title: Transcription of bxd noncoding RNAs promoted by trithorax represses Ubx in cis by transcriptional interference.
abstract: Much of the genome is transcribed into long noncoding RNAs (ncRNAs). Previous data suggested that bithoraxoid (bxd) ncRNAs of the Drosophila bithorax complex (BX-C) prevent silencing of Ultrabithorax (Ubx) and recruit activating proteins of the trithorax group (trxG) to their maintenance elements (MEs). We found that, surprisingly, Ubx and several bxd ncRNAs are expressed in nonoverlapping patterns in both embryos and imaginal discs, suggesting that transcription of these ncRNAs is associated with repression, not activation, of Ubx. Our data rule out siRNA or miRNA-based mechanisms for repression by bxd ncRNAs. Rather, ncRNA transcription itself, acting in cis, represses Ubx. The Trithorax complex TAC1 binds the Ubx coding region in nuclei expressing Ubx, and the bxd region in nuclei not expressing Ubx. We propose that TAC1 promotes the mosaic pattern of Ubx expression by facilitating transcriptional elongation of bxd ncRNAs, which represses Ubx transcription.
authors.affiliation: Department of Biochemistry, Thomas Jefferson University, Philadelphia, PA 19107, USA.
authors.forename: Svetlana
authors.initials: S
authors.lastname: Petruk
authors.forename: Yurii
authors.initials: Y
authors.lastname: Sedkov
authors.forename: Kristen M
authors.initials: KM
authors.lastname: Riley
authors.forename: Jacob
authors.initials: J
authors.lastname: Hodgson
authors.forename: Francois
authors.initials: F
authors.lastname: Schweisguth
authors.forename: Susumu
authors.initials: S
authors.lastname: Hirose
authors.forename: James B
authors.initials: JB
authors.lastname: Jaynes
authors.forename: Hugh W
authors.initials: HW
authors.lastname: Brock
authors.forename: Alexander
authors.initials: A
authors.lastname: Mazo
mesh_terms: D000818:Animals; D002467:Cell Nucleus; D002868:Chromosomal Proteins, Non-Histone / Q000378:metabolism*; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D005260:Female; D005786:Gene Expression Regulation; D017344:Genes, Insect; D006657:Histones / Q000378:metabolism; D018398:Homeodomain Proteins / Q000235:genetics* / Q000378:metabolism; D007814:Larva / Q000235:genetics / Q000378:metabolism; D011401:Promoter Regions, Genetic; D022661:RNA, Untranslated / Q000235:genetics*; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism; D014158:Transcription, Genetic; D035602:Transcriptional Elongation Factors / Q000378:metabolism
chemical_list: D002868:Chromosomal Proteins, Non-Histone; D029721:Drosophila Proteins; D006657:Histones; D018398:Homeodomain Proteins; D022661:RNA, Untranslated; C483403:TAC1 protein, Drosophila; D014157:Transcription Factors; D035602:Transcriptional Elongation Factors; C066177:Ubx protein, Drosophila; C512571:trx protein, Drosophila