Dataset Information

Nuclear pore proteins nup153 and megator define transcriptionally active regions in the Drosophila genome.

ABSTRACT: Transcriptional regulation is one of the most important processes for modulating gene expression. Though much of this control is attributed to transcription factors, histones, and associated enzymes, it is increasingly apparent that the spatial organization of chromosomes within the nucleus has a profound effect on transcriptional activity. Studies in yeast indicate that the nuclear pore complex might promote transcription by recruiting chromatin to the nuclear periphery. In higher eukaryotes, however, it is not known whether such regulation has global significance. Here we establish nucleoporins as a major class of global regulators for gene expression in Drosophila melanogaster. Using chromatin-immunoprecipitation combined with microarray hybridisation, we show that Nup153 and Megator (Mtor) bind to 25% of the genome in continuous domains extending 10 kb to 500 kb. These Nucleoporin-Associated Regions (NARs) are dominated by markers for active transcription, including high RNA polymerase II occupancy and histone H4K16 acetylation. RNAi-mediated knock-down of Nup153 alters the expression of approximately 5,700 genes, with a pronounced down-regulatory effect within NARs. We find that nucleoporins play a central role in coordinating dosage compensation-an organism-wide process involving the doubling of expression of the male X chromosome. NARs are enriched on the male X chromosome and occupy 75% of this chromosome. Furthermore, Nup153-depletion abolishes the normal function of the male-specific dosage compensation complex. Finally, by extensive 3D imaging, we demonstrate that NARs contribute to gene expression control irrespective of their sub-nuclear localization. Therefore, we suggest that NAR-binding is used for chromosomal organization that enables gene expression control.

SUBMITTER: Vaquerizas JM

PROVIDER: S-EPMC2820533 | biostudies-literature | 2010 Feb

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Nuclear pore proteins nup153 and megator define transcriptionally active regions in the Drosophila genome.

Vaquerizas Juan M JM Suyama Ritsuko R Kind Jop J Miura Kota K Luscombe Nicholas M NM Akhtar Asifa A

PLoS genetics 20100212 2

Transcriptional regulation is one of the most important processes for modulating gene expression. Though much of this control is attributed to transcription factors, histones, and associated enzymes, it is increasingly apparent that the spatial organization of chromosomes within the nucleus has a profound effect on transcriptional activity. Studies in yeast indicate that the nuclear pore complex might promote transcription by recruiting chromatin to the nuclear periphery. In higher eukaryotes, h ...[more]

PMID: 20174442

Similar Datasets

Project description:Human immunodeficiency virus type 1 (HIV-1) displays the unique ability to infect nondividing cells. The capsid of HIV-1 is the viral determinant for viral nuclear import. To understand the cellular factors involved in the ability of HIV-1 to infect nondividing cells, we sought to find capsid mutations that allow the virus to infect dividing but not nondividing cells. Because the interaction of capsid with the nucleoporin protein 153 (Nup153) is important for nuclear import of HIV-1, we solved new crystal structures of hexameric HIV-1 capsid in complex with a Nup153-derived peptide containing a phenylalanine-glycine repeat (FG repeat), which we used to guide structure-based mutagenesis of the capsid-binding interface. HIV-1 viruses with mutations in these capsid residues were tested for their ability to infect dividing and nondividing cells. HIV-1 viruses with capsid N57 substitutions infected dividing but not nondividing cells. Interestingly, HIV-1 viruses with N57 mutations underwent reverse transcription but not nuclear translocation. The mutant capsids also lost the ability to interact with Nup153 and CPSF6. The use of small molecules PF74 and BI-2 prevented the interaction of FG-containing nucleoporins (Nups), such as Nup153, with the HIV-1 core. Analysis of integration sites in HIV-1 viruses with N57 mutations revealed diminished integration into transcriptionally active genes in a manner resembling that of HIV-1 in CPSF6 knockout cells or that of HIV-1-N74D. The integration pattern of the N57 mutant HIV-1 can be explained by loss of capsid interaction with CPSF6, whereas capsid interaction with Nup153 is required for HIV-1 to infect nondividing cells. Additionally, the observed viral integration profiles suggested that integration site selection is a multiparameter process that depends upon nuclear factors and the state of the cellular chromatin.IMPORTANCE One of the key advantages that distinguish lentiviruses, such as HIV-1, from all other retroviruses is its ability to infect nondividing cells. Interaction of the HIV-1 capsid with Nup153 and CPSF6 is important for nuclear entry and integration; however, the contribution of each of these proteins to nuclear import and integration is not clear. Using genetics, we demonstrated that these proteins contribute to different processes: Nup153 is essential for the HIV-1 nuclear import in nondividing cells, and CPSF6 is important for HIV-1 integration. In addition, nuclear factors such as CPSF6 and the state of the chromatin are known to be important for integration site selection; nevertheless, the preferential determinant influencing integration site selection is not known. This work demonstrates that integration site selection is a multiparameter process that depends upon nuclear factors and the state of the cellular chromatin.

Project description:The majority of all genes have so far been identified and annotated systematically through in silico gene finding. Here we report the finding of 3,217 strand-specific Transcriptionally Active Regions (TARs) in the genome of Bacillus subtilis by the use of tiling arrays. We have measured the genome-wide expression during mid-exponential growth on rich (LB) and minimal (M9) medium. The identified TARs account for 81.5% of the genes as they are currently annotated and additionally we find 44 novel protein-coding genes, 85 putative non-coding RNAs (ncRNAs) and 184 antisense transcripts. Hybridization of labeled genomic DNA (gDNA) has revealed a few thousand regions giving rise to very low signals. These are mostly caused by sequence errors, as is observed in the highly degenerate trp operon and the folding of stable structures such as the regions containing Rho-independent terminators. Through this work we have discovered a group of membrane-associated genes, among these having a long conserved 3â UnTranslated Region (UTR) predicted to fold into a large and highly stable structure. Among these are YwbN, a target of the twin-arginine translocase (Tat) protein translocation system. The transcriptionally active regions were determined at two different conditions, rich medium (Luria Broth) and minimal medium (M9). Cells were harvested at mid-exponential phase (OD600 = 0.5) and each condition were replicated three times. From each replicate RNA was extracted using FastRNA pro blue kit (Qbiogene) and labelled with Cy3 using a strand-specific protocol. The cDNA was hybridized to 385K NimbleGen tiling arrays 'BaSysBio Bsub T1' covering the entire genome with 45-65 nt isothermal probes, spaced by 22 nt on each strand. Additionally genomic DNA was extracted from 4 replicates at OD600 = 0.5, labelled and hybridized to the tiling arrays. These serve as a reference for the mRNA hybridizations. The normalized RNA hybridization signals were used to create segments using a structural change model (Huber et al, 2006) and transcriptionally active regions were identified by a segment joining-scheme.

Dataset Information

Nuclear pore proteins nup153 and megator define transcriptionally active regions in the Drosophila genome.

Publications

Nuclear pore proteins nup153 and megator define transcriptionally active regions in the Drosophila genome.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets