] Open
Abstract
Essential aspects of the innate immune response to microbial infection appear to be conserved between insects and mammals. Although signaling pathways that activate NF-kappaB during innate immune responses to various microorganisms have been studied in detail, regulatory mechanisms that control other immune responses to fungal infection require further investigation. To identify new Drosophila genes involved in antifungal immune responses, we selected genes known to be differentially regulated in SL2 cells by microbial cell wall components and tested their roles in antifungal defense using mutant flies. From 130 mutant lines, sixteen mutants exhibited increased sensitivity to fungal infection. Examination of their effects on defense against various types of bacteria and fungi revealed nine genes that are involved specifically in defense against fungal infection. All of these mutants displayed defects in phagocytosis or activation of antimicrobial peptide genes following infection. In some mutants, these immune deficiencies were attributed to defects in hemocyte development and differentiation, while other mutants showed specific defects in immune signaling required for humoral or cellular immune responses. Our results identify a new class of genes involved in antifungal immune responses in Drosophila.
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Affiliation(s)
- Li Hua Jin
- Department of Biochemistry, Yonsei University, Seoul, Korea
| | - Jaewon Shim
- Department of Biochemistry, Yonsei University, Seoul, Korea
| | - Joon Sun Yoon
- Department of Biochemistry, Yonsei University, Seoul, Korea
| | - Byungil Kim
- Department of Biochemistry, Yonsei University, Seoul, Korea
| | - Jihyun Kim
- Department of Molecular Biology, Sejong University, Seoul, Korea
| | - Jeongsil Kim-Ha
- Department of Molecular Biology, Sejong University, Seoul, Korea
| | - Young-Joon Kim
- Department of Biochemistry, Yonsei University, Seoul, Korea
- * E-mail:
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Fregoso M, Lainé JP, Aguilar-Fuentes J, Mocquet V, Reynaud E, Coin F, Egly JM, Zurita M. DNA repair and transcriptional deficiencies caused by mutations in the Drosophila p52 subunit of TFIIH generate developmental defects and chromosome fragility. Mol Cell Biol 2007; 27:3640-50. [PMID: 17339330 PMCID: PMC1899989 DOI: 10.1128/mcb.00030-07] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The transcription and DNA repair factor TFIIH is composed of 10 subunits. Mutations in the XPB, XPD, and p8 subunits are genetically linked to human diseases, including cancer. However, no reports of mutations in other TFIIH subunits have been reported in higher eukaryotes. Here, we analyze at genetic, molecular, and biochemical levels the Drosophila melanogaster p52 (DMP52) subunit of TFIIH. We found that DMP52 is encoded by the gene marionette in Drosophila and that a defective DMP52 produces UV light-sensitive flies and specific phenotypes during development: organisms are smaller than their wild-type siblings and present tumors and chromosomal instability. The human homologue of DMP52 partially rescues some of these phenotypes. Some of the defects observed in the fly caused by mutations in DMP52 generate trichothiodystrophy and cancer-like phenotypes. Biochemical analysis of DMP52 point mutations introduced in human p52 at positions homologous to those of defects in DMP52 destabilize the interaction between p52 and XPB, another TFIIH subunit, thus compromising the assembly of the complex. This study significantly extends the role of p52 in regulating XPB ATPase activity and, consequently, both its transcriptional and nucleotide excision repair functions.
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Affiliation(s)
- Mariana Fregoso
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, BP 163, 67404 Illkirch Cedex, C.U. de Strasbourg, France
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