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Vallés AM, Rubin T, Macaisne N, Dal Toe L, Molla-Herman A, Antoniewski C, Huynh JR. Transcriptomic analysis of meiotic genes during the mitosis-to-meiosis transition in Drosophila females. Genetics 2024:iyae130. [PMID: 39225982 DOI: 10.1093/genetics/iyae130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Accepted: 07/12/2024] [Indexed: 09/04/2024] Open
Abstract
Germline cells produce gametes, which are specialized cells essential for sexual reproduction. Germline cells first amplify through several rounds of mitosis before switching to the meiotic program, which requires specific sets of proteins for DNA recombination, chromosome pairing, and segregation. Surprisingly, we previously found that some proteins of the synaptonemal complex, a prophase I meiotic structure, are already expressed and required in the mitotic region of Drosophila females. Here, to assess if additional meiotic genes were expressed earlier than expected, we isolated mitotic and meiotic cell populations to compare their RNA content. Our transcriptomic analysis reveals that all known meiosis I genes are already expressed in the mitotic region; however, only some of them are translated. As a case study, we focused on mei-W68, the Drosophila homolog of Spo11, to assess its expression at both the mRNA and protein levels and used different mutant alleles to assay for a premeiotic function. We could not detect any functional role for Mei-W68 during homologous chromosome pairing in dividing germ cells. Our study paves the way for further functional analysis of meiotic genes expressed in the mitotic region.
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Affiliation(s)
- Ana Maria Vallés
- Center for Interdisciplinary Research in Biology, Collège de France, Université PSL, CNRS, INSERM, 75005 Paris, France
| | - Thomas Rubin
- Center for Interdisciplinary Research in Biology, Collège de France, Université PSL, CNRS, INSERM, 75005 Paris, France
| | - Nicolas Macaisne
- Center for Interdisciplinary Research in Biology, Collège de France, Université PSL, CNRS, INSERM, 75005 Paris, France
| | - Laurine Dal Toe
- Center for Interdisciplinary Research in Biology, Collège de France, Université PSL, CNRS, INSERM, 75005 Paris, France
| | - Anahi Molla-Herman
- Center for Interdisciplinary Research in Biology, Collège de France, Université PSL, CNRS, INSERM, 75005 Paris, France
| | - Christophe Antoniewski
- ARTbio Bioinformatics Analysis Facility, IBPS, CNRS, Sorbonne Université, Institut Français de Bioinformatique, 75005 Paris, France
| | - Jean-René Huynh
- Center for Interdisciplinary Research in Biology, Collège de France, Université PSL, CNRS, INSERM, 75005 Paris, France
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2
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Man B, Kim E, Vadlakonda A, Stern DL, Crown KN. Analysis of meiotic recombination in Drosophila simulans shows no evidence of an interchromosomal effect. Genetics 2024; 227:iyae084. [PMID: 38762892 PMCID: PMC11304986 DOI: 10.1093/genetics/iyae084] [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: 03/09/2024] [Revised: 03/09/2024] [Accepted: 05/09/2024] [Indexed: 05/21/2024] Open
Abstract
Chromosome inversions are of unique importance in the evolution of genomes and species because when heterozygous with a standard arrangement chromosome, they suppress meiotic crossovers within the inversion. In Drosophila species, heterozygous inversions also cause the interchromosomal effect, whereby the presence of a heterozygous inversion induces a dramatic increase in crossover frequencies in the remainder of the genome within a single meiosis. To date, the interchromosomal effect has been studied exclusively in species that also have high frequencies of inversions in wild populations. We took advantage of a recently developed approach for generating inversions in Drosophila simulans, a species that does not have inversions in wild populations, to ask if there is an interchromosomal effect. We used the existing chromosome 3R balancer and generated a new chromosome 2L balancer to assay for the interchromosomal effect genetically and cytologically. We found no evidence of an interchromosomal effect in D. simulans. To gain insights into the underlying mechanistic reasons, we qualitatively analyzed the relationship between meiotic double-stranded break (DSB) formation and synaptonemal complex (SC) assembly. We found that the SC is assembled prior to DSB formation as in D. melanogaster; however, we show that the SC is assembled prior to localization of the oocyte determination factor Orb, whereas in D. melanogaster, SC formation does not begin until the Orb is localized. Together, our data show no evidence that heterozygous inversions in D. simulans induce an interchromosomal effect and that there are differences in the developmental programming of the early stages of meiosis.
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Affiliation(s)
- Bowen Man
- Department of Biology, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Elizabeth Kim
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA
| | - Alekhya Vadlakonda
- Department of Biology, Case Western Reserve University, Cleveland, OH 44106, USA
| | - David L Stern
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA
| | - K Nicole Crown
- Department of Biology, Case Western Reserve University, Cleveland, OH 44106, USA
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3
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Maurya D, Rai G, Mandal D, Mondal BC. Transient caspase-mediated activation of caspase-activated DNase causes DNA damage required for phagocytic macrophage differentiation. Cell Rep 2024; 43:114251. [PMID: 38761374 DOI: 10.1016/j.celrep.2024.114251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Revised: 04/04/2024] [Accepted: 05/03/2024] [Indexed: 05/20/2024] Open
Abstract
Phagocytic macrophages are crucial for innate immunity and tissue homeostasis. Most tissue-resident macrophages develop from embryonic precursors that populate every organ before birth to lifelong self-renew. However, the mechanisms for versatile macrophage differentiation remain unknown. Here, we use in vivo genetic and cell biological analysis of the Drosophila larval hematopoietic organ, the lymph gland that produces macrophages. We show that the developmentally regulated transient activation of caspase-activated DNase (CAD)-mediated DNA strand breaks in intermediate progenitors is essential for macrophage differentiation. Insulin receptor-mediated PI3K/Akt signaling regulates the apoptosis signal-regulating kinase 1 (Ask1)/c-Jun kinase (JNK) axis to control sublethal levels of caspase activation, causing DNA strand breaks during macrophage development. Furthermore, caspase activity is also required for embryonic-origin macrophage development and efficient phagocytosis. Our study provides insights into developmental signaling and CAD-mediated DNA strand breaks associated with multifunctional and heterogeneous macrophage differentiation.
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Affiliation(s)
- Deepak Maurya
- Cytogenetics Laboratory, Department of Zoology, Institute of Science, Banaras Hindu University, Varanasi 221005, India
| | - Gayatri Rai
- Cytogenetics Laboratory, Department of Zoology, Institute of Science, Banaras Hindu University, Varanasi 221005, India
| | - Debleena Mandal
- Cytogenetics Laboratory, Department of Zoology, Institute of Science, Banaras Hindu University, Varanasi 221005, India
| | - Bama Charan Mondal
- Cytogenetics Laboratory, Department of Zoology, Institute of Science, Banaras Hindu University, Varanasi 221005, India.
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4
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Hughes SE, Price A, Briggs S, Staber C, James M, Anderson M, Hawley RS. A transcriptomics-based RNAi screen for regulators of meiosis and early stages of oocyte development in Drosophila melanogaster. G3 (BETHESDA, MD.) 2024; 14:jkae028. [PMID: 38333961 PMCID: PMC10989863 DOI: 10.1093/g3journal/jkae028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Revised: 02/02/2024] [Accepted: 02/05/2024] [Indexed: 02/10/2024]
Abstract
A properly regulated series of developmental and meiotic events must occur to ensure the successful production of gametes. In Drosophila melanogaster ovaries, these early developmental and meiotic events include the production of the 16-cell cyst, meiotic entry, synaptonemal complex (SC) formation, recombination, and oocyte specification. In order to identify additional genes involved in early oocyte development and meiosis, we reanalyzed 3 published single-cell RNA-seq datasets from Drosophila ovaries, using vasa (germline) together with c(3)G, cona, and corolla (SC) as markers. Our analysis generated a list of 2,743 co-expressed genes. Many known SC-related and early oocyte development genes fell within the top 500 genes on this list, as ranked by the abundance and specificity of each gene's expression across individual analyses. We tested 526 available RNAi lines containing shRNA constructs in germline-compatible vectors representing 331 of the top 500 genes. We assessed targeted ovaries for SC formation and maintenance, oocyte specification, cyst development, and double-strand break dynamics. Six uncharacterized genes exhibited early developmental defects. SC and developmental defects were observed for additional genes not well characterized in the early ovary. Interestingly, in some lines with developmental delays, meiotic events could still be completed once oocyte specificity occurred indicating plasticity in meiotic timing. These data indicate that a transcriptomics approach can be used to identify genes involved in functions in a specific cell type in the Drosophila ovary.
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Affiliation(s)
- Stacie E Hughes
- Stowers Institute for Medical Research, Kansas City, MO 64110, USA
| | - Andrew Price
- Stowers Institute for Medical Research, Kansas City, MO 64110, USA
| | - Salam Briggs
- Stowers Institute for Medical Research, Kansas City, MO 64110, USA
| | - Cynthia Staber
- Stowers Institute for Medical Research, Kansas City, MO 64110, USA
| | - Morgan James
- Stowers Institute for Medical Research, Kansas City, MO 64110, USA
| | - Madelyn Anderson
- Stowers Institute for Medical Research, Kansas City, MO 64110, USA
| | - R Scott Hawley
- Stowers Institute for Medical Research, Kansas City, MO 64110, USA
- Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, KS 66160, USA
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5
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Matthew J, Vishwakarma V, Le TP, Agsunod RA, Chung S. Coordination of cell cycle and morphogenesis during organ formation. eLife 2024; 13:e95830. [PMID: 38275142 PMCID: PMC10869137 DOI: 10.7554/elife.95830] [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: 01/07/2024] [Accepted: 01/21/2024] [Indexed: 01/27/2024] Open
Abstract
Organ formation requires precise regulation of cell cycle and morphogenetic events. Using the Drosophila embryonic salivary gland (SG) as a model, we uncover the role of the SP1/KLF transcription factor Huckebein (Hkb) in coordinating cell cycle regulation and morphogenesis. The hkb mutant SG exhibits defects in invagination positioning and organ size due to the abnormal death of SG cells. Normal SG development involves distal-to-proximal progression of endoreplication (endocycle), whereas hkb mutant SG cells undergo abnormal cell division, leading to cell death. Hkb represses the expression of key cell cycle and pro-apoptotic genes in the SG. Knockdown of cyclin E or cyclin-dependent kinase 1, or overexpression of fizzy-related rescues most of the morphogenetic defects observed in the hkb mutant SG. These results indicate that Hkb plays a critical role in controlling endoreplication by regulating the transcription of key cell cycle effectors to ensure proper organ formation.
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Affiliation(s)
- Jeffrey Matthew
- Department of Biological Sciences, Louisiana State UniversityBaton RougeUnited States
| | - Vishakha Vishwakarma
- Department of Biological Sciences, Louisiana State UniversityBaton RougeUnited States
| | - Thao Phuong Le
- Department of Biological Sciences, Louisiana State UniversityBaton RougeUnited States
| | - Ryan A Agsunod
- Department of Biological Sciences, Louisiana State UniversityBaton RougeUnited States
| | - SeYeon Chung
- Department of Biological Sciences, Louisiana State UniversityBaton RougeUnited States
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6
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Tu R, Tang XA, Xu R, Ping Z, Yu Z, Xie T. Gap junction-transported cAMP from the niche controls stem cell progeny differentiation. Proc Natl Acad Sci U S A 2023; 120:e2304168120. [PMID: 37603749 PMCID: PMC10468610 DOI: 10.1073/pnas.2304168120] [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: 03/13/2023] [Accepted: 07/22/2023] [Indexed: 08/23/2023] Open
Abstract
The niche has been shown to control stem cell self-renewal in different tissue types and organisms. Recently, a separate niche has been proposed to control stem cell progeny differentiation, called the differentiation niche. However, it remains poorly understood whether and how the differentiation niche directly signals to stem cell progeny to control their differentiation. In the Drosophila ovary, inner germarial sheath (IGS) cells contribute to two separate niche compartments for controlling both germline stem cell (GSC) self-renewal and progeny differentiation. In this study, we show that IGS cells express Inx2 protein, which forms gap junctions (GJs) with germline-specific Zpg protein to control stepwise GSC lineage development, including GSC self-renewal, germline cyst formation, meiotic double-strand DNA break formation, and oocyte specification. Germline-specific Zpg and IGS-specific Inx2 knockdowns cause similar defects in stepwise GSC development. Additionally, secondary messenger cAMP is transported from IGS cells to GSCs and their progeny via GJs to activate PKA signaling for controlling stepwise GSC development. Therefore, this study demonstrates that the niche directly controls GSC progeny differentiation via the GJ-cAMP-PKA signaling axis, which provides important insights into niche control of stem cell differentiation and highlights the importance of GJ-transported cAMP in tissue regeneration. This may represent a general strategy for the niche to control adult stem cell development in various tissue types and organisms since GJs and cAMP are widely distributed.
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Affiliation(s)
- Renjun Tu
- Division of Life Science, The Hong Kong University of Science and Technology, Kowloon, Hong Kong Special Administrative Region (SAR), China
| | - Xiaohan Alex Tang
- Division of Life Science, The Hong Kong University of Science and Technology, Kowloon, Hong Kong Special Administrative Region (SAR), China
| | - Rui Xu
- Division of Life Science, The Hong Kong University of Science and Technology, Kowloon, Hong Kong Special Administrative Region (SAR), China
| | - Zhaohua Ping
- Stowers Institute for Medical Research, Kansas City, MO64110
| | - Zulin Yu
- Stowers Institute for Medical Research, Kansas City, MO64110
| | - Ting Xie
- Division of Life Science, The Hong Kong University of Science and Technology, Kowloon, Hong Kong Special Administrative Region (SAR), China
- Stowers Institute for Medical Research, Kansas City, MO64110
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7
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Li H, Berent E, Hadjipanteli S, Galey M, Muhammad-Lahbabi N, Miller DE, Crown KN. Heterozygous inversion breakpoints suppress meiotic crossovers by altering recombination repair outcomes. PLoS Genet 2023; 19:e1010702. [PMID: 37053290 PMCID: PMC10128924 DOI: 10.1371/journal.pgen.1010702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 04/25/2023] [Accepted: 03/15/2023] [Indexed: 04/15/2023] Open
Abstract
Heterozygous chromosome inversions suppress meiotic crossover (CO) formation within an inversion, potentially because they lead to gross chromosome rearrangements that produce inviable gametes. Interestingly, COs are also severely reduced in regions nearby but outside of inversion breakpoints even though COs in these regions do not result in rearrangements. Our mechanistic understanding of why COs are suppressed outside of inversion breakpoints is limited by a lack of data on the frequency of noncrossover gene conversions (NCOGCs) in these regions. To address this critical gap, we mapped the location and frequency of rare CO and NCOGC events that occurred outside of the dl-49 chrX inversion in D. melanogaster. We created full-sibling wildtype and inversion stocks and recovered COs and NCOGCs in the syntenic regions of both stocks, allowing us to directly compare rates and distributions of recombination events. We show that COs outside of the proximal inversion breakpoint are distributed in a distance-dependent manner, with strongest suppression near the inversion breakpoint. We find that NCOGCs occur evenly throughout the chromosome and, importantly, are not suppressed near inversion breakpoints. We propose a model in which COs are suppressed by inversion breakpoints in a distance-dependent manner through mechanisms that influence DNA double-strand break repair outcome but not double-strand break formation. We suggest that subtle changes in the synaptonemal complex and chromosome pairing might lead to unstable interhomolog interactions during recombination that permits NCOGC formation but not CO formation.
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Affiliation(s)
- Haosheng Li
- Department of Biology, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Erica Berent
- Department of Biology, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Savannah Hadjipanteli
- Department of Biology, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Miranda Galey
- Division of Genetic Medicine, Department of Pediatrics, University of Washington and Seattle Children's Hospital, Seattle, Washington, United States of America
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, Washington, United States of America
| | - Nigel Muhammad-Lahbabi
- Department of Biology, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Danny E Miller
- Division of Genetic Medicine, Department of Pediatrics, University of Washington and Seattle Children's Hospital, Seattle, Washington, United States of America
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, Washington, United States of America
- Brotman Baty Institute for Precision Medicine, University of Washington, Seattle, Washington, United States of America
| | - K Nicole Crown
- Department of Biology, Case Western Reserve University, Cleveland, Ohio, United States of America
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8
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Amankwaa B, Schoborg T, Labrador M. Drosophila insulator proteins exhibit in vivo liquid-liquid phase separation properties. Life Sci Alliance 2022; 5:5/12/e202201536. [PMID: 35853678 PMCID: PMC9297610 DOI: 10.26508/lsa.202201536] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Revised: 07/05/2022] [Accepted: 07/06/2022] [Indexed: 11/24/2022] Open
Abstract
Drosophila insulator proteins and the cohesin subunit Rad21 coalesce in vivo to form liquid-droplet condensates, suggesting that liquid–liquid phase separation mediates their function in 3D genome organization. Mounting evidence implicates liquid–liquid phase separation (LLPS), the condensation of biomolecules into liquid-like droplets in the formation and dissolution of membraneless intracellular organelles (MLOs). Cells use MLOs or condensates for various biological processes, including emergency signaling and spatiotemporal control over steady-state biochemical reactions and heterochromatin formation. Insulator proteins are architectural elements involved in establishing independent domains of transcriptional activity within eukaryotic genomes. In Drosophila, insulator proteins form nuclear foci known as insulator bodies in response to osmotic stress. However, the mechanism through which insulator proteins assemble into bodies is yet to be investigated. Here, we identify signatures of LLPS by insulator bodies, including high disorder tendency in insulator proteins, scaffold–client–dependent assembly, extensive fusion behavior, sphericity, and sensitivity to 1,6-hexanediol. We also show that the cohesin subunit Rad21 is a component of insulator bodies, adding to the known insulator protein constituents and γH2Av. Our data suggest a concerted role of cohesin and insulator proteins in insulator body formation and under physiological conditions. We propose a mechanism whereby these architectural proteins modulate 3D genome organization through LLPS.
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Affiliation(s)
- Bright Amankwaa
- Department of Biochemistry and Cellular and Molecular Biology, The University of Tennessee, Knoxville, TN, USA
| | - Todd Schoborg
- Department of Biochemistry and Cellular and Molecular Biology, The University of Tennessee, Knoxville, TN, USA
| | - Mariano Labrador
- Department of Biochemistry and Cellular and Molecular Biology, The University of Tennessee, Knoxville, TN, USA
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9
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Simmons JR, An R, Amankwaa B, Zayac S, Kemp J, Labrador M. Phosphorylated histone variant γH2Av is associated with chromatin insulators in Drosophila. PLoS Genet 2022; 18:e1010396. [PMID: 36197938 PMCID: PMC9576066 DOI: 10.1371/journal.pgen.1010396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 10/17/2022] [Accepted: 08/24/2022] [Indexed: 11/27/2022] Open
Abstract
Chromatin insulators are responsible for orchestrating long-range interactions between enhancers and promoters throughout the genome and align with the boundaries of Topologically Associating Domains (TADs). Here, we demonstrate an association between gypsy insulator proteins and the phosphorylated histone variant H2Av (γH2Av), normally a marker of DNA double strand breaks. Gypsy insulator components colocalize with γH2Av throughout the genome, in polytene chromosomes and in diploid cells in which Chromatin IP data shows it is enriched at TAD boundaries. Mutation of insulator components su(Hw) and Cp190 results in a significant reduction in γH2Av levels in chromatin and phosphatase inhibition strengthens the association between insulator components and γH2Av and rescues γH2Av localization in insulator mutants. We also show that γH2Av, but not H2Av, is a component of insulator bodies, which are protein condensates that form during osmotic stress. Phosphatase activity is required for insulator body dissolution after stress recovery. Together, our results implicate the H2A variant with a novel mechanism of insulator function and boundary formation.
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Affiliation(s)
- James R. Simmons
- Department of Biochemistry and Cellular and Molecular Biology, The University of Tennessee, Knoxville, Tennessee, United States of America
| | - Ran An
- Department of Biochemistry and Cellular and Molecular Biology, The University of Tennessee, Knoxville, Tennessee, United States of America
| | - Bright Amankwaa
- Department of Biochemistry and Cellular and Molecular Biology, The University of Tennessee, Knoxville, Tennessee, United States of America
| | - Shannon Zayac
- Department of Biochemistry and Cellular and Molecular Biology, The University of Tennessee, Knoxville, Tennessee, United States of America
| | - Justin Kemp
- Department of Biochemistry and Cellular and Molecular Biology, The University of Tennessee, Knoxville, Tennessee, United States of America
| | - Mariano Labrador
- Department of Biochemistry and Cellular and Molecular Biology, The University of Tennessee, Knoxville, Tennessee, United States of America
- * E-mail:
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10
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Huang S, Si H, Liu J, Qi D, Pei X, Lu D, Zou S, Li Z. Sleep Loss Causes Dysfunction in Murine Extraorbital Lacrimal Glands. Invest Ophthalmol Vis Sci 2022; 63:19. [PMID: 35731510 PMCID: PMC9233287 DOI: 10.1167/iovs.63.6.19] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
Purpose Sleep loss markedly affects the structure and function of the lacrimal gland and may cause ocular surface disease as a common public health problem. This study aims to investigate the circadian disturbance caused by sleep loss leading to dysfunction of extraorbital lacrimal glands (ELGs). Methods A mouse sleep deprivation (SD) model for sleep loss studies was built in C57BL/6J male mice. After four weeks, the ELGs were collected at three-hour intervals during a 24-hour period. The Jonckheere-Terpstra-Kendall algorithm was used to determine the composition, phase, and rhythmicity of transcriptomic profiles in ELGs. Furthermore, we compared the non-sleep-deprived and SD-treated mouse ELG (i) reactive oxygen species (ROS) by fluorescein staining, (ii) DNA damage by immunostaining for γ-H2Ax, and (iii) circadian migration of immune cells by immunostaining for CD4, CD8, γδ-TCR, CD64, and CX3CR1. Finally, we also evaluated (i) the locomotor activity and core body temperature rhythm of mice and (ii) the mass, cell size, and tear secretion of the ELGs. Results SD dramatically altered the composition and phase-associated functional enrichment of the circadian transcriptome, immune cell trafficking, metabolism, cell differentiation, and neural secretory activities of mouse ELGs. Additionally, SD caused the ROS accumulation and consequent DNA damage in the ELGs, and the ELG dysfunction caused by SD was irreversible. Conclusions SD damages the structure, function, and diurnal oscillations of ELGs. These results highlight comprehensive characterization of insufficient sleep–affected ELG circadian transcriptome that may provide a new therapeutic approach to counteract the effects of SD on ELG function.
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Affiliation(s)
- Shenzhen Huang
- Henan Eye Institute, Henan Eye Hospital, Henan Provincial People's Hospital, People's Hospital of Henan University, People's Hospital of Zhengzhou University, Zhengzhou, China
| | - Hongli Si
- Henan Eye Institute, Henan Eye Hospital, Henan Provincial People's Hospital, People's Hospital of Henan University, People's Hospital of Zhengzhou University, Zhengzhou, China
| | - Jiangman Liu
- Henan Eye Institute, Henan Eye Hospital, Henan Provincial People's Hospital, People's Hospital of Henan University, People's Hospital of Zhengzhou University, Zhengzhou, China
| | - Di Qi
- Henan Eye Institute, Henan Eye Hospital, Henan Provincial People's Hospital, People's Hospital of Henan University, People's Hospital of Zhengzhou University, Zhengzhou, China
| | - Xiaoting Pei
- Henan Eye Institute, Henan Eye Hospital, Henan Provincial People's Hospital, People's Hospital of Henan University, People's Hospital of Zhengzhou University, Zhengzhou, China
| | - Dingli Lu
- Henan Eye Institute, Henan Eye Hospital, Henan Provincial People's Hospital, People's Hospital of Henan University, People's Hospital of Zhengzhou University, Zhengzhou, China
| | - Sen Zou
- Henan Eye Institute, Henan Eye Hospital, Henan Provincial People's Hospital, People's Hospital of Henan University, People's Hospital of Zhengzhou University, Zhengzhou, China
| | - Zhijie Li
- Henan Eye Institute, Henan Eye Hospital, Henan Provincial People's Hospital, People's Hospital of Henan University, People's Hospital of Zhengzhou University, Zhengzhou, China
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11
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Chakravarti A, Thirimanne HN, Brown S, Calvi BR. Drosophila p53 isoforms have overlapping and distinct functions in germline genome integrity and oocyte quality control. eLife 2022; 11:61389. [PMID: 35023826 PMCID: PMC8758136 DOI: 10.7554/elife.61389] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Accepted: 12/13/2021] [Indexed: 12/13/2022] Open
Abstract
p53 gene family members in humans and other organisms encode a large number of protein isoforms whose functions are largely undefined. Using Drosophila as a model, we find that a p53B isoform is expressed predominantly in the germline where it colocalizes with p53A into subnuclear bodies. It is only p53A, however, that mediates the apoptotic response to ionizing radiation in the germline and soma. In contrast, p53A and p53B are both required for the normal repair of meiotic DNA breaks, an activity that is more crucial when meiotic recombination is defective. We find that in oocytes with persistent DNA breaks p53A is also required to activate a meiotic pachytene checkpoint. Our findings indicate that Drosophila p53 isoforms have DNA lesion and cell type-specific functions, with parallels to the functions of mammalian p53 family members in the genotoxic stress response and oocyte quality control.
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Affiliation(s)
| | | | - Savanna Brown
- Department of Biology, Indiana University, Bloomington, United States
| | - Brian R Calvi
- Department of Biology, Indiana University, Bloomington, United States
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12
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Liu J, Tao X, Zhu Y, Li C, Ruan K, Diaz-Perez Z, Rai P, Wang H, Zhai RG. NMNAT promotes glioma growth through regulating post-translational modifications of P53 to inhibit apoptosis. eLife 2021; 10:70046. [PMID: 34919052 PMCID: PMC8683086 DOI: 10.7554/elife.70046] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Accepted: 11/10/2021] [Indexed: 12/31/2022] Open
Abstract
Gliomas are highly malignant brain tumors with poor prognosis and short survival. NAD+ has been shown to impact multiple processes that are dysregulated in cancer; however, anti-cancer therapies targeting NAD+ synthesis have had limited success due to insufficient mechanistic understanding. Here, we adapted a Drosophila glial neoplasia model and discovered the genetic requirement for NAD+ synthase nicotinamide mononucleotide adenylyltransferase (NMNAT) in glioma progression in vivo and in human glioma cells. Overexpressing enzymatically active NMNAT significantly promotes glial neoplasia growth and reduces animal viability. Mechanistic analysis suggests that NMNAT interferes with DNA damage-p53-caspase-3 apoptosis signaling pathway by enhancing NAD+-dependent posttranslational modifications (PTMs) poly(ADP-ribosyl)ation (PARylation) and deacetylation of p53. Since PARylation and deacetylation reduce p53 pro-apoptotic activity, modulating p53 PTMs could be a key mechanism by which NMNAT promotes glioma growth. Our findings reveal a novel tumorigenic mechanism involving protein complex formation of p53 with NAD+ synthetic enzyme NMNAT and NAD+-dependent PTM enzymes that regulates glioma growth.
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Affiliation(s)
- Jiaqi Liu
- School of Pharmacy, Key Laboratory of Molecular Pharmacology and Drug Evaluation (Yantai University), Ministry of Education, Collaborative Innovation Center of Advanced Drug Delivery System and Biotech Drugs in Universities of Shandong, Yantai UniversityShandongChina
- Department of Molecular and Cellular Pharmacology, University of Miami Miller School of MedicineMiamiUnited States
| | - Xianzun Tao
- Department of Molecular and Cellular Pharmacology, University of Miami Miller School of MedicineMiamiUnited States
| | - Yi Zhu
- Department of Molecular and Cellular Pharmacology, University of Miami Miller School of MedicineMiamiUnited States
| | - Chong Li
- Department of Molecular and Cellular Pharmacology, University of Miami Miller School of MedicineMiamiUnited States
| | - Kai Ruan
- Department of Molecular and Cellular Pharmacology, University of Miami Miller School of MedicineMiamiUnited States
| | - Zoraida Diaz-Perez
- Department of Molecular and Cellular Pharmacology, University of Miami Miller School of MedicineMiamiUnited States
| | - Priyamvada Rai
- Department of Radiation Oncology, University of Miami Miller School of MedicineMiamiUnited States
- Sylvester Comprehensive Cancer CenterMiamiUnited States
| | - Hongbo Wang
- School of Pharmacy, Key Laboratory of Molecular Pharmacology and Drug Evaluation (Yantai University), Ministry of Education, Collaborative Innovation Center of Advanced Drug Delivery System and Biotech Drugs in Universities of Shandong, Yantai UniversityShandongChina
| | - R Grace Zhai
- Department of Molecular and Cellular Pharmacology, University of Miami Miller School of MedicineMiamiUnited States
- Sylvester Comprehensive Cancer CenterMiamiUnited States
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13
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Modeling Notch-Induced Tumor Cell Survival in the Drosophila Ovary Identifies Cellular and Transcriptional Response to Nuclear NICD Accumulation. Cells 2021; 10:cells10092222. [PMID: 34571871 PMCID: PMC8465586 DOI: 10.3390/cells10092222] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Revised: 08/02/2021] [Accepted: 08/23/2021] [Indexed: 12/26/2022] Open
Abstract
Notch is a conserved developmental signaling pathway that is dysregulated in many cancer types, most often through constitutive activation. Tumor cells with nuclear accumulation of the active Notch receptor, NICD, generally exhibit enhanced survival while patients experience poorer outcomes. To understand the impact of NICD accumulation during tumorigenesis, we developed a tumor model using the Drosophila ovarian follicular epithelium. Using this system we demonstrated that NICD accumulation contributed to larger tumor growth, reduced apoptosis, increased nuclear size, and fewer incidents of DNA damage without altering ploidy. Using bulk RNA sequencing we identified key genes involved in both a pre- and post- tumor response to NICD accumulation. Among these are genes involved in regulating double-strand break repair, chromosome organization, metabolism, like raptor, which we experimentally validated contributes to early Notch-induced tumor growth. Finally, using single-cell RNA sequencing we identified follicle cell-specific targets in NICD-overexpressing cells which contribute to DNA repair and negative regulation of apoptosis. This valuable tumor model for nuclear NICD accumulation in adult Drosophila follicle cells has allowed us to better understand the specific contribution of nuclear NICD accumulation to cell survival in tumorigenesis and tumor progression.
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14
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Nguyen TTN, Shim J, Song YH. Chk2-p53 and JNK in irradiation-induced cell death of hematopoietic progenitors and differentiated cells in Drosophila larval lymph gland. Biol Open 2021; 10:271116. [PMID: 34328173 PMCID: PMC8411456 DOI: 10.1242/bio.058809] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Accepted: 07/22/2021] [Indexed: 11/20/2022] Open
Abstract
Ionizing radiation (IR) induces DNA double-strand breaks that activate the DNA damage response (DDR), which leads to cell cycle arrest, senescence, or apoptotic cell death. Understanding the DDR of stem cells is critical to tissue homeostasis and the survival of the organism. Drosophila hematopoiesis serves as a model system for sensing stress and environmental changes; however, their response to DNA damage remains largely unexplored. The Drosophila lymph gland is the larval hematopoietic organ, where stem-like progenitors proliferate and differentiate into mature blood cells called hemocytes. We found that apoptotic cell death was induced in progenitors and hemocytes after 40 Gy irradiation, with progenitors showing more resistance to IR-induced cell death compared to hemocytes at a lower dose. Furthermore, we found that Drosophila ATM (tefu), Chk2 (lok), p53, and reaper were necessary for IR-induced cell death in the progenitors. Notably, IR-induced cell death in mature hemocytes required tefu, Drosophila JNK (bsk), and reaper, but not lok or p53. In summary, we found that DNA damage induces apoptotic cell death in the late third instar larval lymph gland and identified lok/p53-dependent and -independent cell death pathways in progenitors and mature hemocytes, respectively.
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Affiliation(s)
- Tram Thi Ngoc Nguyen
- Department of Biomedical Gerontology, Hallym University, Chuncheon, Gangwon-do 24252, Republic of Korea.,Ilsong Institute of Life Science, Hallym University, Seoul 07247, Republic of Korea
| | - Jiwon Shim
- Department of Life Science, College of Natural Science, Hanyang University, Seoul 04763, Republic of Korea
| | - Young-Han Song
- Department of Biomedical Gerontology, Hallym University, Chuncheon, Gangwon-do 24252, Republic of Korea.,Ilsong Institute of Life Science, Hallym University, Seoul 07247, Republic of Korea
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15
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VCP maintains nuclear size by regulating the DNA damage-associated MDC1-p53-autophagy axis in Drosophila. Nat Commun 2021; 12:4258. [PMID: 34253734 PMCID: PMC8275807 DOI: 10.1038/s41467-021-24556-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2020] [Accepted: 06/24/2021] [Indexed: 12/20/2022] Open
Abstract
The maintenance of constant karyoplasmic ratios suggests that nuclear size has physiological significance. Nuclear size anomalies have been linked to malignant transformation, although the mechanism remains unclear. By expressing dominant-negative TER94 mutants in Drosophila photoreceptors, here we show disruption of VCP (valosin-containing protein, human TER94 ortholog), a ubiquitin-dependent segregase, causes progressive nuclear size increase. Loss of VCP function leads to accumulations of MDC1 (mediator of DNA damage checkpoint protein 1), connecting DNA damage or associated responses to enlarged nuclei. TER94 can interact with MDC1 and decreases MDC1 levels, suggesting that MDC1 is a VCP substrate. Our evidence indicates that MDC1 accumulation stabilizes p53A, leading to TER94K2A-associated nuclear size increase. Together with a previous report that p53A disrupts autophagic flux, we propose that the stabilization of p53A in TER94K2A-expressing cells likely hinders the removal of nuclear content, resulting in aberrant nuclear size increase. Cells maintain a constant cytoplasm to nucleus volume ratio, although the role of DNA damage is not well explored. Here, the authors use Drosophila to connect TER94, the fly homolog of VCP, to disruption of DNA damage repair, leading to ubiquitinated Mu2 protein accumulation and enlarged nuclei.
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16
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Li F, Lo TY, Miles L, Wang Q, Noristani HN, Li D, Niu J, Trombley S, Goldshteyn JI, Wang C, Wang S, Qiu J, Pogoda K, Mandal K, Brewster M, Rompolas P, He Y, Janmey PA, Thomas GM, Li S, Song Y. The Atr-Chek1 pathway inhibits axon regeneration in response to Piezo-dependent mechanosensation. Nat Commun 2021; 12:3845. [PMID: 34158506 PMCID: PMC8219705 DOI: 10.1038/s41467-021-24131-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Accepted: 05/25/2021] [Indexed: 02/05/2023] Open
Abstract
Atr is a serine/threonine kinase, known to sense single-stranded DNA breaks and activate the DNA damage checkpoint by phosphorylating Chek1, which inhibits Cdc25, causing cell cycle arrest. This pathway has not been implicated in neuroregeneration. We show that in Drosophila sensory neurons removing Atr or Chek1, or overexpressing Cdc25 promotes regeneration, whereas Atr or Chek1 overexpression, or Cdc25 knockdown impedes regeneration. Inhibiting the Atr-associated checkpoint complex in neurons promotes regeneration and improves synapse/behavioral recovery after CNS injury. Independent of DNA damage, Atr responds to the mechanical stimulus elicited during regeneration, via the mechanosensitive ion channel Piezo and its downstream NO signaling. Sensory neuron-specific knockout of Atr in adult mice, or pharmacological inhibition of Atr-Chek1 in mammalian neurons in vitro and in flies in vivo enhances regeneration. Our findings reveal the Piezo-Atr-Chek1-Cdc25 axis as an evolutionarily conserved inhibitory mechanism for regeneration, and identify potential therapeutic targets for treating nervous system trauma.
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Affiliation(s)
- Feng Li
- Raymond G. Perelman Center for Cellular and Molecular Therapeutics, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Tsz Y Lo
- Raymond G. Perelman Center for Cellular and Molecular Therapeutics, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Leann Miles
- The Graduate Group in Biochemistry and Molecular Biophysics, University of Pennsylvania, Philadelphia, PA, USA
| | - Qin Wang
- Raymond G. Perelman Center for Cellular and Molecular Therapeutics, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Harun N Noristani
- Shriners Hospitals Pediatric Research Center (Center for Neurorehabilitation and Neural Repair), Temple University School of Medicine, Philadelphia, PA, USA
- Department of Anatomy and Cell Biology, Temple University School of Medicine, Philadelphia, PA, USA
| | - Dan Li
- Raymond G. Perelman Center for Cellular and Molecular Therapeutics, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Jingwen Niu
- Shriners Hospitals Pediatric Research Center (Center for Neurorehabilitation and Neural Repair), Temple University School of Medicine, Philadelphia, PA, USA
| | - Shannon Trombley
- Raymond G. Perelman Center for Cellular and Molecular Therapeutics, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Jessica I Goldshteyn
- Raymond G. Perelman Center for Cellular and Molecular Therapeutics, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Chuxi Wang
- Raymond G. Perelman Center for Cellular and Molecular Therapeutics, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Shuchao Wang
- Raymond G. Perelman Center for Cellular and Molecular Therapeutics, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Jingyun Qiu
- Raymond G. Perelman Center for Cellular and Molecular Therapeutics, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Katarzyna Pogoda
- Institute for Medicine and Engineering, University of Pennsylvania, Philadelphia, PA, USA
- Institute of Nuclear Physics, Polish Academy of Sciences, Krakow, Poland
| | - Kalpana Mandal
- Institute for Medicine and Engineering, University of Pennsylvania, Philadelphia, PA, USA
| | - Megan Brewster
- Department of Dermatology, University of Pennsylvania, Philadelphia, PA, USA
| | | | - Ye He
- The City University of New York, Graduate Center - Advanced Science Research Center, Neuroscience Initiative, New York, NY, USA
| | - Paul A Janmey
- Institute for Medicine and Engineering, University of Pennsylvania, Philadelphia, PA, USA
| | - Gareth M Thomas
- Shriners Hospitals Pediatric Research Center (Center for Neurorehabilitation and Neural Repair), Temple University School of Medicine, Philadelphia, PA, USA
- Department of Anatomy and Cell Biology, Temple University School of Medicine, Philadelphia, PA, USA
| | - Shuxin Li
- Shriners Hospitals Pediatric Research Center (Center for Neurorehabilitation and Neural Repair), Temple University School of Medicine, Philadelphia, PA, USA
- Department of Anatomy and Cell Biology, Temple University School of Medicine, Philadelphia, PA, USA
| | - Yuanquan Song
- Raymond G. Perelman Center for Cellular and Molecular Therapeutics, The Children's Hospital of Philadelphia, Philadelphia, PA, USA.
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA, USA.
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17
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Suart CE, Perez AM, Al-Ramahi I, Maiuri T, Botas J, Truant R. Spinocerebellar Ataxia Type 1 protein Ataxin-1 is signaled to DNA damage by ataxia-telangiectasia mutated kinase. Hum Mol Genet 2021; 30:706-715. [PMID: 33772540 DOI: 10.1093/hmg/ddab074] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Revised: 02/10/2021] [Accepted: 03/05/2021] [Indexed: 01/16/2023] Open
Abstract
Spinocerebellar Ataxia Type 1 (SCA1) is an autosomal dominant neurodegenerative disorder caused by a polyglutamine expansion in the ataxin-1 protein. Recent genetic correlational studies have implicated DNA damage repair pathways in modifying the age at onset of disease symptoms in SCA1 and Huntington's Disease, another polyglutamine expansion disease. We demonstrate that both endogenous and transfected ataxin-1 localizes to sites of DNA damage, which is impaired by polyglutamine expansion. This response is dependent on ataxia-telangiectasia mutated (ATM) kinase activity. Further, we characterize an ATM phosphorylation motif within ataxin-1 at serine 188. We show reduction of the Drosophila ATM homolog levels in a ATXN1[82Q] Drosophila model through shRNA or genetic cross ameliorates motor symptoms. These findings offer a possible explanation as to why DNA repair was implicated in SCA1 pathogenesis by past studies. The similarities between the ataxin-1 and the huntingtin responses to DNA damage provide further support for a shared pathogenic mechanism for polyglutamine expansion diseases.
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Affiliation(s)
- Celeste E Suart
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada
| | - Alma M Perez
- Department of Molecular and Human Genetics, Department of Molecular and Cellular Biology, Jan and Dan Duncan Neurological Research Institute, Houston, TX, USA
| | - Ismael Al-Ramahi
- Department of Molecular and Human Genetics, Department of Molecular and Cellular Biology, Jan and Dan Duncan Neurological Research Institute, Houston, TX, USA
| | - Tamara Maiuri
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada
| | - Juan Botas
- Department of Molecular and Human Genetics, Department of Molecular and Cellular Biology, Jan and Dan Duncan Neurological Research Institute, Houston, TX, USA
| | - Ray Truant
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada
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18
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Dong YL, Vadla GP, Lu JYJ, Ahmad V, Klein TJ, Liu LF, Glazer PM, Xu T, Chabu CY. Cooperation between oncogenic Ras and wild-type p53 stimulates STAT non-cell autonomously to promote tumor radioresistance. Commun Biol 2021; 4:374. [PMID: 33742110 PMCID: PMC7979758 DOI: 10.1038/s42003-021-01898-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Accepted: 02/23/2021] [Indexed: 12/27/2022] Open
Abstract
Oncogenic RAS mutations are associated with tumor resistance to radiation therapy. Cell-cell interactions in the tumor microenvironment (TME) profoundly influence therapy outcomes. However, the nature of these interactions and their role in Ras tumor radioresistance remain unclear. Here we use Drosophila oncogenic Ras tissues and human Ras cancer cell radiation models to address these questions. We discover that cellular response to genotoxic stress cooperates with oncogenic Ras to activate JAK/STAT non-cell autonomously in the TME. Specifically, p53 is heterogeneously activated in Ras tumor tissues in response to irradiation. This mosaicism allows high p53-expressing Ras clones to stimulate JAK/STAT cytokines, which activate JAK/STAT in the nearby low p53-expressing surviving Ras clones, leading to robust tumor re-establishment. Blocking any part of this cell-cell communication loop re-sensitizes Ras tumor cells to irradiation. These findings suggest that coupling STAT inhibitors to radiotherapy might improve clinical outcomes for Ras cancer patients.
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Affiliation(s)
- Yong-Li Dong
- Howard Hughes Medical Institute, Department of Genetics, Yale University School of Medicine, Boyer Center for Molecular Medicine, New Haven, CT, USA
- State Key Laboratory of Genetic Engineering and National Center for International Research, Fudan-Yale Biomedical Research Center, Institute of Developmental Biology and Molecular Medicine, School of Life Sciences, Fudan University, Shanghai, China
| | - Gangadhara P Vadla
- Division of Biological Sciences, College of Veterinary Medicine, Department of Surgery, University of Missouri, Columbia, MO, USA
| | - Jin-Yu Jim Lu
- Howard Hughes Medical Institute, Department of Genetics, Yale University School of Medicine, Boyer Center for Molecular Medicine, New Haven, CT, USA
- Yale-Waterbury Internal Medicine Residency Program, Waterbury, CT, USA
| | - Vakil Ahmad
- Division of Biological Sciences, College of Veterinary Medicine, Department of Surgery, University of Missouri, Columbia, MO, USA
| | - Thomas J Klein
- Howard Hughes Medical Institute, Department of Genetics, Yale University School of Medicine, Boyer Center for Molecular Medicine, New Haven, CT, USA
- South Florida Radiation Oncology, West Palm Beach, FL, USA
| | - Lu-Fang Liu
- Howard Hughes Medical Institute, Department of Genetics, Yale University School of Medicine, Boyer Center for Molecular Medicine, New Haven, CT, USA
| | - Peter M Glazer
- Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, CT, USA
| | - Tian Xu
- Howard Hughes Medical Institute, Department of Genetics, Yale University School of Medicine, Boyer Center for Molecular Medicine, New Haven, CT, USA.
- Key Laboratory of Growth Regulation and Translation Research of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang Province, China.
| | - Chiswili-Yves Chabu
- Division of Biological Sciences, College of Veterinary Medicine, Department of Surgery, University of Missouri, Columbia, MO, USA.
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19
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Vidaurre V, Chen X. Epigenetic regulation of drosophila germline stem cell maintenance and differentiation. Dev Biol 2021; 473:105-118. [PMID: 33610541 DOI: 10.1016/j.ydbio.2021.02.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 01/26/2021] [Accepted: 02/06/2021] [Indexed: 12/13/2022]
Abstract
Gametogenesis is one of the most extreme cellular differentiation processes that takes place in Drosophila male and female germlines. This process begins at the germline stem cell, which undergoes asymmetric cell division (ACD) to produce a self-renewed daughter that preserves its stemness and a differentiating daughter cell that undergoes epigenetic and genomic changes to eventually produce haploid gametes. Research in molecular genetics and cellular biology are beginning to take advantage of the continually advancing genomic tools to understand: (1) how germ cells are able to maintain their identity throughout the adult reproductive lifetime, and (2) undergo differentiation in a balanced manner. In this review, we focus on the epigenetic mechanisms that address these two questions through their regulation of germline-soma communication to ensure germline stem cell identity and activity.
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Affiliation(s)
- Velinda Vidaurre
- Department of Biology, The Johns Hopkins University, 3400 North Charles Street, Baltimore, Baltimore, MD, 21218, USA
| | - Xin Chen
- Department of Biology, The Johns Hopkins University, 3400 North Charles Street, Baltimore, Baltimore, MD, 21218, USA.
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20
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Sharma A, Akagi K, Pattavina B, Wilson KA, Nelson C, Watson M, Maksoud E, Harata A, Ortega M, Brem RB, Kapahi P. Musashi expression in intestinal stem cells attenuates radiation-induced decline in intestinal permeability and survival in Drosophila. Sci Rep 2020; 10:19080. [PMID: 33154387 PMCID: PMC7644626 DOI: 10.1038/s41598-020-75867-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Accepted: 09/17/2020] [Indexed: 11/30/2022] Open
Abstract
Exposure to genotoxic stress by environmental agents or treatments, such as radiation therapy, can diminish healthspan and accelerate aging. We have developed a Drosophila melanogaster model to study the molecular effects of radiation-induced damage and repair. Utilizing a quantitative intestinal permeability assay, we performed an unbiased GWAS screen (using 156 strains from the Drosophila Genetic Reference Panel) to search for natural genetic variants that regulate radiation-induced gut permeability in adult D. melanogaster. From this screen, we identified an RNA binding protein, Musashi (msi), as one of the possible genes associated with changes in intestinal permeability upon radiation. The overexpression of msi promoted intestinal stem cell proliferation, which increased survival after irradiation and rescued radiation-induced intestinal permeability. In summary, we have established D. melanogaster as an expedient model system to study the effects of radiation-induced damage to the intestine in adults and have identified msi as a potential therapeutic target.
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Affiliation(s)
- Amit Sharma
- SENS Research Foundation, 110 Pioneer Way, Suite J, Mountain View, CA, 94041, USA.
| | - Kazutaka Akagi
- National Center for Geriatrics and Gerontology, 7-430 Morioka-cho, Obu, Aichi, 474-8511, Japan.
| | - Blaine Pattavina
- Buck Institute for Research on Aging, 8001 Redwood Boulevard, Novato, CA, 94945, USA
| | - Kenneth A Wilson
- Buck Institute for Research on Aging, 8001 Redwood Boulevard, Novato, CA, 94945, USA
| | - Christopher Nelson
- Buck Institute for Research on Aging, 8001 Redwood Boulevard, Novato, CA, 94945, USA
| | - Mark Watson
- Buck Institute for Research on Aging, 8001 Redwood Boulevard, Novato, CA, 94945, USA
| | - Elie Maksoud
- Buck Institute for Research on Aging, 8001 Redwood Boulevard, Novato, CA, 94945, USA
| | - Ayano Harata
- National Center for Geriatrics and Gerontology, 7-430 Morioka-cho, Obu, Aichi, 474-8511, Japan
| | - Mauricio Ortega
- Buck Institute for Research on Aging, 8001 Redwood Boulevard, Novato, CA, 94945, USA
| | - Rachel B Brem
- Buck Institute for Research on Aging, 8001 Redwood Boulevard, Novato, CA, 94945, USA
| | - Pankaj Kapahi
- Buck Institute for Research on Aging, 8001 Redwood Boulevard, Novato, CA, 94945, USA.
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21
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Henn L, Szabó A, Imre L, Román Á, Ábrahám A, Vedelek B, Nánási P, Boros IM. Alternative linker histone permits fast paced nuclear divisions in early Drosophila embryo. Nucleic Acids Res 2020; 48:9007-9018. [PMID: 32710625 PMCID: PMC7498357 DOI: 10.1093/nar/gkaa624] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Revised: 06/16/2020] [Accepted: 07/14/2020] [Indexed: 01/09/2023] Open
Abstract
In most animals, the start of embryogenesis requires specific histones. In Drosophila linker histone variant BigH1 is present in early embryos. To uncover the specific role of this alternative linker histone at early embryogenesis, we established fly lines in which domains of BigH1 have been replaced partially or completely with that of H1. Analysis of the resulting Drosophila lines revealed that at normal temperature somatic H1 can substitute the alternative linker histone, but at low temperature the globular and C-terminal domains of BigH1 are essential for embryogenesis. In the presence of BigH1 nucleosome stability increases and core histone incorporation into nucleosomes is more rapid, while nucleosome spacing is unchanged. Chromatin formation in the presence of BigH1 permits the fast-paced nuclear divisions of the early embryo. We propose a model which explains how this specific linker histone ensures the rapid nucleosome reassembly required during quick replication cycles at the start of embryogenesis.
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Affiliation(s)
- László Henn
- Institute of Biochemistry, Biological Research Centre of Szeged, Szeged H-6726, Hungary
| | - Anikó Szabó
- Institute of Biochemistry, Biological Research Centre of Szeged, Szeged H-6726, Hungary.,Department of Biochemistry and Molecular Biology, Faculty of Science and Informatics, University of Szeged, Szeged H-6726, Hungary.,Doctoral School in Biology, Faculty of Science and Informatics, University of Szeged, Szeged H-6726, Hungary
| | - László Imre
- Department of Biophysics and Cell Biology, University of Debrecen, Debrecen H-4032 Hungary
| | - Ádám Román
- Department of Biochemistry and Molecular Biology, Faculty of Science and Informatics, University of Szeged, Szeged H-6726, Hungary
| | - Andrea Ábrahám
- Institute of Biochemistry, Biological Research Centre of Szeged, Szeged H-6726, Hungary.,Department of Biochemistry and Molecular Biology, Faculty of Science and Informatics, University of Szeged, Szeged H-6726, Hungary.,Doctoral School in Biology, Faculty of Science and Informatics, University of Szeged, Szeged H-6726, Hungary
| | - Balázs Vedelek
- Department of Biochemistry and Molecular Biology, Faculty of Science and Informatics, University of Szeged, Szeged H-6726, Hungary
| | - Péter Nánási
- Department of Biophysics and Cell Biology, University of Debrecen, Debrecen H-4032 Hungary
| | - Imre M Boros
- Institute of Biochemistry, Biological Research Centre of Szeged, Szeged H-6726, Hungary.,Department of Biochemistry and Molecular Biology, Faculty of Science and Informatics, University of Szeged, Szeged H-6726, Hungary
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22
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Scacchetti A, Becker PB. Loss of nucleosome remodelers CHRAC/ACF does not sensitize early Drosophila embryos to X-rays. MICROPUBLICATION BIOLOGY 2020; 2020:10.17912/micropub.biology.000287. [PMID: 32760884 PMCID: PMC7396160 DOI: 10.17912/micropub.biology.000287] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Alessandro Scacchetti
- Molecular Biology Division, Biomedical Center, Ludwig-Maximilians-University, Munich, Germany
| | - Peter B. Becker
- Molecular Biology Division, Biomedical Center, Ludwig-Maximilians-University, Munich, Germany,
Correspondence to: Peter B. Becker ()
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23
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Kolesnikova TD, Kolodyazhnaya AV, Pokholkova GV, Schubert V, Dovgan VV, Romanenko SA, Prokopov DY, Zhimulev IF. Effects of Mutations in the Drosophila melanogaster Rif1 Gene on the Replication and Underreplication of Pericentromeric Heterochromatin in Salivary Gland Polytene Chromosomes. Cells 2020; 9:cells9061501. [PMID: 32575592 PMCID: PMC7349278 DOI: 10.3390/cells9061501] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 06/15/2020] [Accepted: 06/16/2020] [Indexed: 01/09/2023] Open
Abstract
In Drosophila salivary gland polytene chromosomes, a substantial portion of heterochromatin is underreplicated. The combination of mutations SuURES and Su(var)3-906 results in the polytenization of a substantial fraction of unique and moderately repeated sequences but has almost no effect on satellite DNA replication. The Rap1 interacting factor 1 (Rif) protein is a conserved regulator of replication timing, and in Drosophila, it affects underreplication in polytene chromosomes. We compared the morphology of pericentromeric regions and labeling patterns of in situ hybridization of heterochromatin-specific DNA probes between wild-type salivary gland polytene chromosomes and the chromosomes of Rif1 mutants and SuUR Su(var)3-906 double mutants. We show that, despite general similarities, heterochromatin zones exist that are polytenized only in the Rif1 mutants, and that there are zones that are under specific control of Su(var)3-9. In the Rif1 mutants, we found additional polytenization of the largest blocks of satellite DNA (in particular, satellite 1.688 of chromosome X and simple satellites in chromosomes X and 4) as well as partial polytenization of chromosome Y. Data on pulsed incorporation of 5-ethynyl-2′-deoxyuridine (EdU) into polytene chromosomes indicated that in the Rif1 mutants, just as in the wild type, most of the heterochromatin becomes replicated during the late S phase. Nevertheless, a significantly increased number of heterochromatin replicons was noted. These results suggest that Rif1 regulates the activation probability of heterochromatic origins in the satellite DNA region.
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Affiliation(s)
- Tatyana D. Kolesnikova
- Institute of Molecular and Cellular Biology, Siberian Branch of Russian Academy of Sciences, 630090 Novosibirsk, Russia; (A.V.K.); (G.V.P.); (V.V.D.); (S.A.R.); (D.Y.P.); (I.F.Z.)
- Laboratory of Structural, Functional and Comparative Genomics, Novosibirsk State University, 630090 Novosibirsk, Russia
- Correspondence:
| | - Alexandra V. Kolodyazhnaya
- Institute of Molecular and Cellular Biology, Siberian Branch of Russian Academy of Sciences, 630090 Novosibirsk, Russia; (A.V.K.); (G.V.P.); (V.V.D.); (S.A.R.); (D.Y.P.); (I.F.Z.)
- Department of Natural Sciences, Novosibirsk State University, 630090 Novosibirsk, Russia
| | - Galina V. Pokholkova
- Institute of Molecular and Cellular Biology, Siberian Branch of Russian Academy of Sciences, 630090 Novosibirsk, Russia; (A.V.K.); (G.V.P.); (V.V.D.); (S.A.R.); (D.Y.P.); (I.F.Z.)
| | - Veit Schubert
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, D-06466 Seeland, Germany;
| | - Viktoria V. Dovgan
- Institute of Molecular and Cellular Biology, Siberian Branch of Russian Academy of Sciences, 630090 Novosibirsk, Russia; (A.V.K.); (G.V.P.); (V.V.D.); (S.A.R.); (D.Y.P.); (I.F.Z.)
- Department of Natural Sciences, Novosibirsk State University, 630090 Novosibirsk, Russia
| | - Svetlana A. Romanenko
- Institute of Molecular and Cellular Biology, Siberian Branch of Russian Academy of Sciences, 630090 Novosibirsk, Russia; (A.V.K.); (G.V.P.); (V.V.D.); (S.A.R.); (D.Y.P.); (I.F.Z.)
| | - Dmitry Yu. Prokopov
- Institute of Molecular and Cellular Biology, Siberian Branch of Russian Academy of Sciences, 630090 Novosibirsk, Russia; (A.V.K.); (G.V.P.); (V.V.D.); (S.A.R.); (D.Y.P.); (I.F.Z.)
| | - Igor F. Zhimulev
- Institute of Molecular and Cellular Biology, Siberian Branch of Russian Academy of Sciences, 630090 Novosibirsk, Russia; (A.V.K.); (G.V.P.); (V.V.D.); (S.A.R.); (D.Y.P.); (I.F.Z.)
- Laboratory of Structural, Functional and Comparative Genomics, Novosibirsk State University, 630090 Novosibirsk, Russia
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24
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Pham TLA, Binh TD, Liu G, Nguyen TQC, Nguyen YDH, Sahashi R, Men TT, Kamei K. Role of Serotonin Transporter in Eye Development of Drosophila melanogaster. Int J Mol Sci 2020; 21:ijms21114086. [PMID: 32521639 PMCID: PMC7312876 DOI: 10.3390/ijms21114086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 05/26/2020] [Accepted: 06/05/2020] [Indexed: 11/30/2022] Open
Abstract
Serotonin transporter (SerT) in the brain is an important neurotransmitter transporter involved in mental health. However, its role in peripheral organs is poorly understood. In this study, we investigated the function of SerT in the development of the compound eye in Drosophila melanogaster. We found that SerT knockdown led to excessive cell death and an increased number of cells in S-phase in the posterior eye imaginal disc. Furthermore, the knockdown of SerT in the eye disc suppressed the activation of Akt, and the introduction of PI3K effectively rescued this phenotype. These results suggested that SerT plays a role in the healthy eye development of D.melanogaster by controlling cell death through the regulation of the PI3K/Akt pathway.
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Affiliation(s)
- Tuan L. A. Pham
- Department of Functional Chemistry, Kyoto Institute of Technology, Kyoto 606-8585, Japan; (T.L.A.P.); (T.D.B.); (G.L.); (T.Q.C.N.); (Y.D.H.N.); (R.S.)
| | - Tran Duy Binh
- Department of Functional Chemistry, Kyoto Institute of Technology, Kyoto 606-8585, Japan; (T.L.A.P.); (T.D.B.); (G.L.); (T.Q.C.N.); (Y.D.H.N.); (R.S.)
| | - Guanchen Liu
- Department of Functional Chemistry, Kyoto Institute of Technology, Kyoto 606-8585, Japan; (T.L.A.P.); (T.D.B.); (G.L.); (T.Q.C.N.); (Y.D.H.N.); (R.S.)
| | - Thanh Q. C. Nguyen
- Department of Functional Chemistry, Kyoto Institute of Technology, Kyoto 606-8585, Japan; (T.L.A.P.); (T.D.B.); (G.L.); (T.Q.C.N.); (Y.D.H.N.); (R.S.)
| | - Yen D. H. Nguyen
- Department of Functional Chemistry, Kyoto Institute of Technology, Kyoto 606-8585, Japan; (T.L.A.P.); (T.D.B.); (G.L.); (T.Q.C.N.); (Y.D.H.N.); (R.S.)
| | - Ritsuko Sahashi
- Department of Functional Chemistry, Kyoto Institute of Technology, Kyoto 606-8585, Japan; (T.L.A.P.); (T.D.B.); (G.L.); (T.Q.C.N.); (Y.D.H.N.); (R.S.)
| | - Tran Thanh Men
- Department of Biology, Cantho University, Cantho 900000, Vietnam;
| | - Kaeko Kamei
- Department of Functional Chemistry, Kyoto Institute of Technology, Kyoto 606-8585, Japan; (T.L.A.P.); (T.D.B.); (G.L.); (T.Q.C.N.); (Y.D.H.N.); (R.S.)
- Correspondence:
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25
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Vaccaro A, Kaplan Dor Y, Nambara K, Pollina EA, Lin C, Greenberg ME, Rogulja D. Sleep Loss Can Cause Death through Accumulation of Reactive Oxygen Species in the Gut. Cell 2020; 181:1307-1328.e15. [PMID: 32502393 DOI: 10.1016/j.cell.2020.04.049] [Citation(s) in RCA: 225] [Impact Index Per Article: 56.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Revised: 01/15/2020] [Accepted: 04/24/2020] [Indexed: 02/06/2023]
Abstract
The view that sleep is essential for survival is supported by the ubiquity of this behavior, the apparent existence of sleep-like states in the earliest animals, and the fact that severe sleep loss can be lethal. The cause of this lethality is unknown. Here we show, using flies and mice, that sleep deprivation leads to accumulation of reactive oxygen species (ROS) and consequent oxidative stress, specifically in the gut. ROS are not just correlates of sleep deprivation but drivers of death: their neutralization prevents oxidative stress and allows flies to have a normal lifespan with little to no sleep. The rescue can be achieved with oral antioxidant compounds or with gut-targeted transgenic expression of antioxidant enzymes. We conclude that death upon severe sleep restriction can be caused by oxidative stress, that the gut is central in this process, and that survival without sleep is possible when ROS accumulation is prevented. VIDEO ABSTRACT.
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Affiliation(s)
- Alexandra Vaccaro
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Yosef Kaplan Dor
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Keishi Nambara
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | | | - Cindy Lin
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | | | - Dragana Rogulja
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA.
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26
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Hassan A, Araguas Rodriguez P, Heidmann SK, Walmsley EL, Aughey GN, Southall TD. Condensin I subunit Cap-G is essential for proper gene expression during the maturation of post-mitotic neurons. eLife 2020; 9:e55159. [PMID: 32255428 PMCID: PMC7170655 DOI: 10.7554/elife.55159] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Accepted: 04/06/2020] [Indexed: 02/07/2023] Open
Abstract
Condensin complexes are essential for mitotic chromosome assembly and segregation during cell divisions, however, little is known about their functions in post-mitotic cells. Here we report a role for the condensin I subunit Cap-G in Drosophila neurons. We show that, despite not requiring condensin for mitotic chromosome compaction, post-mitotic neurons express Cap-G. Knockdown of Cap-G specifically in neurons (from their birth onwards) results in developmental arrest, behavioural defects, and dramatic gene expression changes, including reduced expression of a subset of neuronal genes and aberrant expression of genes that are not normally expressed in the developing brain. Knockdown of Cap-G in mature neurons results in similar phenotypes but to a lesser degree. Furthermore, we see dynamic binding of Cap-G at distinct loci in progenitor cells and differentiated neurons. Therefore, Cap-G is essential for proper gene expression in neurons and plays an important role during the early stages of neuronal development.
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Affiliation(s)
- Amira Hassan
- Department of Life Sciences, Imperial College LondonLondonUnited Kingdom
| | | | | | - Emma L Walmsley
- Department of Life Sciences, Imperial College LondonLondonUnited Kingdom
| | - Gabriel N Aughey
- Department of Life Sciences, Imperial College LondonLondonUnited Kingdom
| | - Tony D Southall
- Department of Life Sciences, Imperial College LondonLondonUnited Kingdom
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27
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Pei X, Du E, Sheng Z, Du W. Rb family-independent activating E2F increases genome stability, promotes homologous recombination, and decreases non-homologous end joining. Mech Dev 2020; 162:103607. [PMID: 32217105 DOI: 10.1016/j.mod.2020.103607] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Revised: 03/13/2020] [Accepted: 03/22/2020] [Indexed: 11/15/2022]
Abstract
The retinoblastoma protein Rb is a prototype tumor suppressor inactivated in a variety of cancers. In addition to deregulated cell proliferation, Rb inactivation also causes genome instability that contributes to tumorigenesis. Although the genome instability effects of Rb inactivation was shown to be mediated mainly by E2F-independent mechanisms, little is known about whether the constitutive free activating E2F proteins released by Rb-inactivation affects genome stability. In this manuscript, we take advantage of the dE2F1su89 mutant, which contains a point mutation in the conserved Rb-binding domain that disrupts its interaction with the Rb family proteins, to characterize the effect of constitutive free activating E2F on genome stability in the presence of WT Rb. We showed that dE2F1su89 promoted genome stability in the mwh genome stability assay. We found that the genome stability effects of dE2F1su89 was sensitive to the levels of activating E2F activity and to the levels of E2F targets involved in DNA replication and repair but not to the level of E2F cell cycle target Cyclin E. Importantly, we showed that dE2F1su89 promoted DNA double-strand break (DSB) repair by homologous recombination and decreased DSB repair by Non-homologous end joining (NHEJ). These results show that the constitutive free activating E2F promotes genome stability, which potentially contributes the observed tumor development in E2F1 knockout mice and the reported NHEJ defects in Rb mutant cells. These results also explain why constitutive free activating E2F alone was not sufficient for tumor development.
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Affiliation(s)
- Xun Pei
- Ben May Department for Cancer Research, The University of Chicago, 929 E. 57(th) St, Chicago, IL 60637, United States of America
| | - Elbert Du
- Harvard University, Cambridge, MA 02138, United States of America
| | - Zhentao Sheng
- Ben May Department for Cancer Research, The University of Chicago, 929 E. 57(th) St, Chicago, IL 60637, United States of America
| | - Wei Du
- Ben May Department for Cancer Research, The University of Chicago, 929 E. 57(th) St, Chicago, IL 60637, United States of America.
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28
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Rastegari E, Kajal K, Tan BS, Huang F, Chen RH, Hsieh TS, Hsu HJ. WD40 protein Wuho controls germline homeostasis via TRIM-NHL tumor suppressor Mei-p26 in Drosophila. Development 2020; 147:147/2/dev182063. [PMID: 31941704 DOI: 10.1242/dev.182063] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Accepted: 12/03/2019] [Indexed: 12/22/2022]
Abstract
WD40 proteins control many cellular processes via protein interactions. Drosophila Wuho (Wh, a WD40 protein) controls fertility, although the involved mechanisms are unclear. Here, we show that Wh promotion of Mei-p26 (a human TRIM32 ortholog) function maintains ovarian germ cell homeostasis. Wh and Mei-p26 are epistatically linked, with wh and mei-p26 mutants showing nearly identical phenotypes, including germline stem cell (GSC) loss, stem-cyst formation due to incomplete cytokinesis between GSCs and daughter cells, and overproliferation of GSC progeny. Mechanistically, Wh interacts with Mei-p26 in different cellular contexts to induce cell type-specific effects. In GSCs, Wh and Mei-p26 promote BMP stemness signaling for proper GSC division and maintenance. In GSC progeny, Wh and Mei-p26 silence nanos translation, downregulate a subset of microRNAs involved in germ cell differentiation and suppress ribosomal biogenesis via dMyc to limit germ cell mitosis. We also found that the human ortholog of Wh (WDR4) interacts with TRIM32 in human cells. Our results show that Wh is a regulator of Mei-p26 in Drosophila germ cells and suggest that the WD40-TRIM interaction may also control tissue homeostasis in other stem cell systems.
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Affiliation(s)
- Elham Rastegari
- Molecular and Cell Biology, Taiwan International Graduate Program, Academia Sinica, Taipei 11529, Taiwan, R.O.C.,Graduate Institute of Life Science, National Defense Medical Center, Taipei 11490, Taiwan, R.O.C.,Institute of Cellular and Organismic Biology, Sinica, Taipei 11529, Taiwan, R.O.C
| | - Kreeti Kajal
- Institute of Cellular and Organismic Biology, Sinica, Taipei 11529, Taiwan, R.O.C.,Molecular and Biological Agricultural Sciences Program, Taiwan International Graduate Program, National Chung Hsing University and Academia Sinica, Taipei 11529, Taiwan, R.O.C.,Graduate Institute of Biotechnology, National Chung Hsing University, Taichung 40227, Taiwan, R.O.C
| | - Boon-Shing Tan
- Institute of Biological Chemistry, Sinica, Taipei 11529, Taiwan, R.O.C
| | - Fu Huang
- Institute of Biological Chemistry, Sinica, Taipei 11529, Taiwan, R.O.C
| | - Ruey-Hwa Chen
- Institute of Biological Chemistry, Sinica, Taipei 11529, Taiwan, R.O.C
| | - Tao-Shieh Hsieh
- Molecular and Cell Biology, Taiwan International Graduate Program, Academia Sinica, Taipei 11529, Taiwan, R.O.C.,Graduate Institute of Life Science, National Defense Medical Center, Taipei 11490, Taiwan, R.O.C.,Institute of Cellular and Organismic Biology, Sinica, Taipei 11529, Taiwan, R.O.C
| | - Hwei-Jan Hsu
- Molecular and Cell Biology, Taiwan International Graduate Program, Academia Sinica, Taipei 11529, Taiwan, R.O.C .,Graduate Institute of Life Science, National Defense Medical Center, Taipei 11490, Taiwan, R.O.C.,Institute of Cellular and Organismic Biology, Sinica, Taipei 11529, Taiwan, R.O.C.,Molecular and Biological Agricultural Sciences Program, Taiwan International Graduate Program, National Chung Hsing University and Academia Sinica, Taipei 11529, Taiwan, R.O.C.,Graduate Institute of Biotechnology, National Chung Hsing University, Taichung 40227, Taiwan, R.O.C
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29
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X chromosome and autosomal recombination are differentially sensitive to disruptions in SC maintenance. Proc Natl Acad Sci U S A 2019; 116:21641-21650. [PMID: 31570610 DOI: 10.1073/pnas.1910840116] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
The synaptonemal complex (SC) is a conserved meiotic structure that regulates the repair of double-strand breaks (DSBs) into crossovers or gene conversions. The removal of any central-region SC component, such as the Drosophila melanogaster transverse filament protein C(3)G, causes a complete loss of SC structure and crossovers. To better understand the role of the SC in meiosis, we used CRISPR/Cas9 to construct 3 in-frame deletions within the predicted coiled-coil region of the C(3)G protein. Since these 3 deletion mutations disrupt SC maintenance at different times during pachytene and exhibit distinct defects in key meiotic processes, they allow us to define the stages of pachytene when the SC is necessary for homolog pairing and recombination during pachytene. Our studies demonstrate that the X chromosome and the autosomes display substantially different defects in pairing and recombination when SC structure is disrupted, suggesting that the X chromosome is potentially regulated differently from the autosomes.
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30
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Hughes SE, Hemenway E, Guo F, Yi K, Yu Z, Hawley RS. The E3 ubiquitin ligase Sina regulates the assembly and disassembly of the synaptonemal complex in Drosophila females. PLoS Genet 2019; 15:e1008161. [PMID: 31107865 PMCID: PMC6544331 DOI: 10.1371/journal.pgen.1008161] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Revised: 05/31/2019] [Accepted: 04/26/2019] [Indexed: 01/04/2023] Open
Abstract
During early meiotic prophase, homologous chromosomes are connected along their entire lengths by a proteinaceous tripartite structure known as the synaptonemal complex (SC). Although the components that comprise the SC are predominantly studied in this canonical ribbon-like structure, they can also polymerize into repeated structures known as polycomplexes. We find that in Drosophila oocytes, the ability of SC components to assemble into canonical tripartite SC requires the E3 ubiquitin ligase Seven in absentia (Sina). In sina mutant oocytes, SC components assemble into large rod-like polycomplexes instead of proper SC. Thus, the wild-type Sina protein inhibits the polymerization of SC components, including those of the lateral element, into polycomplexes. These polycomplexes persist into meiotic stages when canonical SC has been disassembled, indicating that Sina also plays a role in controlling SC disassembly. Polycomplexes induced by loss-of-function sina mutations associate with centromeres, sites of double-strand breaks, and cohesins. Perhaps as a consequence of these associations, centromere clustering is defective and crossing over is reduced. These results suggest that while features of the polycomplexes can be recognized as SC by other components of the meiotic nucleus, polycomplexes nonetheless fail to execute core functions of canonical SC.
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Affiliation(s)
- Stacie E. Hughes
- Stowers Institute for Medical Research, Kansas City, Missouri, United States of America
| | - Elizabeth Hemenway
- Stowers Institute for Medical Research, Kansas City, Missouri, United States of America
| | - Fengli Guo
- Stowers Institute for Medical Research, Kansas City, Missouri, United States of America
| | - Kexi Yi
- Stowers Institute for Medical Research, Kansas City, Missouri, United States of America
| | - Zulin Yu
- Stowers Institute for Medical Research, Kansas City, Missouri, United States of America
| | - R. Scott Hawley
- Stowers Institute for Medical Research, Kansas City, Missouri, United States of America
- Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, Kansas, United States of America
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31
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Lake CM, Nielsen RJ, Bonner AM, Eche S, White-Brown S, McKim KS, Hawley RS. Narya, a RING finger domain-containing protein, is required for meiotic DNA double-strand break formation and crossover maturation in Drosophila melanogaster. PLoS Genet 2019; 15:e1007886. [PMID: 30615609 PMCID: PMC6336347 DOI: 10.1371/journal.pgen.1007886] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Revised: 01/17/2019] [Accepted: 12/10/2018] [Indexed: 11/19/2022] Open
Abstract
Meiotic recombination, which is necessary to ensure that homologous chromosomes segregate properly, begins with the induction of meiotic DNA double-strand breaks (DSBs) and ends with the repair of a subset of those breaks into crossovers. Here we investigate the roles of two paralogous genes, CG12200 and CG31053, which we have named Narya and Nenya, respectively, due to their relationship with a structurally similar protein named Vilya. We find that narya recently evolved from nenya by a gene duplication event, and we show that these two RING finger domain-containing proteins are functionally redundant with respect to a critical role in DSB formation. Narya colocalizes with Vilya foci, which are known to define recombination nodules, or sites of crossover formation. A separation-of-function allele of narya retains the capacity for DSB formation but cannot mature those DSBs into crossovers. We further provide data on the physical interaction of Narya, Nenya and Vilya, as assayed by the yeast two-hybrid system. Together these data support the view that all three RING finger domain-containing proteins function in the formation of meiotic DNA DSBs and in the process of crossing over. Errors in chromosome segregation during meiosis are the leading cause of miscarriages and can result in genetic abnormalities like Down syndrome or Turner syndrome. For chromosomes to segregate faithfully, they must recombine with their homolog during the early steps of meiosis. An essential component of the process of meiotic recombination is creating the lesions (double-strand breaks, DSBs) that are required to form a crossover with the homologous chromosome. Crossovers are required to ensure chromosomes segregate properly at the first meiotic division. In this study we have identified two genes, narya and nenya, that are essential in DSB formation. We found that narya arose from a duplication of nenya, and these two genes are functionally redundant. In addition to its role in DSB formation, narya also plays a role in processing DSBs into crossovers. Strengthening our knowledge about the mechanism by which Narya both creates DSBs and processes them into crossovers will lead to a better understanding of the process of meiotic chromosome segregation not only in flies but many other organisms, as these genes have homologs in yeast, worms, plants, mice and humans.
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Affiliation(s)
- Cathleen M. Lake
- Stowers Institute for Medical Research, Kansas City, Missouri, United States of America
| | - Rachel J. Nielsen
- Stowers Institute for Medical Research, Kansas City, Missouri, United States of America
| | - Amanda M. Bonner
- Stowers Institute for Medical Research, Kansas City, Missouri, United States of America
| | - Salam Eche
- Stowers Institute for Medical Research, Kansas City, Missouri, United States of America
| | - Sanese White-Brown
- Waksman Institute and Department of Genetics, Rutgers, the State University of New Jersey, Piscataway, New Jersey, United States of America
| | - Kim S. McKim
- Waksman Institute and Department of Genetics, Rutgers, the State University of New Jersey, Piscataway, New Jersey, United States of America
| | - R. Scott Hawley
- Stowers Institute for Medical Research, Kansas City, Missouri, United States of America
- Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, Kansas, United States of America
- * E-mail:
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32
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Female Meiosis: Synapsis, Recombination, and Segregation in Drosophila melanogaster. Genetics 2018; 208:875-908. [PMID: 29487146 PMCID: PMC5844340 DOI: 10.1534/genetics.117.300081] [Citation(s) in RCA: 75] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Accepted: 10/18/2017] [Indexed: 12/11/2022] Open
Abstract
A century of genetic studies of the meiotic process in Drosophila melanogaster females has been greatly augmented by both modern molecular biology and major advances in cytology. These approaches, and the findings they have allowed, are the subject of this review. Specifically, these efforts have revealed that meiotic pairing in Drosophila females is not an extension of somatic pairing, but rather occurs by a poorly understood process during premeiotic mitoses. This process of meiotic pairing requires the function of several components of the synaptonemal complex (SC). When fully assembled, the SC also plays a critical role in maintaining homolog synapsis and in facilitating the maturation of double-strand breaks (DSBs) into mature crossover (CO) events. Considerable progress has been made in elucidating not only the structure, function, and assembly of the SC, but also the proteins that facilitate the formation and repair of DSBs into both COs and noncrossovers (NCOs). The events that control the decision to mature a DSB as either a CO or an NCO, as well as determining which of the two CO pathways (class I or class II) might be employed, are also being characterized by genetic and genomic approaches. These advances allow a reconsideration of meiotic phenomena such as interference and the centromere effect, which were previously described only by genetic studies. In delineating the mechanisms by which the oocyte controls the number and position of COs, it becomes possible to understand the role of CO position in ensuring the proper orientation of homologs on the first meiotic spindle. Studies of bivalent orientation have occurred in the context of numerous investigations into the assembly, structure, and function of the first meiotic spindle. Additionally, studies have examined the mechanisms ensuring the segregation of chromosomes that have failed to undergo crossing over.
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33
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Li Y, Wang C, Cai W, Sengupta S, Zavortink M, Deng H, Girton J, Johansen J, Johansen KM. H2Av facilitates H3S10 phosphorylation but is not required for heat shock-induced chromatin decondensation or transcriptional elongation. Development 2017; 144:3232-3240. [PMID: 28807902 PMCID: PMC5612252 DOI: 10.1242/dev.151134] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Accepted: 07/19/2017] [Indexed: 01/30/2023]
Abstract
A model has been proposed in which JIL-1 kinase-mediated H3S10 and H2Av phosphorylation is required for transcriptional elongation and heat shock-induced chromatin decondensation. However, here we show that although H3S10 phosphorylation is indeed compromised in the H2Av null mutant, chromatin decondensation at heat shock loci is unaffected in the absence of JIL-1 as well as of H2Av and that there is no discernable decrease in the elongating form of RNA polymerase II in either mutant. Furthermore, mRNA for the major heat shock protein Hsp70 is transcribed at robust levels in both H2Av and JIL-1 null mutants. Using a different chromatin remodeling paradigm that is JIL-1 dependent, we provide evidence that ectopic tethering of JIL-1 and subsequent H3S10 phosphorylation recruits PARP-1 to the remodeling site independently of H2Av phosphorylation. These data strongly suggest that H2Av or H3S10 phosphorylation by JIL-1 is not required for chromatin decondensation or transcriptional elongation in Drosophila.
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Affiliation(s)
- Yeran Li
- Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, Iowa 50011, USA
| | - Chao Wang
- Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, Iowa 50011, USA
| | - Weili Cai
- Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, Iowa 50011, USA
| | - Saheli Sengupta
- Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, Iowa 50011, USA
| | - Michael Zavortink
- Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, Iowa 50011, USA
| | - Huai Deng
- Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, Iowa 50011, USA
| | - Jack Girton
- Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, Iowa 50011, USA
| | - Jørgen Johansen
- Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, Iowa 50011, USA
| | - Kristen M Johansen
- Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, Iowa 50011, USA
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34
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Cicconi A, Micheli E, Vernì F, Jackson A, Gradilla AC, Cipressa F, Raimondo D, Bosso G, Wakefield JG, Ciapponi L, Cenci G, Gatti M, Cacchione S, Raffa GD. The Drosophila telomere-capping protein Verrocchio binds single-stranded DNA and protects telomeres from DNA damage response. Nucleic Acids Res 2017; 45:3068-3085. [PMID: 27940556 PMCID: PMC5389638 DOI: 10.1093/nar/gkw1244] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Accepted: 11/28/2016] [Indexed: 12/17/2022] Open
Abstract
Drosophila telomeres are sequence-independent structures maintained by transposition to chromosome ends of three specialized retroelements rather than by telomerase activity. Fly telomeres are protected by the terminin complex that includes the HOAP, HipHop, Moi and Ver proteins. These are fast evolving, non-conserved proteins that localize and function exclusively at telomeres, protecting them from fusion events. We have previously suggested that terminin is the functional analogue of shelterin, the multi-protein complex that protects human telomeres. Here, we use electrophoretic mobility shift assay (EMSA) and atomic force microscopy (AFM) to show that Ver preferentially binds single-stranded DNA (ssDNA) with no sequence specificity. We also show that Moi and Ver form a complex in vivo. Although these two proteins are mutually dependent for their localization at telomeres, Moi neither binds ssDNA nor facilitates Ver binding to ssDNA. Consistent with these results, we found that Ver-depleted telomeres form RPA and γH2AX foci, like the human telomeres lacking the ssDNA-binding POT1 protein. Collectively, our findings suggest that Drosophila telomeres possess a ssDNA overhang like the other eukaryotes, and that the terminin complex is architecturally and functionally similar to shelterin.
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Affiliation(s)
- Alessandro Cicconi
- Dipartimento di Biologia e Biotecnologie 'C. Darwin', Sapienza, Università di Roma, 00185 Roma, Italy.,Istituto Pasteur Italia - Fondazione Cenci Bolognetti, 00185 Roma, Italy
| | - Emanuela Micheli
- Dipartimento di Biologia e Biotecnologie 'C. Darwin', Sapienza, Università di Roma, 00185 Roma, Italy.,Istituto Pasteur Italia - Fondazione Cenci Bolognetti, 00185 Roma, Italy
| | - Fiammetta Vernì
- Dipartimento di Biologia e Biotecnologie 'C. Darwin', Sapienza, Università di Roma, 00185 Roma, Italy
| | - Alison Jackson
- Biosciences, College of Life and Environmental Sciences, University of Exeter, Exeter EX4 4QD, UK
| | - Ana Citlali Gradilla
- Biosciences, College of Life and Environmental Sciences, University of Exeter, Exeter EX4 4QD, UK
| | - Francesca Cipressa
- Dipartimento di Biologia e Biotecnologie 'C. Darwin', Sapienza, Università di Roma, 00185 Roma, Italy.,Istituto Pasteur Italia - Fondazione Cenci Bolognetti, 00185 Roma, Italy.,Centro Fermi, Piazza del Viminale 1, 00184 Roma, Italy
| | - Domenico Raimondo
- Dipartimento di Medicina Molecolare, Sapienza, Università di Roma, 00185 Roma, Italy
| | - Giuseppe Bosso
- Dipartimento di Biologia e Biotecnologie 'C. Darwin', Sapienza, Università di Roma, 00185 Roma, Italy.,Istituto Pasteur Italia - Fondazione Cenci Bolognetti, 00185 Roma, Italy
| | - James G Wakefield
- Biosciences, College of Life and Environmental Sciences, University of Exeter, Exeter EX4 4QD, UK
| | - Laura Ciapponi
- Dipartimento di Biologia e Biotecnologie 'C. Darwin', Sapienza, Università di Roma, 00185 Roma, Italy
| | - Giovanni Cenci
- Dipartimento di Biologia e Biotecnologie 'C. Darwin', Sapienza, Università di Roma, 00185 Roma, Italy.,Istituto Pasteur Italia - Fondazione Cenci Bolognetti, 00185 Roma, Italy
| | - Maurizio Gatti
- Dipartimento di Biologia e Biotecnologie 'C. Darwin', Sapienza, Università di Roma, 00185 Roma, Italy.,Istituto di Biologia e Patologia Molecolari (IBPM) del CNR, 00185 Roma, Italy
| | - Stefano Cacchione
- Dipartimento di Biologia e Biotecnologie 'C. Darwin', Sapienza, Università di Roma, 00185 Roma, Italy.,Istituto Pasteur Italia - Fondazione Cenci Bolognetti, 00185 Roma, Italy
| | - Grazia Daniela Raffa
- Dipartimento di Biologia e Biotecnologie 'C. Darwin', Sapienza, Università di Roma, 00185 Roma, Italy.,Istituto Pasteur Italia - Fondazione Cenci Bolognetti, 00185 Roma, Italy
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35
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Bellendir SP, Rognstad DJ, Morris LP, Zapotoczny G, Walton WG, Redinbo MR, Ramsden DA, Sekelsky J, Erie DA. Substrate preference of Gen endonucleases highlights the importance of branched structures as DNA damage repair intermediates. Nucleic Acids Res 2017; 45:5333-5348. [PMID: 28369583 PMCID: PMC5435919 DOI: 10.1093/nar/gkx214] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Revised: 02/16/2017] [Accepted: 03/21/2017] [Indexed: 11/20/2022] Open
Abstract
Human GEN1 and yeast Yen1 are endonucleases with the ability to cleave Holliday junctions (HJs), which are proposed intermediates in recombination. In vivo, GEN1 and Yen1 function secondarily to Mus81, which has weak activity on intact HJs. We show that the genetic relationship is reversed in Drosophila, with Gen mutants having more severe defects than mus81 mutants. In vitro, DmGen, like HsGEN1, efficiently cleaves HJs, 5΄ flaps, splayed arms, and replication fork structures. We find that the cleavage rates for 5΄ flaps are significantly higher than those for HJs for both DmGen and HsGEN1, even in vast excess of enzyme over substrate. Kinetic studies suggest that the difference in cleavage rates results from a slow, rate-limiting conformational change prior to HJ cleavage: formation of a productive dimer on the HJ. Despite the stark difference in vivo that Drosophila uses Gen over Mus81 and humans use MUS81 over GEN1, we find the in vitro activities of DmGen and HsGEN1 to be strikingly similar. These findings suggest that simpler branched structures may be more important substrates for Gen orthologs in vivo, and highlight the utility of using the Drosophila model system to further understand these enzymes.
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Affiliation(s)
| | | | - Lydia P. Morris
- Lineberger Comprehensive Cancer Center, Chapel Hill, NC 27599, USA
| | | | | | - Matthew R. Redinbo
- Department of Chemistry, Chapel Hill, NC 27599, USA
- Integrative Program for Biological and Genome Sciences, Chapel Hill, NC 27599, USA
| | - Dale A. Ramsden
- Curriculum in Genetics and Molecular Biology, Chapel Hill, NC 27599, USA
- Lineberger Comprehensive Cancer Center, Chapel Hill, NC 27599, USA
- Department of Biochemistry and Biophysics, Chapel Hill, NC 27599, USA
| | - Jeff Sekelsky
- Curriculum in Genetics and Molecular Biology, Chapel Hill, NC 27599, USA
- Lineberger Comprehensive Cancer Center, Chapel Hill, NC 27599, USA
- Integrative Program for Biological and Genome Sciences, Chapel Hill, NC 27599, USA
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Dorothy A. Erie
- Department of Chemistry, Chapel Hill, NC 27599, USA
- Integrative Program for Biological and Genome Sciences, Chapel Hill, NC 27599, USA
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36
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Grigorian M, DeBruhl H, Lipsick JS. The role of variant histone H2AV in Drosophila melanogaster larval hematopoiesis. Development 2017; 144:1441-1449. [PMID: 28242611 DOI: 10.1242/dev.142729] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Accepted: 02/20/2017] [Indexed: 11/20/2022]
Abstract
Replication-independent histone variants can replace the canonical replication-dependent histones. Vertebrates have multiple H2A variant histones, including H2AZ and H2AX that are present in most eukaryotes. H2AZ regulates transcriptional activation as well as the maintenance of gene silencing, while H2AX is important in DNA damage repair. The fruit fly Drosophila melanogaster has only one histone H2A variant (H2AV), which is a chimera of H2AZ and H2AX. In this study we found that lack of H2AV led to the formation of black melanotic masses in Drosophila third instar larvae. The formation of these masses was found in conjunction with a loss of the majority of the primary lymph gland lobes. Interestingly, the cells of the posterior signaling center were preserved in these mutants. Reduction of H2AV levels by RNAi knockdown caused a milder phenotype that preserved the lymph gland structure but that included precocious differentiation of the prohemocytes located within the medullary zone and the secondary lobes of the lymph gland. Mutant rescue experiments suggest that the H2AZ-like rather than the H2AX-like function of H2AV is primarily required for normal hematopoiesis.
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Affiliation(s)
- Melina Grigorian
- Departments of Pathology, Genetics, and Biology, Stanford University, Stanford, CA 94305-5323, USA
| | - Heather DeBruhl
- Departments of Pathology, Genetics, and Biology, Stanford University, Stanford, CA 94305-5323, USA
| | - Joseph S Lipsick
- Departments of Pathology, Genetics, and Biology, Stanford University, Stanford, CA 94305-5323, USA
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37
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Sekelsky J. DNA Repair in Drosophila: Mutagens, Models, and Missing Genes. Genetics 2017; 205:471-490. [PMID: 28154196 PMCID: PMC5289830 DOI: 10.1534/genetics.116.186759] [Citation(s) in RCA: 80] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Accepted: 10/18/2016] [Indexed: 12/22/2022] Open
Abstract
The numerous processes that damage DNA are counterbalanced by a complex network of repair pathways that, collectively, can mend diverse types of damage. Insights into these pathways have come from studies in many different organisms, including Drosophila melanogaster Indeed, the first ideas about chromosome and gene repair grew out of Drosophila research on the properties of mutations produced by ionizing radiation and mustard gas. Numerous methods have been developed to take advantage of Drosophila genetic tools to elucidate repair processes in whole animals, organs, tissues, and cells. These studies have led to the discovery of key DNA repair pathways, including synthesis-dependent strand annealing, and DNA polymerase theta-mediated end joining. Drosophila appear to utilize other major repair pathways as well, such as base excision repair, nucleotide excision repair, mismatch repair, and interstrand crosslink repair. In a surprising number of cases, however, DNA repair genes whose products play important roles in these pathways in other organisms are missing from the Drosophila genome, raising interesting questions for continued investigations.
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Affiliation(s)
- Jeff Sekelsky
- Department of Biology and Integrative Program for Biological and Genome Sciences, University of North Carolina at Chapel Hill, North Carolina 27599
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38
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Khan C, Muliyil S, Ayyub C, Rao BJ. DNA damage signalling in D. melanogaster requires non-apoptotic function of initiator caspase Dronc. J Cell Sci 2017; 130:2984-2995. [DOI: 10.1242/jcs.200782] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Accepted: 07/24/2017] [Indexed: 01/31/2023] Open
Abstract
ϒH2Av response constitutes an important signalling event in DNA damage sensing ensuring effective repair by recruiting DNA repair machinery. In contrast, the occurrence of ϒH2Av response has also been reported in dying cells where it is shown to require activation of CAD (caspase activated DNase). Moreover, caspases are known to be required downstream of DNA damage for cell death execution. We show, for the first time, that initiator caspase Dronc, independent of executioner caspases, acts as an upstream regulator of DNA Damage Response (DDR) by facilitating ϒH2Av signalling perhaps involving non-apoptotic function. Such ϒH2Av response is mediated by ATM rather than ATR, suggesting that Dronc function is required upstream of ATM. In contrast, ϒH2Av appearance during cell death requires effector caspase and is associated with fragmented nuclei. Our study uncovers a novel function of Dronc in response to DNA damage aimed at promoting DDR via ϒH2Av signalling in intact nuclei. We propose that Dronc plays a dual role that can either initiate DDR or apoptosis depending upon the level and the required threshold of its activation in damaged cells.
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Affiliation(s)
- Chaitali Khan
- Department of Biological Sciences, Tata Institute of Fundamental Research, Colaba, Mumbai 400005, India
| | - Sonia Muliyil
- Current affiliation: Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK
| | - Champakali Ayyub
- Department of Biological Sciences, Tata Institute of Fundamental Research, Colaba, Mumbai 400005, India
| | - B. J. Rao
- Department of Biological Sciences, Tata Institute of Fundamental Research, Colaba, Mumbai 400005, India
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39
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Sengupta S, Rath U, Yao C, Zavortink M, Wang C, Girton J, Johansen KM, Johansen J. Digitor/dASCIZ Has Multiple Roles in Drosophila Development. PLoS One 2016; 11:e0166829. [PMID: 27861562 PMCID: PMC5115829 DOI: 10.1371/journal.pone.0166829] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Accepted: 11/05/2016] [Indexed: 12/02/2022] Open
Abstract
In this study we provide evidence that the spindle matrix protein Skeletor in Drosophila interacts with the human ASCIZ (also known as ATMIN and ZNF822) ortholog, Digitor/dASCIZ. This interaction was first detected in a yeast two-hybrid screen and subsequently confirmed by pull-down assays. We also confirm a previously documented function of Digitor/dASCIZ as a regulator of Dynein light chain/Cut up expression. Using transgenic expression of a mCitrine-labeled Digitor construct, we show that Digitor/dASCIZ is a nuclear protein that is localized to interband and developmental puff chromosomal regions during interphase but redistributes to the spindle region during mitosis. Its mitotic localization and physical interaction with Skeletor suggest the possibility that Digitor/dASCIZ plays a direct role in mitotic progression as a member of the spindle matrix complex. Furthermore, we have characterized a P-element insertion that is likely to be a true null Digitor/dASCIZ allele resulting in complete pupal lethality when homozygous, indicating that Digitor/dASCIZ is an essential gene. Phenotypic analysis of the mutant provided evidence that Digitor/dASCIZ plays critical roles in regulation of metamorphosis and organogenesis as well as in the DNA damage response. In the Digitor/dASCIZ null mutant larvae there was greatly elevated levels of γH2Av, indicating accumulation of DNA double-strand breaks. Furthermore, reduced levels of Digitor/dASCIZ decreased the resistance to paraquat-induced oxidative stress resulting in increased mortality in a stress test paradigm. We show that an early developmental consequence of the absence of Digitor/dASCIZ is reduced third instar larval brain size although overall larval development appeared otherwise normal at this stage. While Digitor/dASCIZ mutant larvae initiate pupation, all mutant pupae failed to eclose and exhibited various defects in metamorphosis such as impaired differentiation, incomplete disc eversion, and faulty apoptosis. Altogether we provide evidence that Digitor/dASCIZ is a nuclear protein that performs multiple roles in Drosophila larval and pupal development.
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Affiliation(s)
- Saheli Sengupta
- Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, Iowa, United States of America
| | - Uttama Rath
- Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, Iowa, United States of America
| | - Changfu Yao
- Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, Iowa, United States of America
| | - Michael Zavortink
- Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, Iowa, United States of America
| | - Chao Wang
- Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, Iowa, United States of America
| | - Jack Girton
- Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, Iowa, United States of America
| | - Kristen M. Johansen
- Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, Iowa, United States of America
- * E-mail: (JJ); (KMJ)
| | - Jørgen Johansen
- Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, Iowa, United States of America
- * E-mail: (JJ); (KMJ)
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40
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Contribution of sleep to the repair of neuronal DNA double-strand breaks: evidence from flies and mice. Sci Rep 2016; 6:36804. [PMID: 27830758 PMCID: PMC5103291 DOI: 10.1038/srep36804] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Accepted: 10/21/2016] [Indexed: 12/22/2022] Open
Abstract
Exploration of a novel environment leads to neuronal DNA double-strand breaks (DSBs). These DSBs are generated by type 2 topoisomerase to relieve topological constrains that limit transcription of plasticity-related immediate early genes. If not promptly repaired, however, DSBs may lead to cell death. Since the induction of plasticity-related genes is higher in wake than in sleep, we asked whether it is specifically wake associated with synaptic plasticity that leads to DSBs, and whether sleep provides any selective advantage over wake in their repair. In flies and mice, we find that enriched wake, more than simply time spent awake, induces DSBs, and their repair in mice is delayed or prevented by subsequent wake. In both species the repair of irradiation-induced neuronal DSBs is also quicker during sleep, and mouse genes mediating the response to DNA damage are upregulated in sleep. Thus, sleep facilitates the repair of neuronal DSBs.
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41
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Drosophila Wnt and STAT Define Apoptosis-Resistant Epithelial Cells for Tissue Regeneration after Irradiation. PLoS Biol 2016; 14:e1002536. [PMID: 27584613 PMCID: PMC5008734 DOI: 10.1371/journal.pbio.1002536] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2015] [Accepted: 07/27/2016] [Indexed: 01/05/2023] Open
Abstract
Drosophila melanogaster larvae irradiated with doses of ionizing radiation (IR) that kill about half of the cells in larval imaginal discs still develop into viable adults. How surviving cells compensate for IR-induced cell death to produce organs of normal size and appearance remains an active area of investigation. We have identified a subpopulation of cells within the continuous epithelium of Drosophila larval wing discs that shows intrinsic resistance to IR- and drug-induced apoptosis. These cells reside in domains of high Wingless (Wg, Drosophila Wnt-1) and STAT92E (sole Drosophila signal transducer and activator of transcription [STAT] homolog) activity and would normally form the hinge in the adult fly. Resistance to IR-induced apoptosis requires STAT and Wg and is mediated by transcriptional repression of the pro-apoptotic gene reaper. Lineage tracing experiments show that, following irradiation, apoptosis-resistant cells lose their identity and translocate to areas of the wing disc that suffered abundant cell death. Our findings provide a new paradigm for regeneration in which it is unnecessary to invoke special damage-resistant cell types such as stem cells. Instead, differences in gene expression within a population of genetically identical epithelial cells can create a subpopulation with greater resistance, which, following damage, survive, alter their fate, and help regenerate the tissue. After widespread radiation damage in the developing fruit fly, organs are formed by regeneration from an apoptosis-resistant subpopulation of cells marked by high levels of Wingless and STAT. Like other insects, Drosophila larvae have epithelial structures called imaginal discs that will give rise to most of the external adult structures, such as wings, limbs, or antennae; these organ precursors are formed by a single layer of epithelial cells that folds into a sac. Imaginal discs manage to regenerate efficiently if they are damaged. Previous studies have shown that dying cells produce signals that activate cell proliferation of some of their neighbors, allowing them to regenerate the disc and thereby enabling the flies to develop into normal adults. But a dedicated stem cell population that contributes to regeneration, if any, remained to be identified. Here, we report the identification of a subpopulation of cells in wing imaginal discs that is more resistant to the cytotoxic effects of radiation and drugs. We show that the protection of these cells depends on two signaling pathways—Wingless and STAT—that are conserved in humans. Following tissue damage by radiation, we observe that protected cells change their location and their identity, allowing them to fill in for dead cells in other parts of the same organ precursor. In sum, this work identified ways in which a subset of cells in Drosophila imaginal wing discs is preserved through radiation exposure so that they could participate in regeneration of the organ after radiation damage. We also discuss how this situation may resemble human cancers.
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42
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Tran M, Tsarouhas V, Kegel A. Early development of Drosophila embryos requires Smc5/6 function during oogenesis. Biol Open 2016; 5:928-41. [PMID: 27288507 PMCID: PMC4958276 DOI: 10.1242/bio.019000] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Mutations in structural maintenance of chromosomes (Smc) proteins are frequently associated with chromosomal abnormalities commonly observed in developmental disorders. However, the role of Smc proteins in development still remains elusive. To investigate Smc5/6 function during early embryogenesis we examined smc5 and smc6 mutants of the fruit fly Drosophila melanogaster using a combination of reverse genetics and microscopy approaches. Smc5/6 exhibited a maternally contributed function in maintaining chromosome stability during early embryo development, which manifested as female subfertility in its absence. Loss of Smc5/6 caused an arrest and a considerable delay in embryo development accompanied by fragmented nuclei and increased anaphase-bridge formation, respectively. Surprisingly, early embryonic arrest was attributable to the absence of Smc5/6 during oogenesis, which resulted in insufficient repair of pre-meiotic and meiotic DNA double-strand breaks. Thus, our findings contribute to the understanding of Smc proteins in higher eukaryotic development by highlighting a maternal function in chromosome maintenance and a link between oogenesis and early embryogenesis. Summary: Early emerging problems during oogenesis, such as DNA double-strand breaks, can affect chromosome duplication and segregation in embryogenesis in Drosophila. Moreover, environmental cues including temperature are important for proper oogenesis.
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Affiliation(s)
- Martin Tran
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm S-17177, Sweden
| | - Vasilios Tsarouhas
- Department of Molecular Bioscience, The Wenner-Gren Institute, Stockholm University, Stockholm S-10691, Sweden
| | - Andreas Kegel
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm S-17177, Sweden
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43
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Bretscher HS, Fox DT. Proliferation of Double-Strand Break-Resistant Polyploid Cells Requires Drosophila FANCD2. Dev Cell 2016; 37:444-57. [PMID: 27270041 PMCID: PMC4901310 DOI: 10.1016/j.devcel.2016.05.004] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Revised: 02/22/2016] [Accepted: 05/02/2016] [Indexed: 12/17/2022]
Abstract
Conserved DNA-damage responses (DDRs) sense genome damage and prevent mitosis of broken chromosomes. How cells lacking DDRs cope with broken chromosomes during mitosis is poorly understood. DDRs are frequently inactivated in cells with extra genomes (polyploidy), suggesting that study of polyploidy can reveal how cells with impaired DDRs/genome damage continue dividing. Here, we show that continued division and normal organ development occurs in polyploid, DDR-impaired Drosophila papillar cells. As papillar cells become polyploid, they naturally accumulate broken acentric chromosomes but do not apoptose/arrest the cell cycle. To survive mitosis with acentric chromosomes, papillar cells require Fanconi anemia proteins FANCD2 and FANCI, as well as Blm helicase, but not canonical DDR signaling. FANCD2 acts independently of previous S phases to promote alignment and segregation of acentric DNA produced by double-strand breaks, thus avoiding micronuclei and organ malformation. Because polyploidy and impaired DDRs can promote cancer, our findings provide insight into disease-relevant DNA-damage tolerance mechanisms.
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Affiliation(s)
- Heidi S Bretscher
- Department of Pharmacology & Cancer Biology, Duke University School of Medicine, DUMC Box 3813, Durham, NC 27710, USA
| | - Donald T Fox
- Department of Pharmacology & Cancer Biology, Duke University School of Medicine, DUMC Box 3813, Durham, NC 27710, USA.
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44
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Li Y, Armstrong RL, Duronio RJ, MacAlpine DM. Methylation of histone H4 lysine 20 by PR-Set7 ensures the integrity of late replicating sequence domains in Drosophila. Nucleic Acids Res 2016; 44:7204-18. [PMID: 27131378 PMCID: PMC5009726 DOI: 10.1093/nar/gkw333] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Accepted: 04/15/2016] [Indexed: 12/16/2022] Open
Abstract
The methylation state of lysine 20 on histone H4 (H4K20) has been linked to chromatin compaction, transcription, DNA repair and DNA replication. Monomethylation of H4K20 (H4K20me1) is mediated by the cell cycle-regulated histone methyltransferase PR-Set7. PR-Set7 depletion in mammalian cells results in defective S phase progression and the accumulation of DNA damage, which has been partially attributed to defects in origin selection and activation. However, these studies were limited to only a handful of mammalian origins, and it remains unclear how PR-Set7 and H4K20 methylation impact the replication program on a genomic scale. We employed genetic, cytological, and genomic approaches to better understand the role of PR-Set7 and H4K20 methylation in regulating DNA replication and genome stability in Drosophila cells. We find that deregulation of H4K20 methylation had no impact on origin activation throughout the genome. Instead, depletion of PR-Set7 and loss of H4K20me1 results in the accumulation of DNA damage and an ATR-dependent cell cycle arrest. Coincident with the ATR-dependent cell cycle arrest, we find increased DNA damage that is specifically limited to late replicating regions of the Drosophila genome, suggesting that PR-Set7-mediated monomethylation of H4K20 is critical for maintaining the genomic integrity of late replicating domains.
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Affiliation(s)
- Yulong Li
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC 27710, USA
| | - Robin L Armstrong
- Curriculum in Genetics and Molecular Biology, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Robert J Duronio
- Curriculum in Genetics and Molecular Biology, University of North Carolina, Chapel Hill, NC 27599, USA Departments of Biology and Genetics, Lineberger Comprehensive Cancer Center, and Integrative Program for Biological and Genome Sciences, University of North Carolina, Chapel Hill, NC 27599, USA
| | - David M MacAlpine
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC 27710, USA
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45
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Qi S, Calvi BR. Different cell cycle modifications repress apoptosis at different steps independent of developmental signaling in Drosophila. Mol Biol Cell 2016; 27:1885-97. [PMID: 27075174 PMCID: PMC4907722 DOI: 10.1091/mbc.e16-03-0139] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Accepted: 04/08/2016] [Indexed: 11/11/2022] Open
Abstract
Genetic manipulations of the cell cycle repress apoptosis independent of developmental signaling. The findings have broader relevance to understanding the coordination of cell proliferation and apoptosis in development and disease. Apoptotic cell death is important for the normal development of a variety of organisms. Apoptosis is also a response to DNA damage and an important barrier to oncogenesis. The apoptotic response to DNA damage is dampened in specific cell types during development. Developmental signaling pathways can repress apoptosis, and reduced cell proliferation also correlates with a lower apoptotic response. However, because developmental signaling regulates both cell proliferation and apoptosis, the relative contribution of cell division to the apoptotic response has been hard to discern in vivo. Here we use Drosophila oogenesis as an in vivo model system to determine the extent to which cell proliferation influences the apoptotic response to DNA damage. We find that different types of cell cycle modifications are sufficient to repress the apoptotic response to ionizing radiation independent of developmental signaling. The step(s) at which the apoptosis pathway was repressed depended on the type of cell cycle modification—either upstream or downstream of expression of the p53-regulated proapoptotic genes. Our findings have important implications for understanding the coordination of cell proliferation with the apoptotic response in development and disease, including cancer and the tissue-specific responses to radiation therapy.
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Affiliation(s)
- Suozhi Qi
- Department of Biology, Indiana University, Bloomington, IN 47405
| | - Brian R Calvi
- Department of Biology, Indiana University, Bloomington, IN 47405
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46
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The Deadbeat Paternal Effect of Uncapped Sperm Telomeres on Cell Cycle Progression and Chromosome Behavior in Drosophila melanogaster. Genetics 2016; 203:799-816. [PMID: 27029731 DOI: 10.1534/genetics.115.182436] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Accepted: 03/27/2016] [Indexed: 12/24/2022] Open
Abstract
Telomere-capping complexes (TCCs) protect the ends of linear chromosomes from illegitimate repair and end-to-end fusions and are required for genome stability. The identity and assembly of TCC components have been extensively studied, but whether TCCs require active maintenance in nondividing cells remains an open question. Here we show that Drosophila melanogaster requires Deadbeat (Ddbt), a sperm nuclear basic protein (SNBP) that is recruited to the telomere by the TCC and is required for TCC maintenance during genome-wide chromatin remodeling, which transforms spermatids to mature sperm. Ddbt-deficient males produce sperm lacking TCCs. Their offspring delay the initiation of anaphase as early as cycle 1 but progress through the first two cycles. Persistence of uncapped paternal chromosomes induces arrest at or around cycle 3. This early arrest can be rescued by selective elimination of paternal chromosomes and production of gynogenetic haploid or haploid mosaics. Progression past cycle 3 can also occur if embryos have reduced levels of the maternally provided checkpoint kinase Chk2. The findings provide insights into how telomere integrity affects the regulation of the earliest embryonic cell cycles. They also suggest that other SNBPs, including those in humans, may have analogous roles and manifest as paternal effects on embryo quality.
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47
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Whole-Genome Analysis of Individual Meiotic Events in Drosophila melanogaster Reveals That Noncrossover Gene Conversions Are Insensitive to Interference and the Centromere Effect. Genetics 2016; 203:159-71. [PMID: 26944917 PMCID: PMC4858771 DOI: 10.1534/genetics.115.186486] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Accepted: 02/29/2016] [Indexed: 11/18/2022] Open
Abstract
A century of genetic analysis has revealed that multiple mechanisms control the distribution of meiotic crossover events. In Drosophila melanogaster, two significant positional controls are interference and the strongly polar centromere effect. Here, we assess the factors controlling the distribution of crossovers (COs) and noncrossover gene conversions (NCOs) along all five major chromosome arms in 196 single meiotic divisions to generate a more detailed understanding of these controls on a genome-wide scale. Analyzing the outcomes of single meiotic events allows us to distinguish among different classes of meiotic recombination. In so doing, we identified 291 NCOs spread uniformly among the five major chromosome arms and 541 COs (including 52 double crossovers and one triple crossover). We find that unlike COs, NCOs are insensitive to the centromere effect and do not demonstrate interference. Although the positions of COs appear to be determined predominately by the long-range influences of interference and the centromere effect, each chromosome may display a different pattern of sensitivity to interference, suggesting that interference may not be a uniform global property. In addition, unbiased sequencing of a large number of individuals allows us to describe the formation of de novo copy number variants, the majority of which appear to be mediated by unequal crossing over between transposable elements. This work has multiple implications for our understanding of how meiotic recombination is regulated to ensure proper chromosome segregation and maintain genome stability.
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Lake CM, Nielsen RJ, Guo F, Unruh JR, Slaughter BD, Hawley RS. Vilya, a component of the recombination nodule, is required for meiotic double-strand break formation in Drosophila. eLife 2015; 4:e08287. [PMID: 26452093 PMCID: PMC4703084 DOI: 10.7554/elife.08287] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2015] [Accepted: 10/08/2015] [Indexed: 01/25/2023] Open
Abstract
Meiotic recombination begins with the induction of programmed double-strand breaks (DSBs). In most organisms only a fraction of DSBs become crossovers. Here we report a novel meiotic gene, vilya, which encodes a protein with homology to Zip3-like proteins shown to determine DSB fate in other organisms. Vilya is required for meiotic DSB formation, perhaps as a consequence of its interaction with the DSB accessory protein Mei-P22, and localizes to those DSB sites that will mature into crossovers. In early pachytene Vilya localizes along the central region of the synaptonemal complex and to discrete foci. The accumulation of Vilya at foci is dependent on DSB formation. Immuno-electron microscopy demonstrates that Vilya is a component of recombination nodules, which mark the sites of crossover formation. Thus Vilya links the mechanism of DSB formation to either the selection of those DSBs that will become crossovers or to the actual process of crossing over.
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Affiliation(s)
- Cathleen M Lake
- Stowers Institute for Medical Research, Kansas City, United States
| | - Rachel J Nielsen
- Stowers Institute for Medical Research, Kansas City, United States
| | - Fengli Guo
- Stowers Institute for Medical Research, Kansas City, United States
| | - Jay R Unruh
- Stowers Institute for Medical Research, Kansas City, United States
| | | | - R Scott Hawley
- Stowers Institute for Medical Research, Kansas City, United States.,Department of Molecular and Integrative Physiology, Kansas University Medical Center, Kansas City, United States
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Alexander JL, Barrasa MI, Orr-Weaver TL. Replication fork progression during re-replication requires the DNA damage checkpoint and double-strand break repair. Curr Biol 2015; 25:1654-60. [PMID: 26051888 DOI: 10.1016/j.cub.2015.04.058] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2014] [Revised: 03/02/2015] [Accepted: 04/24/2015] [Indexed: 11/19/2022]
Abstract
Replication origins are under tight regulation to ensure activation occurs only once per cell cycle [1, 2]. Origin re-firing in a single S phase leads to the generation of DNA double-strand breaks (DSBs) and activation of the DNA damage checkpoint [2-7]. If the checkpoint is blocked, cells enter mitosis with partially re-replicated DNA that generates chromosome breaks and fusions [5]. These types of chromosomal aberrations are common in numerous human cancers, suggesting that re-replication events contribute to cancer progression. It was proposed that fork instability and DSBs formed during re-replication are the result of head-to-tail collisions and collapse of adjacent replication forks [3]. However, previously studied systems lack the resolution to determine whether the observed DSBs are generated at sites of fork collisions. Here, we utilize the Drosophila ovarian follicle cells, which exhibit re-replication under precise developmental control [8-10], to model the consequences of re-replication at actively elongating forks. Re-replication occurs from specific replication origins at six genomic loci, termed Drosophila amplicons in follicle cells (DAFCs) [10-12]. Precise developmental timing of DAFC origin firing permits identification of forks at defined points after origin initiation [13, 14]. Here, we show that DAFC re-replication causes fork instability and generates DSBs at sites of potential fork collisions. Immunofluorescence and ChIP-seq demonstrate the DSB marker γH2Av is enriched at elongating forks. Fork progression is reduced in the absence of DNA damage checkpoint components and nonhomologous end-joining (NHEJ), but not homologous recombination. NHEJ appears to continually repair forks during re-replication to maintain elongation.
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Affiliation(s)
- Jessica L Alexander
- Whitehead Institute for Biomedical Research, 9 Cambridge Center, Cambridge, MA 02142, USA; Department of Biology, Massachusetts Institute of Technology, 77 Massachusetts Avenue, 68-132, Cambridge, MA 02139, USA
| | - M Inmaculada Barrasa
- Whitehead Institute for Biomedical Research, 9 Cambridge Center, Cambridge, MA 02142, USA
| | - Terry L Orr-Weaver
- Whitehead Institute for Biomedical Research, 9 Cambridge Center, Cambridge, MA 02142, USA; Department of Biology, Massachusetts Institute of Technology, 77 Massachusetts Avenue, 68-132, Cambridge, MA 02139, USA.
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Nakamura M, Ohsawa S, Igaki T. Mitochondrial defects trigger proliferation of neighbouring cells via a senescence-associated secretory phenotype in Drosophila. Nat Commun 2014; 5:5264. [DOI: 10.1038/ncomms6264] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2014] [Accepted: 09/12/2014] [Indexed: 12/27/2022] Open
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