Cooperative and antagonistic contributions of two heterochromatin proteins to transcriptional regulation of the Drosophila sex determination decision.

Eukaryotic nuclei contain regions of differentially staining chromatin (heterochromatin), which remain condensed throughout the cell cycle and are largely transcriptionally silent. RNAi knockdown of the highly conserved heterochromatin protein HP1 in Drosophila was previously shown to preferentially...

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Main Authors: Hui Li, Janel Rodriguez, Youngdong Yoo, Momin Mohammed Shareef, Ramakrishna Badugu, Jamila I Horabin, Rebecca Kellum
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2011-06-01
Series:PLoS Genetics
Online Access:http://europepmc.org/articles/PMC3111545?pdf=render
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author Hui Li
Janel Rodriguez
Youngdong Yoo
Momin Mohammed Shareef
Ramakrishna Badugu
Jamila I Horabin
Rebecca Kellum
author_facet Hui Li
Janel Rodriguez
Youngdong Yoo
Momin Mohammed Shareef
Ramakrishna Badugu
Jamila I Horabin
Rebecca Kellum
author_sort Hui Li
collection DOAJ
description Eukaryotic nuclei contain regions of differentially staining chromatin (heterochromatin), which remain condensed throughout the cell cycle and are largely transcriptionally silent. RNAi knockdown of the highly conserved heterochromatin protein HP1 in Drosophila was previously shown to preferentially reduce male viability. Here we report a similar phenotype for the telomeric partner of HP1, HOAP, and roles for both proteins in regulating the Drosophila sex determination pathway. Specifically, these proteins regulate the critical decision in this pathway, firing of the establishment promoter of the masterswitch gene, Sex-lethal (Sxl). Female-specific activation of this promoter, Sxl(Pe), is essential to females, as it provides SXL protein to initiate the productive female-specific splicing of later Sxl transcripts, which are transcribed from the maintenance promoter (Sxl(Pm)) in both sexes. HOAP mutants show inappropriate Sxl(Pe) firing in males and the concomitant inappropriate splicing of Sxl(Pm)-derived transcripts, while females show premature firing of Sxl(Pe). HP1 mutants, by contrast, display Sxl(Pm) splicing defects in both sexes. Chromatin immunoprecipitation assays show both proteins are associated with Sxl(Pe) sequences. In embryos from HP1 mutant mothers and Sxl mutant fathers, female viability and RNA polymerase II recruitment to Sxl(Pe) are severely compromised. Our genetic and biochemical assays indicate a repressing activity for HOAP and both activating and repressing roles for HP1 at Sxl(Pe).
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spelling doaj.art-4cfd86c502c9447196971693a9b51a382022-12-21T17:58:10ZengPublic Library of Science (PLoS)PLoS Genetics1553-73901553-74042011-06-0176e100212210.1371/journal.pgen.1002122Cooperative and antagonistic contributions of two heterochromatin proteins to transcriptional regulation of the Drosophila sex determination decision.Hui LiJanel RodriguezYoungdong YooMomin Mohammed ShareefRamakrishna BaduguJamila I HorabinRebecca KellumEukaryotic nuclei contain regions of differentially staining chromatin (heterochromatin), which remain condensed throughout the cell cycle and are largely transcriptionally silent. RNAi knockdown of the highly conserved heterochromatin protein HP1 in Drosophila was previously shown to preferentially reduce male viability. Here we report a similar phenotype for the telomeric partner of HP1, HOAP, and roles for both proteins in regulating the Drosophila sex determination pathway. Specifically, these proteins regulate the critical decision in this pathway, firing of the establishment promoter of the masterswitch gene, Sex-lethal (Sxl). Female-specific activation of this promoter, Sxl(Pe), is essential to females, as it provides SXL protein to initiate the productive female-specific splicing of later Sxl transcripts, which are transcribed from the maintenance promoter (Sxl(Pm)) in both sexes. HOAP mutants show inappropriate Sxl(Pe) firing in males and the concomitant inappropriate splicing of Sxl(Pm)-derived transcripts, while females show premature firing of Sxl(Pe). HP1 mutants, by contrast, display Sxl(Pm) splicing defects in both sexes. Chromatin immunoprecipitation assays show both proteins are associated with Sxl(Pe) sequences. In embryos from HP1 mutant mothers and Sxl mutant fathers, female viability and RNA polymerase II recruitment to Sxl(Pe) are severely compromised. Our genetic and biochemical assays indicate a repressing activity for HOAP and both activating and repressing roles for HP1 at Sxl(Pe).http://europepmc.org/articles/PMC3111545?pdf=render
spellingShingle Hui Li
Janel Rodriguez
Youngdong Yoo
Momin Mohammed Shareef
Ramakrishna Badugu
Jamila I Horabin
Rebecca Kellum
Cooperative and antagonistic contributions of two heterochromatin proteins to transcriptional regulation of the Drosophila sex determination decision.
PLoS Genetics
title Cooperative and antagonistic contributions of two heterochromatin proteins to transcriptional regulation of the Drosophila sex determination decision.
title_full Cooperative and antagonistic contributions of two heterochromatin proteins to transcriptional regulation of the Drosophila sex determination decision.
title_fullStr Cooperative and antagonistic contributions of two heterochromatin proteins to transcriptional regulation of the Drosophila sex determination decision.
title_full_unstemmed Cooperative and antagonistic contributions of two heterochromatin proteins to transcriptional regulation of the Drosophila sex determination decision.
title_short Cooperative and antagonistic contributions of two heterochromatin proteins to transcriptional regulation of the Drosophila sex determination decision.
title_sort cooperative and antagonistic contributions of two heterochromatin proteins to transcriptional regulation of the drosophila sex determination decision
url http://europepmc.org/articles/PMC3111545?pdf=render
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