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. Overall design: 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
The Nuclear Pore-Associated TREX-2 Complex Employs Mediator to Regulate Gene Expression.
Subject
View SamplesStudies of the Xenopus organizer have laid the foundation for our understanding of the conserved signaling pathways that pattern vertebrate embryos during gastrulation. Here, we use this wealth of knowledge as leverage in the design and analysis of a genomic visualization of organizer-related gene transcription. Using ectopic expression of the two major activities of the organizer, BMP and Wnt inhibition, as well as endogenous tissues, we generate a focused set of samples that represent different aspects of organizer signaling. The genomic expression values of each sample are then measured with oligonucleotide arrays. From this data, genes regulated by organizer signaling are selected and then clustered by their patterns of regulation. A new GO biological process annotation of the Xenopus genome allows us to rapidly identify clusters that are highly enriched for known gastrula patterning genes. Within these clusters, we can predict the expression patterns of unknown genes with remarkable accuracy, leading to the discovery of new organizer-related gastrula stage expression patterns for 19 genes. Moreover, the patterns of gene response observed within these clusters allow us to parse apart the contributions of BMP and Wnt inhibition in organizer function. We find that the majority of gastrula patterning genes respond transcriptionally to these activities according to only a few stereotyped patterns, allowing us to describe suites of genes that are likely to share similar regulatory mechanisms. These suites of genes demonstrate a mechanism where BMP inhibition initiates the organizer program before gastrulation, and Wnt inhibition maintains and drives the organizer program during gastrulation.
Genomic analysis of Xenopus organizer function.
Specimen part
View SamplesWe used human gene expression microarray to interrogate how glutamine deprivation differentially impact gene expession in isogenic PIK3CA mutant and WT cells.
5-Fluorouracil Enhances the Antitumor Activity of the Glutaminase Inhibitor CB-839 against <i>PIK3CA</i>-Mutant Colorectal Cancers.
Specimen part, Cell line, Treatment
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Combinatorial recruitment of CREB, C/EBPβ and c-Jun determines activation of promoters upon keratinocyte differentiation.
Specimen part, Treatment
View SamplesCombinatorial recruitment of CREB, C/EBPb and Jun determines activation of promoters upon keratinocyte differentiation
Combinatorial recruitment of CREB, C/EBPβ and c-Jun determines activation of promoters upon keratinocyte differentiation.
Specimen part, Treatment
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Integrative analysis reveals novel pathways mediating the interaction between adipose tissue and pancreatic islets in obesity in rats.
Specimen part
View SamplesChanges in the secretion profile of visceral-pancreatic white adipose tissue due to diet-induced obesity are partially responsible for increased beta cell replication, suggesting that a crosstalk between pWAT and beta cells may play a role in regulating beta cell plasticity. The molecular mechanisms underlying this cross-talk are still not fully understood.
Integrative analysis reveals novel pathways mediating the interaction between adipose tissue and pancreatic islets in obesity in rats.
Specimen part
View SamplesGene expression array analysis component. Ligand-dependent transcription by the nuclear receptor glucocorticoid receptor (GR) is mediated by interactions with co-regulators. The role of these interactions in determining selective binding of GR to regulatory elements remains unclear. Recent findings indicate a large fraction of genomic GR binding coincides with chromatin that is accessible prior to hormone treatment, suggesting that receptor binding is dictated by proteins that maintain chromatin in an open state. Combining nucleolytic cleavage and chromatin immunoprecipitation with high-throughput sequencing, we identify the activator protein 1 (AP1) as a major partner for productive GR-chromatin interactions. AP1 is critical for GR-regulated transcription and recruitment to co-occupied regulatory elements, illustrating an extensive AP1-GR interaction network. Importantly, the maintenance of baseline chromatin accessibility facilitates GR recruitment and is dependent on AP1 binding. We propose a model where the basal occupancy of transcription factors act to prime chromatin and direct inducible transcription factors to select regions in the genome.
Transcription factor AP1 potentiates chromatin accessibility and glucocorticoid receptor binding.
Sex, Cell line, Treatment, Time
View SamplesrGal1 (recombinant Galectin-1) vs non treated (Ctrl) pancreatic cancer cell line RWP-1
Targeting galectin-1 inhibits pancreatic cancer progression by modulating tumor-stroma crosstalk.
Specimen part, Cell line
View SamplesThe mechanisms that allow breast cancer cells to metabolically sustain growth are poorly understood. In breast cancer, FoxA1 transcription factor, along with estrogen receptor, regulates luminal cell specification and proliferation. Here we report that FoxA transcription factor family members FoxA1 and FoxA2 fuel cellular growth in breast cancer through the expression of a common target gene, namely the endothelial lipase (LIPG)
FoxA and LIPG endothelial lipase control the uptake of extracellular lipids for breast cancer growth.
Cell line
View Samples