Background And Aim: Colorectal cancer (CRC) is the second leading cause of cancer death worldwide. To improve outcomes for these patients, we need to develop new treatment strategies. Personalized cancer medicine, where patients are treated based on the characteristics of their own tumor, has gained significant interest for its promise to improve outcomes and reduce unnecessary side effects.
View Article and Find Full Text PDFBackground: Congenital heart diseases are the major cause of death in newborns, but the genetic etiology of this developmental disorder is not fully known. The conventional approach to identify the disease-causing genes focuses on screening genes that display heart-specific expression during development. However, this approach would have discounted genes that are expressed widely in other tissues but may play critical roles in heart development.
View Article and Find Full Text PDFSplicing introns from precursor-messenger RNA (pre-mRNA) transcripts is essential for translating functional proteins. Here, we report that the previously uncharacterized Caenorhabditis elegans protein MOG-7 acts as a pre-mRNA splicing factor. Depleting MOG-7 from the C.
View Article and Find Full Text PDFWe characterized two bacteriophages, ΦFG02 and ΦCO01, against clinical isolates of Acinetobacter baumannii and established that the bacterial capsule is the receptor for these phages. Phage-resistant mutants harboured loss-of-function mutations in genes responsible for capsule biosynthesis, resulting in capsule loss and disruption of phage adsorption. The phage-resistant strains were resensitized to human complement, beta-lactam antibiotics and alternative phages and exhibited diminished fitness in vivo.
View Article and Find Full Text PDFRNA structures that impede ribosome binding or subsequent scanning of the 5'-untranslated region (5'-UTR) for the AUG initiation codon reduce translation efficiency. Yeast DEAD-box RNA helicase Ded1 appears to promote translation by resolving 5'-UTR structures, but whether its paralog, Dbp1, performs similar functions is unknown. Furthermore, direct in vivo evidence was lacking that Ded1 or Dbp1 resolves 5'-UTR structures that impede attachment of the 43S preinitiation complex (PIC) or scanning.
View Article and Find Full Text PDFObjective: Congenital heart disease (CHD) is the most frequent birth defect worldwide. The number of adult patients with CHD, now referred to as ACHD, is increasing with improved surgical and treatment interventions. However the mechanisms whereby ACHD predisposes patients to heart dysfunction are still unclear.
View Article and Find Full Text PDFThe establishment and maintenance of pluripotency depend on precise coordination of gene expression. We establish serine-arginine-rich splicing factor 3 (SRSF3) as an essential regulator of RNAs encoding key components of the mouse pluripotency circuitry, SRSF3 ablation resulting in the loss of pluripotency and its overexpression enhancing reprogramming. Strikingly, SRSF3 binds to the core pluripotency transcription factor mRNA to facilitate its nucleo-cytoplasmic export independent of splicing.
View Article and Find Full Text PDFThe thymus plays a crucial role in immune tolerance by exposing developing T cells (thymocytes) to a myriad of self-antigens. Strong T-cell receptor (TCR) engagement induces tolerance in self-reactive thymocytes by stimulating apoptosis or selection into specialized T-cell lineages, including intestinal TCRαβ CD8αα intraepithelial lymphocytes (IEL). TCR-intrinsic amino acid motifs that can be used to predict whether a TCR will be strongly self-reactive remain elusive.
View Article and Find Full Text PDFMessenger RNA (mRNA) translation is a tightly controlled process that is integral to gene expression. It features intricate and dynamic interactions of the small and large subunits of the ribosome with mRNAs, aided by multiple auxiliary factors during distinct initiation, elongation and termination phases. The recently developed ribosome profiling method can generate transcriptome-wide surveys of translation and its regulation.
View Article and Find Full Text PDFRegulation of messenger RNA translation is central to eukaryotic gene expression control. Regulatory inputs are specified by them RNA untranslated regions (UTRs) and often target translation initiation. Initiation involves binding of the 40S ribosomal small subunit (SSU) and associated eukaryotic initiation factors (eIFs)near the mRNA 5′ cap; the SSU then scans in the 3′ direction until it detects the start codon and is joined by the 60S ribosomal large subunit (LSU) to form the 80S ribosome.
View Article and Find Full Text PDFPathogen components, such as lipopolysaccharides of Gram-negative bacteria that activate Toll-like receptor 4, induce mitogen activated protein kinases and NFκB through different downstream pathways to stimulate pro- and anti-inflammatory cytokine expression. Importantly, post-transcriptional control of the expression of Toll-like receptor 4 downstream signaling molecules contributes to the tight regulation of inflammatory cytokine synthesis in macrophages. Emerging evidence highlights the role of RNA-binding proteins (RBPs) in the post-transcriptional control of the innate immune response.
View Article and Find Full Text PDFThe presence of multiple variants for many mRNAs is a major contributor to protein diversity. The processing of these variants is tightly controlled in a cell-type specific manner and has a significant impact on gene expression control. Here we investigate the differential translation rates of individual mRNA variants in embryonic stem cells (ESCs) and in ESC derived Neural Precursor Cells (NPCs) using polysome profiling coupled to RNA sequencing.
View Article and Find Full Text PDFMost applications for RNA-seq require the depletion of abundant transcripts to gain greater coverage of the underlying transcriptome. The sequences to be targeted for depletion depend on application and species and in many cases may not be supported by commercial depletion kits. This unit describes a method for generating RNA-seq libraries that incorporates probe-directed degradation (PDD), which can deplete any unwanted sequence set, with the low-bias split-adapter method of library generation (although many other library generation methods are in principle compatible).
View Article and Find Full Text PDFThe mRNA closed-loop, formed through interactions between the cap structure, poly(A) tail, eIF4E, eIF4G and PAB, features centrally in models of eukaryotic translation initiation, although direct support for its existence in vivo is not well established. Here, we investigated the closed-loop using a combination of mRNP isolation from rapidly cross-linked cells and high-throughput qPCR. Using the interaction between these factors and the opposing ends of mRNAs as a proxy for the closed-loop, we provide evidence that it is prevalent for eIF4E/4G-bound but unexpectedly sparse for PAB1-bound mRNAs, suggesting it primarily occurs during a distinct phase of polysome assembly.
View Article and Find Full Text PDFBackground: A major hurdle to transcriptome profiling by deep-sequencing technologies is that abundant transcripts, such as rRNAs, can overwhelm the libraries, severely reducing transcriptome-wide coverage. Methods for depletion of such unwanted sequences typically require treatment of RNA samples prior to library preparation, are costly and not suited to unusual species and applications. Here we describe Probe-Directed Degradation (PDD), an approach that employs hybridisation to DNA oligonucleotides at the single-stranded cDNA library stage and digestion with Duplex-Specific Nuclease (DSN).
View Article and Find Full Text PDFProgression of the eukaryotic cell cycle requires the regulation of hundreds of genes to ensure that they are expressed at the required times. Integral to cell cycle progression in yeast and animal cells are temporally controlled, progressive waves of transcription mediated by cell cycle-regulated transcription factors. However, in the kinetoplastids, a group of early-branching eukaryotes including many important pathogens, transcriptional regulation is almost completely absent, raising questions about the extent of cell-cycle regulation in these organisms and the mechanisms whereby regulation is achieved.
View Article and Find Full Text PDFMany genes that are required at specific points in the cell cycle exhibit cell cycle-dependent expression. In the early-diverging model eukaryote and important human pathogen Trypanosoma brucei, regulation of gene expression in the cell cycle and other processes is almost entirely post-transcriptional. Here, we show that the T.
View Article and Find Full Text PDFMol Biochem Parasitol
March 2009
Trypanosoma brucei can be cultured in vitro in the mammalian bloodstream form or in the procyclic (PC) form found in the insect vector. Bloodstream trypanosomes can be cloned by limiting dilution, but PCs can only be diluted in conditioned medium, i.e.
View Article and Find Full Text PDFThe gelsolin gene family encodes a number of higher eukaryotic actin-binding proteins that are thought to function in the cytoplasm by severing, capping, nucleating or bundling actin filaments. Recent evidence, however, suggests that several members of the gelsolin family may have adopted unexpected nuclear functions including a role in regulating transcription. In particular, flightless I, supervillin and gelsolin itself have roles as coactivators for nuclear receptors, despite the fact that their divergence appears to predate the evolutionary appearance of nuclear receptors.
View Article and Find Full Text PDF