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Pamula MC, Lehmann R. How germ granules promote germ cell fate. Nat Rev Genet 2024:10.1038/s41576-024-00744-8. [PMID: 38890558 DOI: 10.1038/s41576-024-00744-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/08/2024] [Indexed: 06/20/2024]
Abstract
Germ cells are the only cells in the body capable of giving rise to a new organism, and this totipotency hinges on their ability to assemble membraneless germ granules. These specialized RNA and protein complexes are hallmarks of germ cells throughout their life cycle: as embryonic germ granules in late oocytes and zygotes, Balbiani bodies in immature oocytes, and nuage in maturing gametes. Decades of developmental, genetic and biochemical studies have identified protein and RNA constituents unique to germ granules and have implicated these in germ cell identity, genome integrity and gamete differentiation. Now, emerging research is defining germ granules as biomolecular condensates that achieve high molecular concentrations by phase separation, and it is assigning distinct roles to germ granules during different stages of germline development. This organization of the germ cell cytoplasm into cellular subcompartments seems to be critical not only for the flawless continuity through the germline life cycle within the developing organism but also for the success of the next generation.
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Affiliation(s)
| | - Ruth Lehmann
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA.
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA.
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2
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Siddiqui NU, Karaiskakis A, Goldman AL, Eagle WVI, Low TCH, Luo H, Smibert CA, Gavis ER, Lipshitz HD. Smaug regulates germ plasm assembly and primordial germ cell number in Drosophila embryos. SCIENCE ADVANCES 2024; 10:eadg7894. [PMID: 38608012 PMCID: PMC11014450 DOI: 10.1126/sciadv.adg7894] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2023] [Accepted: 03/12/2024] [Indexed: 04/14/2024]
Abstract
During Drosophila oogenesis, the Oskar (OSK) RNA binding protein (RBP) determines the amount of germ plasm that assembles at the posterior pole of the oocyte. Here, we identify mechanisms that subsequently regulate germ plasm assembly in the early embryo. We show that the Smaug (SMG) RBP is transported into the germ plasm of the early embryo where it accumulates in the germ granules. SMG binds to and represses translation of the osk messenger RNA (mRNA) as well as the bruno 1 (bru1) mRNA, which encodes an RBP that we show promotes germ plasm production. Loss of SMG or mutation of SMG's binding sites in the osk or bru1 mRNA results in excess translation of these transcripts in the germ plasm, accumulation of excess germ plasm, and budding of excess primordial germ cells (PGCs). Therefore, SMG triggers a posttranscriptional regulatory pathway that attenuates the amount of germ plasm in embryos to modulate the number of PGCs.
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Affiliation(s)
- Najeeb U. Siddiqui
- Department of Molecular Genetics, University of Toronto, 661 University Avenue, Toronto, ON M5G 1M1, Canada
- Program in Developmental and Stem Cell Biology, Research Institute, Hospital for Sick Children, Toronto, ON M5G 0A4, Canada
| | - Angelo Karaiskakis
- Department of Molecular Genetics, University of Toronto, 661 University Avenue, Toronto, ON M5G 1M1, Canada
| | - Aaron L. Goldman
- Department of Molecular Genetics, University of Toronto, 661 University Avenue, Toronto, ON M5G 1M1, Canada
- Program in Developmental and Stem Cell Biology, Research Institute, Hospital for Sick Children, Toronto, ON M5G 0A4, Canada
| | - Whitby V. I. Eagle
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Timothy C. H. Low
- Department of Molecular Genetics, University of Toronto, 661 University Avenue, Toronto, ON M5G 1M1, Canada
| | - Hua Luo
- Department of Molecular Genetics, University of Toronto, 661 University Avenue, Toronto, ON M5G 1M1, Canada
| | - Craig A. Smibert
- Department of Molecular Genetics, University of Toronto, 661 University Avenue, Toronto, ON M5G 1M1, Canada
- Department of Biochemistry, University of Toronto, 661 University Avenue, Toronto, ON M5G 1M1, Canada
| | - Elizabeth R. Gavis
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Howard D. Lipshitz
- Department of Molecular Genetics, University of Toronto, 661 University Avenue, Toronto, ON M5G 1M1, Canada
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3
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Salgania HK, Metz J, Jeske M. ReLo is a simple and rapid colocalization assay to identify and characterize direct protein-protein interactions. Nat Commun 2024; 15:2875. [PMID: 38570497 PMCID: PMC10991417 DOI: 10.1038/s41467-024-47233-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2022] [Accepted: 03/22/2024] [Indexed: 04/05/2024] Open
Abstract
The characterization of protein-protein interactions (PPIs) is fundamental to the understanding of biochemical processes. Many methods have been established to identify and study direct PPIs; however, screening and investigating PPIs involving large or poorly soluble proteins remains challenging. Here, we introduce ReLo, a simple, rapid, and versatile cell culture-based method for detecting and investigating interactions in a cellular context. Our experiments demonstrate that ReLo specifically detects direct binary PPIs. Furthermore, we show that ReLo bridging experiments can also be used to determine the binding topology of subunits within multiprotein complexes. In addition, ReLo facilitates the identification of protein domains that mediate complex formation, allows screening for interfering point mutations, and it is sensitive to drugs that mediate or disrupt an interaction. In summary, ReLo is a simple and rapid alternative for the study of PPIs, especially when studying structurally complex proteins or when established methods fail.
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Affiliation(s)
- Harpreet Kaur Salgania
- Heidelberg University Biochemistry Center (BZH), Im Neuenheimer Feld 328, 69120, Heidelberg, Germany
| | - Jutta Metz
- Heidelberg University Biochemistry Center (BZH), Im Neuenheimer Feld 328, 69120, Heidelberg, Germany
| | - Mandy Jeske
- Heidelberg University Biochemistry Center (BZH), Im Neuenheimer Feld 328, 69120, Heidelberg, Germany.
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4
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Warden M, DeRose E, Tamayo J, Mueller G, Gavis E, Hall T. The translational repressor Glorund uses interchangeable RNA recognition domains to recognize Drosophila nanos. Nucleic Acids Res 2023; 51:8836-8849. [PMID: 37427795 PMCID: PMC10484662 DOI: 10.1093/nar/gkad586] [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: 04/12/2023] [Revised: 06/01/2023] [Accepted: 06/30/2023] [Indexed: 07/11/2023] Open
Abstract
The Drosophila melanogaster protein Glorund (Glo) represses nanos (nos) translation and uses its quasi-RNA recognition motifs (qRRMs) to recognize both G-tract and structured UA-rich motifs within the nos translational control element (TCE). We showed previously that each of the three qRRMs is multifunctional, capable of binding to G-tract and UA-rich motifs, yet if and how the qRRMs combine to recognize the nos TCE remained unclear. Here we determined solution structures of a nos TCEI_III RNA containing the G-tract and UA-rich motifs. The RNA structure demonstrated that a single qRRM is physically incapable of recognizing both RNA elements simultaneously. In vivo experiments further indicated that any two qRRMs are sufficient to repress nos translation. We probed interactions of Glo qRRMs with TCEI_III RNA using NMR paramagnetic relaxation experiments. Our in vitro and in vivo data support a model whereby tandem Glo qRRMs are indeed multifunctional and interchangeable for recognition of TCE G-tract or UA-rich motifs. This study illustrates how multiple RNA recognition modules within an RNA-binding protein may combine to diversify the RNAs that are recognized and regulated.
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Affiliation(s)
- Meghan S Warden
- Epigenetics and Stem Cell Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Eugene F DeRose
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Joel V Tamayo
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Geoffrey A Mueller
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Elizabeth R Gavis
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Traci M Tanaka Hall
- Epigenetics and Stem Cell Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
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5
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Pieplow C, Wessel G. Functional annotation of a hugely expanded nanos repertoire in Lytechinus variegatus, the green sea urchin. Mol Reprod Dev 2023; 90:310-322. [PMID: 37039283 PMCID: PMC10225336 DOI: 10.1002/mrd.23684] [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: 11/21/2022] [Revised: 02/17/2023] [Accepted: 03/18/2023] [Indexed: 04/12/2023]
Abstract
Nanos genes encode essential RNA-binding proteins involved in germline determination and germline stem cell maintenance. When examining diverse classes of echinoderms, typically three, sometimes four, nanos genes are present. In this analysis, we identify and annotate nine nanos orthologs in the green sea urchin, Lytechinus variegatus (Lv). All nine genes are transcribed and grouped into three distinct classes. Class one includes the germline Nanos, with one member: Nanos2. Class two includes Nanos3-like genes, with significant sequence similarity to Nanos3 in the purple sea urchin, Strongylocentrotus purpuratus (Sp), but with wildly variable expression patterns. The third class includes several previously undescribed nanos zinc-finger genes that may be the result of duplications of Nanos2. All nine nanos transcripts occupy unique genomic loci and are expressed with unique temporal profiles during development. Importantly, here we describe and characterize the unique genomic location, conservation, and phylogeny of the Lv ortholog of the well-studied Sp Nanos2. However, in addition to the conserved germline functioning Nanos2, the green sea urchin appears to be an outlier in the echinoderm phyla with eight additional nanos genes. We hypothesize that this expansion of nanos gene members may be the result of a previously uncharacterized L1-class transposon encoded on the opposite strand of a nanos2 pseudogene present on chromosome 12 in this species. The expansion of nanos genes described here represents intriguing insights into germline specification and nanos evolution in this species of sea urchin.
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Affiliation(s)
- Cosmo Pieplow
- MCB Department, Division of Biomedicine, Brown University, Providence RI 02912
| | - Gary Wessel
- MCB Department, Division of Biomedicine, Brown University, Providence RI 02912
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6
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Siddiqui NU, Karaiskakis A, Goldman AL, Eagle WV, Smibert CA, Gavis ER, Lipshitz HD. Smaug regulates germ plasm synthesis and primordial germ cell number in Drosophila embryos by repressing the oskar and bruno 1 mRNAs. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.27.530189. [PMID: 36909513 PMCID: PMC10002672 DOI: 10.1101/2023.02.27.530189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/02/2023]
Abstract
During Drosophila oogenesis, the Oskar (OSK) RNA-binding protein (RBP) determines the amount of germ plasm that assembles at the posterior pole of the oocyte. Here we identify the mechanisms that regulate the osk mRNA in the early embryo. We show that the Smaug (SMG) RBP is transported into the germ plasm of the early embryo where it accumulates in the germ granules. SMG binds to and represses translation of the osk mRNA itself as well as the bruno 1 (bru1) mRNA, which encodes an RBP that we show promotes germ plasm production. Loss of SMG or mutation of SMG's binding sites in the osk or bru1 mRNAs results in ectopic translation of these transcripts in the germ plasm and excess PGCs. SMG therefore triggers a post-transcriptional regulatory pathway that attenuates germ plasm synthesis in embryos, thus modulating the number of PGCs.
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Affiliation(s)
- Najeeb U. Siddiqui
- Department of Molecular Genetics, University of Toronto, 661 University Avenue, Toronto, Ontario, Canada M5G 1M1
- Program in Developmental & Stem Cell Biology, Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada M5G 0A4
| | - Angelo Karaiskakis
- Department of Molecular Genetics, University of Toronto, 661 University Avenue, Toronto, Ontario, Canada M5G 1M1
| | - Aaron L. Goldman
- Department of Molecular Genetics, University of Toronto, 661 University Avenue, Toronto, Ontario, Canada M5G 1M1
- Program in Developmental & Stem Cell Biology, Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada M5G 0A4
| | - Whitby V.I. Eagle
- Department of Molecular Biology, Princeton University, Princeton, New Jersey 08544, USA
| | - Craig A. Smibert
- Department of Molecular Genetics, University of Toronto, 661 University Avenue, Toronto, Ontario, Canada M5G 1M1
- Department of Biochemistry, University of Toronto, 661 University Avenue, Toronto, Ontario, Canada M5G 1M1
| | - Elizabeth R. Gavis
- Department of Molecular Biology, Princeton University, Princeton, New Jersey 08544, USA
| | - Howard D. Lipshitz
- Department of Molecular Genetics, University of Toronto, 661 University Avenue, Toronto, Ontario, Canada M5G 1M1
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7
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Wang XY, Zhang LN. RNA binding protein SAMD4: current knowledge and future perspectives. Cell Biosci 2023; 13:21. [PMID: 36732864 PMCID: PMC9893680 DOI: 10.1186/s13578-023-00968-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Accepted: 01/22/2023] [Indexed: 02/04/2023] Open
Abstract
SAMD4 protein family is a class of novel RNA-binding proteins that can mediate post-transcriptional regulation and translation repression in eukaryotes, which are highly conserved from yeast to humans during evolution. In mammalian cells, SAMD4 protein family consists of two members including SAMD4A/Smaug1 and SAMD4B/Smaug2, both of which contain common SAM domain that can specifically bind to different target mRNAs through stem-loop structures, also known as Smaug recognition elements (SREs), and regulate the mRNA stability, degradation and translation. In addition, SAMD4 can form the cytoplasmic mRNA silencing foci and regulate the translation of SRE-containing mRNAs in neurons. SAMD4 also can form the cytosolic membrane-less organelles (MLOs), termed as Smaug1 bodies, and regulate mitochondrial function. Importantly, many studies have identified that SAMD4 family members are involved in various pathological processes including myopathy, bone development, neural development, and cancer occurrence and progression. In this review, we mainly summarize the structural characteristics, biological functions and molecular regulatory mechanisms of SAMD4 protein family members, which will provide a basis for further research and clinical application of SAMD4 protein family.
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Affiliation(s)
- Xin-Ya Wang
- grid.28703.3e0000 0000 9040 3743Beijing International Science and Technology Cooperation Base of Antivirus Drug, Faculty of Environment and Life, Beijing University of Technology, 100124 Beijing, People’s Republic of China
| | - Li-Na Zhang
- grid.28703.3e0000 0000 9040 3743Beijing International Science and Technology Cooperation Base of Antivirus Drug, Faculty of Environment and Life, Beijing University of Technology, 100124 Beijing, People’s Republic of China
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8
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Peng Y, Gavis ER. The Drosophila hnRNP F/H homolog Glorund recruits dFMRP to inhibit nanos translation elongation. Nucleic Acids Res 2022; 50:7067-7083. [PMID: 35699205 PMCID: PMC9262583 DOI: 10.1093/nar/gkac500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Revised: 05/24/2022] [Accepted: 05/27/2022] [Indexed: 12/24/2022] Open
Abstract
Translational control of maternal mRNAs generates spatial and temporal patterns of protein expression necessary to begin animal development. Translational repression of unlocalized nanos (nos) mRNA in late-stage Drosophila oocytes by the hnRNP F/H homolog, Glorund (Glo), is important for embryonic body patterning. While previous work has suggested that repression occurs at both the translation initiation and elongation phases, the molecular mechanism by which Glo regulates nos translation remains elusive. Here, we have identified the Drosophila fragile X mental retardation protein, dFMRP, as a Glo interaction partner with links to the translational machinery. Using an oocyte-based in vitro translation system, we confirmed that Glo regulates both initiation and elongation of a nos translational reporter and showed that dFMRP specifically represses translation elongation and promotes ribosome stalling. Furthermore, we combined mutational analysis and in vivo and in vitro binding assays to show that Glo's qRRM2 domain specifically and directly interacts with dFMRP. Our findings suggest that Glo regulates nos translation elongation by recruiting dFMRP and that Glo's RNA-binding domains can also function as protein-protein interaction interfaces critical for its regulatory functions. Additionally, they reveal a mechanism for targeting dFMRP to specific transcripts.
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Affiliation(s)
- Yingshi Peng
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
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9
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Arsala D, Wu X, Yi SV, Lynch JA. Dnmt1a is essential for gene body methylation and the regulation of the zygotic genome in a wasp. PLoS Genet 2022; 18:e1010181. [PMID: 35522715 PMCID: PMC9075658 DOI: 10.1371/journal.pgen.1010181] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Accepted: 04/01/2022] [Indexed: 11/19/2022] Open
Abstract
Gene body methylation (GBM) is an ancestral mode of DNA methylation whose role in development has been obscured by the more prominent roles of promoter and CpG island methylation. The wasp Nasonia vitripennis has little promoter and CpG island methylation, yet retains strong GBM, making it an excellent model for elucidating the roles of GBM. Here we show that N. vitripennis DNA methyltransferase 1a (Nv-Dnmt1a) knockdown leads to failures in cellularization and gastrulation of the embryo. Both of these disrupted events are hallmarks of the maternal-zygotic transition (MZT) in insects. Analysis of the embryonic transcriptome and methylome revealed strong reduction of GBM and widespread disruption of gene expression during embryogenesis after Nv-Dnmt1a knockdown. Strikingly, there was a strong correlation between loss of GBM and reduced gene expression in thousands of methylated loci, consistent with the hypothesis that GBM directly facilitates high levels of transcription. We propose that lower expression levels of methylated genes due to reduced GBM is the crucial direct effect of Nv-Dnmt1 knockdown. Subsequently, the disruption of methylated genes leads to downstream dysregulation of the MZT, culminating in developmental failure at gastrulation.
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Affiliation(s)
- Deanna Arsala
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, Illinois, United States of America
- Department of Ecology & Evolution, University of Chicago, Chicago, Illinois, United States of America
| | - Xin Wu
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia, United States of America
| | - Soojin V. Yi
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia, United States of America
- Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara, Santa Barbara, California, United States of America
| | - Jeremy A. Lynch
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, Illinois, United States of America
- * E-mail:
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10
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When Down Is Up: Heterochromatin, Nuclear Organization and X Upregulation. Cells 2021; 10:cells10123416. [PMID: 34943924 PMCID: PMC8700316 DOI: 10.3390/cells10123416] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Revised: 11/29/2021] [Accepted: 12/01/2021] [Indexed: 12/21/2022] Open
Abstract
Organisms with highly differentiated sex chromosomes face an imbalance in X-linked gene dosage. Male Drosophila solve this problem by increasing expression from virtually every gene on their single X chromosome, a process known as dosage compensation. This involves a ribonucleoprotein complex that is recruited to active, X-linked genes to remodel chromatin and increase expression. Interestingly, the male X chromosome is also enriched for several proteins associated with heterochromatin. Furthermore, the polytenized male X is selectively disrupted by the loss of factors involved in repression, silencing, heterochromatin formation or chromatin remodeling. Mutations in many of these factors preferentially reduce male survival or enhance the lethality of mutations that prevent normal recognition of the X chromosome. The involvement of primarily repressive factors in a process that elevates expression has long been puzzling. Interestingly, recent work suggests that the siRNA pathway, often associated with heterochromatin formation and repression, also helps the dosage compensation machinery identify the X chromosome. In light of this finding, we revisit the evidence that links nuclear organization and heterochromatin to regulation of the male X chromosome.
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11
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Cao WX, Karaiskakis A, Lin S, Angers S, Lipshitz HD. The F-box protein Bard (CG14317) targets the Smaug RNA-binding protein for destruction during the Drosophila maternal-to-zygotic transition. Genetics 2021; 220:6404591. [PMID: 34757425 PMCID: PMC8733446 DOI: 10.1093/genetics/iyab177] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Accepted: 10/11/2021] [Indexed: 01/12/2023] Open
Abstract
During the maternal-to-zygotic transition (MZT), which encompasses the earliest stages of animal embryogenesis, a subset of maternally supplied gene products is cleared, thus permitting activation of zygotic gene expression. In the Drosophila melanogaster embryo, the RNA-binding protein Smaug (SMG) plays an essential role in progression through the MZT by translationally repressing and destabilizing a large number of maternal mRNAs. The SMG protein itself is rapidly cleared at the end of the MZT by a Skp/Cullin/F-box (SCF) E3-ligase complex. Clearance of SMG requires zygotic transcription and is required for an orderly MZT. Here, we show that an F-box protein, which we name Bard (encoded by CG14317), is required for degradation of SMG. Bard is expressed zygotically and physically interacts with SMG at the end of the MZT, coincident with binding of the maternal SCF proteins, SkpA and Cullin1, and with degradation of SMG. shRNA-mediated knock-down of Bard or deletion of the bard gene in the early embryo results in stabilization of SMG protein, a phenotype that is rescued by transgenes expressing Bard. Bard thus times the clearance of SMG at the end of the MZT.
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Affiliation(s)
- Wen Xi Cao
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5G 1M1, Canada
| | - Angelo Karaiskakis
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5G 1M1, Canada
| | - Sichun Lin
- Department of Pharmaceutical Sciences & Donnelly Centre, University of Toronto, Toronto, ON M5S 3E1, Canada
| | - Stephane Angers
- Department of Pharmaceutical Sciences & Donnelly Centre, University of Toronto, Toronto, ON M5S 3E1, Canada
| | - Howard D Lipshitz
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5G 1M1, Canada
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12
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Zhou M, Wang B, Li H, Han J, Li A, Lu W. RNA-binding protein SAMD4A inhibits breast tumor angiogenesis by modulating the balance of angiogenesis program. Cancer Sci 2021; 112:3835-3845. [PMID: 34219323 PMCID: PMC8409301 DOI: 10.1111/cas.15053] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Revised: 06/22/2021] [Accepted: 06/29/2021] [Indexed: 12/13/2022] Open
Abstract
Tumor-induced angiogenesis is important for further progression of solid tumors. The initiation of tumor angiogenesis is dictated by a shift in the balance between proangiogenic and antiangiogenic gene expression programs. However, the potential mechanism controlling the expression of angiogenesis-related genes in the tumor cells, especially the process mediated by RNA-binding protein (RBP) remains unclear. SAMD4A is a conserved RBP across fly to mammals, and is believed to play an important role in controlling gene translation and stability. In this study, we identified the potential role of SAMD4A in modulating angiogenesis-related gene expression and tumor progression in breast cancer. SAMD4A expression was repressed in breast cancer tissues and cells and low SAMD4A expression in human breast tumor samples was strongly associated with poor survival of patients. Overexpression of SAMD4A inhibited breast tumor angiogenesis and caner progression, whereas knockdown of SAMD4A demonstrated a reversed effect. Mechanistically, SAMD4A was found to specifically destabilize the proangiogenic gene transcripts, including C-X-C motif chemokine ligand 5 (CXCL5), endoglin (ENG), interleukin 1β (IL1β), and angiopoietin 1 (ANGPT1), by directly interacting with the stem-loop structure in the 3' untranslated region (3'UTR) of these mRNAs through its sterile alpha motif (SAM) domain, resulting in the imbalance of angiogenic genes expression. Collectively, our results suggest that SAMD4A is a novel breast tumor suppressor that inhibits tumor angiogenesis by specifically downregulating the expression of proangiogenic genes, which might be a potential antiangiogenic target for breast cancer therapy.
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Affiliation(s)
- Meicen Zhou
- Department of Endocrinology, Beijing Jishuitan Hospital, The 4th Clinical Medical College of Peking University, Beijing, China
| | - Bing Wang
- Institute of Microcirculation, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Hongwei Li
- Institute of Microcirculation, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Jianqun Han
- Institute of Microcirculation, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Ailing Li
- Institute of Microcirculation, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Wenbao Lu
- Institute of Microcirculation, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
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13
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Voronina AS, Pshennikova ES. mRNPs: Structure and role in development. Cell Biochem Funct 2021; 39:832-843. [PMID: 34212408 DOI: 10.1002/cbf.3656] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 06/05/2021] [Accepted: 06/17/2021] [Indexed: 11/11/2022]
Abstract
In eukaryotic cells, mRNA molecules are coated with numerous RNA-binding proteins and so exist in ribonucleoproteins (mRNPs). The proteins associated with the mRNA regulate the fate of mRNA, including its localization, translation and decay. Before activation of translation, the mRNA does not display any template functions-it is masked. The coordinated activity of certain RNA-binding proteins determines the future fate of each mRNA individually. In embryo development, the temporal and spatial regulation of translation can cause a situation when the mRNA and the encoded protein are localized in different compartments and so the differentiation of the cells can be determined. The fundamentals of regulation of the mRNAs fate and functioning in nerves are similar to those already described for oo- and embryogenesis. Disorders in the mRNA masking and demasking result in the emergence of various diseases, in particular cancers and neuro-degenerative diseases.
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Affiliation(s)
- Anna S Voronina
- Bach Institute of Biochemistry, Research Center of Biotechnology, Russian Academy of Sciences, Moscow, Russia
| | - Elena S Pshennikova
- Bach Institute of Biochemistry, Research Center of Biotechnology, Russian Academy of Sciences, Moscow, Russia
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14
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Cao WX, Kabelitz S, Gupta M, Yeung E, Lin S, Rammelt C, Ihling C, Pekovic F, Low TCH, Siddiqui NU, Cheng MHK, Angers S, Smibert CA, Wühr M, Wahle E, Lipshitz HD. Precise Temporal Regulation of Post-transcriptional Repressors Is Required for an Orderly Drosophila Maternal-to-Zygotic Transition. Cell Rep 2021; 31:107783. [PMID: 32579915 PMCID: PMC7372737 DOI: 10.1016/j.celrep.2020.107783] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 05/06/2020] [Accepted: 05/28/2020] [Indexed: 12/12/2022] Open
Abstract
In animal embryos, the maternal-to-zygotic transition (MZT) hands developmental control from maternal to zygotic gene products. We show that the maternal proteome represents more than half of the protein-coding capacity of Drosophila melanogaster’s genome, and that 2% of this proteome is rapidly degraded during the MZT. Cleared proteins include the post-transcriptional repressors Cup, Trailer hitch (TRAL), Maternal expression at 31B (ME31B), and Smaug (SMG). Although the ubiquitin-proteasome system is necessary for clearance of these repressors, distinct E3 ligase complexes target them: the C-terminal to Lis1 Homology (CTLH) complex targets Cup, TRAL, and ME31B for degradation early in the MZT and the Skp/Cullin/F-box-containing (SCF) complex targets SMG at the end of the MZT. Deleting the C-terminal 233 amino acids of SMG abrogates F-box protein interaction and confers immunity to degradation. Persistent SMG downregulates zygotic re-expression of mRNAs whose maternal contribution is degraded by SMG. Thus, clearance of SMG permits an orderly MZT. Cao et al. show that 2% of the proteome is degraded in early Drosophila embryos, including a repressive ribonucleoprotein complex. Two E3 ubiquitin ligases separately act on distinct components of this complex to phase their clearance. Failure to degrade a key component, the Smaug RNA-binding protein, disrupts an orderly maternal-to-zygotic transition.
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Affiliation(s)
- Wen Xi Cao
- Department of Molecular Genetics, University of Toronto, 661 University Avenue, Toronto, ON M5G 1M1, Canada
| | - Sarah Kabelitz
- Institute of Biochemistry and Biotechnology and Charles Tanford Protein Center, Martin Luther University Halle-Wittenberg, Kurt-Mothes-Str. 3, 06099 Halle, Germany
| | - Meera Gupta
- Department of Molecular Biology and the Lewis-Sigler Institute, Princeton University, Washington Road, Princeton, NJ 08544, USA
| | - Eyan Yeung
- Department of Molecular Biology and the Lewis-Sigler Institute, Princeton University, Washington Road, Princeton, NJ 08544, USA
| | - Sichun Lin
- Department of Pharmaceutical Sciences, University of Toronto, 144 College Street, Toronto, ON M5S 3M2, Canada
| | - Christiane Rammelt
- Institute of Biochemistry and Biotechnology and Charles Tanford Protein Center, Martin Luther University Halle-Wittenberg, Kurt-Mothes-Str. 3, 06099 Halle, Germany
| | - Christian Ihling
- Institute of Pharmacy and Charles Tanford Protein Center, Martin Luther University Halle-Wittenberg, Kurt-Mothes-Str. 3, 06099 Halle, Germany
| | - Filip Pekovic
- Institute of Biochemistry and Biotechnology and Charles Tanford Protein Center, Martin Luther University Halle-Wittenberg, Kurt-Mothes-Str. 3, 06099 Halle, Germany
| | - Timothy C H Low
- Department of Molecular Genetics, University of Toronto, 661 University Avenue, Toronto, ON M5G 1M1, Canada
| | - Najeeb U Siddiqui
- Department of Molecular Genetics, University of Toronto, 661 University Avenue, Toronto, ON M5G 1M1, Canada
| | - Matthew H K Cheng
- Department of Biochemistry, University of Toronto, 661 University Avenue, Toronto, ON M5G 1M1, Canada
| | - Stephane Angers
- Department of Pharmaceutical Sciences, University of Toronto, 144 College Street, Toronto, ON M5S 3M2, Canada; Department of Biochemistry, University of Toronto, 661 University Avenue, Toronto, ON M5G 1M1, Canada
| | - Craig A Smibert
- Department of Molecular Genetics, University of Toronto, 661 University Avenue, Toronto, ON M5G 1M1, Canada; Department of Biochemistry, University of Toronto, 661 University Avenue, Toronto, ON M5G 1M1, Canada
| | - Martin Wühr
- Department of Molecular Biology and the Lewis-Sigler Institute, Princeton University, Washington Road, Princeton, NJ 08544, USA
| | - Elmar Wahle
- Institute of Biochemistry and Biotechnology and Charles Tanford Protein Center, Martin Luther University Halle-Wittenberg, Kurt-Mothes-Str. 3, 06099 Halle, Germany.
| | - Howard D Lipshitz
- Department of Molecular Genetics, University of Toronto, 661 University Avenue, Toronto, ON M5G 1M1, Canada.
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15
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Grützner J, Billenkamp F, Spanka DT, Rick T, Monzon V, Förstner KU, Klug G. The small DUF1127 protein CcaF1 from Rhodobacter sphaeroides is an RNA-binding protein involved in sRNA maturation and RNA turnover. Nucleic Acids Res 2021; 49:3003-3019. [PMID: 33706375 PMCID: PMC8034643 DOI: 10.1093/nar/gkab146] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 02/10/2021] [Accepted: 02/26/2021] [Indexed: 12/16/2022] Open
Abstract
Many different protein domains are conserved among numerous species, but their function remains obscure. Proteins with DUF1127 domains number >17 000 in current databases, but a biological function has not yet been assigned to any of them. They are mostly found in alpha- and gammaproteobacteria, some of them plant and animal pathogens, symbionts or species used in industrial applications. Bioinformatic analyses revealed similarity of the DUF1127 domain of bacterial proteins to the RNA binding domain of eukaryotic Smaug proteins that are involved in RNA turnover and have a role in development from Drosophila to mammals. This study demonstrates that the 71 amino acid DUF1127 protein CcaF1 from the alphaproteobacterium Rhodobacter sphaeroides participates in maturation of the CcsR sRNAs that are processed from the 3' UTR of the ccaF mRNA and have a role in the oxidative stress defense. CcaF1 binds to many cellular RNAs of different type, several mRNAs with a function in cysteine / methionine / sulfur metabolism. It affects the stability of the CcsR RNAs and other non-coding RNAs and mRNAs. Thus, the widely distributed DUF1127 domain can mediate RNA-binding, affect stability of its binding partners and consequently modulate the bacterial transcriptome, thereby influencing different physiological processes.
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Affiliation(s)
- Julian Grützner
- Institute of Microbiology and Molecular Biology, Justus Liebig University Giessen, IFZ, Heinrich-Buff-Ring 26–32, D-35292 Giessen, Germany
| | - Fabian Billenkamp
- Institute of Microbiology and Molecular Biology, Justus Liebig University Giessen, IFZ, Heinrich-Buff-Ring 26–32, D-35292 Giessen, Germany
- Institute of Animal Nutrition, Friedrich Loeffler Institute, Bundesalle 37, D-38116 Braunschweig, Germany
| | - Daniel-Timon Spanka
- Institute of Microbiology and Molecular Biology, Justus Liebig University Giessen, IFZ, Heinrich-Buff-Ring 26–32, D-35292 Giessen, Germany
| | - Tim Rick
- Institute of Microbiology and Molecular Biology, Justus Liebig University Giessen, IFZ, Heinrich-Buff-Ring 26–32, D-35292 Giessen, Germany
| | | | - Konrad U Förstner
- ZB MED-Information Center of Life Science, Germany
- Institute of Information Science, TH Köln, University of Applied Science, Gustav-Heinemann-Ufer 54, D-50968 Köln, Cologne, Germany
| | - Gabriele Klug
- Institute of Microbiology and Molecular Biology, Justus Liebig University Giessen, IFZ, Heinrich-Buff-Ring 26–32, D-35292 Giessen, Germany
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16
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Kubíková J, Reinig R, Salgania HK, Jeske M. LOTUS-domain proteins - developmental effectors from a molecular perspective. Biol Chem 2020; 402:7-23. [DOI: 10.1515/hsz-2020-0270] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2020] [Accepted: 10/19/2020] [Indexed: 12/15/2022]
Abstract
Abstract
The LOTUS domain (also known as OST-HTH) is a highly conserved protein domain found in a variety of bacteria and eukaryotes. In animals, the LOTUS domain is present in the proteins Oskar, TDRD5/Tejas, TDRD7/TRAP/Tapas, and MARF1/Limkain B1, all of which play essential roles in animal development, in particular during oogenesis and/or spermatogenesis. This review summarizes the diverse biological as well as molecular functions of LOTUS-domain proteins and discusses their roles as helicase effectors, post-transcriptional regulators, and critical cofactors of piRNA-mediated transcript silencing.
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Affiliation(s)
- Jana Kubíková
- Heidelberg University Biochemistry Center , Im Neuenheimer Feld 328 , D-69120 Heidelberg , Germany
| | - Rebecca Reinig
- Heidelberg University Biochemistry Center , Im Neuenheimer Feld 328 , D-69120 Heidelberg , Germany
| | - Harpreet Kaur Salgania
- Heidelberg University Biochemistry Center , Im Neuenheimer Feld 328 , D-69120 Heidelberg , Germany
| | - Mandy Jeske
- Heidelberg University Biochemistry Center , Im Neuenheimer Feld 328 , D-69120 Heidelberg , Germany
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17
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Dixson JD, Azad RK. Prions: Roles in Development and Adaptive Evolution. J Mol Evol 2020; 88:427-434. [PMID: 32388713 DOI: 10.1007/s00239-020-09944-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Accepted: 04/28/2020] [Indexed: 12/14/2022]
Abstract
Prions are often considered as anomalous proteins associated primarily with disease rather than as a fundamental source of diversity within biological proteomes. Whereas this longstanding viewpoint has its genesis in the discovery of the original namesake prions as causative agents of several complex diseases, the underlying assumption of a strict disease basis for prions could not be further from the truth. Prions and the spectrum of functions they comprise, likely represent one of the largest paradigm shifts concerning molecular-encoded phenotypic diversity since identification of DNA as the principle molecule of heredity. The ability of prions to recruit similar proteins to alternate conformations may engender a reservoir of diversity supplementing the genetic diversity resulting from stochastic mutations of DNA and subsequent natural selection. Here we present several currently known prions and how many of their functions as well as modes of transmission are intricately linked to adaptation from an evolutionary perspective. Further, the stability of some prion conformations across generations indicates that heritable prion-based adaptation is a reality.
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Affiliation(s)
- Jamie D Dixson
- Department of Biological Sciences and BioDiscovery Institute, University of North Texas, Denton, TX, 76203, USA
| | - Rajeev K Azad
- Department of Biological Sciences and BioDiscovery Institute, University of North Texas, Denton, TX, 76203, USA.
- Department of Mathematics, University of North Texas, Denton, TX, 76203, USA.
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18
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Bruzzone L, Argüelles C, Sanial M, Miled S, Alvisi G, Gonçalves-Antunes M, Qasrawi F, Holmgren RA, Smibert CA, Lipshitz HD, Boccaccio GL, Plessis A, Bécam I. Regulation of the RNA-binding protein Smaug by the GPCR Smoothened via the kinase Fused. EMBO Rep 2020; 21:e48425. [PMID: 32383557 DOI: 10.15252/embr.201948425] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Revised: 03/17/2020] [Accepted: 04/14/2020] [Indexed: 12/13/2022] Open
Abstract
From fly to mammals, the Smaug/Samd4 family of prion-like RNA-binding proteins control gene expression by destabilizing and/or repressing the translation of numerous target transcripts. However, the regulation of its activity remains poorly understood. We show that Smaug's protein levels and mRNA repressive activity are downregulated by Hedgehog signaling in tissue culture cells. These effects rely on the interaction of Smaug with the G-protein coupled receptor Smoothened, which promotes the phosphorylation of Smaug by recruiting the kinase Fused. The activation of Fused and its binding to Smaug are sufficient to suppress its ability to form cytosolic bodies and to antagonize its negative effects on endogenous targets. Importantly, we demonstrate in vivo that HH reduces the levels of smaug mRNA and increases the level of several mRNAs downregulated by Smaug. Finally, we show that Smaug acts as a positive regulator of Hedgehog signaling during wing morphogenesis. These data constitute the first evidence for a post-translational regulation of Smaug and reveal that the fate of several mRNAs bound to Smaug is modulated by a major signaling pathway.
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Affiliation(s)
- Lucia Bruzzone
- CNRS, Institut Jacques Monod, Université de Paris, Paris, France
| | | | - Matthieu Sanial
- CNRS, Institut Jacques Monod, Université de Paris, Paris, France
| | - Samia Miled
- CNRS, Institut Jacques Monod, Université de Paris, Paris, France
| | - Giorgia Alvisi
- CNRS, Institut Jacques Monod, Université de Paris, Paris, France
| | | | - Fairouz Qasrawi
- CNRS, Institut Jacques Monod, Université de Paris, Paris, France
| | - Robert A Holmgren
- Department of Mol. Biosci., Northwestern University, Evanston, IL, USA
| | - Craig A Smibert
- Department of Biochemistry, University of Toronto, Toronto, ON, Canada.,Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada
| | - Howard D Lipshitz
- Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada
| | - Graciela L Boccaccio
- Fundación Instituto Leloir, Instituto de Investigaciones Bioquímicas Buenos Aires-Consejo Nacional de Investigaciones Científicas y Tecnológicas, Facultad de Ciencias Exactas y Naturales, University of Buenos Aires, Buenos Aires, Argentina
| | - Anne Plessis
- CNRS, Institut Jacques Monod, Université de Paris, Paris, France
| | - Isabelle Bécam
- CNRS, Institut Jacques Monod, Université de Paris, Paris, France
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19
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Kluge F, Götze M, Wahle E. Establishment of 5'-3' interactions in mRNA independent of a continuous ribose-phosphate backbone. RNA (NEW YORK, N.Y.) 2020; 26:613-628. [PMID: 32111664 PMCID: PMC7161349 DOI: 10.1261/rna.073759.119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Accepted: 02/24/2020] [Indexed: 06/10/2023]
Abstract
Functions of eukaryotic mRNAs are characterized by intramolecular interactions between their ends. We have addressed the question whether 5' and 3' ends meet by diffusion-controlled encounter "through solution" or by a mechanism involving the RNA backbone. For this purpose, we used a translation system derived from Drosophila embryos that displays two types of 5'-3' interactions: Cap-dependent translation initiation is stimulated by the poly(A) tail and inhibited by Smaug recognition elements (SREs) in the 3' UTR. Chimeric RNAs were made consisting of one RNA molecule carrying a luciferase coding sequence and a second molecule containing SREs and a poly(A) tail; the two were connected via a protein linker. The poly(A) tail stimulated translation of such chimeras even when disruption of the RNA backbone was combined with an inversion of the 5'-3' polarity between the open reading frame and poly(A) segment. Stimulation by the poly(A) tail also decreased with increasing RNA length. Both observations suggest that contacts between the poly(A) tail and the 5' end are established through solution, independently of the RNA backbone. In the same chimeric constructs, SRE-dependent inhibition of translation was also insensitive to disruption of the RNA backbone. Thus, tracking of the backbone is not involved in the repression of cap-dependent initiation. However, SRE-dependent repression was insensitive to mRNA length, suggesting that the contact between the SREs in the 3' UTR and the 5' end of the RNA might be established in a manner that differs from the contact between the poly(A) tail and the cap.
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Affiliation(s)
- Florian Kluge
- Institute of Biochemistry and Biotechnology and Charles Tanford Protein Center, Martin Luther University Halle-Wittenberg, 06099 Halle, Germany
| | - Michael Götze
- Institute of Biochemistry and Biotechnology and Charles Tanford Protein Center, Martin Luther University Halle-Wittenberg, 06099 Halle, Germany
| | - Elmar Wahle
- Institute of Biochemistry and Biotechnology and Charles Tanford Protein Center, Martin Luther University Halle-Wittenberg, 06099 Halle, Germany
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20
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Ramat A, Garcia-Silva MR, Jahan C, Naït-Saïdi R, Dufourt J, Garret C, Chartier A, Cremaschi J, Patel V, Decourcelle M, Bastide A, Juge F, Simonelig M. The PIWI protein Aubergine recruits eIF3 to activate translation in the germ plasm. Cell Res 2020; 30:421-435. [PMID: 32132673 PMCID: PMC7196074 DOI: 10.1038/s41422-020-0294-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Accepted: 02/11/2020] [Indexed: 12/13/2022] Open
Abstract
Piwi-interacting RNAs (piRNAs) and PIWI proteins are essential in germ cells to repress transposons and regulate mRNAs. In Drosophila, piRNAs bound to the PIWI protein Aubergine (Aub) are transferred maternally to the embryo and regulate maternal mRNA stability through two opposite roles. They target mRNAs by incomplete base pairing, leading to their destabilization in the soma and stabilization in the germ plasm. Here, we report a function of Aub in translation. Aub is required for translational activation of nanos mRNA, a key determinant of the germ plasm. Aub physically interacts with the poly(A)-binding protein (PABP) and the translation initiation factor eIF3. Polysome gradient profiling reveals the role of Aub at the initiation step of translation. In the germ plasm, PABP and eIF3d assemble in foci that surround Aub-containing germ granules, and Aub acts with eIF3d to promote nanos translation. These results identify translational activation as a new mode of mRNA regulation by Aub, highlighting the versatility of PIWI proteins in mRNA regulation.
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Affiliation(s)
- Anne Ramat
- mRNA Regulation and Development, Institute of Human Genetics, UMR9002 CNRS-Univ Montpellier, 141 rue de la Cardonille, 34396, Montpellier Cedex 5, France
| | - Maria-Rosa Garcia-Silva
- mRNA Regulation and Development, Institute of Human Genetics, UMR9002 CNRS-Univ Montpellier, 141 rue de la Cardonille, 34396, Montpellier Cedex 5, France
| | - Camille Jahan
- mRNA Regulation and Development, Institute of Human Genetics, UMR9002 CNRS-Univ Montpellier, 141 rue de la Cardonille, 34396, Montpellier Cedex 5, France
| | - Rima Naït-Saïdi
- mRNA Regulation and Development, Institute of Human Genetics, UMR9002 CNRS-Univ Montpellier, 141 rue de la Cardonille, 34396, Montpellier Cedex 5, France
| | - Jérémy Dufourt
- mRNA Regulation and Development, Institute of Human Genetics, UMR9002 CNRS-Univ Montpellier, 141 rue de la Cardonille, 34396, Montpellier Cedex 5, France
- Institut de Génétique Moléculaire de Montpellier, Univ Montpellier, CNRS, Montpellier, France
| | - Céline Garret
- mRNA Regulation and Development, Institute of Human Genetics, UMR9002 CNRS-Univ Montpellier, 141 rue de la Cardonille, 34396, Montpellier Cedex 5, France
| | - Aymeric Chartier
- mRNA Regulation and Development, Institute of Human Genetics, UMR9002 CNRS-Univ Montpellier, 141 rue de la Cardonille, 34396, Montpellier Cedex 5, France
| | - Julie Cremaschi
- mRNA Regulation and Development, Institute of Human Genetics, UMR9002 CNRS-Univ Montpellier, 141 rue de la Cardonille, 34396, Montpellier Cedex 5, France
| | - Vipul Patel
- mRNA Regulation and Development, Institute of Human Genetics, UMR9002 CNRS-Univ Montpellier, 141 rue de la Cardonille, 34396, Montpellier Cedex 5, France
| | | | | | - François Juge
- Institut de Génétique Moléculaire de Montpellier, Univ Montpellier, CNRS, Montpellier, France
| | - Martine Simonelig
- mRNA Regulation and Development, Institute of Human Genetics, UMR9002 CNRS-Univ Montpellier, 141 rue de la Cardonille, 34396, Montpellier Cedex 5, France.
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21
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Murakami C, Hoshino F, Sakai H, Hayashi Y, Yamashita A, Sakane F. Diacylglycerol kinase δ and sphingomyelin synthase-related protein functionally interact via their sterile α motif domains. J Biol Chem 2020; 295:2932-2947. [PMID: 31980461 DOI: 10.1074/jbc.ra119.012369] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 01/23/2020] [Indexed: 12/27/2022] Open
Abstract
The δ isozyme of diacylglycerol kinase (DGKδ) plays critical roles in lipid signaling by converting diacylglycerol (DG) to phosphatidic acid (PA). We previously demonstrated that DGKδ preferably phosphorylates palmitic acid (16:0)- and/or palmitoleic acid (16:1)-containing DG molecular species, but not arachidonic acid (20:4)-containing DG species, which are recognized as DGK substrates derived from phosphatidylinositol turnover, in high glucose-stimulated myoblasts. However, little is known about the origin of these DG molecular species. DGKδ and two DG-generating enzymes, sphingomyelin synthase (SMS) 1 and SMS-related protein (SMSr), contain a sterile α motif domain (SAMD). In this study, we found that SMSr-SAMD, but not SMS1-SAMD, co-immunoprecipitates with DGKδ-SAMD. Full-length DGKδ co-precipitated with full-length SMSr more strongly than with SMS1. However, SAMD-deleted variants of SMSr and DGKδ interacted only weakly with full-length DGKδ and SMSr, respectively. These results strongly suggested that DGKδ interacts with SMSr through their respective SAMDs. To determine the functional outcomes of the relationship between DGKδ and SMSr, we used LC-MS/MS to investigate whether overexpression of DGKδ and/or SMSr in COS-7 cells alters the levels of PA species. We found that SMSr overexpression significantly enhances the production of 16:0- or 16:1-containing PA species such as 14:0/16:0-, 16:0/16:0-, 16:0/18:1-, and/or 16:1/18:1-PA in DGKδ-overexpressing COS-7 cells. Moreover, SMSr enhanced DGKδ activity via their SAMDs in vitro Taken together, these results strongly suggest that SMSr is a candidate DG-providing enzyme upstream of DGKδ and that the two enzymes represent a new pathway independent of phosphatidylinositol turnover.
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Affiliation(s)
- Chiaki Murakami
- Department of Chemistry, Graduate School of Science, Chiba University, Chiba 263-8522, Japan
| | - Fumi Hoshino
- Department of Chemistry, Graduate School of Science, Chiba University, Chiba 263-8522, Japan
| | - Hiromichi Sakai
- Department of Biosignaling and Radioisotope Experiment, Interdisciplinary Center for Science Research, Organization for Research and Academic Information, Shimane University, Izumo 693-8501, Japan
| | - Yasuhiro Hayashi
- Faculty of Pharma Sciences, Teikyo University, Kaga 2-11-1, Itabashi-ku, Tokyo 173-8605, Japan
| | - Atsushi Yamashita
- Faculty of Pharma Sciences, Teikyo University, Kaga 2-11-1, Itabashi-ku, Tokyo 173-8605, Japan
| | - Fumio Sakane
- Department of Chemistry, Graduate School of Science, Chiba University, Chiba 263-8522, Japan.
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22
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Wen L, Liu Q, Xu J, Liu X, Shi C, Yang Z, Zhang Y, Xu H, Liu J, Yang H, Huang H, Qiao J, Tang F, Chen ZJ. Recent advances in mammalian reproductive biology. SCIENCE CHINA. LIFE SCIENCES 2020; 63:18-58. [PMID: 31813094 DOI: 10.1007/s11427-019-1572-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Accepted: 10/22/2019] [Indexed: 01/05/2023]
Abstract
Reproductive biology is a uniquely important topic since it is about germ cells, which are central for transmitting genetic information from generation to generation. In this review, we discuss recent advances in mammalian germ cell development, including preimplantation development, fetal germ cell development and postnatal development of oocytes and sperm. We also discuss the etiologies of female and male infertility and describe the emerging technologies for studying reproductive biology such as gene editing and single-cell technologies.
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Affiliation(s)
- Lu Wen
- Beijing Advanced Innovation Center for Genomics, Department of Obstetrics and Gynecology Third Hospital, College of Life Sciences, Peking University, Beijing, 100871, China
| | - Qiang Liu
- Beijing Advanced Innovation Center for Genomics, Department of Obstetrics and Gynecology Third Hospital, College of Life Sciences, Peking University, Beijing, 100871, China
| | - Jingjing Xu
- International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai Key Laboratory of Embryo Original Diseases, Shanghai, 200030, China
| | - Xixi Liu
- Beijing Advanced Innovation Center for Genomics, Department of Obstetrics and Gynecology Third Hospital, College of Life Sciences, Peking University, Beijing, 100871, China
| | - Chaoyi Shi
- International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai Key Laboratory of Embryo Original Diseases, Shanghai, 200030, China
| | - Zuwei Yang
- International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai Key Laboratory of Embryo Original Diseases, Shanghai, 200030, China
| | - Yili Zhang
- International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai Key Laboratory of Embryo Original Diseases, Shanghai, 200030, China
| | - Hong Xu
- International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai Key Laboratory of Embryo Original Diseases, Shanghai, 200030, China
| | - Jiang Liu
- CAS Key Laboratory of Genome Sciences and Information, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, 100101, China.
| | - Hui Yang
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Key Laboratory of Primate Neurobiology, CAS Center for Excellence in Brain Science and Intelligence Technology, Shanghai Research Center for Brain Science and Brain-Inspired Intelligence, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200031, China.
| | - Hefeng Huang
- International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai Key Laboratory of Embryo Original Diseases, Shanghai, 200030, China.
| | - Jie Qiao
- Beijing Advanced Innovation Center for Genomics, Department of Obstetrics and Gynecology Third Hospital, College of Life Sciences, Peking University, Beijing, 100871, China.
| | - Fuchou Tang
- Beijing Advanced Innovation Center for Genomics, Department of Obstetrics and Gynecology Third Hospital, College of Life Sciences, Peking University, Beijing, 100871, China.
| | - Zi-Jiang Chen
- National Research Center for Assisted Reproductive Technology and Reproductive Genetics, Jinan, 250021, China.
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23
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Vejnar CE, Abdel Messih M, Takacs CM, Yartseva V, Oikonomou P, Christiano R, Stoeckius M, Lau S, Lee MT, Beaudoin JD, Musaev D, Darwich-Codore H, Walther TC, Tavazoie S, Cifuentes D, Giraldez AJ. Genome wide analysis of 3' UTR sequence elements and proteins regulating mRNA stability during maternal-to-zygotic transition in zebrafish. Genome Res 2019; 29:1100-1114. [PMID: 31227602 PMCID: PMC6633259 DOI: 10.1101/gr.245159.118] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Accepted: 06/07/2019] [Indexed: 12/16/2022]
Abstract
Posttranscriptional regulation plays a crucial role in shaping gene expression. During the maternal-to-zygotic transition (MZT), thousands of maternal transcripts are regulated. However, how different cis-elements and trans-factors are integrated to determine mRNA stability remains poorly understood. Here, we show that most transcripts are under combinatorial regulation by multiple decay pathways during zebrafish MZT. By using a massively parallel reporter assay, we identified cis-regulatory sequences in the 3′ UTR, including U-rich motifs that are associated with increased mRNA stability. In contrast, miR-430 target sequences, UAUUUAUU AU-rich elements (ARE), CCUC, and CUGC elements emerged as destabilizing motifs, with miR-430 and AREs causing mRNA deadenylation upon genome activation. We identified trans-factors by profiling RNA–protein interactions and found that poly(U)-binding proteins are preferentially associated with 3′ UTR sequences and stabilizing motifs. We show that this activity is antagonized by C-rich motifs and correlated with protein binding. Finally, we integrated these regulatory motifs into a machine learning model that predicts reporter mRNA stability in vivo.
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Affiliation(s)
- Charles E Vejnar
- Department of Genetics, Yale University School of Medicine, New Haven, Connecticut 06510, USA
| | - Mario Abdel Messih
- Department of Genetics, Yale University School of Medicine, New Haven, Connecticut 06510, USA
| | - Carter M Takacs
- Department of Genetics, Yale University School of Medicine, New Haven, Connecticut 06510, USA.,University of New Haven, West Haven, Connecticut 06516, USA
| | - Valeria Yartseva
- Department of Genetics, Yale University School of Medicine, New Haven, Connecticut 06510, USA.,Department of Neuroscience, Genentech, Incorporated, South San Francisco, California 94080, USA
| | - Panos Oikonomou
- Department of Systems Biology, Columbia University, New York, New York 10032, USA
| | - Romain Christiano
- Department of Genetics and Complex Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts 02115, USA
| | - Marlon Stoeckius
- Department of Genetics, Yale University School of Medicine, New Haven, Connecticut 06510, USA.,New York Genome Center, New York, New York 10013, USA
| | - Stephanie Lau
- Department of Genetics, Yale University School of Medicine, New Haven, Connecticut 06510, USA
| | - Miler T Lee
- Department of Genetics, Yale University School of Medicine, New Haven, Connecticut 06510, USA.,Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA
| | - Jean-Denis Beaudoin
- Department of Genetics, Yale University School of Medicine, New Haven, Connecticut 06510, USA
| | - Damir Musaev
- Department of Genetics, Yale University School of Medicine, New Haven, Connecticut 06510, USA
| | - Hiba Darwich-Codore
- Department of Genetics, Yale University School of Medicine, New Haven, Connecticut 06510, USA
| | - Tobias C Walther
- Department of Genetics and Complex Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts 02115, USA.,Department of Cell Biology, Harvard Medical School, Boston, Massachusetts 02115, USA.,Broad Institute of Harvard and MIT, Cambridge, Massachusetts 02124, USA.,Howard Hughes Medical Institute, Boston, Massachusetts 02115, USA
| | - Saeed Tavazoie
- Department of Biochemistry and Molecular Biophysics, and Department of Systems Biology, Columbia University, New York, New York 10032, USA
| | - Daniel Cifuentes
- Department of Genetics, Yale University School of Medicine, New Haven, Connecticut 06510, USA.,Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts 02118, USA
| | - Antonio J Giraldez
- Department of Genetics, Yale University School of Medicine, New Haven, Connecticut 06510, USA.,Yale Stem Cell Center, Yale University School of Medicine, New Haven, Connecticut 06510, USA.,Yale Cancer Center, Yale University School of Medicine, New Haven, Connecticut 06510, USA
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24
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Vastenhouw NL, Cao WX, Lipshitz HD. The maternal-to-zygotic transition revisited. Development 2019; 146:146/11/dev161471. [PMID: 31189646 DOI: 10.1242/dev.161471] [Citation(s) in RCA: 198] [Impact Index Per Article: 39.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The development of animal embryos is initially directed by maternal gene products. Then, during the maternal-to-zygotic transition (MZT), developmental control is handed to the zygotic genome. Extensive research in both vertebrate and invertebrate model organisms has revealed that the MZT can be subdivided into two phases, during which very different modes of gene regulation are implemented: initially, regulation is exclusively post-transcriptional and post-translational, following which gradual activation of the zygotic genome leads to predominance of transcriptional regulation. These changes in the gene expression program of embryos are precisely controlled and highly interconnected. Here, we review current understanding of the mechanisms that underlie handover of developmental control during the MZT.
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Affiliation(s)
- Nadine L Vastenhouw
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstraße 108, 01307 Dresden, Germany
| | - Wen Xi Cao
- Department of Molecular Genetics, University of Toronto, 661 University Avenue, Toronto, Ontario M5G 1M1, Canada
| | - Howard D Lipshitz
- Department of Molecular Genetics, University of Toronto, 661 University Avenue, Toronto, Ontario M5G 1M1, Canada
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25
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Teixeira FK, Lehmann R. Translational Control during Developmental Transitions. Cold Spring Harb Perspect Biol 2019; 11:cshperspect.a032987. [PMID: 30082467 DOI: 10.1101/cshperspect.a032987] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The many steps of gene expression, from the transcription of a gene to the production of its protein product, are well understood. Yet, transcriptional regulation has been the focal point for the study of gene expression during development. However, quantitative studies reveal that messenger RNA (mRNA) levels are not necessarily good predictors of the respective proteins' levels in a cell. This discrepancy is, at least in part, the result of developmentally regulated, translational mechanisms that control the spatiotemporal regulation of gene expression. In this review, we focus on translational regulatory mechanisms mediating global transitions in gene expression: the shift from the maternal to the embryonic developmental program in the early embryo and the switch from the self-renewal of stem cells to differentiation in the adult.
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Affiliation(s)
| | - Ruth Lehmann
- Howard Hughes Medical Institute (HHMI) and Kimmel Center for Biology and Medicine of the Skirball Institute, Department of Cell Biology, New York University School of Medicine, New York, New York 10016
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26
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Asymmetric Inheritance of Cell Fate Determinants: Focus on RNA. Noncoding RNA 2019; 5:ncrna5020038. [PMID: 31075989 PMCID: PMC6630313 DOI: 10.3390/ncrna5020038] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Revised: 04/30/2019] [Accepted: 05/06/2019] [Indexed: 12/20/2022] Open
Abstract
During the last decade, and mainly primed by major developments in high-throughput sequencing technologies, the catalogue of RNA molecules harbouring regulatory functions has increased at a steady pace. Current evidence indicates that hundreds of mammalian RNAs have regulatory roles at several levels, including transcription, translation/post-translation, chromatin structure, and nuclear architecture, thus suggesting that RNA molecules are indeed mighty controllers in the flow of biological information. Therefore, it is logical to suggest that there must exist a series of molecular systems that safeguard the faithful inheritance of RNA content throughout cell division and that those mechanisms must be tightly controlled to ensure the successful segregation of key molecules to the progeny. Interestingly, whilst a handful of integral components of mammalian cells seem to follow a general pattern of asymmetric inheritance throughout division, the fate of RNA molecules largely remains a mystery. Herein, we will discuss current concepts of asymmetric inheritance in a wide range of systems, including prions, proteins, and finally RNA molecules, to assess overall the biological impact of RNA inheritance in cellular plasticity and evolutionary fitness.
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27
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Abstract
Small RNAs govern almost every biological process in eukaryotes associating with the Argonaute (AGO) proteins to form the RNA-induced silencing complex (mRISC). AGO proteins constitute the core of RISCs with different members having variety of protein-binding partners and biochemical properties. This review focuses on the AGO subfamily of the AGOs that are ubiquitously expressed and are associated with small RNAs. The structure, function and role of the AGO proteins in the cell is discussed in detail.
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Affiliation(s)
- Saife Niaz
- Department of Biotechnology, University of Kashmir, Srinagar 190006, Jammu and Kashmir, India
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28
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Mayya VK, Duchaine TF. Ciphers and Executioners: How 3'-Untranslated Regions Determine the Fate of Messenger RNAs. Front Genet 2019; 10:6. [PMID: 30740123 PMCID: PMC6357968 DOI: 10.3389/fgene.2019.00006] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Accepted: 01/07/2019] [Indexed: 12/29/2022] Open
Abstract
The sequences and structures of 3'-untranslated regions (3'UTRs) of messenger RNAs govern their stability, localization, and expression. 3'UTR regulatory elements are recognized by a wide variety of trans-acting factors that include microRNAs (miRNAs), their associated machinery, and RNA-binding proteins (RBPs). In turn, these factors instigate common mechanistic strategies to execute the regulatory programs encoded by 3'UTRs. Here, we review classes of factors that recognize 3'UTR regulatory elements and the effector machineries they guide toward mRNAs to dictate their expression and fate. We outline illustrative examples of competitive, cooperative, and coordinated interplay such as mRNA localization and localized translation. We further review the recent advances in the study of mRNP granules and phase transition, and their possible significance for the functions of 3'UTRs. Finally, we highlight some of the most recent strategies aimed at deciphering the complexity of the regulatory codes of 3'UTRs, and identify some of the important remaining challenges.
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Affiliation(s)
| | - Thomas F. Duchaine
- Goodman Cancer Research Centre and Department of Biochemistry, McGill University, Montreal, QC, Canada
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29
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Hamm DC, Harrison MM. Regulatory principles governing the maternal-to-zygotic transition: insights from Drosophila melanogaster. Open Biol 2018; 8:180183. [PMID: 30977698 PMCID: PMC6303782 DOI: 10.1098/rsob.180183] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Accepted: 11/09/2018] [Indexed: 12/19/2022] Open
Abstract
The onset of metazoan development requires that two terminally differentiated germ cells, a sperm and an oocyte, become reprogrammed to the totipotent embryo, which can subsequently give rise to all the cell types of the adult organism. In nearly all animals, maternal gene products regulate the initial events of embryogenesis while the zygotic genome remains transcriptionally silent. Developmental control is then passed from mother to zygote through a process known as the maternal-to-zygotic transition (MZT). The MZT comprises an intimately connected set of molecular events that mediate degradation of maternally deposited mRNAs and transcriptional activation of the zygotic genome. This essential developmental transition is conserved among metazoans but is perhaps best understood in the fruit fly, Drosophila melanogaster. In this article, we will review our understanding of the events that drive the MZT in Drosophila embryos and highlight parallel mechanisms driving this transition in other animals.
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Affiliation(s)
| | - Melissa M. Harrison
- Department of Biomolecular Chemistry, University of Wisconsin School of Medicine and Public Health, Madison, WI 53706, USA
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30
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Krishnakumar P, Riemer S, Perera R, Lingner T, Goloborodko A, Khalifa H, Bontems F, Kaufholz F, El-Brolosy MA, Dosch R. Functional equivalence of germ plasm organizers. PLoS Genet 2018; 14:e1007696. [PMID: 30399145 PMCID: PMC6219760 DOI: 10.1371/journal.pgen.1007696] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Accepted: 09/16/2018] [Indexed: 11/18/2022] Open
Abstract
The proteins Oskar (Osk) in Drosophila and Bucky ball (Buc) in zebrafish act as germ plasm organizers. Both proteins recapitulate germ plasm activities but seem to be unique to their animal groups. Here, we discover that Osk and Buc show similar activities during germ cell specification. Drosophila Osk induces additional PGCs in zebrafish. Surprisingly, Osk and Buc do not show homologous protein motifs that would explain their related function. Nonetheless, we detect that both proteins contain stretches of intrinsically disordered regions (IDRs), which seem to be involved in protein aggregation. IDRs are known to rapidly change their sequence during evolution, which might obscure biochemical interaction motifs. Indeed, we show that Buc binds to the known Oskar interactors Vasa protein and nanos mRNA indicating conserved biochemical activities. These data provide a molecular framework for two proteins with unrelated sequence but with equivalent function to assemble a conserved core-complex nucleating germ plasm. Multicellular organisms use gametes for their propagation. Gametes are formed from germ cells, which are specified during embryogenesis in some animals by the inheritance of RNP granules known as germ plasm. Transplantation of germ plasm induces extra germ cells, whereas germ plasm ablation leads to the loss of gametes and sterility. Therefore, germ plasm is key for germ cell formation and reproduction. However, the molecular mechanisms of germ cell specification by germ plasm in the vertebrate embryo remain an unsolved question. Proteins, which assemble the germ plasm, are known as germ plasm organizers. Here, we show that the two germ plasm organizers Oskar from the fly and Bucky ball from the fish show similar functions by using a cross species approach. Both are intrinsically disordered proteins, which rapidly changed their sequence during evolution. Moreover, both proteins still interact with conserved components of the germ cell specification pathway. These data might provide a first example of two proteins with the same biological role, but distinct sequence.
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Affiliation(s)
- Pritesh Krishnakumar
- Institute for Developmental Biochemistry, University Medical Center, Göttingen, Germany
| | - Stephan Riemer
- Institute for Developmental Biochemistry, University Medical Center, Göttingen, Germany
| | - Roshan Perera
- Institute for Developmental Biochemistry, University Medical Center, Göttingen, Germany
| | - Thomas Lingner
- Institute for Developmental Biochemistry, University Medical Center, Göttingen, Germany
| | - Alexander Goloborodko
- Institute for Developmental Biochemistry, University Medical Center, Göttingen, Germany
| | - Hazem Khalifa
- Institute for Developmental Biochemistry, University Medical Center, Göttingen, Germany
| | - Franck Bontems
- Laboratory of Metabolism, Department of Internal Medicine Specialties, Faculty of Medicine, University of Geneva, Switzerland
| | - Felix Kaufholz
- Institute for Developmental Biochemistry, University Medical Center, Göttingen, Germany
| | - Mohamed A. El-Brolosy
- Institute for Developmental Biochemistry, University Medical Center, Göttingen, Germany
| | - Roland Dosch
- Institute for Developmental Biochemistry, University Medical Center, Göttingen, Germany
- Institute of Human Genetics, University Medical Center, Göttingen, Germany
- * E-mail:
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31
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Subcellular Specialization and Organelle Behavior in Germ Cells. Genetics 2018; 208:19-51. [PMID: 29301947 DOI: 10.1534/genetics.117.300184] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2016] [Accepted: 08/17/2017] [Indexed: 11/18/2022] Open
Abstract
Gametes, eggs and sperm, are the highly specialized cell types on which the development of new life solely depends. Although all cells share essential organelles, such as the ER (endoplasmic reticulum), Golgi, mitochondria, and centrosomes, germ cells display unique regulation and behavior of organelles during gametogenesis. These germ cell-specific functions of organelles serve critical roles in successful gamete production. In this chapter, I will review the behaviors and roles of organelles during germ cell differentiation.
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32
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Ylla G, Piulachs MD, Belles X. Comparative Transcriptomics in Two Extreme Neopterans Reveals General Trends in the Evolution of Modern Insects. iScience 2018; 4:164-179. [PMID: 30240738 PMCID: PMC6147021 DOI: 10.1016/j.isci.2018.05.017] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Revised: 04/13/2018] [Accepted: 05/23/2018] [Indexed: 01/08/2023] Open
Abstract
The success of neopteran insects, with 1 million species described, is associated with developmental innovations such as holometaboly and the evolution from short to long germband embryogenesis. To unveil the mechanisms underlining these innovations, we compared gene expression during the ontogeny of two extreme neopterans, the cockroach Blattella germanica (polyneopteran, hemimetabolan, and short germband species) and the fly Drosophila melanogaster (endopterygote, holometabolan, and long germband species). Results revealed that genes associated with metamorphosis are predominantly expressed in late nymphal stages in B. germanica and in the early-mid embryo in D. melanogaster. In B. germanica the maternal to zygotic transition (MZT) concentrates early in embryogenesis, when juvenile hormone factors are significantly expressed. In D. melanogaster, the MZT extends throughout embryogenesis, during which time juvenile hormone factors appear to be unimportant. These differences possibly reflect broad trends in the evolution of development within neopterans, related to the germband type and the metamorphosis mode. Transcriptomes of cockroaches and flies show key differences along development Cockroaches and flies express metamorphosis factors with distinct timings in ontogeny Cockroaches methylate DNA in early embryogenesis, whereas flies do not MZT is limited to the early embryo in cockroaches, but it extends until hatching in flies
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Affiliation(s)
- Guillem Ylla
- Institute of Evolutionary Biology (CSIC-Universitat Pompeu Fabra), Passeig Marítim 37, 08003 Barcelona, Spain
| | - Maria-Dolors Piulachs
- Institute of Evolutionary Biology (CSIC-Universitat Pompeu Fabra), Passeig Marítim 37, 08003 Barcelona, Spain
| | - Xavier Belles
- Institute of Evolutionary Biology (CSIC-Universitat Pompeu Fabra), Passeig Marítim 37, 08003 Barcelona, Spain.
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33
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Yamashiro H, Siomi MC. PIWI-Interacting RNA in Drosophila: Biogenesis, Transposon Regulation, and Beyond. Chem Rev 2017; 118:4404-4421. [PMID: 29281264 DOI: 10.1021/acs.chemrev.7b00393] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
PIWI-interacting RNAs (piRNAs) are germline-enriched small RNAs that control transposons to maintain genome integrity. To achieve this, upon being processed from piRNA precursors, most of which are transcripts of intergenic piRNA clusters, piRNAs bind PIWI proteins, germline-specific Argonaute proteins, to form effector complexes. The mechanism of this piRNA-mediated transposon silencing pathway is fundamentally similar to that of siRNA/miRNA-dependent gene silencing in that a small RNA guides its partner Argonaute protein to target gene transcripts for repression via RNA-RNA base pairing. However, the uniqueness of this piRNA pathway has emerged through intensive genetic, biochemical, bioinformatic, and structural investigations. Here, we review the studies that elucidated the piRNA pathway, mainly in Drosophila, by describing both historical and recent progress. Studies in other species that have made important contributions to the field are also described.
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Affiliation(s)
- Haruna Yamashiro
- Department of Biological Sciences, Graduate School of Science , The University of Tokyo , Tokyo 113-0032 , Japan
| | - Mikiko C Siomi
- Department of Biological Sciences, Graduate School of Science , The University of Tokyo , Tokyo 113-0032 , Japan
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34
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Tamayo JV, Teramoto T, Chatterjee S, Hall TMT, Gavis ER. The Drosophila hnRNP F/H Homolog Glorund Uses Two Distinct RNA-Binding Modes to Diversify Target Recognition. Cell Rep 2017; 19:150-161. [PMID: 28380354 DOI: 10.1016/j.celrep.2017.03.022] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2016] [Revised: 11/03/2016] [Accepted: 03/03/2017] [Indexed: 12/25/2022] Open
Abstract
The Drosophila hnRNP F/H homolog, Glorund (Glo), regulates nanos mRNA translation by interacting with a structured UA-rich motif in the nanos 3' untranslated region. Glo regulates additional RNAs, however, and mammalian homologs bind G-tract sequences to regulate alternative splicing, suggesting that Glo also recognizes G-tract RNA. To gain insight into how Glo recognizes both structured UA-rich and G-tract RNAs, we used mutational analysis guided by crystal structures of Glo's RNA-binding domains and identified two discrete RNA-binding surfaces that allow Glo to recognize both RNA motifs. By engineering Glo variants that favor a single RNA-binding mode, we show that a subset of Glo's functions in vivo is mediated solely by the G-tract binding mode, whereas regulation of nanos requires both recognition modes. Our findings suggest a molecular mechanism for the evolution of dual RNA motif recognition in Glo that may be applied to understanding the functional diversity of other RNA-binding proteins.
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Affiliation(s)
- Joel V Tamayo
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Takamasa Teramoto
- Epigenetics and Stem Cell Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Seema Chatterjee
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Traci M Tanaka Hall
- Epigenetics and Stem Cell Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA.
| | - Elizabeth R Gavis
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA.
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35
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Reichardt I, Bonnay F, Steinmann V, Loedige I, Burkard TR, Meister G, Knoblich JA. The tumor suppressor Brat controls neuronal stem cell lineages by inhibiting Deadpan and Zelda. EMBO Rep 2017; 19:102-117. [PMID: 29191977 DOI: 10.15252/embr.201744188] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Revised: 10/31/2017] [Accepted: 11/10/2017] [Indexed: 11/09/2022] Open
Abstract
The TRIM-NHL protein Brain tumor (Brat) acts as a tumor suppressor in the Drosophila brain, but how it suppresses tumor formation is not completely understood. Here, we combine temperature-controlled brat RNAi with transcriptome analysis to identify the immediate Brat targets in Drosophila neuroblasts. Besides the known target Deadpan (Dpn), our experiments identify the transcription factor Zelda (Zld) as a critical target of Brat. Our data show that Zld is expressed in neuroblasts and required to allow re-expression of Dpn in transit-amplifying intermediate neural progenitors. Upon neuroblast division, Brat is enriched in one daughter cell where its NHL domain directly binds to specific motifs in the 3'UTR of dpn and zld mRNA to mediate their degradation. In brat mutants, both Dpn and Zld continue to be expressed, but inhibition of either transcription factor prevents tumorigenesis. Our genetic and biochemical data indicate that Dpn inhibition requires higher Brat levels than Zld inhibition and suggest a model where stepwise post-transcriptional inhibition of distinct factors ensures sequential generation of fates in a stem cell lineage.
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Affiliation(s)
- Ilka Reichardt
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna, Austria
| | - François Bonnay
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna, Austria
| | - Victoria Steinmann
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna, Austria
| | - Inga Loedige
- Laboratory for RNA Biology, Biochemistry Center Regensburg (BZR), University of Regensburg, Regensburg, Germany
| | - Thomas R Burkard
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna, Austria
| | - Gunter Meister
- Laboratory for RNA Biology, Biochemistry Center Regensburg (BZR), University of Regensburg, Regensburg, Germany
| | - Juergen A Knoblich
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna, Austria
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36
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Dufourt J, Bontonou G, Chartier A, Jahan C, Meunier AC, Pierson S, Harrison PF, Papin C, Beilharz TH, Simonelig M. piRNAs and Aubergine cooperate with Wispy poly(A) polymerase to stabilize mRNAs in the germ plasm. Nat Commun 2017; 8:1305. [PMID: 29101389 PMCID: PMC5670238 DOI: 10.1038/s41467-017-01431-5] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Accepted: 09/18/2017] [Indexed: 11/12/2022] Open
Abstract
Piwi-interacting RNAs (piRNAs) and PIWI proteins play a crucial role in germ cells by repressing transposable elements and regulating gene expression. In Drosophila, maternal piRNAs are loaded into the embryo mostly bound to the PIWI protein Aubergine (Aub). Aub targets maternal mRNAs through incomplete base-pairing with piRNAs and can induce their destabilization in the somatic part of the embryo. Paradoxically, these Aub-dependent unstable mRNAs encode germ cell determinants that are selectively stabilized in the germ plasm. Here we show that piRNAs and Aub actively protect germ cell mRNAs in the germ plasm. Aub directly interacts with the germline-specific poly(A) polymerase Wispy, thus leading to mRNA polyadenylation and stabilization in the germ plasm. These results reveal a role for piRNAs in mRNA stabilization and identify Aub as an interactor of Wispy for mRNA polyadenylation. They further highlight the role of Aub and piRNAs in embryonic patterning through two opposite functions.
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Affiliation(s)
- Jérémy Dufourt
- mRNA Regulation and Development, Institute of Human Genetics, UMR9002 CNRS-University of Montpellier, 141 rue de la Cardonille, 34396, Montpellier Cedex 5, France
| | - Gwénaëlle Bontonou
- mRNA Regulation and Development, Institute of Human Genetics, UMR9002 CNRS-University of Montpellier, 141 rue de la Cardonille, 34396, Montpellier Cedex 5, France
| | - Aymeric Chartier
- mRNA Regulation and Development, Institute of Human Genetics, UMR9002 CNRS-University of Montpellier, 141 rue de la Cardonille, 34396, Montpellier Cedex 5, France
| | - Camille Jahan
- mRNA Regulation and Development, Institute of Human Genetics, UMR9002 CNRS-University of Montpellier, 141 rue de la Cardonille, 34396, Montpellier Cedex 5, France
| | - Anne-Cécile Meunier
- mRNA Regulation and Development, Institute of Human Genetics, UMR9002 CNRS-University of Montpellier, 141 rue de la Cardonille, 34396, Montpellier Cedex 5, France
| | - Stéphanie Pierson
- mRNA Regulation and Development, Institute of Human Genetics, UMR9002 CNRS-University of Montpellier, 141 rue de la Cardonille, 34396, Montpellier Cedex 5, France
| | - Paul F Harrison
- Monash Bioinformatics Platform, Monash University, Melbourne, VIC, 3800, Australia
- Development and Stem Cells Program, Monash Biomedicine Discovery Institute, Monash University, Melbourne, VIC, 3800, Australia
| | - Catherine Papin
- mRNA Regulation and Development, Institute of Human Genetics, UMR9002 CNRS-University of Montpellier, 141 rue de la Cardonille, 34396, Montpellier Cedex 5, France
| | - Traude H Beilharz
- Development and Stem Cells Program, Monash Biomedicine Discovery Institute, Monash University, Melbourne, VIC, 3800, Australia
| | - Martine Simonelig
- mRNA Regulation and Development, Institute of Human Genetics, UMR9002 CNRS-University of Montpellier, 141 rue de la Cardonille, 34396, Montpellier Cedex 5, France.
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37
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Götze M, Dufourt J, Ihling C, Rammelt C, Pierson S, Sambrani N, Temme C, Sinz A, Simonelig M, Wahle E. Translational repression of the Drosophila nanos mRNA involves the RNA helicase Belle and RNA coating by Me31B and Trailer hitch. RNA (NEW YORK, N.Y.) 2017; 23:1552-1568. [PMID: 28701521 PMCID: PMC5602113 DOI: 10.1261/rna.062208.117] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Accepted: 07/10/2017] [Indexed: 05/10/2023]
Abstract
Translational repression of maternal mRNAs is an essential regulatory mechanism during early embryonic development. Repression of the Drosophila nanos mRNA, required for the formation of the anterior-posterior body axis, depends on the protein Smaug binding to two Smaug recognition elements (SREs) in the nanos 3' UTR. In a comprehensive mass spectrometric analysis of the SRE-dependent repressor complex, we identified Smaug, Cup, Me31B, Trailer hitch, eIF4E, and PABPC, in agreement with earlier data. As a novel component, the RNA-dependent ATPase Belle (DDX3) was found, and its involvement in deadenylation and repression of nanos was confirmed in vivo. Smaug, Cup, and Belle bound stoichiometrically to the SREs, independently of RNA length. Binding of Me31B and Tral was also SRE-dependent, but their amounts were proportional to the length of the RNA and equimolar to each other. We suggest that "coating" of the RNA by a Me31B•Tral complex may be at the core of repression.
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Affiliation(s)
- Michael Götze
- Institute of Biochemistry and Biotechnology, Martin Luther University Halle-Wittenberg, 06099 Halle, Germany
| | - Jérémy Dufourt
- Institute of Human Genetics, UMR9002 CNRS-University of Montpellier, 34396 Montpellier Cedex 5, France
| | - Christian Ihling
- Institute of Pharmacy, Martin Luther University Halle-Wittenberg, 06099 Halle, Germany
| | - Christiane Rammelt
- Institute of Biochemistry and Biotechnology, Martin Luther University Halle-Wittenberg, 06099 Halle, Germany
| | - Stephanie Pierson
- Institute of Human Genetics, UMR9002 CNRS-University of Montpellier, 34396 Montpellier Cedex 5, France
| | - Nagraj Sambrani
- Institute of Human Genetics, UMR9002 CNRS-University of Montpellier, 34396 Montpellier Cedex 5, France
| | - Claudia Temme
- Institute of Biochemistry and Biotechnology, Martin Luther University Halle-Wittenberg, 06099 Halle, Germany
| | - Andrea Sinz
- Institute of Pharmacy, Martin Luther University Halle-Wittenberg, 06099 Halle, Germany
| | - Martine Simonelig
- Institute of Human Genetics, UMR9002 CNRS-University of Montpellier, 34396 Montpellier Cedex 5, France
| | - Elmar Wahle
- Institute of Biochemistry and Biotechnology, Martin Luther University Halle-Wittenberg, 06099 Halle, Germany
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38
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Wang M, Ly M, Lugowski A, Laver JD, Lipshitz HD, Smibert CA, Rissland OS. ME31B globally represses maternal mRNAs by two distinct mechanisms during the Drosophila maternal-to-zygotic transition. eLife 2017; 6:27891. [PMID: 28875934 PMCID: PMC5779226 DOI: 10.7554/elife.27891] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Accepted: 09/04/2017] [Indexed: 12/27/2022] Open
Abstract
In animal embryos, control of development is passed from exclusively maternal gene products to those encoded by the embryonic genome in a process referred to as the maternal-to-zygotic transition (MZT). We show that the RNA-binding protein, ME31B, binds to and represses the expression of thousands of maternal mRNAs during the Drosophila MZT. However, ME31B carries out repression in different ways during different phases of the MZT. Early, it represses translation while, later, its binding leads to mRNA destruction, most likely as a consequence of translational repression in the context of robust mRNA decay. In a process dependent on the PNG kinase, levels of ME31B and its partners, Cup and Trailer Hitch (TRAL), decrease by over 10-fold during the MZT, leading to a change in the composition of mRNA-protein complexes. We propose that ME31B is a global repressor whose regulatory impact changes based on its biological context.
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Affiliation(s)
- Miranda Wang
- Molecular Medicine Program, The Hospital for Sick Children Research Institute, Toronto, Canada.,Department of Molecular Genetics, University of Toronto, Toronto, Canada
| | - Michael Ly
- Molecular Medicine Program, The Hospital for Sick Children Research Institute, Toronto, Canada
| | - Andrew Lugowski
- Molecular Medicine Program, The Hospital for Sick Children Research Institute, Toronto, Canada.,Department of Molecular Genetics, University of Toronto, Toronto, Canada
| | - John D Laver
- Department of Molecular Genetics, University of Toronto, Toronto, Canada
| | - Howard D Lipshitz
- Department of Molecular Genetics, University of Toronto, Toronto, Canada
| | - Craig A Smibert
- Department of Molecular Genetics, University of Toronto, Toronto, Canada.,Department of Biochemistry, University of Toronto, Toronto, Canada
| | - Olivia S Rissland
- Molecular Medicine Program, The Hospital for Sick Children Research Institute, Toronto, Canada.,Department of Molecular Genetics, University of Toronto, Toronto, Canada.,Department of Biochemistry and Molecular Genetics, University of Colorado Denver School of Medicine, Aurora, United States.,RNA Bioscience Initiative, University of Colorado Denver School of Medicine, Aurora, United States
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39
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Abstract
Asymmetric localization of mRNAs is a widespread gene regulatory mechanism that is crucial for many cellular processes. The localization of a transcript involves multiple steps and requires several protein factors to mediate transport, anchoring and translational repression of the mRNA. Specific recognition of the localizing transcript is a key step that depends on linear or structured localization signals, which are bound by RNA-binding proteins. Genetic studies have identified many components involved in mRNA localization. However, mechanistic aspects of the pathway are still poorly understood. Here we provide an overview of structural studies that contributed to our understanding of the mechanisms underlying mRNA localization, highlighting open questions and future challenges.
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Affiliation(s)
| | - Fulvia Bono
- a Max Planck Institute for Developmental Biology , Tübingen , Germany
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40
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Hovland E, Beyene GT, Frye SA, Homberset H, Balasingham SV, Gómez-Muñoz M, Derrick JP, Tønjum T, Ambur OH. DprA from Neisseria meningitidis: properties and role in natural competence for transformation. MICROBIOLOGY-SGM 2017; 163:1016-1029. [PMID: 28696187 PMCID: PMC5817196 DOI: 10.1099/mic.0.000489] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
DNA processing chain A (DprA) is a DNA-binding protein that is ubiquitous in bacteria and expressed in some archaea. DprA is active in many bacterial species that are competent for transformation of DNA, but its role in Neisseriameningitidis (Nm) is not well characterized. An Nm mutant lacking DprA was constructed, and the phenotypes of the wild-type and ΔdprA mutant were compared. The salient feature of the phenotype of dprA null cells is the total lack of competence for genetic transformation shown by all of the donor DNA substrates tested in this study. Here, Nm wild-type and dprA null cells appeared to be equally resistant to genotoxic stress. The gene encoding DprANm was cloned and overexpressed, and the biological activities of DprANm were further investigated. DprANm binds ssDNA more strongly than dsDNA, but lacks DNA uptake sequence-specific DNA binding. DprANm dimerization and interaction with the C-terminal part of the single-stranded binding protein SSBNmwere demonstrated. dprA is co-expressed with smg, a downstream gene of unknown function, and the gene encoding topoisomerase 1, topA.
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Affiliation(s)
- Eirik Hovland
- Department of Microbiology, University of Oslo, Oslo, Norway.,Present address: Lovisenberg Diaconal Hospital, Oslo, Norway
| | | | - Stephan A Frye
- Department of Microbiology, Oslo University Hospital, Oslo, Norway
| | | | | | | | - Jeremy P Derrick
- Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre, University of Manchester, Oxford Road, Manchester, UK
| | - Tone Tønjum
- Department of Microbiology, Oslo University Hospital, Oslo, Norway.,Department of Microbiology, University of Oslo, Oslo, Norway
| | - Ole H Ambur
- Department of Microbiology, Oslo University Hospital, Oslo, Norway.,Present address: Department of Life Sciences and Health, Oslo and Akershus University College of Applied Sciences, Norway
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41
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Arsala D, Lynch JA. Ploidy has little effect on timing early embryonic events in the haplo-diploid wasp Nasonia. Genesis 2017; 55. [PMID: 28432826 DOI: 10.1002/dvg.23029] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Revised: 02/20/2017] [Accepted: 03/06/2017] [Indexed: 12/18/2022]
Abstract
The nucleocytoplasmic (N/C) ratio plays a prominent role in the maternal-to-zygotic transition (MZT) in many animals. The effect of the N/C ratio on cell-cycle lengthening and zygotic genome activation (ZGA) has been studied extensively in Drosophila, where haploid embryos experience an additional division prior to completing cellularization and triploid embryos cellularize precociously by one division. In this study, we set out to understand how the obligate difference in ploidy in the haplodiploid wasp, Nasonia, affects the MZT and which aspects of the Drosophila MZT are conserved. While subtle differences in early embryonic development were observed in comparisons among haploid, diploid, and triploid embryos, in all cases embryos cellularize at cell cycle 12. When ZGA was inhibited, both diploid female, and haploid male, embryos went through 12 syncytial divisions and failed to cellularize before dying without further divisions. We also found that key players of the Drosophila MZT are conserved in Nasonia but have novel expression patterns. Our results suggest that zygotically expressed genes have a reduced role in determining the timing of cellularization in Nasonia relative to Drosophila, and that a stronger reliance on a maternal timer is more compatible with species where variations in embryonic ploidy are obligatory.
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Affiliation(s)
- Deanna Arsala
- University of Illinois at Chicago, Chicago, Illinois
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42
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RNA-binding protein SAMD4 regulates skeleton development through translational inhibition of Mig6 expression. Cell Discov 2017; 3:16050. [PMID: 28163927 PMCID: PMC5259697 DOI: 10.1038/celldisc.2016.50] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Accepted: 12/05/2016] [Indexed: 12/11/2022] Open
Abstract
Protein translation regulation has essential roles in inflammatory responses, cancer initiation and the pathogenesis of several neurodegenerative disorders. However, the role of the regulation of protein translation in mammalian skeleton development has been rarely elaborated. Here we report that the lack of the RNA-binding protein sterile alpha motif domain containing protein 4 (SAMD4) resulted in multiple developmental defects in mice, including delayed bone development and decreased osteogenesis. Samd4-deficient mesenchymal progenitors exhibit impaired osteoblast differentiation and function. Mechanism study demonstrates that SAMD4 binds the Mig6 mRNA and inhibits MIG6 protein synthesis. Consistent with this, Samd4-deficient cells have increased MIG6 protein level and knockdown of Mig6 rescues the impaired osteogenesis in Samd4-deficient cells. Furthermore, Samd4-deficient mice also display chondrocyte defects, which is consistent with the regulation of MIG6 protein level by SAMD4. These findings define SAMD4 as a previously unreported key regulator of osteoblastogenesis and bone development, implying that regulation of protein translation is an important mechanism governing skeletogenesis and that control of protein translation could have therapeutic potential in metabolic bone diseases, such as osteoporosis.
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43
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Abstract
Acquisition of oocyte polarity involves complex translocation and aggregation of intracellular organelles, RNAs, and proteins, along with strict posttranscriptional regulation. While much is still unknown regarding the formation of the animal-vegetal axis, an early marker of polarity, animal models have contributed to our understanding of these early processes controlling normal oogenesis and embryo development. In recent years, it has become clear that proteins with self-assembling properties are involved in assembling discrete subcellular compartments or domains underlying subcellular asymmetries in the early mitotic and meiotic cells of the female germline. These include asymmetries in duplication of the centrioles and formation of centrosomes and assembly of the organelle and RNA-rich Balbiani body, which plays a critical role in oocyte polarity. Notably, at specific stages of germline development, these transient structures in oocytes are temporally coincident and align with asymmetries in the position and arrangement of nuclear components, such as the nuclear pore and the chromosomal bouquet and the centrioles and cytoskeleton in the cytoplasm. Formation of these critical, transient structures and arrangements involves microtubule pathways, intrinsically disordered proteins (proteins with domains that tend to be fluid or lack a rigid ordered three-dimensional structure ranging from random coils, globular domains, to completely unstructured proteins), and translational repressors and activators. This review aims to examine recent literature and key players in oocyte polarity.
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Affiliation(s)
- Mara Clapp
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine of Yeshiva University, Bronx, NY, USA
| | - Florence L Marlow
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine of Yeshiva University, Bronx, NY, USA.
- Department of Neuroscience, Albert Einstein College of Medicine of Yeshiva University, Bronx, NY, USA.
- Department of Cell, Developmental and Regenerative Medicine, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, Box 1020, New York, NY, 10029-6574, USA.
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44
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Pushpa K, Kumar GA, Subramaniam K. Translational Control of Germ Cell Decisions. Results Probl Cell Differ 2017; 59:175-200. [PMID: 28247049 DOI: 10.1007/978-3-319-44820-6_6] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Germline poses unique challenges to gene expression control at the transcriptional level. While the embryonic germline maintains a global hold on new mRNA transcription, the female adult germline produces transcripts that are not translated into proteins until embryogenesis of subsequent generation. As a consequence, translational control plays a central role in governing various germ cell decisions including the formation of primordial germ cells, self-renewal/differentiation decisions in the adult germline, onset of gametogenesis and oocyte maturation. Mechanistically, several common themes such as asymmetric localization of mRNAs, conserved RNA-binding proteins that control translation by 3' UTR binding, translational activation by the cytoplasmic elongation of the polyA tail and the assembly of mRNA-protein complexes called mRNPs have emerged from the studies on Caenorhabditis elegans, Xenopus and Drosophila. How mRNPs assemble, what influences their dynamics, and how a particular 3' UTR-binding protein turns on the translation of certain mRNAs while turning off other mRNAs at the same time and space are key challenges for future work.
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Affiliation(s)
- Kumari Pushpa
- Regional Centre for Biotechnology, Faridabad, Haryana, India
| | - Ganga Anil Kumar
- Indian Institute of Technology-Kanpur, Kanpur, India.,Indian Institute of Technology-Madras, Chennai, India
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45
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Abstract
Until the zygotic genome is activated, early development relies on the products deposited by the mother. Once the zygotic genome starts to be transcribed, most maternal products are not needed anymore by the developing embryo. This emancipation from the maternal genome occurs during the Zygotic Genome Activation (ZGA). Although the process by which the maternal content is replaced with zygotic products differs from species to species, there is a common theme to all of them: maternal transcripts are actively degraded. Here, a review of how the degradation of maternal RNAs is regulated during early development and discussions on some computational tools that may be of use in this research area are outlined.
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Affiliation(s)
- Antonio Marco
- School of Biological Sciences, University of Essex, Wivenhoe Park, Colchester, CO4 3SQ, UK.
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46
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The Smaug RNA-Binding Protein Is Essential for microRNA Synthesis During the Drosophila Maternal-to-Zygotic Transition. G3-GENES GENOMES GENETICS 2016; 6:3541-3551. [PMID: 27591754 PMCID: PMC5100853 DOI: 10.1534/g3.116.034199] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Metazoan embryos undergo a maternal-to-zygotic transition (MZT) during which maternal gene products are eliminated and the zygotic genome becomes transcriptionally active. During this process, RNA-binding proteins (RBPs) and the microRNA-induced silencing complex (miRISC) target maternal mRNAs for degradation. In Drosophila, the Smaug (SMG), Brain tumor (BRAT), and Pumilio (PUM) RBPs bind to and direct the degradation of largely distinct subsets of maternal mRNAs. SMG has also been shown to be required for zygotic synthesis of mRNAs and several members of the miR-309 family of microRNAs (miRNAs) during the MZT. Here, we have carried out global analysis of small RNAs both in wild-type and in smg mutants. Our results show that 85% of all miRNA species encoded by the genome are present during the MZT. Whereas loss of SMG has no detectable effect on Piwi-interacting RNAs (piRNAs) or small interfering RNAs (siRNAs), zygotic production of more than 70 species of miRNAs fails or is delayed in smg mutants. SMG is also required for the synthesis and stability of a key miRISC component, Argonaute 1 (AGO1), but plays no role in accumulation of the Argonaute family proteins associated with piRNAs or siRNAs. In smg mutants, maternal mRNAs that are predicted targets of the SMG-dependent zygotic miRNAs fail to be cleared. BRAT and PUM share target mRNAs with these miRNAs but not with SMG itself. We hypothesize that SMG controls the MZT, not only through direct targeting of a subset of maternal mRNAs for degradation but, indirectly, through production and function of miRNAs and miRISC, which act together with BRAT and/or PUM to control clearance of a distinct subset of maternal mRNAs.
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47
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A Smaug2-Based Translational Repression Complex Determines the Balance between Precursor Maintenance versus Differentiation during Mammalian Neurogenesis. J Neurosci 2016; 35:15666-81. [PMID: 26609159 DOI: 10.1523/jneurosci.2172-15.2015] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
UNLABELLED Here, we have asked about post-transcriptional mechanisms regulating murine developmental neurogenesis, focusing upon the RNA-binding proteins Smaug2 and Nanos1. We identify, in embryonic neural precursors of the murine cortex, a Smaug2 protein/nanos1 mRNA complex that is present in cytoplasmic granules with the translational repression proteins Dcp1 and 4E-T. We show that Smaug2 inhibits and Nanos1 promotes neurogenesis, with Smaug2 knockdown enhancing neurogenesis and depleting precursors, and Nanos1 knockdown inhibiting neurogenesis and maintaining precursors. Moreover, we show that Smaug2 likely regulates neurogenesis by silencing nanos1 mRNA. Specifically, Smaug2 knockdown inappropriately increases Nanos1 protein, and the Smaug2 knockdown-mediated neurogenesis is rescued by preventing this increase. Thus, Smaug2 and Nanos1 function as a bimodal translational repression switch to control neurogenesis, with Smaug2 acting in transcriptionally primed precursors to silence mRNAs important for neurogenesis, including nanos1 mRNA, and Nanos1 acting during the transition to neurons to repress the precursor state. SIGNIFICANCE STATEMENT The mechanisms instructing neural stem cells to generate the appropriate progeny are still poorly understood. Here, we show that the RNA-binding proteins Smaug2 and Nanos1 are critical regulators of this balance and provide evidence supporting the idea that neural precursors are transcriptionally primed to generate neurons but translational regulation maintains these precursors in a stem cell state until the appropriate developmental time.
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48
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Abstract
Oskar (Osk) protein plays critical roles during Drosophila germ cell development, yet its functions in germ-line formation and body patterning remain poorly understood. This situation contrasts sharply with the vast knowledge about the function and mechanism of osk mRNA localization. Osk is predicted to have an N-terminal LOTUS domain (Osk-N), which has been suggested to bind RNA, and a C-terminal hydrolase-like domain (Osk-C) of unknown function. Here, we report the crystal structures of Osk-N and Osk-C. Osk-N shows a homodimer of winged-helix-fold modules, but without detectable RNA-binding activity. Osk-C has a lipase-fold structure but lacks critical catalytic residues at the putative active site. Surprisingly, we found that Osk-C binds the 3'UTRs of osk and nanos mRNA in vitro. Mutational studies identified a region of Osk-C important for mRNA binding. These results suggest possible functions of Osk in the regulation of stability, regulation of translation, and localization of relevant mRNAs through direct interaction with their 3'UTRs, and provide structural insights into a novel protein-RNA interaction motif involving a hydrolase-related domain.
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49
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Positive mRNA Translational Control in Germ Cells by Initiation Factor Selectivity. BIOMED RESEARCH INTERNATIONAL 2015; 2015:327963. [PMID: 26357652 PMCID: PMC4556832 DOI: 10.1155/2015/327963] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Accepted: 07/22/2015] [Indexed: 01/04/2023]
Abstract
Ultimately, the production of new proteins in undetermined cells pushes them to new fates. Other proteins hold a stem cell in a mode of self-renewal. In germ cells, these decision-making proteins are produced largely from translational control of preexisting mRNAs. To date, all of the regulation has been attributed to RNA binding proteins (RBPs) that repress mRNAs in many models of germ cell development (Drosophila, mouse, C. elegans, and Xenopus). In this review, we focus on the selective, positive function of translation initiation factors eIF4E and eIF4G, which recruit mRNAs to ribosomes upon derepression. Evidence now shows that the two events are not separate but rather are coordinated through composite complexes of repressors and germ cell isoforms of eIF4 factors. Strikingly, the initiation factor isoforms are themselves mRNA selective. The mRNP complexes of translation factors and RBPs are built on specific populations of mRNAs to prime them for subsequent translation initiation. Simple rearrangement of the partners causes a dormant mRNP to become synthetically active in germ cells when and where they are required to support gametogenesis.
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50
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Laver JD, Marsolais AJ, Smibert CA, Lipshitz HD. Regulation and Function of Maternal Gene Products During the Maternal-to-Zygotic Transition in Drosophila. Curr Top Dev Biol 2015; 113:43-84. [PMID: 26358870 DOI: 10.1016/bs.ctdb.2015.06.007] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Drosophila late-stage oocytes and early embryos are transcriptionally silent. Thus, control of gene expression during these developmental periods is posttranscriptional and posttranslational. Global changes in the transcriptome and proteome occur during oocyte maturation, after egg activation and fertilization, and upon zygotic genome activation. We review the scale, content, and dynamics of these global changes; the factors that regulate these changes; and the mechanisms by which they are accomplished. We highlight the intimate relationship between the clearance of maternal gene products and the activation of the embryo's own genome, and discuss the fact that each of these complementary components of the maternal-to-zygotic transition can be subdivided into several phases that serve different biological roles and are regulated by distinct factors.
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Affiliation(s)
- John D Laver
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | | | - Craig A Smibert
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada; Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
| | - Howard D Lipshitz
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada.
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