During S-phase of the cell cycle production of the core histone proteins is precisely balanced with DNA replication. Metazoan mRNAs encoding replication dependent (RD) histones lack polyA tail normally formed by 3' end cleavage and coupled polyadenylation of the pre-mRNA. Instead, they undergoes to endonucleolytic cleavage on the 3' side of an RNA hairpin (stem loop) producing mRNA with a 3´-stem loop (SL), which is exported from the nucleus for use in translation. The same endonuclease that is involved in normal protein-coding pre-mRNA cleavage, i.e. cleavage and poyladenylation specificity factor 73 (CPSF73), is proposed to catalyse RD pre-histone mRNA cleavage. Additional factors specific to RD pre-histone mRNA processing, including stem loop binding protein (SLBP) and the U7 small nuclear ribonucleoprotein (U7snRNP) that binds to a histone downstream element (HDE) are thought to be involved in CPSF73 targeting to RD pre-histone mRNA. We report that a different histone specific endonuclease (HSE), which like CPSF73 is a metallo ß lactamase (MBL) fold protein, is specific for RD pre-histone mRNA cleavage10,11. Crystallographic and biochemical studies reveal HSE has a di-zinc ion containing active site related to that of CPSF73, but which has distinct overall fold. Notably HSE depletion from cells leads to the production of unprocessed RD pre-histone mRNA due to inefficient 3' end processing. The consequent depletion of core histone proteins correlates with a cell cycle defect due to a delay in entering/progressing through S-phase. HSE thus may represent a new type of S-phase specific cancer target. Overall design: Examination of chromatin mRNA profiles in HeLa cells after depletion of HSE or CPSF73 by siRNA treatment.
Biosynthesis of histone messenger RNA employs a specific 3' end endonuclease.
Specimen part, Subject
View SamplesTo investigate transcriptional differences between HCM and WT cells Overall design: Examination of HCM vs WT Cells, with 3 replicates of each sample
A Contraction Stress Model of Hypertrophic Cardiomyopathy due to Sarcomere Mutations.
Specimen part, Disease, Disease stage, Subject
View SamplesPolymorphonuclear leukocytes (PMN) from patients with chronic granulomatous disease (CGD) fail to produce microbicidal concentrations of reactive oxygen species due to mutations in NOX2. Patients with CGD suffer from severe, life-threatening infections and inflammatory complications. Granulibacter bethesdensis is an emerging Gram-negative pathogen in CGD that resists killing by CGD PMN and inhibits PMN apoptosis through unknown mechanisms. Microarray analysis was used to study mRNA expression in normal and CGD PMN during incubation with G. bethesdensis and, simultaneously, in G. bethesdensis with normal and CGD PMN. We detected upregulation of anti-apoptotic genes (e.g., XIAP, GADD45B) and downregulation of pro-apoptotic genes (e.g., CASP8, APAF1) in infected PMN. Transcript and protein levels of inflammation and immunity-related genes were also altered. Upon interaction with PMN, G. bethesdensis altered expression of ROS-resistance genes in the presence of normal but not CGD PMN. Bacterial stress response genes, including ClpB, increased during phagocytosis by both normal and CGD PMN demonstrating responses to oxygen-independent PMN antimicrobial systems. Antisense knock down demonstrated that ClpB is dispensable for extracellular growth but is essential for bacterial resistance to both normal and CGD PMN. Metabolic adaptation of Granulibacter growth in PMN included upregulation of pyruvate dehydrogenase. Pharmacologic inhibition of pyruvate dehydrogenase by triphenylbismuthdichloride was lethal to Granulibacter. This study expands knowledge of microbial pathogenesis by Granulibacter in cells from permissive (CGD) and non-permissive (normal) hosts and identifies potentially druggable microbial factors, such as pyruvate dehydrogenase and ClpB, to help combat this antibiotic-resistant pathogen.
Simultaneous Host-Pathogen Transcriptome Analysis during Granulibacter bethesdensis Infection of Neutrophils from Healthy Subjects and Patients with Chronic Granulomatous Disease.
Specimen part, Disease, Disease stage, Time
View SamplesSREBF-1c is a transcription factor regulating fatty acid biosynthesis. We have charaterized the impact of the abcence of SREBF-1c on the development of peripheral neuropathy
Lack of sterol regulatory element binding factor-1c imposes glial Fatty Acid utilization leading to peripheral neuropathy.
Age
View SamplesIn order to define the targets of two miRNA overexpressed in NK cells in CFS/ME paitents, miRNA precursors for hsa-miR-99b and hsa-miR-330-3p were transfected in to buffy coat derived Natural Killer cells isolated by negative magnetic selection.
MicroRNAs hsa-miR-99b, hsa-miR-330, hsa-miR-126 and hsa-miR-30c: Potential Diagnostic Biomarkers in Natural Killer (NK) Cells of Patients with Chronic Fatigue Syndrome (CFS)/ Myalgic Encephalomyelitis (ME).
Specimen part, Disease, Disease stage
View SamplesMultiple myeloma is largely incurable, despite development of therapies that target myeloma cell-intrinsic pathways. Disease relapse is thought to originate from dormant myeloma cells, localized in specialized niches, which resist therapy and re-populate the tumor. However, little is known about the niche, and how it exerts cell-extrinsic control over myeloma cell dormancy and re-activation. In this study we track individual myeloma cells by intravital imaging as they colonize the endosteal niche, enter a dormant state and subsequently become activated to form colonies. We demonstrate that dormancy is a reversible state which is switched on by engagement with bone lining cells or osteoblasts, and switched off by osteoclasts remodeling the endosteal niche. Dormant myeloma cells are resistant to chemotherapy targeting dividing cells. The demonstration that the endosteal niche is pivotal in controlling myeloma cell dormancy highlights the potential for targeting cell-extrinsic mechanisms to overcome cell-intrinsic drug resistance and prevent disease relapse.
Osteoclasts control reactivation of dormant myeloma cells by remodelling the endosteal niche.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
PPARG binding landscapes in macrophages suggest a genome-wide contribution of PU.1 to divergent PPARG binding in human and mouse.
Specimen part, Cell line, Treatment
View SamplesGenome-wide comparisons of transcription factor binding sites in different species allow for a direct evaluation of the evolutionary constraints that shape transcription factor binding landscapes. To gain insights into the evolution of the PPARg-dependent transcriptional network we obtained binding data for PPARg, RXR and PU.1 in human macrophages and compared the profiles to matching data from mouse macrophages. We found that PPARg binding was highly divergent and only 5% of the PPARg bound regions were occupied in both species. Despite the low conservation of PPARg binding sites, conserved PPARg target genes contribute more than 30% to the functional target genes identified in human macrophages. In addition conserved target genes are strongly enriched for lipid metabolic functions. We detected the lineage-specification factor PU.1 at the majority of human PPARg binding sites. This confirmed the juxtaposed binding configuration found in mouse macrophages and demonstrated the preservation of tissue-specific adjacent PPARg-Pu.1 binding in the absence of individual binding site conservation. Finally, based on this of PPARg and PU.1 binding between human and mouse we suggest a mechanism by which PU.1 facilitates PPARg binding site turnover in macrophages.
PPARG binding landscapes in macrophages suggest a genome-wide contribution of PU.1 to divergent PPARG binding in human and mouse.
Cell line, Treatment
View SamplesSir2 is an NAD+-dependent histone deacetylase, and is the founding member of a large, phylogentically conserved, family of such deacetylases called the Sirtuins. The budding yeast, Saccharomyces cerevisiae, harbors 4 paralogs of Sir2, known as Hst1, Hst2, Hst3, and Hst4. Reducing the intracellular NAD+ concentration is inhibitory for the Sirtuins, and raising the intracellular nicotinamide (NAM) concentration is inhibitory. Microarray gene expression analysis was used to identify novel classes of yeast genes whose expression is altered when either NAD+ concentration is reduced or NAM is elevated. A subset of genes involved in thiamine biosynthesis was identified as being upregulated when Sir2 or Hst1 was inactivated.
Thiamine biosynthesis in Saccharomyces cerevisiae is regulated by the NAD+-dependent histone deacetylase Hst1.
No sample metadata fields
View SamplesTo test the effect of silencing Rae1 on expression on RNA polymerase II transcripts, host mRNAs were analysed by cDNA microarrays. We hypothesized that if silencing Rae1 expression increases cellular resistance to inhibition of transcription in VSV infected cells, mRNA characteristic of host antiviral response would be increased than compared to cells transfected with control siRNA.
Complexes of vesicular stomatitis virus matrix protein with host Rae1 and Nup98 involved in inhibition of host transcription.
Cell line
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