title: Tandem stem-loops in roX RNAs act together to mediate X chromosome dosage compensation in Drosophila.
abstract: Dosage compensation in Drosophila is an epigenetic phenomenon utilizing proteins and long noncoding RNAs (lncRNAs) for transcriptional upregulation of the male X chromosome. Here, by using UV crosslinking followed by deep sequencing, we show that two enzymes in the Male-Specific Lethal complex, MLE RNA helicase and MSL2 ubiquitin ligase, bind evolutionarily conserved domains containing tandem stem-loops in roX1 and roX2 RNAs in vivo. These domains constitute the minimal RNA unit present in multiple copies in diverse arrangements for nucleation of the MSL complex. MLE binds to these domains with distinct ATP-independent and ATP-dependent behavior. Importantly, we show that different roX RNA domains have overlapping function, since only combinatorial mutations in the tandem stem-loops result in severe loss of dosage compensation and consequently male-specific lethality. We propose that repetitive structural motifs in lncRNAs could provide plasticity during multiprotein complex assemblies to ensure efficient targeting in cis or in trans along chromosomes.
authors.affiliation: Max-Planck Institute of Immunobiology and Epigenetics, Stübeweg 51, 79108 Freiburg im Breisgau, Germany.
authors.forename: Ibrahim Avsar
authors.initials: IA
authors.lastname: Ilik
authors.forename: Jeffrey J
authors.initials: JJ
authors.lastname: Quinn
authors.forename: Plamen
authors.initials: P
authors.lastname: Georgiev
authors.forename: Filipe
authors.initials: F
authors.lastname: Tavares-Cadete
authors.forename: Daniel
authors.initials: D
authors.lastname: Maticzka
authors.forename: Sarah
authors.initials: S
authors.lastname: Toscano
authors.forename: Yue
authors.initials: Y
authors.lastname: Wan
authors.forename: Robert C
authors.initials: RC
authors.lastname: Spitale
authors.forename: Nicholas
authors.initials: N
authors.lastname: Luscombe
authors.forename: Rolf
authors.initials: R
authors.lastname: Backofen
authors.forename: Howard Y
authors.initials: HY
authors.lastname: Chang
authors.forename: Asifa
authors.initials: A
authors.lastname: Akhtar
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D020029:Base Pairing; D015153:Blotting, Western; D002843:Chromatin / Q000235:genetics; D002868:Chromosomal Proteins, Non-Histone / Q000235:genetics / Q000378:metabolism; D004265:DNA Helicases / Q000235:genetics / Q000378:metabolism; D004303:Dosage Compensation, Genetic / Q000235:genetics*; D029721:Drosophila Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D004331:Drosophila melanogaster / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D047468:Immunoprecipitation; D008297:Male; D009154:Mutation / Q000235:genetics; D009690:Nucleic Acid Conformation; D012313:RNA / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D020080:Tandem Repeat Sequences / Q000235:genetics; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D014158:Transcription, Genetic; D044767:Ubiquitin-Protein Ligases / Q000235:genetics / Q000378:metabolism; D014960:X Chromosome / Q000235:genetics* / Q000378:metabolism
chemical_list: D002843:Chromatin; D002868:Chromosomal Proteins, Non-Histone; D029721:Drosophila Proteins; C092595:Pabp2 protein, Drosophila; D016601:RNA-Binding Proteins; D014157:Transcription Factors; C070837:mle protein, Drosophila; C454144:roX1 protein, Drosophila; D012313:RNA; D044767:Ubiquitin-Protein Ligases; D004265:DNA Helicases