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Ricolo D, Casanova J, Giannios P. Drosophila and human Headcase define a new family of ribonucleotide granule proteins required for stress response. SCIENCE ADVANCES 2025; 11:eads2086. [PMID: 40153502 PMCID: PMC11952099 DOI: 10.1126/sciadv.ads2086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/05/2024] [Accepted: 02/25/2025] [Indexed: 03/30/2025]
Abstract
Cells have means to adapt to environmental stresses such as temperature fluctuations, toxins, or nutrient availability. Stress responses, being dynamic, extend beyond transcriptional control and encompass post-transcriptional mechanisms allowing for rapid changes in protein synthesis. Previous research has established headcase as a fundamental gene for stress responses and survival of the Drosophila adult progenitor cells (APCs). However, the molecular role of Headcase has remained elusive. Here, we identify Headcase as a component of ribonucleoprotein (RNP) granules. We also show that, Headcase is required for proper RNP granule formation and remodeling upon stress and is crucial for translation control. Likewise, the human Headcase homolog (HECA) is identified as a component of RNP granules and has similar roles in translational regulation and stress protection. Thus, Headcase proteins define a new family contributing to specific roles among the RNP heterogeneous network.
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Affiliation(s)
- Delia Ricolo
- Institut de Biologia Molecular de Barcelona (CSIC), Baldiri Reixac 4, 08028 Barcelona, Catalonia, Spain
- Institut de Recerca Biomèdica de Barcelona, (IRB Barcelona), The Barcelona Institute of Science and Technology (BIST), Baldiri Reixac 10, 08028 Barcelona, Catalonia, Spain
| | - Jordi Casanova
- Institut de Biologia Molecular de Barcelona (CSIC), Baldiri Reixac 4, 08028 Barcelona, Catalonia, Spain
- Institut de Recerca Biomèdica de Barcelona, (IRB Barcelona), The Barcelona Institute of Science and Technology (BIST), Baldiri Reixac 10, 08028 Barcelona, Catalonia, Spain
| | - Panagiotis Giannios
- Institut de Biologia Molecular de Barcelona (CSIC), Baldiri Reixac 4, 08028 Barcelona, Catalonia, Spain
- Institut de Recerca Biomèdica de Barcelona, (IRB Barcelona), The Barcelona Institute of Science and Technology (BIST), Baldiri Reixac 10, 08028 Barcelona, Catalonia, Spain
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2
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Lei L, Ikami K, Diaz Miranda EA, Ko S, Wilson F, Abbott H, Pandoy R, Jin S. The mouse Balbiani body regulates primary oocyte quiescence via RNA storage. Commun Biol 2024; 7:1247. [PMID: 39358443 PMCID: PMC11447053 DOI: 10.1038/s42003-024-06900-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Accepted: 09/16/2024] [Indexed: 10/04/2024] Open
Abstract
In mammalian females, the transition from dormancy in primordial follicles to follicular development is critical for maintaining ovarian function and reproductive longevity. In mice, the quiescent primary oocyte of the primordial follicle contains a Balbiani body (B-body), an organelle aggregate comprised of a spherical structure of Golgi complexes. Here we show that the structure of the B-body is maintained by microtubules and actin. The B-body stores mRNA-capping enzyme and 597 mRNAs associated with mRNA-decapping enzyme 1 A (DCP1A). Gene ontology analysis results indicate that proteins encoded by these mRNAs function in enzyme binding, cellular component organization and packing of telomere ends. Pharmacological depolymerization of microtubules or actin led to B-body disassociation and nascent protein synthesis around the dissociated B-bodies within three hours. An increased number of activated developing follicles were observed in ovaries with prolonged culture and the in vivo mouse model. Our results indicate that the mouse B-body is involved in the activation of dormant primordial follicles likely via translation of the B-body-associated RNAs in primary oocytes.
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Affiliation(s)
- Lei Lei
- Department of Obstetrics, Gynecology and Women's Health, University of Missouri School of Medicine, Columbia, MO, 65211, USA.
- Division of Biological Sciences, College of Arts and Sciences, University of Missouri, Columbia, MO, 65211, USA.
| | - Kanako Ikami
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI, 48109, USA
- Buck Institute for Research on Aging, Novato, California, 94949, USA
- Department of Microbiology & Molecular Genetics, University of California, Davis, Davis, California, 95616, USA
| | - Edgar Andres Diaz Miranda
- Department of Obstetrics, Gynecology and Women's Health, University of Missouri School of Medicine, Columbia, MO, 65211, USA
| | - Sooah Ko
- Department of Obstetrics, Gynecology and Women's Health, University of Missouri School of Medicine, Columbia, MO, 65211, USA
| | - Faith Wilson
- Department of Obstetrics, Gynecology and Women's Health, University of Missouri School of Medicine, Columbia, MO, 65211, USA
- Division of Biological Sciences, College of Arts and Sciences, University of Missouri, Columbia, MO, 65211, USA
| | - Haley Abbott
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI, 48109, USA
| | - Ronald Pandoy
- Buck Institute for Research on Aging, Novato, California, 94949, USA
| | - Shiying Jin
- Department of Obstetrics, Gynecology and Women's Health, University of Missouri School of Medicine, Columbia, MO, 65211, USA
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3
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Cassani M, Seydoux G. P-body-like condensates in the germline. Semin Cell Dev Biol 2024; 157:24-32. [PMID: 37407370 PMCID: PMC10761593 DOI: 10.1016/j.semcdb.2023.06.010] [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: 05/08/2023] [Revised: 06/20/2023] [Accepted: 06/27/2023] [Indexed: 07/07/2023]
Abstract
P-bodies are cytoplasmic condensates that accumulate low-translation mRNAs for temporary storage before translation or degradation. P-bodies have been best characterized in yeast and mammalian tissue culture cells. We describe here related condensates in the germline of animal models. Germline P-bodies have been reported at all stages of germline development from primordial germ cells to gametes. The activity of the universal germ cell fate regulator, Nanos, is linked to the mRNA decay function of P-bodies, and spatially-regulated condensation of P-body like condensates in embryos is required to localize mRNA regulators to primordial germ cells. In most cases, however, it is not known whether P-bodies represent functional compartments or non-functional condensation by-products that arise when ribonucleoprotein complexes saturate the cytoplasm. We speculate that the ubiquity of P-body-like condensates in germ cells reflects the strong reliance of the germline on cytoplasmic, rather than nuclear, mechanisms of gene regulation.
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Affiliation(s)
- Madeline Cassani
- HHMI and Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Geraldine Seydoux
- HHMI and Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
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4
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Du Z, Shi K, Brown JS, He T, Wu WS, Zhang Y, Lee HC, Zhang D. Condensate cooperativity underlies transgenerational gene silencing. Cell Rep 2023; 42:112859. [PMID: 37505984 PMCID: PMC10540246 DOI: 10.1016/j.celrep.2023.112859] [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: 02/07/2023] [Revised: 05/26/2023] [Accepted: 07/10/2023] [Indexed: 07/30/2023] Open
Abstract
Biomolecular condensates have been shown to interact in vivo, yet it is unclear whether these interactions are functionally meaningful. Here, we demonstrate that cooperativity between two distinct condensates-germ granules and P bodies-is required for transgenerational gene silencing in C. elegans. We find that P bodies form a coating around perinuclear germ granules and that P body components CGH-1/DDX6 and CAR-1/LSM14 are required for germ granules to organize into sub-compartments and concentrate small RNA silencing factors. Functionally, while the P body mutant cgh-1 is competent to initially trigger gene silencing, it is unable to propagate the silencing to subsequent generations. Mechanistically, we trace this loss of transgenerational silencing to defects in amplifying secondary small RNAs and the stability of WAGO-4 Argonaute, both known carriers of gene silencing memories. Together, these data reveal that cooperation between condensates results in an emergent capability of germ cells to establish heritable memory.
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Affiliation(s)
- Zhenzhen Du
- Department of Biochemistry and Molecular Biology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430032, China
| | - Kun Shi
- Department of Biochemistry and Molecular Biology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430032, China
| | - Jordan S Brown
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, IL 60637, USA
| | - Tao He
- Department of Biochemistry and Molecular Biology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430032, China
| | - Wei-Sheng Wu
- Department of Electrical Engineering, National Cheng Kung University, Tainan 701, Taiwan
| | - Ying Zhang
- Department of Biochemistry and Molecular Biology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430032, China.
| | - Heng-Chi Lee
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, IL 60637, USA.
| | - Donglei Zhang
- Department of Biochemistry and Molecular Biology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430032, China; Cell Architecture Research Institute, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China.
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5
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Wippich F, Vaishali, Hennrich ML, Ephrussi A. Nutritional stress-induced regulation of microtubule organization and mRNP transport by HDAC1 controlled α-tubulin acetylation. Commun Biol 2023; 6:776. [PMID: 37491525 PMCID: PMC10368696 DOI: 10.1038/s42003-023-05138-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Accepted: 07/12/2023] [Indexed: 07/27/2023] Open
Abstract
In response to nutritional stress, microtubules in cells of the Drosophila female germline are depleted from the cytoplasm and accumulate cortically. This triggers aggregation of mRNPs into large processing bodies (P-bodies) and oogenesis arrest. Here, we show that hyperacetylation of α-tubulin at lysine 40 (K40) alters microtubule dynamics and P-body formation. We found that depletion of histone deacetylase 1 (HDAC1) by RNAi phenocopies the nutritional stress response, causing α-tubulin hyperacetylation and accumulation of maternally deposited mRNPs in P-bodies. Through in vitro and in vivo studies, we identify HDAC1 as a direct regulator of α-tubulin K40 acetylation status. In well-fed flies, HDAC1 maintains low levels of α-tubulin acetylation, enabling the microtubule dynamics required for mRNP transport. Using quantitative phosphoproteomics we identify nutritional stress-induced changes in protein phosphorylation that act upstream of α-tubulin acetylation, including phosphorylation of HDAC1 at S391, which reduces its ability to deacetylate α-tubulin. These results reveal that Drosophila HDAC1 senses and relays the nutritional status, which regulates germline development through modulation of cytoskeleton dynamics.
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Affiliation(s)
- Frank Wippich
- Developmental Biology Unit, European Molecular Biology Laboratory (EMBL) Heidelberg, Meyerhofstrasse 1, Heidelberg, 69117, Germany
- Cellzome GmbH, GlaxoSmithKline, Heidelberg, Germany
| | - Vaishali
- Developmental Biology Unit, European Molecular Biology Laboratory (EMBL) Heidelberg, Meyerhofstrasse 1, Heidelberg, 69117, Germany
- Department of Cell and Developmental Biology, University College London, Gower Street, London, WC1E 6BT, UK
| | - Marco L Hennrich
- Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL) Heidelberg, Meyerhofstrasse 1, Heidelberg, 69117, Germany
- Cellzome GmbH, GlaxoSmithKline, Heidelberg, Germany
| | - Anne Ephrussi
- Developmental Biology Unit, European Molecular Biology Laboratory (EMBL) Heidelberg, Meyerhofstrasse 1, Heidelberg, 69117, Germany.
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6
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Hakes AC, Gavis ER. Plasticity of Drosophila germ granules during germ cell development. PLoS Biol 2023; 21:e3002069. [PMID: 37053289 PMCID: PMC10128949 DOI: 10.1371/journal.pbio.3002069] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Revised: 04/25/2023] [Accepted: 03/07/2023] [Indexed: 04/15/2023] Open
Abstract
Compartmentalization of RNAs and proteins into membraneless structures called granules is a ubiquitous mechanism for organizing and regulating cohorts of RNAs. Germ granules are ribonucleoprotein (RNP) assemblies required for germline development across the animal kingdom, but their regulatory roles in germ cells are not fully understood. We show that after germ cell specification, Drosophila germ granules enlarge through fusion and this growth is accompanied by a shift in function. Whereas germ granules initially protect their constituent mRNAs from degradation, they subsequently target a subset of these mRNAs for degradation while maintaining protection of others. This functional shift occurs through the recruitment of decapping and degradation factors to the germ granules, which is promoted by decapping activators and renders these structures P body-like. Disrupting either the mRNA protection or degradation function results in germ cell migration defects. Our findings reveal plasticity in germ granule function that allows them to be repurposed at different stages of development to ensure population of the gonad by germ cells. Additionally, these results reveal an unexpected level of functional complexity whereby constituent RNAs within the same granule type can be differentially regulated.
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Affiliation(s)
- Anna C Hakes
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, United States of America
| | - Elizabeth R Gavis
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, United States of America
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Baker FC, Neiswender H, Veeranan-Karmegam R, Gonsalvez GB. In vivo proximity biotin ligation identifies the interactome of Egalitarian, a Dynein cargo adaptor. Development 2021; 148:dev199935. [PMID: 35020877 PMCID: PMC8645207 DOI: 10.1242/dev.199935] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Accepted: 10/18/2021] [Indexed: 06/21/2024]
Abstract
Numerous motors of the Kinesin family contribute to plus-end-directed microtubule transport. However, almost all transport towards the minus-end of microtubules involves Dynein. Understanding the mechanism by which Dynein transports this vast diversity of cargo is the focus of intense research. In selected cases, adaptors that link a particular cargo with Dynein have been identified. However, the sheer diversity of cargo suggests that additional adaptors must exist. We used the Drosophila egg chamber as a model to address this issue. Within egg chambers, Egalitarian is required for linking mRNA with Dynein. However, in the absence of Egalitarian, Dynein transport into the oocyte is severely compromised. This suggests that additional cargoes might be linked to Dynein in an Egalitarian-dependent manner. We therefore used proximity biotin ligation to define the interactome of Egalitarian. This approach yielded several novel interacting partners, including P body components and proteins that associate with Dynein in mammalian cells. We also devised and validated a nanobody-based proximity biotinylation strategy that can be used to define the interactome of any GFP-tagged protein.
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Affiliation(s)
| | | | | | - Graydon B. Gonsalvez
- Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, 1460 Laney Walker Blvd, Augusta, GA 30912, USA
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Kunar R, Roy JK. The mRNA decapping protein 2 (DCP2) is a major regulator of developmental events in Drosophila-insights from expression paradigms. Cell Tissue Res 2021; 386:261-280. [PMID: 34536141 DOI: 10.1007/s00441-021-03503-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Accepted: 07/01/2021] [Indexed: 02/07/2023]
Abstract
The Drosophila genome codes for two decapping proteins, DCP1 and DCP2, out of which DCP2 is the active decapping enzyme. The present endeavour explores the endogenous promoter firing, transcript and protein expression of DCP2 in Drosophila wherein, besides a ubiquitous expression across development, we identify an active expression paradigm during dorsal closure and a plausible moonlighting expression in the Corazonin neurons of the larval brain. We also demonstrate that the ablation of DCP2 leads to embryonic lethality and defects in vital morphogenetic processes whereas a knockdown of DCP2 in the Corazonin neurons reduces the sensitivity to ethanol in adults, thereby ascribing novel regulatory roles to DCP2. Our findings unravel novel putative roles for DCP2 and identify it as a candidate for studies on the regulated interplay of essential molecules during early development in Drosophila, nay the living world.
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Affiliation(s)
- Rohit Kunar
- Cytogenetics Laboratory, Department of Zoology, Institute of Science, Banaras Hindu University, Uttar Pradesh, Varanasi, 221005, India
| | - Jagat Kumar Roy
- Cytogenetics Laboratory, Department of Zoology, Institute of Science, Banaras Hindu University, Uttar Pradesh, Varanasi, 221005, India.
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9
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Borbolis F, Syntichaki P. Biological implications of decapping: beyond bulk mRNA decay. FEBS J 2021; 289:1457-1475. [PMID: 33660392 DOI: 10.1111/febs.15798] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Revised: 02/21/2021] [Accepted: 03/07/2021] [Indexed: 12/12/2022]
Abstract
It is well established that mRNA steady-state levels do not directly correlate with transcription rate. This is attributed to the multiple post-transcriptional mechanisms, which control both mRNA turnover and translation within eukaryotic cells. One such mechanism is the removal of the 5' end cap structure of RNAs (decapping). This 5' cap plays a fundamental role in cellular functions related to mRNA processing, transport, translation, quality control, and decay, while its chemical modifications influence the fate of cytoplasmic mRNAs. Decapping is a highly controlled process, performed by multiple decapping enzymes, and regulated by complex cellular networks. In this review, we provide an updated synopsis of 5' end modifications and functions, and give an overview of mRNA decapping enzymes, presenting their enzymatic properties. Focusing on DCP2 decapping enzyme, a major component on the 5'-3' mRNA decay pathway, we describe cis-elements and trans-acting factors that affect its activity, substrate specificity, and cellular localization. Finally, we discuss current knowledge on the biological functions of mRNA decapping and decay factors, highlighting the major questions that remain to be addressed.
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Affiliation(s)
- Fivos Borbolis
- Biomedical Research Foundation of the Academy of Athens, Center of Basic Research, Athens, Greece
| | - Popi Syntichaki
- Biomedical Research Foundation of the Academy of Athens, Center of Basic Research, Athens, Greece
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Mukherjee N, Mukherjee C. Germ cell ribonucleoprotein granules in different clades of life: From insects to mammals. WILEY INTERDISCIPLINARY REVIEWS-RNA 2021; 12:e1642. [PMID: 33555143 DOI: 10.1002/wrna.1642] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2020] [Revised: 01/04/2021] [Accepted: 01/05/2021] [Indexed: 12/12/2022]
Abstract
Ribonucleoprotein (RNP) granules are no newcomers in biology. Found in all life forms, ranging across taxa, these membrane-less "organelles" have been classified into different categories based on their composition, structure, behavior, function, and localization. Broadly, they can be listed as stress granules (SGs), processing bodies (PBs), neuronal granules (NGs), and germ cell granules (GCGs). Keeping in line with the topic of this review, RNP granules present in the germ cells have been implicated in a wide range of cellular functions including cellular specification, differentiation, proliferation, and so forth. The mechanisms used by them can be diverse and many of them remain partly obscure and active areas of research. GCGs can be of different types in different organisms and at different stages of development, with multiple types coexisting in the same cell. In this review, the different known subcategories of GCGs have been studied with respect to five distinct model organisms, namely, Drosophila, Caenorhabditis elegans, Xenopus, Zebrafish, and mammals. Of them, the cytoplasmic polar granules in Drosophila, P granules in C. elegans, balbiani body in Xenopus and Zebrafish, and chromatoid bodies in mammals have been specifically emphasized upon. A descriptive account of the same has been provided along with insights into our current understanding of their functional significance with respect to cellular events relating to different developmental and reproductive processes. This article is categorized under: RNA Interactions with Proteins and Other Molecules > RNA-Protein Complexes RNA Export and Localization > RNA Localization RNA in Disease and Development > RNA in Disease.
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Ruan T, Zhang Y, Liu W, Li Y, Wang D, Du Z, Tao K, Wu C. Expression of DCP1a in gastric cancer and its biological function and mechanism in chemotherapy resistance in gastric cancer cells. Dig Liver Dis 2020; 52:1351-1358. [PMID: 32646734 DOI: 10.1016/j.dld.2020.06.031] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 06/17/2020] [Accepted: 06/19/2020] [Indexed: 12/11/2022]
Abstract
AIMS To detect the role of DCP1a in gastric cancer. To estimate the effect of DCP1a in gastric cancer cells on proliferation, invasion, migration and anti-drug behavior in vitro by down-regulating its expression. METHODS Using IHC staining and Western blot to check the expression of DCP1a in tissues and the cell lines. SGC7901 and BGC823 cells were transfected with DCP1a siRNA, and the expression of DCP1a protein and mRNA were detected. The cell proliferation rate was detected by MTT assay and plate cloning assay. Transwell assay was used to detect the change of cell metastasis. The inhibition rates of cells to chemotherapy were detected by MTT assay. And signal pathways were also detected. RESULTS The expression of DCP1a in cancer tissues is higher (p < 0.05), and higher expression of DCP1a is related to poor prognosis. After down-regulating the expression of DCP1a in cells, the proliferation rates, migration abilities and chemotherapy resistance decrease. We find that the expression of MRP-1 and the activation of AKT and STAT3 pathways might be involved in regulation. CONCLUSION The high expression of DCP1a might be associated with cancer development and prognosis. Down-regulating the expression of DCP1a will help to reduce chemotherapy resistance, which will help with further improvement of chemotherapy in gastric cancer.
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Affiliation(s)
- Tuo Ruan
- Department of Gastrointestinal Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1277 Jiefang Avenue, Wuhan 430022, Hubei, PR China
| | - Yazhi Zhang
- Department of Pediatrics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1277 Jiefang Avenue, Wuhan 430022, Hubei, PR China
| | - Weizhen Liu
- Department of Gastrointestinal Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1277 Jiefang Avenue, Wuhan 430022, Hubei, PR China
| | - Yuan Li
- Department of Gastrointestinal Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1277 Jiefang Avenue, Wuhan 430022, Hubei, PR China
| | - Dianshi Wang
- Department of Gastrointestinal Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1277 Jiefang Avenue, Wuhan 430022, Hubei, PR China
| | - Zhouyuan Du
- Department of Gastrointestinal Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1277 Jiefang Avenue, Wuhan 430022, Hubei, PR China
| | - Kaixiong Tao
- Department of Gastrointestinal Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1277 Jiefang Avenue, Wuhan 430022, Hubei, PR China.
| | - Chuanqing Wu
- Department of Gastrointestinal Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1277 Jiefang Avenue, Wuhan 430022, Hubei, PR China.
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12
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Borbolis F, Rallis J, Kanatouris G, Kokla N, Karamalegkos A, Vasileiou C, Vakaloglou KM, Diallinas G, Stravopodis DJ, Zervas CG, Syntichaki P. mRNA decapping is an evolutionarily conserved modulator of neuroendocrine signaling that controls development and ageing. eLife 2020; 9:e53757. [PMID: 32366357 PMCID: PMC7200159 DOI: 10.7554/elife.53757] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Accepted: 04/22/2020] [Indexed: 12/24/2022] Open
Abstract
Eukaryotic 5'-3' mRNA decay plays important roles during development and in response to stress, regulating gene expression post-transcriptionally. In Caenorhabditis elegans, deficiency of DCAP-1/DCP1, the essential co-factor of the major cytoplasmic mRNA decapping enzyme, impacts normal development, stress survival and ageing. Here, we show that overexpression of dcap-1 in neurons of worms is sufficient to increase lifespan through the function of the insulin/IGF-like signaling and its effector DAF-16/FOXO transcription factor. Neuronal DCAP-1 affects basal levels of INS-7, an ageing-related insulin-like peptide, which acts in the intestine to determine lifespan. Short-lived dcap-1 mutants exhibit a neurosecretion-dependent upregulation of intestinal ins-7 transcription, and diminished nuclear localization of DAF-16/FOXO. Moreover, neuronal overexpression of DCP1 in Drosophila melanogaster confers longevity in adults, while neuronal DCP1 deficiency shortens lifespan and affects wing morphogenesis, cell non-autonomously. Our genetic analysis in two model-organisms suggests a critical and conserved function of DCAP-1/DCP1 in developmental events and lifespan modulation.
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Affiliation(s)
- Fivos Borbolis
- Biomedical Research Foundation of the Academy of Athens, Center of Basic ResearchAthensGreece
- Department of Biology, School of Science, National and Kapodistrian University of AthensAthensGreece
| | - John Rallis
- Biomedical Research Foundation of the Academy of Athens, Center of Basic ResearchAthensGreece
- Department of Biology, School of Science, National and Kapodistrian University of AthensAthensGreece
| | - George Kanatouris
- Biomedical Research Foundation of the Academy of Athens, Center of Basic ResearchAthensGreece
- Department of Biology, School of Science, National and Kapodistrian University of AthensAthensGreece
| | - Nikolitsa Kokla
- Biomedical Research Foundation of the Academy of Athens, Center of Basic ResearchAthensGreece
- Department of Biology, School of Science, National and Kapodistrian University of AthensAthensGreece
| | - Antonis Karamalegkos
- Biomedical Research Foundation of the Academy of Athens, Center of Basic ResearchAthensGreece
- Department of Biology, School of Science, National and Kapodistrian University of AthensAthensGreece
| | - Christina Vasileiou
- Biomedical Research Foundation of the Academy of Athens, Center of Basic ResearchAthensGreece
- Department of Molecular Biology and Genetics, Democritus University of ThraceAlex/polisGreece
| | - Katerina M Vakaloglou
- Biomedical Research Foundation of the Academy of Athens, Center of Basic ResearchAthensGreece
| | - George Diallinas
- Department of Biology, School of Science, National and Kapodistrian University of AthensAthensGreece
| | - Dimitrios J Stravopodis
- Department of Biology, School of Science, National and Kapodistrian University of AthensAthensGreece
| | - Christos G Zervas
- Biomedical Research Foundation of the Academy of Athens, Center of Basic ResearchAthensGreece
| | - Popi Syntichaki
- Biomedical Research Foundation of the Academy of Athens, Center of Basic ResearchAthensGreece
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13
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Lee YM, Chiang PH, Cheng JH, Shen WH, Chen CH, Wu ML, Tian YL, Ni CH, Wang TF, Lin MD, Chou TB. Drosophila decapping protein 2 modulates the formation of cortical F-actin for germ plasm assembly. Dev Biol 2020; 461:96-106. [PMID: 32007453 DOI: 10.1016/j.ydbio.2020.01.013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2019] [Revised: 01/20/2020] [Accepted: 01/28/2020] [Indexed: 10/25/2022]
Abstract
In Drosophila, the deposition of the germ plasm at the posterior pole of the oocyte is essential for the abdomen and germ cell formation during embryogenesis. To assemble the germ plasm, oskar (osk) mRNA, produced by nurse cells, should be localized and anchored on the posterior cortex of the oocyte. Processing bodies (P-bodies) are cytoplasmic RNA granules responsible for the 5'-3' mRNA degradation. Evidence suggests that the components of P-bodies, such as Drosophila decapping protein 1 and Ge-1, are involved in the posterior localization of osk. However, whether the decapping core enzyme, Drosophila decapping protein 2 (dDcp2), is also involved remains unclear. Herein, we generated a dDcp2 null allele and showed that dDcp2 was required for the posterior localization of germ plasm components including osk. dDcp2 was distributed on the oocyte cortex and was localized posterior to the osk. In the posterior pole of dDcp2 mutant oocytes, osk was mislocalized and colocalized with F-actin detached from the cortex; moreover, considerably fewer F-actin projections were observed. Using the F-actin cosedimentation assay, we proved that dDcp2 interacted with F-actin through its middle region. In conclusion, our findings explored a novel function of dDcp2 in assisting osk localization by modulating the formation of F-actin projections on the posterior cortex.
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Affiliation(s)
- Yi-Mei Lee
- Institute of Molecular and Cellular Biology, College of Life Sciences, National Taiwan University, No.1, Sec.4, Roosevelt Rd, Taipei, 10617, Taiwan
| | - Po-Hsun Chiang
- Institute of Molecular and Cellular Biology, College of Life Sciences, National Taiwan University, No.1, Sec.4, Roosevelt Rd, Taipei, 10617, Taiwan
| | - Jen-Ho Cheng
- Institute of Molecular and Cellular Biology, College of Life Sciences, National Taiwan University, No.1, Sec.4, Roosevelt Rd, Taipei, 10617, Taiwan
| | - Wei-Hong Shen
- Institute of Molecular and Cellular Biology, College of Life Sciences, National Taiwan University, No.1, Sec.4, Roosevelt Rd, Taipei, 10617, Taiwan
| | - Chao-Han Chen
- Institute of Molecular and Cellular Biology, College of Life Sciences, National Taiwan University, No.1, Sec.4, Roosevelt Rd, Taipei, 10617, Taiwan
| | - Mei-Ling Wu
- Institute of Molecular and Cellular Biology, College of Life Sciences, National Taiwan University, No.1, Sec.4, Roosevelt Rd, Taipei, 10617, Taiwan
| | - Yi-Lu Tian
- Institute of Molecular and Cellular Biology, College of Life Sciences, National Taiwan University, No.1, Sec.4, Roosevelt Rd, Taipei, 10617, Taiwan
| | - Chao-Heng Ni
- Department of Life Sciences, College of Medicine, Tzu Chi University, 701 Zhongyang Rd, Sec. 3, Hualien, 97004, Taiwan
| | - Ting-Fang Wang
- Department of Life Sciences, College of Medicine, Tzu Chi University, 701 Zhongyang Rd, Sec. 3, Hualien, 97004, Taiwan
| | - Ming-Der Lin
- Department of Life Sciences, College of Medicine, Tzu Chi University, 701 Zhongyang Rd, Sec. 3, Hualien, 97004, Taiwan; Department of Molecular Biology and Human Genetics, College of Medicine, Tzu Chi University, 701 Zhongyang Rd, Sec. 3, Hualien, 97004, Taiwan; Department of Medical Research, Hualien Tzu Chi Hospital, 707 Zhongyang Rd, Sec. 3, Hualien, 97004, Taiwan.
| | - Tze-Bin Chou
- Institute of Molecular and Cellular Biology, College of Life Sciences, National Taiwan University, No.1, Sec.4, Roosevelt Rd, Taipei, 10617, Taiwan.
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14
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Tudor-domain containing protein 5-like promotes male sexual identity in the Drosophila germline and is repressed in females by Sex lethal. PLoS Genet 2019; 15:e1007617. [PMID: 31329582 PMCID: PMC6645463 DOI: 10.1371/journal.pgen.1007617] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Accepted: 06/26/2019] [Indexed: 11/19/2022] Open
Abstract
For sexually reproducing organisms, production of male or female gametes depends on specifying the correct sexual identity in the germline. In D. melanogaster, Sex lethal (Sxl) is the key gene that controls sex determination in both the soma and the germline, but how it does so in the germline is unknown, other than that it is different than in the soma. We conducted an RNA expression profiling experiment to identify direct and indirect germline targets of Sxl specifically in the undifferentiated germline. We find that, in these cells, Sxl loss does not lead to a global masculinization observed at the whole-genome level. In contrast, Sxl appears to affect a discrete set of genes required in the male germline, such as Phf7. We also identify Tudor domain containing protein 5-like (Tdrd5l) as a target for Sxl regulation that is important for male germline identity. Tdrd5l is repressed by Sxl in female germ cells, but is highly expressed in male germ cells where it promotes proper male fertility and germline differentiation. Additionally, Tdrd5l localizes to cytoplasmic granules with some characteristics of RNA Processing (P-) Bodies, suggesting that it promotes male identity in the germline by regulating post-transcriptional gene expression.
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15
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Primus S, Pozmanter C, Baxter K, Van Doren M. Tudor-domain containing protein 5-like promotes male sexual identity in the Drosophila germline and is repressed in females by Sex lethal. PLoS Genet 2019. [PMID: 31329582 DOI: 10.1101/388850] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/28/2023] Open
Abstract
For sexually reproducing organisms, production of male or female gametes depends on specifying the correct sexual identity in the germline. In D. melanogaster, Sex lethal (Sxl) is the key gene that controls sex determination in both the soma and the germline, but how it does so in the germline is unknown, other than that it is different than in the soma. We conducted an RNA expression profiling experiment to identify direct and indirect germline targets of Sxl specifically in the undifferentiated germline. We find that, in these cells, Sxl loss does not lead to a global masculinization observed at the whole-genome level. In contrast, Sxl appears to affect a discrete set of genes required in the male germline, such as Phf7. We also identify Tudor domain containing protein 5-like (Tdrd5l) as a target for Sxl regulation that is important for male germline identity. Tdrd5l is repressed by Sxl in female germ cells, but is highly expressed in male germ cells where it promotes proper male fertility and germline differentiation. Additionally, Tdrd5l localizes to cytoplasmic granules with some characteristics of RNA Processing (P-) Bodies, suggesting that it promotes male identity in the germline by regulating post-transcriptional gene expression.
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Affiliation(s)
- Shekerah Primus
- Department of Biology, Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Caitlin Pozmanter
- Department of Biology, Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Kelly Baxter
- Department of Biology, Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Mark Van Doren
- Department of Biology, Johns Hopkins University, Baltimore, Maryland, United States of America
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16
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Kistler KE, Trcek T, Hurd TR, Chen R, Liang FX, Sall J, Kato M, Lehmann R. Phase transitioned nuclear Oskar promotes cell division of Drosophila primordial germ cells. eLife 2018; 7:37949. [PMID: 30260314 PMCID: PMC6191285 DOI: 10.7554/elife.37949] [Citation(s) in RCA: 68] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2018] [Accepted: 09/09/2018] [Indexed: 12/25/2022] Open
Abstract
Germ granules are non-membranous ribonucleoprotein granules deemed the hubs for post-transcriptional gene regulation and functionally linked to germ cell fate across species. Little is known about the physical properties of germ granules and how these relate to germ cell function. Here we study two types of germ granules in the Drosophila embryo: cytoplasmic germ granules that instruct primordial germ cells (PGCs) formation and nuclear germ granules within early PGCs with unknown function. We show that cytoplasmic and nuclear germ granules are phase transitioned condensates nucleated by Oskar protein that display liquid as well as hydrogel-like properties. Focusing on nuclear granules, we find that Oskar drives their formation in heterologous cell systems. Multiple, independent Oskar protein domains synergize to promote granule phase separation. Deletion of Oskar’s nuclear localization sequence specifically ablates nuclear granules in cell systems. In the embryo, nuclear germ granules promote germ cell divisions thereby increasing PGC number for the next generation.
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Affiliation(s)
- Kathryn E Kistler
- Skirball Institute of Biomolecular Medicine, Howard Hughes Medical Institute, NYU School of Medicine, New York, United States.,Department of Molecular and Cellular Biology, University of Washington, Washington, United States
| | - Tatjana Trcek
- Skirball Institute of Biomolecular Medicine, Howard Hughes Medical Institute, NYU School of Medicine, New York, United States
| | - Thomas R Hurd
- Skirball Institute of Biomolecular Medicine, Howard Hughes Medical Institute, NYU School of Medicine, New York, United States.,Department of Molecular Genetics, University of Toronto, Toronto, Canada
| | - Ruoyu Chen
- Skirball Institute of Biomolecular Medicine, Howard Hughes Medical Institute, NYU School of Medicine, New York, United States
| | - Feng-Xia Liang
- Department of Cell Biology, NYU School of Medicine, New York, United States.,DART Microscopy Laboratory, NYU Langone Health, New York, United States
| | - Joseph Sall
- DART Microscopy Laboratory, NYU Langone Health, New York, United States
| | - Masato Kato
- Department of Biochemistry, University of Texas Southwestern Medical Center, Texas, United States
| | - Ruth Lehmann
- Skirball Institute of Biomolecular Medicine, Howard Hughes Medical Institute, NYU School of Medicine, New York, United States.,Department of Cell Biology, NYU School of Medicine, New York, United States
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17
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Hamada-Kawaguchi N, Yamamoto D. Ovarian polarity and cell shape determination by Btk29A in Drosophila. Genesis 2017. [PMID: 28639397 DOI: 10.1002/dvg.23042] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Drosophila Btk29A is a Tec family nonreceptor tyrosine kinase, the ortholog of which causes X-linked agammaglobulinemia in humans when mutant. In Btk29AficP mutant ovaries, multiple defects are observed: extrapolar cells form ectopically; osk mRNA fails to accumulate posteriorly in mature oocytes; the shape and alignment of follicle cells are grossly distorted. All these phenotypes are rescued by selectively overexpressing the type 2 isoform of wild-type Btk29A in follicle cells. Expression of certain proteins enriched in adherens junctions is markedly affected in Btk29AficP mutants; the anterior-posterior gradient normally observed in the expression of DE-Cadherin and Armadillo are lost and Canoe is sequestered from adherens junctions. Intriguingly, tyrosine phosphorylation of Canoe is reduced in Btk29AficP mutants. It is proposed that Btk29A is required for the establishment of egg chamber polarity presumably through the regulation of subcellular localization of its downstream proteins, including Cno.
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Affiliation(s)
- Noriko Hamada-Kawaguchi
- Division of Neurogenetics, Tohoku University Graduate School of Life Sciences, Katahira, Aoba-ku, Sendai, 980-8577, Japan
| | - Daisuke Yamamoto
- Division of Neurogenetics, Tohoku University Graduate School of Life Sciences, Katahira, Aoba-ku, Sendai, 980-8577, Japan
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18
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Patel PH, Barbee SA, Blankenship JT. GW-Bodies and P-Bodies Constitute Two Separate Pools of Sequestered Non-Translating RNAs. PLoS One 2016; 11:e0150291. [PMID: 26930655 PMCID: PMC4773245 DOI: 10.1371/journal.pone.0150291] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Accepted: 02/11/2016] [Indexed: 01/05/2023] Open
Abstract
Non-translating RNAs that have undergone active translational repression are culled from the cytoplasm into P-bodies for decapping-dependent decay or for sequestration. Organisms that use microRNA-mediated RNA silencing have an additional pathway to remove RNAs from active translation. Consequently, proteins that govern microRNA-mediated silencing, such as GW182/Gw and AGO1, are often associated with the P-bodies of higher eukaryotic organisms. Due to the presence of Gw, these structures have been referred to as GW-bodies. However, several reports have indicated that GW-bodies have different dynamics to P-bodies. Here, we use live imaging to examine GW-body and P-body dynamics in the early Drosophila melanogaster embryo. While P-bodies are present throughout early embryonic development, cytoplasmic GW-bodies only form in significant numbers at the midblastula transition. Unlike P-bodies, which are predominantly cytoplasmic, GW-bodies are present in both nuclei and the cytoplasm. RNA decapping factors such as DCP1, Me31B, and Hpat are not associated with GW-bodies, indicating that P-bodies and GW-bodies are distinct structures. Furthermore, known Gw interactors such as AGO1 and the CCR4-NOT deadenylation complex, which have been shown to be important for Gw function, are also not present in GW-bodies. Use of translational inhibitors puromycin and cycloheximide, which respectively increase or decrease cellular pools of non-translating RNAs, alter GW-body size, underscoring that GW-bodies are composed of non-translating RNAs. Taken together, these data indicate that active translational silencing most likely does not occur in GW-bodies. Instead GW-bodies most likely function as repositories for translationally silenced RNAs. Finally, inhibition of zygotic gene transcription is unable to block the formation of either P-bodies or GW-bodies in the early embryo, suggesting that these structures are composed of maternal RNAs.
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Affiliation(s)
- Prajal H. Patel
- Department of Biological Sciences and Eleanor Roosevelt Institute, University of Denver, Denver, Colorado, United States of America
| | - Scott A. Barbee
- Department of Biological Sciences and Eleanor Roosevelt Institute, University of Denver, Denver, Colorado, United States of America
- Molecular and Cellular Biophysics Program, University of Denver, Denver, Colorado, United States of America
- * E-mail: (JTB); (SAB)
| | - J. Todd Blankenship
- Department of Biological Sciences and Eleanor Roosevelt Institute, University of Denver, Denver, Colorado, United States of America
- Molecular and Cellular Biophysics Program, University of Denver, Denver, Colorado, United States of America
- * E-mail: (JTB); (SAB)
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19
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Abstract
Messenger ribonucleoprotein (mRNP) granules are dynamic, self-assembling structures that harbor non-translating mRNAs bound by various proteins that regulate mRNA translation, localization, and turnover. Their importance in gene expression regulation is far reaching, ranging from precise spatial-temporal control of mRNAs that drive developmental programs in oocytes and embryos, to similarly exquisite control of mRNAs in neurons that underpin synaptic plasticity, and thus, memory formation. Analysis of mRNP granules in their various contexts has revealed common themes of assembly, disassembly, and modes of mRNA regulation, yet new studies continue to reveal unexpected and important findings, such as links between aberrant mRNP granule assembly and neurodegenerative disease. Continued study of these enigmatic structures thus promises fascinating new insights into cellular function, and may also suggest novel therapeutic strategies in various disease states.
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Affiliation(s)
- J Ross Buchan
- a Department of Molecular and Cellular Biology ; University of Arizona ; Tucson , AZ USA
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20
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Little SC, Sinsimer KS, Lee JJ, Wieschaus EF, Gavis ER. Independent and coordinate trafficking of single Drosophila germ plasm mRNAs. Nat Cell Biol 2015; 17:558-68. [PMID: 25848747 PMCID: PMC4417036 DOI: 10.1038/ncb3143] [Citation(s) in RCA: 128] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2014] [Accepted: 02/20/2015] [Indexed: 11/24/2022]
Abstract
mRNA localization is a conserved mechanism for spatial control of protein synthesis, with key roles in generating cellular and developmental asymmetry. While different transcripts may be targeted to the same subcellular domain, the extent to which their localization is coordinated is unclear. Using quantitative single molecule imaging, we analyzed the assembly of Drosophila germ plasm mRNA granules inherited by nascent germ cells. We find that the germ cell-destined transcripts nanos, cyclin B, and polar granule component travel within the oocyte as ribonucleoprotein particles containing single mRNA molecules but co-assemble into multi-copy heterogeneous granules selectively at the posterior of the oocyte. The stoichiometry and dynamics of assembly indicate a defined stepwise sequence. Our data suggest that co-packaging of these transcripts ensures their effective segregation to germ cells. In contrast, compartmentalization of the germline determinant oskar mRNA into different granules limits its entry into germ cells. This exclusion is required for proper germline development.
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Affiliation(s)
- Shawn C Little
- 1] Department of Molecular Biology, Princeton University, Princeton, New Jersey 08544, USA [2] Howard Hughes Medical Institute, Princeton University, Princeton, New Jersey 08544, USA
| | - Kristina S Sinsimer
- Department of Molecular Biology, Princeton University, Princeton, New Jersey 08544, USA
| | - Jack J Lee
- Department of Molecular Biology, Princeton University, Princeton, New Jersey 08544, USA
| | - Eric F Wieschaus
- 1] Department of Molecular Biology, Princeton University, Princeton, New Jersey 08544, USA [2] Howard Hughes Medical Institute, Princeton University, Princeton, New Jersey 08544, USA
| | - Elizabeth R Gavis
- Department of Molecular Biology, Princeton University, Princeton, New Jersey 08544, USA
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21
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22
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Schisa JA. Effects of stress and aging on ribonucleoprotein assembly and function in the germ line. WILEY INTERDISCIPLINARY REVIEWS-RNA 2013; 5:231-46. [PMID: 24523207 DOI: 10.1002/wrna.1204] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2013] [Revised: 10/03/2013] [Accepted: 10/09/2013] [Indexed: 11/08/2022]
Abstract
In a variety of cell types, ribonucleoprotein (RNP) complexes play critical roles in regulating RNA metabolism. The germ line contains RNPs found also in somatic cells, such as processing (P) bodies and stress granules, as well as several RNPs unique to the germ line, including germ granules, nuage, Balbiani bodies, P granules, U bodies, and sponge bodies. Recent advances have identified a conserved response of germ line RNPs to environmental stresses such as nutritional stress and heat shock. The RNPs increase significantly in size based on cytology; their morphology and subcellular localization changes, and their composition changes. These dynamic changes are reversible when stresses diminish, and similar changes occur in response to aging or extended meiotic arrest prior to fertilization of oocytes. Intriguing correlations exist between the dynamics of the RNPs and the microtubule cytoskeleton and its motor proteins, suggesting a possible mechanism for the assembly and dissociation of the large RNP granules. Similarly, coordinated changes of the nuclear membrane and endoplasmic reticulum may also help unravel the regulatory mechanisms of RNP dynamics. Based on their composition, the RNPs are thought to regulate mRNA decay and/or translation, and initial support for some of these roles is now at hand. Ultimately, the question of why RNP remodeling occurs to such a large extent during a variety of stresses and aging remains to be fully answered, but a current attractive hypothesis is that the plasticity promotes the maintenance of oocyte quality.
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Affiliation(s)
- Jennifer A Schisa
- Department of Biology, Central Michigan University, Mount Pleasant, MI, USA
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23
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Hopkins KC, McLane LM, Maqbool T, Panda D, Gordesky-Gold B, Cherry S. A genome-wide RNAi screen reveals that mRNA decapping restricts bunyaviral replication by limiting the pools of Dcp2-accessible targets for cap-snatching. Genes Dev 2013; 27:1511-25. [PMID: 23824541 DOI: 10.1101/gad.215384.113] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Bunyaviruses are an emerging group of medically important viruses, many of which are transmitted from insects to mammals. To identify host factors that impact infection, we performed a genome-wide RNAi screen in Drosophila and identified 131 genes that impacted infection of the mosquito-transmitted bunyavirus Rift Valley fever virus (RVFV). Dcp2, the catalytic component of the mRNA decapping machinery, and two decapping activators, DDX6 and LSM7, were antiviral against disparate bunyaviruses in both insect cells and adult flies. Bunyaviruses 5' cap their mRNAs by "cap-snatching" the 5' ends of poorly defined host mRNAs. We found that RVFV cap-snatches the 5' ends of Dcp2 targeted mRNAs, including cell cycle-related genes. Loss of Dcp2 allows increased viral transcription without impacting viral mRNA stability, while ectopic expression of Dcp2 impedes viral transcription. Furthermore, arresting cells in late S/early G2 led to increased Dcp2 mRNA targets and increased RVFV replication. Therefore, RVFV competes for the Dcp2-accessible mRNA pool, which is dynamically regulated and can present a bottleneck for viral replication.
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24
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Chang WL, Chang CW, Chang YY, Sung HH, Lin MD, Chang SC, Chen CH, Huang CW, Tung KS, Chou TB. The Drosophila GOLPH3 homolog regulates the biosynthesis of heparan sulfate proteoglycans by modulating the retrograde trafficking of exostosins. Development 2013; 140:2798-807. [DOI: 10.1242/dev.087171] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The exostosin (EXT) genes encode glycosyltransferases required for glycosaminoglycan chain polymerization in the biosynthesis of heparan sulfate proteoglycans (HSPGs). Mutations in the tumor suppressor genes EXT1 and EXT2 disturb HSPG biosynthesis and cause multiple osteochondroma (MO). How EXT1 and EXT2 traffic within the Golgi complex is not clear. Here, we show that Rotini (Rti), the Drosophila GOLPH3, regulates the retrograde trafficking of EXTs. A reduction in Rti shifts the steady-state distribution of EXTs to the trans-Golgi. These accumulated EXTs tend to be degraded and their re-entrance towards the route for polymerizing GAG chains is disengaged. Conversely, EXTs are mislocalized towards the transitional endoplasmic reticulum/cis-Golgi when Rti is overexpressed. Both loss of function and overexpression of rti result in incomplete HSPGs and perturb Hedgehog signaling. Consistent with Drosophila, GOLPH3 modulates the dynamic retention and protein stability of EXT1/2 in mammalian species. Our data demonstrate that GOLPH3 modulates the activities of EXTs, thus implicating a putative role for GOLPH3 in the formation of MO.
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Affiliation(s)
- Wei-Ling Chang
- Institute of Molecular and Cellular Biology, National Taiwan University, No.1 Sec.4 Roosevelt Road, Taipei, 10617, Taiwan
| | - Che-Wei Chang
- Institute of Molecular and Cellular Biology, National Taiwan University, No.1 Sec.4 Roosevelt Road, Taipei, 10617, Taiwan
| | - Yu-Yun Chang
- Institute of Molecular and Cellular Biology, National Taiwan University, No.1 Sec.4 Roosevelt Road, Taipei, 10617, Taiwan
| | - Hsin-Ho Sung
- Institute of Molecular and Cellular Biology, National Taiwan University, No.1 Sec.4 Roosevelt Road, Taipei, 10617, Taiwan
| | - Ming-Der Lin
- Institute of Molecular and Cellular Biology, National Taiwan University, No.1 Sec.4 Roosevelt Road, Taipei, 10617, Taiwan
| | - Shu-Chuan Chang
- Institute of Molecular and Cellular Biology, National Taiwan University, No.1 Sec.4 Roosevelt Road, Taipei, 10617, Taiwan
| | - Chung-Hao Chen
- Institute of Molecular and Cellular Biology, National Taiwan University, No.1 Sec.4 Roosevelt Road, Taipei, 10617, Taiwan
| | - Chia-Wei Huang
- Institute of Molecular and Cellular Biology, National Taiwan University, No.1 Sec.4 Roosevelt Road, Taipei, 10617, Taiwan
| | - Kuei-Shu Tung
- Institute of Molecular and Cellular Biology, National Taiwan University, No.1 Sec.4 Roosevelt Road, Taipei, 10617, Taiwan
| | - Tze-Bin Chou
- Institute of Molecular and Cellular Biology, National Taiwan University, No.1 Sec.4 Roosevelt Road, Taipei, 10617, Taiwan
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25
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Kibanov MV, Kotov AA, Olenina LV. Multicolor fluorescence imaging of whole-mount Drosophila testes for studying spermatogenesis. Anal Biochem 2013; 436:55-64. [PMID: 23357237 DOI: 10.1016/j.ab.2013.01.009] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2012] [Revised: 12/21/2012] [Accepted: 01/10/2013] [Indexed: 01/11/2023]
Abstract
Drosophila testes are generally considered a useful model for studying the fundamental developmental processes of heterogametic organisms. However, immunostaining of the whole Drosophila testis is often associated with insufficient resolution at the subcellular level, poor reproducibility, and incomplete staining of fixed preparations. The main problem for adequate staining is poor permeability of the organs for antibodies and antibody-coupled fluorophores. To overcome this problem we developed a protocol for whole-mount testis immunostaining yielding high-quality preparations for confocal microscopy. Many subcellular structures can be successfully resolved, such as the spectrosome, fusome, nuage granules, apoptotic bodies, and protein crystals. This method preserves the inner architecture of the testes, enabling 3D image reconstruction from a set of confocal sections. It allows one to combine the simultaneous detection of fluorescently tagged and immunostained proteins as well as TUNEL analysis for apoptosis detection.
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Affiliation(s)
- Mikhail V Kibanov
- Laboratory of Biochemical Genetics of Animals, Institute of Molecular Genetics, Russian Academy of Science, Moscow 123182, Russia
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26
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Barckmann B, Simonelig M. Control of maternal mRNA stability in germ cells and early embryos. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2013; 1829:714-24. [PMID: 23298642 DOI: 10.1016/j.bbagrm.2012.12.011] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2012] [Revised: 12/21/2012] [Accepted: 12/28/2012] [Indexed: 10/27/2022]
Abstract
mRNA regulation is essential in germ cells and early embryos. In particular, late oogenesis and early embryogenesis occur in the absence of transcription and rely on maternal mRNAs stored in oocytes. These maternal mRNAs subsequently undergo a general decay in embryos during the maternal-to-zygotic transition in which the control of development switches from the maternal to the zygotic genome. Regulation of mRNA stability thus plays a key role during these early stages of development and is tightly interconnected with translational regulation and mRNA localization. A common mechanism in these three types of regulation implicates variations in mRNA poly(A) tail length. Recent advances in the control of mRNA stability include the widespread and essential role of regulated deadenylation in early developmental processes, as well as the mechanisms regulating mRNA stability which involve RNA binding proteins, microRNAs and interplay between the two. Also emerging are the roles that other classes of small non-coding RNAs, endo-siRNAs and piRNAs play in the control of mRNA decay, including connections between the regulation of transposable elements and cellular mRNA regulation through the piRNA pathway. This article is part of a Special Issue entitled: RNA Decay mechanisms.
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Affiliation(s)
- Bridlin Barckmann
- mRNA Regulation and Development, Institute of Human Genetics, Montpellier Cedex 5, France
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27
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Li J, Hobman TC, Simmonds AJ. Gawky (GW) is the Drosophila melanogaster GW182 homologue. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2013; 768:127-45. [PMID: 23224968 DOI: 10.1007/978-1-4614-5107-5_8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Jing Li
- Department of Cell Biology, University of Alberta, Edmonton, Canada.
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28
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The discovery and analysis of P Bodies. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2013; 768:23-43. [PMID: 23224963 DOI: 10.1007/978-1-4614-5107-5_3] [Citation(s) in RCA: 77] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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29
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Moser JJ, Fritzler MJ. Relationship of other cytoplasmic ribonucleoprotein bodies (cRNPB) to GW/P bodies. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2013; 768:213-42. [PMID: 23224973 DOI: 10.1007/978-1-4614-5107-5_13] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
GW/P body components are involved in the post-transcriptional -processing of messenger RNA (mRNA) through the RNA interference and 5' → 3' mRNA degradation pathways, as well as functioning in mRNA transport and stabilization. It is currently thought that the relevant mRNA silencing and degrading factors are partitioned to these cytoplasmic microdomains thus effecting post-transcriptional regulation and the prevention of accidental degradation of functional mRNA. Although much attention has focused on GW/P bodies, a variety of other cytoplasmic RNP bodies (cRNPB) also have highly specialized functions and have been shown to interact or co-localize with components of GW/P bodies. These cRNPB include neuronal transport RNP granules, stress granules, RNP-rich cytoplasmic germline granules or chromatoid bodies, sponge bodies, cytoplasmic prion protein-induced RNP granules, U bodies and TAM bodies. Of clinical relevance, autoantibodies directed against protein and miRNA components of GW/P bodies have been associated with autoimmune diseases, neurological diseases and cancer. Understanding the molecular function of GW/P bodies and their interactions with other cRNPB may provide clues to the etiology or pathogenesis of diseases associated with autoantibodies directed to these structures. This chapter will focus on the similarities and differences of the various cRNPB as an approach to understanding their functional relationships to GW/P bodies.
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Affiliation(s)
- Joanna J Moser
- Department of Biochemistry and Molecular Biology, University of Calgary, Calgary, Canada
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Buschmann J, Moritz B, Jeske M, Lilie H, Schierhorn A, Wahle E. Identification of Drosophila and human 7-methyl GMP-specific nucleotidases. J Biol Chem 2012; 288:2441-51. [PMID: 23223233 DOI: 10.1074/jbc.m112.426700] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Turnover of mRNA releases, in addition to the four regular nucleoside monophosphates, the methylated cap nucleotide in the form of 7-methylguanosine monophosphate (m(7)GMP) or diphosphate (m(7)GDP). The existence of pathways to eliminate the modified nucleotide seems likely, as its incorporation into nucleic acids is undesirable. Here we describe a novel 5' nucleotidase from Drosophila that cleaves m(7)GMP to 7-methylguanosine and inorganic phosphate. The enzyme, encoded by the predicted gene CG3362, also efficiently dephosphorylates CMP, although with lower apparent affinity; UMP and the purine nucleotides are poor substrates. The enzyme is inhibited by elevated concentrations of AMP and also cleaves m(7)GDP to the nucleoside and two inorganic phosphates, albeit less efficiently. CG3362 has equivalent sequence similarity to two human enzymes, cytosolic nucleotidase III (cNIII) and the previously uncharacterized cytosolic nucleotidase III-like (cNIII-like). We show that cNIII-like also displays 5' nucleotidase activity with a high affinity for m(7)GMP. CMP is a slightly better substrate but again with a higher K(m). The activity of cNIII-like is stimulated by phosphate. In contrast to cNIII-like, cNIII and human cytosolic nucleotidase II do not accept m(7)GMP as a substrate. We suggest that the m(7)G-specific nucleotidases protect cells against undesired salvage of m(7)GMP and its incorporation into nucleic acids.
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Affiliation(s)
- Juliane Buschmann
- Institute of Biochemistry and Biotechnology, Martin Luther University Halle-Wittenberg, 06099 Halle, Germany
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Sengupta MS, Boag PR. Germ granules and the control of mRNA translation. IUBMB Life 2012; 64:586-94. [DOI: 10.1002/iub.1039] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2012] [Accepted: 03/17/2012] [Indexed: 12/18/2022]
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Ottone C, Gigliotti S, Giangrande A, Graziani F, Verrotti di Pianella A. The translational repressor Cup is required for germ cell development in Drosophila. J Cell Sci 2012; 125:3114-23. [PMID: 22454519 DOI: 10.1242/jcs.095208] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In Drosophila, germ cell formation depends on inherited maternal factors localized in the posterior pole region of oocytes and early embryos, known as germ plasm. Here, we report that heterozygous cup mutant ovaries and embryos have reduced levels of Staufen (Stau), Oskar (Osk) and Vasa (Vas) proteins at the posterior pole. Moreover, we demonstrate that Cup interacts with Osk and Vas to ensure anchoring and/or maintenance of germ plasm particles at the posterior pole of oocytes and early embryos. Homozygous cup mutant embryos have a reduced number of germ cells, compared to heterozygous cup mutants, which, in turn, have fewer germ cells than wild-type embryos. In addition, we show that cup and osk interact genetically, because reducing cup copy number further decreases the total number of germ cells observed in heterozygous osk mutant embryos. Finally, we detected cup mRNA and protein within both early and late embryonic germ cells, suggesting a novel role of Cup during germ cell development in Drosophila.
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Cauchi RJ. Conserved requirement for DEAD-box RNA helicase Gemin3 in Drosophila oogenesis. BMC Res Notes 2012; 5:120. [PMID: 22361416 PMCID: PMC3392723 DOI: 10.1186/1756-0500-5-120] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2011] [Accepted: 02/23/2012] [Indexed: 11/10/2022] Open
Abstract
Background DEAD-box RNA helicase Gemin3 is an essential protein since its deficiency is lethal in both vertebrates and invertebrates. In addition to playing a role in transcriptional regulation and RNA silencing, as a core member of the SMN (survival of motor neurons) complex, Gemin3 is required for the biogenesis of spliceosomal snRNPs (small nuclear ribonucleoproteins), and axonal mRNA metabolism. Studies in the mouse and C. elegans revealed that loss of Gemin3 function has a negative impact on ovarian physiology and development. Findings This work reports on the generation and characterisation of gemin3 mutant germline clones in Drosophila adult females. Gemin3 was found to be required for the completion of oogenesis and its loss led to egg polarity defects, oocyte mislocalisation, and abnormal chromosome morphology. Canonical Cajal bodies were absent in the majority of gemin3 mutant egg chambers and histone locus bodies displayed an atypical morphology. snRNP distribution was perturbed so that on gemin3 loss, snRNP cytoplasmic aggregates (U bodies) were only visible in wild type. Conclusions These findings establish a conserved requirement for Gemin3 in Drosophila oogenesis. Furthermore, in view of the similarity to the phenotypes described previously in smn mutant germ cells, the present results confirm the close functional relationship between SMN and Gemin3 on a cellular level.
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Affiliation(s)
- Ruben J Cauchi
- Department of Physiology and Biochemistry, Faculty of Medicine & Surgery, University of Malta, Msida MSD 2080, Malta G.C.
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Schisa JA. New insights into the regulation of RNP granule assembly in oocytes. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2012; 295:233-89. [PMID: 22449492 DOI: 10.1016/b978-0-12-394306-4.00013-7] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
In a variety of cell types in plants, animals, and fungi, ribonucleoprotein (RNP) complexes play critical roles in regulating RNA metabolism. These RNP granules include processing bodies and stress granules that are found broadly across cell types, as well as RNP granules unique to the germline, such as P granules, polar granules, sponge bodies, and germinal granules. This review focuses on RNP granules localized in oocytes of the major model systems, Caenorhabditis elegans, Drosophila, Xenopus, mouse, and zebrafish. The signature families of proteins within oocyte RNPs include Vasa and other RNA-binding proteins, decapping activators and enzymes, Argonaute family proteins, and translation initiation complex proteins. This review describes the many recent insights into the dynamics and functions of RNP granules, including their roles in mRNA degradation, mRNA localization, translational regulation, and fertility. The roles of the cytoskeleton and cell organelles in regulating RNP granule assembly are also discussed.
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Affiliation(s)
- Jennifer A Schisa
- Department of Biology, Central Michigan University, Mount Pleasant, Michigan, USA
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Abstract
"Germ granules" are cytoplasmic, nonmembrane-bound organelles unique to germline. Germ granules share components with the P bodies and stress granules of somatic cells, but also contain proteins and RNAs uniquely required for germ cell development. In this review, we focus on recent advances in our understanding of germ granule assembly, dynamics, and function. One hypothesis is that germ granules operate as hubs for the posttranscriptional control of gene expression, a function at the core of the germ cell differentiation program.
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Affiliation(s)
- Ekaterina Voronina
- Department of Molecular Biology and Genetics and Howard Hughes Medical Institute, Center for Cell Dynamics, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
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Kato Y, Nakamura A. Roles of cytoplasmic RNP granules in intracellular RNA localization and translational control in the Drosophila oocyte. Dev Growth Differ 2011; 54:19-31. [PMID: 22111938 DOI: 10.1111/j.1440-169x.2011.01314.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Intracellular mRNA localization and translation are ways to achieve asymmetric protein sorting in polarized cells, and they play fundamental roles in cell-fate decisions and body patterning during animal development. These processes are regulated by the interplay between cis-acting elements and trans-acting RNA-binding proteins that form and occur within a ribonucleoprotein (RNP) complex. Recent studies in the Drosophila oocyte have revealed that RNP complex assembly in the nucleus is critical for the regulation of cytoplasmic mRNA localization and translation. Furthermore, several trans-acting factors promote the reorganization of target mRNAs in the cytoplasm into higher-order RNP granules, which are often visible by light microscopy. Therefore, RNA localization and translation are likely to be coupled within these RNP granules. Notably, diverse cytoplasmic RNP granules observed in different cell types share conserved sets of proteins, suggesting they have fundamental and common cellular functions.
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Affiliation(s)
- Yasuko Kato
- Laboratory for Germline Development, RIKEN Center for Developmental Biology, Kobe, Hyogo 650-0047, Japan
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A genetic in vivo system to detect asymmetrically distributed RNA. EMBO Rep 2011; 12:1167-74. [PMID: 21921935 DOI: 10.1038/embor.2011.178] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2011] [Revised: 08/10/2011] [Accepted: 08/15/2011] [Indexed: 11/08/2022] Open
Abstract
Many RNAs show polarized or otherwise non-random subcellular distributions. To create a method for genome-wide genetic screens for RNAs with asymmetric subcellular distributions, we have combined methods for gene tagging and live imaging of messenger RNA (mRNA). A pilot screen in a highly polarized, differentiated cell in the Drosophila larva, the branched terminal cell of the tracheal system, demonstrates the feasibility of the method for identifying new asymmetrically localized mRNAs in vivo.
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Shimada Y, Burn KM, Niwa R, Cooley L. Reversible response of protein localization and microtubule organization to nutrient stress during Drosophila early oogenesis. Dev Biol 2011; 355:250-62. [PMID: 21570389 PMCID: PMC3118931 DOI: 10.1016/j.ydbio.2011.04.022] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2010] [Revised: 04/17/2011] [Accepted: 04/18/2011] [Indexed: 11/15/2022]
Abstract
The maturation of animal oocytes is highly sensitive to nutrient availability. During Drosophila oogenesis, a prominent metabolic checkpoint occurs at the onset of yolk uptake (vitellogenesis): under nutrient stress, egg chambers degenerate by apoptosis. To investigate additional responses to nutrient deprivation, we studied the intercellular transport of cytoplasmic components between nurse cells and the oocyte during previtellogenic stages. Using GFP protein-traps, we showed that Ypsilon Schachtel (Yps), a putative RNA binding protein, moved into the oocyte by both microtubule (MT)-dependent and -independent mechanisms, and was retained in the oocyte in a MT-dependent manner. These data suggest that oocyte enrichment is accomplished by a combination of MT-dependent polarized transport and MT-independent flow coupled with MT-dependent trapping within the oocyte. Under nutrient stress, Yps and other components of the oskar ribonucleoprotein complex accumulated in large processing bodies in nurse cells, accompanied by MT reorganization. This response was detected as early as 2h after starvation, suggesting that young egg chambers rapidly respond to nutrient stress. Moreover, both Yps aggregation and MT reorganization were reversed with re-feeding of females or the addition of exogenous insulin to cultured egg chambers. Our results suggest that egg chambers rapidly mount a stress response by altering intercellular transport upon starvation. This response implies a mechanism for preserving young egg chambers so that egg production can rapidly resume when nutrient availability improves.
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Affiliation(s)
- Yuko Shimada
- Department of Genetics, Yale School of Medicine, 333 Cedar Street, New Haven, CT 06520, USA
- Graduate school of Life and Environmental Sciences, University of Tsukuba, Tennoudai 1-1-1, Tsukuba, Ibaraki 305-8572, Japan
| | - K. Mahala Burn
- Department of Cell Biology, Yale School of Medicine 333 Cedar Street, New Haven, CT 06520, USA
| | - Ryusuke Niwa
- Graduate school of Life and Environmental Sciences, University of Tsukuba, Tennoudai 1-1-1, Tsukuba, Ibaraki 305-8572, Japan
- Initiative for the Promotion of Young Scientists’ Independent Research, University of Tsukuba, Tennoudai 1-1-1, Tsukuba, Ibaraki 305-8571, Japan
| | - Lynn Cooley
- Department of Genetics, Yale School of Medicine, 333 Cedar Street, New Haven, CT 06520, USA
- Department of Cell Biology, Yale School of Medicine 333 Cedar Street, New Haven, CT 06520, USA
- Department of Molecular, Cellular and Developmental Biology, Yale University, 260 Whitney Ave., New Haven, CT 05610, USA
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Vazquez-Pianzola P, Urlaub H, Suter B. Pabp binds to the osk 3'UTR and specifically contributes to osk mRNA stability and oocyte accumulation. Dev Biol 2011; 357:404-18. [PMID: 21782810 DOI: 10.1016/j.ydbio.2011.07.009] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2011] [Revised: 07/05/2011] [Accepted: 07/07/2011] [Indexed: 12/16/2022]
Abstract
RNA localization is tightly coordinated with RNA stability and translation control. Bicaudal-D (Bic-D), Egalitarian (Egl), microtubules and their motors are part of a Drosophila transport machinery that localizes mRNAs to specific cellular regions during oogenesis and embryogenesis. We identified the Poly(A)-binding protein (Pabp) as a protein that forms an RNA-dependent complex with Bic-D in embryos and ovaries. pabp also interacts genetically with Bic-D and, similar to Bic-D, pabp is essential in the germline for oocyte growth and accumulation of osk mRNA in the oocyte. In the absence of pabp, reduced stability of osk mRNA and possibly also defects in osk mRNA transport prevent normal oocyte localization of osk mRNA. pabp also interacts genetically with osk and lack of one copy of pabp(+) causes osk to become haploinsufficient. Moreover, pointing to a poly(A)-independent role, Pabp binds to A-rich sequences (ARS) in the osk 3'UTR and these turned out to be required in vivo for osk function during early oogenesis. This effect of pabp on osk mRNA is specific for this RNA and other tested mRNAs localizing to the oocyte are less and more indirectly affected by the lack of pabp.
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Fan SJ, Marchand V, Ephrussi A. Drosophila Ge-1 promotes P body formation and oskar mRNA localization. PLoS One 2011; 6:e20612. [PMID: 21655181 PMCID: PMC3105097 DOI: 10.1371/journal.pone.0020612] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2011] [Accepted: 05/05/2011] [Indexed: 11/30/2022] Open
Abstract
mRNA localization coupled with translational control is a widespread and conserved strategy that allows the localized production of proteins within eukaryotic cells. In Drosophila, oskar (osk) mRNA localization and translation at the posterior pole of the oocyte are essential for proper patterning of the embryo. Several P body components are involved in osk mRNA localization and translational repression, suggesting a link between P bodies and osk RNPs. In cultured mammalian cells, Ge-1 protein is required for P body formation. Combining genetic, biochemical and immunohistochemical approaches, we show that, in vivo, Drosophila Ge-1 (dGe-1) is an essential gene encoding a P body component that promotes formation of these structures in the germline. dGe-1 partially colocalizes with osk mRNA and is required for osk RNP integrity. Our analysis reveals that although under normal conditions dGe-1 function is not essential for osk mRNA localization, it becomes critical when other components of the localization machinery, such as staufen, Drosophila decapping protein 1 and barentsz are limiting. Our findings suggest an important role of dGe-1 in optimization of the osk mRNA localization process required for patterning the Drosophila embryo.
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Affiliation(s)
- Shih-Jung Fan
- Developmental Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Virginie Marchand
- Developmental Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Anne Ephrussi
- Developmental Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany
- * E-mail:
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Patterson JR, Wood MP, Schisa J. Assembly of RNP granules in stressed and aging oocytes requires nucleoporins and is coordinated with nuclear membrane blebbing. Dev Biol 2011; 353:173-85. [PMID: 21382369 PMCID: PMC3096477 DOI: 10.1016/j.ydbio.2011.02.028] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2010] [Revised: 02/02/2011] [Accepted: 02/02/2011] [Indexed: 01/19/2023]
Abstract
Protective cellular responses to stress and aging in the germline are essential for perpetuation of a species; however, relatively few studies have focused on how germ cells respond to stress and aging. We have previously shown that large ribonucleoprotein (RNP) complexes assemble in oocytes of Caenorhabditis during extended meiotic arrest or after environmental stress. Here we explore the regulation of these dynamic RNPs and demonstrate their assembly is coordinated with dramatic, nuclear membrane blebbing in oocytes. Our ultrastructural analyses reveal distinct changes in the endoplasmic reticulum, and the first evidence for the assembly of stacked annulate lamellae in Caenorhabditis. We further show several nucleoporins are required for the complete assembly of RNP granules, and a disruption in RNP granule assembly coupled with a low frequency of nuclear blebbing in arrested oocytes negatively impacts embryonic viability. Our observations support a model where nuclear membrane blebbing is required to increase the trafficking of nucleoporins to the cell cortex in stressed or meiotically arrested cells and to facilitate the recruitment of RNA and protein components of RNPs into large complexes. These new insights may have general implications for better understanding how germ cells preserve their integrity when fertilization is delayed and how cells respond to stress.
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Affiliation(s)
- Joseph R. Patterson
- Central Michigan University, Department of Biology, Mount Pleasant, MI 48859
| | - Megan P. Wood
- Central Michigan University, Department of Biology, Mount Pleasant, MI 48859
| | - Jennifer Schisa
- Central Michigan University, Department of Biology, Mount Pleasant, MI 48859
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Olivieri D, Sykora MM, Sachidanandam R, Mechtler K, Brennecke J. An in vivo RNAi assay identifies major genetic and cellular requirements for primary piRNA biogenesis in Drosophila. EMBO J 2010; 29:3301-17. [PMID: 20818334 DOI: 10.1038/emboj.2010.212] [Citation(s) in RCA: 215] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2010] [Accepted: 08/10/2010] [Indexed: 11/09/2022] Open
Abstract
In Drosophila, PIWI proteins and bound PIWI-interacting RNAs (piRNAs) form the core of a small RNA-mediated defense system against selfish genetic elements. Within germline cells, piRNAs are processed from piRNA clusters and transposons to be loaded into Piwi/Aubergine/AGO3 and a subset of piRNAs undergoes target-dependent amplification. In contrast, gonadal somatic support cells express only Piwi, lack signs of piRNA amplification and exhibit primary piRNA biogenesis from piRNA clusters. Neither piRNA processing/loading nor Piwi-mediated target silencing is understood at the genetic, cellular or molecular level. We developed an in vivo RNAi assay for the somatic piRNA pathway and identified the RNA helicase Armitage, the Tudor domain containing RNA helicase Yb and the putative nuclease Zucchini as essential factors for primary piRNA biogenesis. Lack of any of these proteins leads to transposon de-silencing, to a collapse in piRNA levels and to a failure in Piwi-nuclear accumulation. We show that Armitage and Yb interact physically and co-localize in cytoplasmic Yb bodies, which flank P bodies. Loss of Zucchini leads to an accumulation of Piwi and Armitage in Yb bodies, indicating that Yb bodies are sites of primary piRNA biogenesis.
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Affiliation(s)
- Daniel Olivieri
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna, Austria
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Schaefer M, Pollex T, Hanna K, Tuorto F, Meusburger M, Helm M, Lyko F. RNA methylation by Dnmt2 protects transfer RNAs against stress-induced cleavage. Genes Dev 2010; 24:1590-5. [PMID: 20679393 DOI: 10.1101/gad.586710] [Citation(s) in RCA: 556] [Impact Index Per Article: 37.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Dnmt2 proteins are the most conserved members of the DNA methyltransferase enzyme family, but their substrate specificity and biological functions have been a subject of controversy. We show here that, in addition to tRNA(Asp-GTC), tRNA(Val-AAC) and tRNA(Gly-GCC) are also methylated by Dnmt2. Drosophila Dnmt2 mutants showed reduced viability under stress conditions, and Dnmt2 relocalized to stress granules following heat shock. Strikingly, stress-induced cleavage of tRNAs was Dnmt2-dependent, and Dnmt2-mediated methylation protected tRNAs against ribonuclease cleavage. These results uncover a novel biological function of Dnmt2-mediated tRNA methylation, and suggest a role for Dnmt2 enzymes during the biogenesis of tRNA-derived small RNAs.
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Affiliation(s)
- Matthias Schaefer
- Division of Epigenetics, DKFZ-ZMBH Alliance, German Cancer Research Center, Heidelberg 69120, Germany
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Ewen-Campen B, Schwager EE, Extavour CGM. The molecular machinery of germ line specification. Mol Reprod Dev 2010; 77:3-18. [PMID: 19790240 DOI: 10.1002/mrd.21091] [Citation(s) in RCA: 129] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Germ cells occupy a unique position in animal reproduction, development, and evolution. In sexually reproducing animals, only they can produce gametes and contribute genetically to subsequent generations. Nonetheless, germ line specification during embryogenesis is conceptually the same as the specification of any somatic cell type: germ cells must activate a specific gene regulatory network in order to differentiate and go through gametogenesis. While many genes with critical roles in the germ line have been characterized with respect to expression pattern and genetic interactions, it is the molecular interactions of the relevant gene products that are ultimately responsible for germ cell differentiation. This review summarizes the current state of knowledge on the molecular functions and biochemical connections between germ line gene products. We find that homologous genes often interact physically with the same conserved molecular partners across the metazoans. We also point out cases of nonhomologous genes from different species whose gene products play analogous biological roles in the germ line. We suggest a preliminary molecular definition of an ancestral "pluripotency module" that could have been modified during metazoan evolution to become specific to the germ line.
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Affiliation(s)
- Ben Ewen-Campen
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, Massachusetts, USA
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Checkley MA, Nagashima K, Lockett SJ, Nyswaner KM, Garfinkel DJ. P-body components are required for Ty1 retrotransposition during assembly of retrotransposition-competent virus-like particles. Mol Cell Biol 2010; 30:382-98. [PMID: 19901074 PMCID: PMC2798465 DOI: 10.1128/mcb.00251-09] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2009] [Revised: 04/20/2009] [Accepted: 10/29/2009] [Indexed: 01/24/2023] Open
Abstract
Ty1 is a retrovirus-like retrotransposon whose replication is influenced by diverse cellular processes in Saccharomyces cerevisiae. We have identified cytoplasmic P-body components encoded by DHH1, KEM1, LSM1, and PAT1 as cofactors that posttranscriptionally enhance Ty1 retrotransposition. Using fluorescent in situ hybridization and immunofluorescence microscopy, we found that Ty1 mRNA and Gag colocalize to discrete cytoplasmic foci in wild-type cells. These foci, which are distinct from P-bodies, do not form in P-body component mutants or under conditions suboptimal for retrotransposition. Our immunoelectron microscopy (IEM) data suggest that mRNA/Gag foci are sites where virus-like particles (VLPs) cluster. Overexpression of Ty1 leads to a large increase in retrotransposition in wild-type cells, which allows VLPs to be detected by IEM. However, retrotransposition is still reduced in P-body component mutants under these conditions. Moreover, the percentage of Ty1 mRNA/Gag foci and VLP clusters and levels of integrase and reverse transcriptase are reduced in these mutants. Ty1 antisense RNAs, which have been reported to inhibit Ty1 transposition, are more abundant in the kem1Delta mutant and colocalize with Ty1 mRNA in the cytoplasm. Therefore, Kem1p may prevent the aggregation of Ty1 antisense and mRNAs. Overall, our results suggest that P-body components enhance the formation of retrotransposition-competent Ty1 VLPs.
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Affiliation(s)
- Mary Ann Checkley
- Gene Regulation and Chromosome Biology Laboratory, Center for Cancer Research National Cancer Institute, Frederick, Maryland 21702-1201, Advanced Technology Program, SAIC—Frederick, Inc., NCI—Frederick, Frederick, Maryland 21702-1201
| | - Kunio Nagashima
- Gene Regulation and Chromosome Biology Laboratory, Center for Cancer Research National Cancer Institute, Frederick, Maryland 21702-1201, Advanced Technology Program, SAIC—Frederick, Inc., NCI—Frederick, Frederick, Maryland 21702-1201
| | - Stephen J. Lockett
- Gene Regulation and Chromosome Biology Laboratory, Center for Cancer Research National Cancer Institute, Frederick, Maryland 21702-1201, Advanced Technology Program, SAIC—Frederick, Inc., NCI—Frederick, Frederick, Maryland 21702-1201
| | - Katherine M. Nyswaner
- Gene Regulation and Chromosome Biology Laboratory, Center for Cancer Research National Cancer Institute, Frederick, Maryland 21702-1201, Advanced Technology Program, SAIC—Frederick, Inc., NCI—Frederick, Frederick, Maryland 21702-1201
| | - David J. Garfinkel
- Gene Regulation and Chromosome Biology Laboratory, Center for Cancer Research National Cancer Institute, Frederick, Maryland 21702-1201, Advanced Technology Program, SAIC—Frederick, Inc., NCI—Frederick, Frederick, Maryland 21702-1201
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Maisonneuve C, Guilleret I, Vick P, Weber T, Andre P, Beyer T, Blum M, Constam DB. Bicaudal C, a novel regulator of Dvl signaling abutting RNA-processing bodies, controls cilia orientation and leftward flow. Development 2009; 136:3019-30. [PMID: 19666828 DOI: 10.1242/dev.038174] [Citation(s) in RCA: 104] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Polycystic diseases and left-right (LR) axis malformations are frequently linked to cilia defects. Renal cysts also arise in mice and frogs lacking Bicaudal C (BicC), a conserved RNA-binding protein containing K-homology (KH) domains and a sterile alpha motif (SAM). However, a role for BicC in cilia function has not been demonstrated. Here, we report that targeted inactivation of BicC randomizes left-right (LR) asymmetry by disrupting the planar alignment of motile cilia required for cilia-driven fluid flow. Furthermore, depending on its SAM domain, BicC can uncouple Dvl2 signaling from the canonical Wnt pathway, which has been implicated in antagonizing planar cell polarity (PCP). The SAM domain concentrates BicC in cytoplasmic structures harboring RNA-processing bodies (P-bodies) and Dvl2. These results suggest a model whereby BicC links the orientation of cilia with PCP, possibly by regulating RNA silencing in P-bodies.
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Translational control during early development. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2009; 90:211-54. [PMID: 20374743 DOI: 10.1016/s1877-1173(09)90006-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Translational control of specific messenger RNAs, which themselves are often asymmetrically localized within the cytoplasm of a cell, underlies many events in germline development, and in embryonic axis specification. This comprehensive, but by no means exhaustive, review attempts to present a picture of the present state of knowledge about mechanisms underlying mRNA localization and translational control of specific mRNAs that are mediated by trans-acting protein factors. While RNA localization and translational control are widespread in evolution and have been studied in many experimental systems, this article will focus mainly on three particularly well-characterized systems: Drosophila, Caenorhabditis elegans, and Xenopus. In keeping with the overall theme of this volume, instances in which translational control factors have been linked to human disease states will also be discussed.
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Lim AK, Tao L, Kai T. piRNAs mediate posttranscriptional retroelement silencing and localization to pi-bodies in the Drosophila germline. ACTA ACUST UNITED AC 2009; 186:333-42. [PMID: 19651888 PMCID: PMC2728408 DOI: 10.1083/jcb.200904063] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Nuage, a well-conserved perinuclear organelle found in germline cells, is thought to mediate retroelement repression in Drosophila melanogaster by regulating the production of Piwi-interacting RNAs (piRNAs). In this study, we present evidence that the nuage-piRNA pathway components can be found in cytoplasmic foci that also contain retroelement transcripts, antisense piRNAs, and proteins involved in messenger RNA (mRNA) degradation. These mRNA degradation proteins, decapping protein 1/2 (DCP1/2), Me31B (maternal expression at 31B), and pacman (PCM), are normally thought of as components of processing bodies. In spindle-E (spn-E) and aubergine (aub) mutants that lack piRNA production, piRNA pathway proteins no longer overlap the mRNA degradation proteins. Concomitantly, spn-E and aub mutant ovaries show an accumulation of full-length retroelement transcripts and prolonged stabilization of HeT-A mRNA, supporting the role of piRNAs in mediating posttranscriptional retroelement silencing. HeT-A mRNA is derepressed in mRNA degradation mutants twin, dcp1, and ski3, indicating that these enzymes also aid in removing full-length transcripts and/or decay intermediates.
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Affiliation(s)
- Ai Khim Lim
- Temasek Life Sciences Laboratory, The National University of Singapore, 117604 Singapore
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Lee L, Davies SE, Liu JL. The spinal muscular atrophy protein SMN affects Drosophila germline nuclear organization through the U body-P body pathway. Dev Biol 2009; 332:142-55. [PMID: 19464282 DOI: 10.1016/j.ydbio.2009.05.553] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2008] [Revised: 05/15/2009] [Accepted: 05/15/2009] [Indexed: 11/19/2022]
Abstract
Survival motor neuron protein (SMN) is the determining factor for the human neurodegenerative disease spinal muscular atrophy (SMA). SMN is critical for small nuclear ribonucleoprotein (snRNP) assembly. Using Drosophila oogenesis as a model system, we show that mutations in smn cause abnormal nuclear organization in nurse cells and oocytes. Germline and mitotic clonal analysis reveals that both nurse cells and oocytes require SMN to maintain normal organization of nuclear compartments including chromosomes, nucleoli, Cajal bodies and histone locus bodies. We previously found that SMN-containing U bodies invariably associate with P bodies (Liu, J. L., and Gall, J. G. (2007). U bodies are cytoplasmic structures that contain uridine-rich small nuclear ribonucleoproteins and associate with P bodies. Proc. Natl. Acad. Sci. U. S. A. 104, 11655-11659.). Multiple lines of evidence implicate SMN in the regulation of germline nuclear organization through the connection of U bodies and P bodies. Firstly, smn germline clones phenocopy mutations for two P body components, Cup and Ovarian tumour (Otu). Secondly, P body mutations disrupt SMN distribution and the organization of U bodies. Finally, mutations in smn disrupt the function and organization of U bodies and P bodies. Taken together, our results suggest that SMN is required for the functional integrity of the U body-P body pathway, which in turn is important for maintaining proper nuclear architecture.
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Affiliation(s)
- Lin Lee
- Medical Research Council Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, Henry Wellcome Building for Gene Function, University of Oxford, Oxford OX1 3QX, UK
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Snee MJ, Macdonald PM. Bicaudal C and trailer hitch have similar roles in gurken mRNA localization and cytoskeletal organization. Dev Biol 2009; 328:434-44. [PMID: 19217894 PMCID: PMC2850203 DOI: 10.1016/j.ydbio.2009.02.003] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2008] [Revised: 01/13/2009] [Accepted: 02/03/2009] [Indexed: 01/16/2023]
Abstract
Bicaudal C and trailer hitch are both required for dorsoventral patterning of the Drosophila oocyte. Each mutant produces ventralized eggs, a phenotype typically associated with failure of the oocyte to provide a dorsalization signal--the Gurken protein--to the follicle cells. Bicaudal C and trailer hitch are both implicated in post-transcriptional gene regulation. Bicaudal C acts in recruiting a deadenylase to specific mRNAs, leading to translational repression. The role of trailer hitch is less well defined, but mutants have defects in protein secretion, and show aberrant distribution of an endoplasmic reticulum exit site marker whose mRNA is associated with Trailer hitch protein. We show that Bicaudal C and trailer hitch interact genetically. Mutants of these two genes have shared defects in localization of gurken and other anteriorly-localized mRNAs, as well as altered microtubule organization which may underlie the mRNA localization defects. Bicaudal C and trailer hitch mutants also share a syndrome of actin-related abnormalities, including the formation of ectopic actin cages near the anterior of the oocyte. The cages sequester Gurken protein, blocking its secretion and thus interfering with signaling of the follicle cells to specify dorsal fate.
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Affiliation(s)
- Mark J Snee
- Institute for Cellular and Molecular Biology, Section of Molecular, Cell, and Developmental Biology, University of Texas, Austin, Texas 78712, USA
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