Genetic Analysis of Transvection Effects Involving &Regulatory
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Long Noncoding Rnas: Functional Surprises from the RNA World
Downloaded from genesdev.cshlp.org on September 25, 2021 - Published by Cold Spring Harbor Laboratory Press REVIEW Long noncoding RNAs: functional surprises from the RNA world Jeremy E. Wilusz,1 Hongjae Sunwoo,2 and David L. Spector1,3 1Watson School of Biological Sciences, Cold Spring Harbor Laboratory, Cold Spring Harbor, New York 11724, USA; 2Graduate Program in Molecular and Cellular Biology, Stony Brook University, Stony Brook, New York 11794 Most of the eukaryotic genome is transcribed, yielding complexity. In addition, there has been an explosion of a complex network of transcripts that includes tens of research addressing possible functional roles for the thousands of long noncoding RNAs with little or no other 98% of the human genome that does not encode protein-coding capacity. Although the vast majority of proteins. Rather unexpectedly, transcription is not lim- long noncoding RNAs have yet to be characterized thor- ited to protein-coding regions, but is instead pervasive oughly, many of these transcripts are unlikely to represent throughout the mammalian genome as demonstrated by transcriptional ‘‘noise’’ as a significant number have been large-scale cDNA cloning projects (Carninci et al. 2005; shown to exhibit cell type-specific expression, localiza- Katayama et al. 2005) and genomic tiling arrays (Bertone tion to subcellular compartments, and association with et al. 2004; Cheng et al. 2005; Birney et al. 2007; Kapranov human diseases. Here, we highlight recent efforts that et al. 2007a). In fact, >90% of the human genome is likely have identified a myriad of molecular functions for long to be transcribed (Birney et al. 2007), yielding a complex noncoding RNAs. -
Perspectives
Copyright 0 1994 by the Genetics Society of America Perspectives Anecdotal, Historical and Critical Commentaries on Genetics Edited by James F. Crow and William F. Dove A Century of Homeosis, A Decade of Homeoboxes William McGinnis Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06520-8114 NE hundred years ago, while the science of genet- ing mammals, and were proposed to encode DNA- 0 ics still existed only in the yellowing reprints of a binding homeodomainsbecause of a faint resemblance recently deceased Moravian abbot, WILLIAMBATESON to mating-type transcriptional regulatory proteins of (1894) coined the term homeosis to define a class of budding yeast and an even fainter resemblance to bac- biological variations in whichone elementof a segmen- terial helix-turn-helix transcriptional regulators. tally repeated array of organismal structures is trans- The initial stream of papers was a prelude to a flood formed toward the identity of another. After the redis- concerning homeobox genes and homeodomain pro- coveryof MENDEL’Sgenetic principles, BATESONand teins, a flood that has channeled into a steady river of others (reviewed in BATESON1909) realized that some homeo-publications, fed by many tributaries. A major examples of homeosis in floral organs and animal skel- reason for the continuing flow of studies is that many etons could be attributed to variation in genes. Soon groups, working on disparate lines of research, have thereafter, as the discipline of Drosophila genetics was found themselves swept up in the currents when they born and was evolving into a formidable intellectual found that their favorite protein contained one of the force enriching many biologicalsubjects, it gradually be- many subtypes of homeodomain. -
Phosphorylation, Expression and Function of the Ultrabithorax Protein Family in Drosophila Melanogaster
Development 112, 1077-1093 (1991) 1077 Printed in Great Britain © The Company of Biologists Limited 1991 Phosphorylation, expression and function of the Ultrabithorax protein family in Drosophila melanogaster ELIZABETH R. GAVIS* and DAVID S. HOGNESSt't Department of Biochemistry, Beckman Center, Stanford University School of Medicine, Stanford, California 94305 USA * Present address: Whitehead Institute for Biomedical Research, 9 Cambridge Center, Cambridge, Massachusetts 02142 USA t Present address: Department of Developmental Biology, Beckman Center, Stanford University School of Medicine, Stanford, California, 94305 USA $ Author for correspondence Summary Alternative splicing of the Ultrabithorax homeotic gene parallel those for the respective mRNAs, and all transcript generates a family of five proteins (UBX isoforms are similarly phosphorylated throughout em- isoforms) that function as transcription factors. All bryogenesis. Analysis by cotransfection assays of the isoforms contain a homeodomain within a common 99 aa promoter activation and repression functions of mutant C-terminal region (C-constant region) which is joined to UBX proteins with various deletions in the N-constant a common 247 aa N-terminal (N-constant) region by region shows that repression is generally insensitive to different combinations of three small optional elements. deletion and, hence, presumably to phosphorylation. By Unlike the UBX proteins expressed in E. coli, UBX contrast, the activation function is differentially sensitive isoforms expressed in D. melanogaster cells are phos- to the different deletions in a manner indicating the phorylated on serine and threonine residues, located absence of a discrete activating domain and instead, the primarily within a 53 aa region near the middle of the presence of multiple activating sequences spread N-constant region, to form at least five phosphorylated throughout the region. -
Mechanisms of Wnt Signaling in Development
P1: APR/ary P2: ARS/dat QC: ARS/APM T1: ARS August 29, 1998 9:42 Annual Reviews AR066-03 Annu. Rev. Cell Dev. Biol. 1998. 14:59–88 Copyright c 1998 by Annual Reviews. All rights reserved MECHANISMS OF WNT SIGNALING IN DEVELOPMENT Andreas Wodarz Institut f¨ur Genetik, Universit¨at D¨usseldorf, Universit¨atsstrasse 1, 40225 D¨usseldorf, Germany; e-mail: [email protected] Roel Nusse Howard Hughes Medical Institute and Department of Developmental Biology, Stanford University, Stanford, CA 94305-5428; e-mail: [email protected] KEY WORDS: Wnt, wingless, frizzled, catenin, signal transduction ABSTRACT Wnt genes encode a large family of secreted, cysteine-rich proteins that play key roles as intercellular signaling molecules in development. Genetic studies in Drosophila and Caenorhabditis elegans, ectopic gene expression in Xenopus, and gene knockouts in the mouse have demonstrated the involvement of Wnts in pro- cesses as diverse as segmentation, CNS patterning, and control of asymmetric cell divisions. The transduction of Wnt signals between cells proceeds in a complex series of events including post-translational modification and secretion of Wnts, binding to transmembrane receptors, activation of cytoplasmic effectors, and, finally, transcriptional regulation of target genes. Over the past two years our understanding of Wnt signaling has been substantially improved by the identifi- cation of Frizzled proteins as cell surface receptors for Wnts and by the finding that -catenin, a component downstream of the receptor, can translocate to the nucleus and function as a transcriptional activator. Here we review recent data that have started to unravel the mechanisms of Wnt signaling. -
Transvection in 2012: Site-Specific Transgenes Reveal a Plethora of Trans-Regulatory Effects
COMMENTARY Transvection in 2012: Site-Specific Transgenes Reveal a Plethora of Trans-Regulatory Effects Judith A. Kassis1 Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892 In this commentary, Judith Kassis discusses Bateman et al., widespread in the Drosophila genome (Bateman et al. 2012; “Comparing Enhancer Action in cis and in trans” and Mellert Mellert and Truman 2012). and Truman “Transvection is Common Throughout the Dro- Both groups of researchers used the phi-C31 system to in- sophila Genome”, which are published in this issue of GENETICS. tegrate transgenes into specific genomic locations to look at the ability of one transgene to activate the expression of another, N Drosophila, homologous chromosomes are paired in so- greatly increasing our knowledge of trans-interactions and sug- Imatic cells (reviewed in McKee 2004), leading to the oppor- gesting many experiments for the future. However, beyond that, tunity for regulatory DNA on one chromosome to influence their approaches to studying transvection and the questions they the expression of a promoter located on the homologous addressed differ. Bateman et al. (2012) used recombination- chromosome (reviewed in Duncan 2002; Kennison and mediated cassette exchange (Bateman et al. 2006) to insert Southworth 2002). Such trans-regulatory interactions were a simple, defined enhancer, the GMR (which consists of five first reported by Ed Lewis (Lewis 1954) who found that binding sites for the eye transcriptional activator Glass) and allelic complementation between particular mutations within adefined promoter driving the expression of either GFP or the bithorax complex did not occur when the pairing of ho- mCherry into three different chromosomal insertion sites to ad- mologous chromosomes was disrupted. -
Multi-Scale Organization of the Drosophila Melanogaster Genome
G C A T T A C G G C A T genes Review Multi-Scale Organization of the Drosophila melanogaster Genome Samantha C. Peterson † , Kaylah B. Samuelson † and Stacey L. Hanlon * Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT 06269, USA; [email protected] (S.C.P.); [email protected] (K.B.S.) * Correspondence: [email protected] † These authors contributed equally to this work. Abstract: Interphase chromatin, despite its appearance, is a highly organized framework of loops and bends. Chromosomes are folded into topologically associating domains, or TADs, and each chromosome and its homolog occupy a distinct territory within the nucleus. In Drosophila, genome organization is exceptional because homologous chromosome pairing is in both germline and somatic tissues, which promote interhomolog interactions such as transvection that can affect gene expression in trans. In this review, we focus on what is known about genome organization in Drosophila and discuss it from TADs to territory. We start by examining intrachromosomal organization at the sub-chromosome level into TADs, followed by a comprehensive analysis of the known proteins that play a key role in TAD formation and boundary establishment. We then zoom out to examine interhomolog interactions such as pairing and transvection that are abundant in Drosophila but rare in other model systems. Finally, we discuss chromosome territories that form within the nucleus, resulting in a complete picture of the multi-scale organization of the Drosophila genome. Keywords: Drosophila; topologically associating domain; insulator; pairing; transvection; B chromo- some; cytogenetics Citation: Peterson, S.C.; Samuelson, K.B.; Hanlon, S.L. -
And Abdominal-B in Drosqbhilu Melanogaster
Copyright 0 1995 by the Genetics Society of America and Trans Interactions Between the iab Regulatory Regions and abdominal-A and Abdominal-B in Drosqbhilu melanogaster Jd Eileen Hendrickson and Shigeru Sakonju Department of Human Genetics, Howard Hughes Medical Institute, University of Utah, Salt Lake City, Utah 841 12 Manuscript received August 15, 1994 Accepted for publication November 8, 1994 ABSTRACT The infra-abdominal ( iab) elements in the bithorax complex of Drosophila melanogaster regulate the transcription of the homeotic genesabdominal-A ( abd-A) and Abdominal-B ( Abd-B) in cis. Here we describe two unusual aspects of regulation by the iab elements, revealed by an analysis of an unexpected comple- mentation between mutations in the Abd-B transcription unit and these regulatory regions. First,we find that iab-6 and iab7 can regulate Abd-B in trans. This iab trans regulation is insensitive to chromosomal rearrangements that disrupt transvection effects at the nearby Ubx locus. In addition, we show that a transposed Abd-B transcription unitand promoter on the Ychromosomecan be activatedby iabelements located on the third chromosome. These results suggest that the iab regions can regulate their target promoter located ata distant sitein the genomein a manner that is much less dependent on homologue pairing than other transvection effects.The iab regulatory regionsmay have a very strong affinity for the target promoter, allowing them to interactwith each other despite the inhibitory effectsof chromosomal rearrangements. Second, by generating abd-A mutations on rearrangement chromosomes that break in the iab-7 region, we show that these breaks induce theiab elements to switch their target promoter from Abd-B to abd-A. -
Mrg15 Stimulates Ash1 H3K36 Methyltransferase Activity and Facilitates Ash1 Trithorax Group Protein Function in Drosophila
ARTICLE DOI: 10.1038/s41467-017-01897-3 OPEN Mrg15 stimulates Ash1 H3K36 methyltransferase activity and facilitates Ash1 Trithorax group protein function in Drosophila Chang Huang1, Fu Yang2, Zhuqiang Zhang1, Jing Zhang1, Gaihong Cai2, Lin Li2, Yong Zheng1, She Chen2, Rongwen Xi2 & Bing Zhu1,3 fi 1234567890 Ash1 is a Trithorax group protein that possesses H3K36-speci c histone methyltransferase activity, which antagonizes Polycomb silencing. Here we report the identification of two Ash1 complex subunits, Mrg15 and Nurf55. In vitro, Mrg15 stimulates the enzymatic activity of Ash1. In vivo, Mrg15 is recruited by Ash1 to their common targets, and Mrg15 reinforces Ash1 chromatin association and facilitates the proper deposition of H3K36me2. To dissect the functional role of Mrg15 in the context of the Ash1 complex, we identify an Ash1 point mutation (Ash1-R1288A) that displays a greatly attenuated interaction with Mrg15. Knock-in flies bearing this mutation display multiple homeotic transformation phenotypes, and these phenotypes are partially rescued by overexpressing the Mrg15-Nurf55 fusion protein, which stabilizes the association of Mrg15 with Ash1. In summary, Mrg15 is a subunit of the Ash1 complex, a stimulator of Ash1 enzymatic activity and a critical regulator of the TrxG protein function of Ash1 in Drosophila. 1 National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China. 2 National institute of Biological Sciences, Beijing 102206, China. 3 College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, China. Chang Huang, Fu Yang and Zhuqiang Zhang contributed equally to this work. Correspondence and requests for materials should be addressed to R.X. -
Control of Tissue Morphogenesis by the HOX Gene Ultrabithorax Maria-Del-Carmen Diaz-De-La-Loza1, Ryan Loker2,3, Richard S
© 2020. Published by The Company of Biologists Ltd | Development (2020) 147, dev184564. doi:10.1242/dev.184564 RESEARCH ARTICLE Control of tissue morphogenesis by the HOX gene Ultrabithorax Maria-del-Carmen Diaz-de-la-Loza1, Ryan Loker2,3, Richard S. Mann2,3 and Barry J. Thompson1,4,* ABSTRACT domain named the ‘homeobox’ that is found throughout the HOX Mutations in the Ultrabithorax (Ubx) gene cause homeotic family of transcription factors (Affolter et al., 1990a,b, 2008; Akam transformation of the normally two-winged Drosophila into a four- et al., 1984; Akam, 1983; Beachy et al., 1985; Bender et al., 1983; winged mutant fly. Ubx encodes a HOX family transcription factor that Casanova et al., 1985; Chan et al., 1994; Chan and Mann, 1993; specifies segment identity, including transformation of the second set Desplan et al., 1988; Gehring, 1992; Mann and Hogness, 1990; of wings into rudimentary halteres. Ubx is known to control the McGinnis et al., 1984a,b; Sánchez-Herrero et al., 1985; Scott and expression of many genes that regulate tissue growth and patterning, Weiner, 1984; Struhl, 1982). but how it regulates tissue morphogenesis to reshape the wing into a In Drosophila, mutations in Ubx alter the identity of an entire haltere is still unclear. Here, we show that Ubx acts by repressing the segment of the body plan, namely transformation of the third expression of two genes in the haltere, Stubble and Notopleural, both thoracic segment into a duplicated second thoracic segment of which encode transmembrane proteases that remodel the apical (Bridges, 1944; Lewis, 1963, 1978, 1998). Ubx is strongly extracellular matrix to promote wing morphogenesis. -
Interallelic Transcriptional Enhancement As an in Vivo Measure of Transvection in Drosophila Melanogaster
INVESTIGATION Interallelic Transcriptional Enhancement as an in Vivo Measure of Transvection in Drosophila melanogaster Geoffrey P. Noble,*,† Patrick J. Dolph,‡ and Surachai Supattapone*,†,1 *Department of Biochemistry and Cell Biology and †Department of Medicine, Geisel School of Medicine, and ‡Department of Biology, Dartmouth College, Hanover, New Hampshire 03755 ABSTRACT Transvection—pairing-dependent interallelic regulation resulting from enhancer action in KEYWORDS trans—occurs throughout the Drosophila melanogaster genome, likely as a result of the extensive somatic transvection homolog pairing seen in Dipteran species. Recent studies of transvection in Drosophila have demonstrated enhancer important qualitative differences between enhancer action in cis vs. in trans, as well as a modest synergistic somatic pairing effect of cis- and trans-acting enhancers on total tissue transcript levels at a given locus. In the present study, GAL4-UAS we identify a system in which cis- and trans-acting GAL4-UAS enhancer synergism has an unexpectedly large quantitative influence on gene expression, boosting total tissue transcript levels at least fourfold relative to those seen in the absence of transvection. We exploit this strong quantitative effect by using publicly available UAS-shRNA constructs from the TRiP library to assay candidate genes for transvection activity in vivo. The results of the present study, which demonstrate that in trans activation by simple UAS enhancers can have large quantitative effects on gene expression in Drosophila, have important new implications for experimental design utilizing the GAL4-UAS system. The nuclear genome is often pictured to function as a linear arrange- which there is widespread physical interaction between maternal and ment of nucleotides grouped into genes and regulatory elements paternal homologous chromosomes (McKee 2004; Metz 1916; Stevens operating more or less locally in cis . -
Transvection Is Common Throughout the Drosophila Genome
INVESTIGATION Transvection Is Common Throughout the Drosophila Genome David J. Mellert1 and James W. Truman Janelia Farm Research Campus, Howard Hughes Medical Institute, Ashburn, Virginia 20147 ABSTRACT Higher-order genome organization plays an important role in transcriptional regulation. In Drosophila, somatic pairing of homologous chromosomes can lead to transvection, by which the regulatory region of a gene can influence transcription in trans.We observe transvection between transgenes inserted at commonly used phiC31 integration sites in the Drosophila genome. When two transgenes that carry endogenous regulatory elements driving the expression of either LexA or GAL4 are inserted at the same integration site and paired, the enhancer of one transgene can drive or repress expression of the paired transgene. These transvection effects depend on compatibility between regulatory elements and are often restricted to a subset of cell types within a given expression pattern. We further show that activated UAS transgenes can also drive transcription in trans. We discuss the implication of these findings for (1) understanding the molecular mechanisms that underlie transvection and (2) the design of experiments that utilize site- specific integration. HOUGH much of transcriptional regulation is due to hypomorphic or loss-of-function alleles of a gene exhibit Tregulatory elements that act in cis, relatively near the pairing-dependent complementation. Because of the low transcriptional start site of a gene, long-range and trans frequency of finding such complementary mutations, work interactions can also affect gene regulation (reviewed in on understanding transvection has focused on test cases in- Henikoff and Comai 1998; Dekker 2008). To understand cluding, but not limited to, the yellow (Geyer et al. -
Unifying Homology Effects Carlo Cogoni
news & views Unifying homology effects Carlo Cogoni University of Rome ‘La Sapienza’, Dipartimento di Biotecnologie Cellulari ed Ematologia, Viale Regina Elena, 324, 00161 Rome, Italy. e-mail: [email protected] Meiotic silencing by unpaired DNA is a new mechanism, related to other homology-dependent gene silencing phenomena, with implications not only for genome protection against invasive nucleic acids but for genome maintenance and speciation as well. The ability of DNA sequences to pair with A single ancient origin silencing). Based on these characteristics, each other on the basis of sequence homol- Neurospora crassa is haploid during vege- which differ from transvection as it is ogy is well recognized, being the basis for tative growth, whereas in the sexual cycle, observed in Drosophila, meiotic transvec- homologous chromosome pairing during two haploid nuclei of opposite mating tion has been renamed ‘meiotic silencing meiotic prophase. In the past decade, it has type fuse to produce a diploid cell, the by unpaired DNA’ (MSUD). Shiu et al.2 become clear that homology-based interac- zygote. The zygote immediately under- also discovered that MSUD is not tions between nucleic acids, both DNA and goes the two meiotic divisions, followed restricted to a few genes as was previously RNA, can be influential not only in accom- by one mitotic division, to produce hap- believed, but that virtually the entire plishing pairing and recombination during loid ascospores. Thus, the brief period genome is subject to this process. A note- meiosis, but also in regulation of gene after karyogamy and before meiosis is the worthy finding is that a putative RNA- expression at other times in the cell cycle.