Project description:Nuclear pores associate with active protein-coding genes in yeast and have been implicated in transcriptional regulation. Here, we show that in addition to transcriptional regulation, key components of C. elegans nuclear pores are required for processing of a subset of small nucleolar RNAs (snoRNAs) and tRNAs transcribed by RNA Polymerase (Pol) III. Chromatin immunoprecipitation of NPP-13 and NPP-3, two integral nuclear pore components, and importin-ß IMB-1, provides strong evidence that this requirement is direct. All three proteins associate specifically with tRNA and snoRNA genes undergoing Pol III transcription. These pore components bind immediately downstream of the Pol III pre-initiation complex, but are not required for Pol III recruitment. Instead, NPP-13 is required for cleavage of tRNA and snoRNA precursors into mature RNAs, whereas Pol II transcript processing occurs normally. Our data suggest that integral nuclear pore proteins act to coordinate transcription and processing of Pol III transcripts in C. elegans.
Project description:Nuclear pores associate with active protein-coding genes in yeast and have been implicated in transcriptional regulation. Here, we show that in addition to transcriptional regulation, key components of C. elegans nuclear pores are required for processing of a subset of small nucleolar RNAs (snoRNAs) and tRNAs transcribed by RNA Polymerase (Pol) III. Chromatin immunoprecipitation of NPP-13 and NPP-3, two integral nuclear pore components, and importin-ß IMB-1, provides strong evidence that this requirement is direct. All three proteins associate specifically with tRNA and snoRNA genes undergoing Pol III transcription. These pore components bind immediately downstream of the Pol III pre-initiation complex, but are not required for Pol III recruitment. Instead, NPP-13 is required for cleavage of tRNA and snoRNA precursors into mature RNAs, whereas Pol II transcript processing occurs normally. Our data suggest that integral nuclear pore proteins act to coordinate transcription and processing of Pol III transcripts in C. elegans.
Project description:Nuclear pores associate with active protein-coding genes in yeast and have been implicated in transcriptional regulation. Here, we show that in addition to transcriptional regulation, key components of C. elegans nuclear pores are required for processing of a subset of small nucleolar RNAs (snoRNAs) and tRNAs transcribed by RNA Polymerase (Pol) III. Chromatin immunoprecipitation of NPP-13 and NPP-3, two integral nuclear pore components, and importin-M-CM-^_ IMB-1, provides strong evidence that this requirement is direct. All three proteins associate specifically with tRNA and snoRNA genes undergoing Pol III transcription. These pore components bind immediately downstream of the Pol III pre-initiation complex, but are not required for Pol III recruitment. Instead, NPP-13 is required for cleavage of tRNA and snoRNA precursors into mature RNAs, whereas Pol II transcript processing occurs normally. Our data suggest that integral nuclear pore proteins act to coordinate transcription and processing of Pol III transcripts in C. elegans. Genome-wide ChIP-seq and ChIP-chip were performed in mixed-stage C. elegans embryos for nuclear pore proteins NPP-13, NPP-3, IMB-1 and chromatin proteins Pol III (RPC-1), TBP-1, TFC-1 (SFC-1), TFC-4 (TAG-315), and Pol II (AMA-1). For RPC-1 and TBP-1 ChIP-seq, embryos depleted for NPP-13 were also used. Total RNAs from wild-type, NPP-13 RNAi, and IMB-1 RNAi embryos were analyzed by RNA-seq.
Project description:Nuclear pores associate with active protein-coding genes in yeast and have been implicated in transcriptional regulation. Here, we show that in addition to transcriptional regulation, key components of C. elegans nuclear pores are required for processing of a subset of small nucleolar RNAs (snoRNAs) and tRNAs transcribed by RNA Polymerase (Pol) III. Chromatin immunoprecipitation of NPP-13 and NPP-3, two integral nuclear pore components, and importin-M-CM-^_ IMB-1, provides strong evidence that this requirement is direct. All three proteins associate specifically with tRNA and snoRNA genes undergoing Pol III transcription. These pore components bind immediately downstream of the Pol III pre-initiation complex, but are not required for Pol III recruitment. Instead, NPP-13 is required for cleavage of tRNA and snoRNA precursors into mature RNAs, whereas Pol II transcript processing occurs normally. Our data suggest that integral nuclear pore proteins act to coordinate transcription and processing of Pol III transcripts in C. elegans. Genome-wide ChIP-seq and ChIP-chip were performed in mixed-stage C. elegans embryos for nuclear pore proteins NPP-13, NPP-3, IMB-1 and chromatin proteins Pol III (RPC-1), TBP-1, TFC-1 (SFC-1), TFC-4 (TAG-315), and Pol II (AMA-1). For RPC-1 and TBP-1 ChIP-seq, embryos depleted for NPP-13 were also used. Total RNAs from wild-type, NPP-13 RNAi, and IMB-1 RNAi embryos were analyzed by RNA-seq.
Project description:Transcription is regulated by a multitude of activators and repressors, which bind to the RNA polymerase II (Pol II) machinery and modulate its progression. Death-inducer obliterator (DIDO) and PHD finger protein 3 (PHF3) are paralogue proteins that regulate transcription elongation by docking onto phosphorylated serine-2 in the C-terminal domain (CTD) of Pol II through their SPOC domains. Here we show that DIDO3 and PHF3 form a complex that bridges the Pol II elongation machinery with chromatin and RNA processing factors, and tethers Pol II in a phase-separated microenvironment. Their SPOC domains and C-terminal intrinsically disordered regions are critical for transcription regulation. The dataset contains 3' Sequencing of WT, PHF3 KO, and PHF3 dSPOC mutant HEK293 cell line. Cytoplasmic and nuclear fractions were profiled separately.
Project description:Nuclear pore complexes (NPCs) influence gene expression besides their established function in nuclear transport. The TREX-2 complex localizes to the NPC basket and affects gene-NPC interactions, transcription and mRNA export. How TREX-2 regulates the gene expression machinery is unknown. Here, we show that TREX-2 interacts with the Mediator complex, an essential regulator of RNA Polymerase (Pol) II. Structural and biochemical studies identify a conserved region on TREX-2, which directly binds the Mediator Med31/Med7N submodule. TREX-2 regulates assembly of Mediator with its Cdk8 kinase and is required for recruitment and site-specific phosphorylation of Pol II. Transcriptome and phenotypic profiling confirm that TREX-2 and Med31 are functionally interdependent. TREX-2 additionally uses its Mediator-interacting surface to regulate mRNA export suggesting a mechanism for coupling transcription initiation and early steps of mRNA processing at the Mediator level. In sum, we provide insight into how NPC-associated adaptor complexes can access the core transcription machinery. RNAseq was performed from WT, sac3∆, cdk8∆ and Sac3 R288D mutant cells. For each strain triplicates were analyzed. WT strain was sac3∆ transformed with pRS315 SAC3 WT
Project description:C. elegans nuclear pore protein NPP-13 associates with small RNA genes transcribed by RNA Polymerase III. To test if the nuclear pore-chromatin interactions play a role in large-scale chromatin organization, we determined nuclear membrane-genome interactions and RNA Polymerase II localization in C. elegans embryos depleted for NPP-13.
Project description:C. elegans nuclear pore protein NPP-13 associates with small RNA genes transcribed by RNA Polymerase III. To test if the nuclear pore-chromatin interactions play a role in large-scale chromatin organization, we determined nuclear membrane-genome interactions and RNA Polymerase II localization in C. elegans embryos depleted for NPP-13.
Project description:RNA polymerase (RNA Pol) III synthesizes the tRNAs, the 5S ribosomal RNA and a small number of untranslated RNAs. In vitro, it also transcribes short interspersed nuclear elements (SINEs). We investigated the distribution of RNA Pol III and its associated transcription factors on the genome of mouse embryonic stem (ES) cell using a highly specific tandem ChIP-Seq method. Only a subset of the annotated class-III genes was bound and thus transcribed. A few hundred SINEs were associated with the RNA Pol III transcription machinery. We observed that RNA Pol III and its transcription factors were present at thirty unannotated sites on the mouse genome, only one of which was conserved in human. An RNA was associated with more than 80% of these regions. More than 2200 regions bound by TFIIIC transcription factor were devoid of RNA Pol III. These sites are correlated with association of CTCF and the cohesin. Cohesin has been shown to occupy sites bound by CTCF and to contribute to DNA loop formation associated with gene repression or activation. This observation suggests that TFIIIC may play a role in chromosome organization in mouse. We also investigated the genome-wide distribution of the ubiquitous TFIIS variant, TCEA1. We found that, as in Saccharomyces cerevisiae, TFIIS is associated with class III genes and also with SINEs suggesting that TFIIS is a RNA Pol III transcription factor in mammals. We performed ChIP-seq experiment on mouse ES cells, in order to analyse the distribution of the RNA Pol III, with two of its subunits, RPC1 and RPC4, of the two distinct forms of the transcription factor TFIIIB, with BRF1 and BRF2, respectively subunit of TFIIIB-beta, and TFIIIB-alpha form, and three subunits of the transcription factor TFIIIC, TFIIIC90, TFIIIC110, TFIIIC220. We also analysed the distribution of the RNA Pol II elongation factor TCEA1. We used tagged proteins, in order to develop a highly specific and generic ChIP-seq protocol. A sequence encoding a 6 histidine-Flag-HA tag was inserted just after the last codon of the gene encoding proteins of the RNA Pol III machinery subunits, or just after the start codon for TCEA1, using the recombineering technology. Untagged ES cell line was used as negative control for data processing. Our dataset comprises of ten ChIP-seq samples, eight from tagged proteins, two from untagged cell line.