RNA-protein interaction screening for SNORD50A and SNORD50B
ABSTRACT: Putative RNA-protein interactions with selected snoRNAs were screened using labaled RNA hybridized to a human protein microarray snoRNAs SNORD50A and SNORD50B were in vitro transcribed, labeled with Cy5 and independently hybridized on human protein microarrays. The labeling process was optimized in order to achieve ~ 3 pmol dye per every microgram RNA while maintaining signal intensities that were readily visualized.
Project description:We describe a refined approach to identify new human RNA-protein interactions. In vitro transcribed labeled RNA is bound to ~9,400 human recombinant proteins spotted on protein microarrays. This approach identified 137 RNA-protein interactions for 10 human coding and non-coding RNAs, including an interaction between Staufen 1 protein and TP53 mRNA that promoted the latter’s stability. RNA hybridization to protein microarrays allows rapid identification of human RNA-protein interactions on a large scale. Sense and antisense strands for 10 RNA transcripts representing protein coding RNAs TP53, HRAS, MYC, BCL2 and non-coding sequences PWRN1, SOX2OT, OCC1, IGF2RNC, lncRBM26 and DLEU1 were in vitro transcribed, labeled with Cy5 and independently hybridized on human protein microarrays. The labeling process was optimized in order to achieve ~ 3 pmol dye per every microgram RNA with average efficacy of 1 dye molecule for approximately every 850 bp RNA to minimally influence RNA native structure and at the same time yield in signal intensities that were readily visualized.
Project description:Pattern discovery algorithms are methods for discovering recurrent, non-random motifs widely used in the analysis of biological sequences. Many algorithms exist but few comparisons have been made amongst them. We systematically profile eight representative methods at multiple parameter settings across 174 diverse experimental datasets, including ten novel ChIP-on-chip datasets. We executed 16,777 pattern discovery analyses to assess prediction accuracy, CPU usage and memory consumption. For 144 datasets we developed a gold-standard using machine-learning algorithms; cross-validation was used for the remaining datasets. Performance was highly disparate, with median accuracy ranging from 32% to 96%. Importantly we were unable to replicate previously reported algorithm-rankings, emphasizing the need to use many and diverse experimental datasets. We found deterministic algorithms like Projection and Oligo/Dyad had the highest prediction accuracy. Computational efficiency was not linearly related to dataset size and becomes critical: some algorithms are intractably slow on large datasets. This work provides the first combined assessment of the CPU, memory, and prediction accuracies of pattern discovery algorithms on real experimental datasets. HL60-Mnt-ChIP: ChIP-Chip with 10 biological replicates HL60-Trrap-ChIP: ChIP-Chip with 13 biological replicates
Project description:Hybridization of amplified genomic DNA against unamplified genomic DNA using three different amplification methods to assess the bias introduced by amplification alone. Keywords: genomic DNA Three different amplification methods were assessed and total genomic DNA hybridized against equal amounts of amplified genomic DNA for each method.
Project description:Analysis of technical variance of ChIP-on-Chip studies by characterization of Myc-binding in HL60 cells. Keywords: Chip-on-chip Fully-blocked study of technical variance in Myc-binding in HL60 cells. Two different antibodies were used to generate 6 biologically independent replicates each. Each replicate was hybridized to arrays from two different batches in both dye-swap orientations, leading to 48 total arrays.
Project description:Analysis of technical variance of ChIP-on-Chip studies by characterization of Myc-binding in HL60 cells. Keywords: Chip-on-chip Characterization of c-Myc binding in HL60 cells. Thirteen biologically independent replicates of growing HL60 cells were subjected to ChIP with an N-terminal c-Myc antibody and hybridized to CpG island microarrays
Project description:The purpose is to determine the role of TLR3-/- on the regulation of the host immune response during lethal SARS-CoV infection Groups of 10 week old C57BL6/NJ or TLR3-/- mice were infected with MA15 virus at a dose of 10^5 PFU or time-matched mock infected. Time points were 2, 4 and 7 days post infection. There were 4 or 5 animals/time point. Lung samples were collected for virus load, lung pathology, and transcriptional analysis. Weight loss and animal survival were also monitored.
Project description:Peripheral infusion of human umbilical cord mesenchymal stem cells (hUC-MSCs) can profoundly suppress the activation of c-Mos and remarkably improve hepatic histology, suppress the systemic inflammatory reaction, and promote animal survival in a large non-human primate model of acute liver failure (ALF). The mechanism through which hUC-MSCs inhibits c-Mos activation in vivo remains unclear. We hypothesized that hUC-MSCs can adaptively produce certain inhibitory cytokines in response to the pro-inflammatory microenvironment. To confirm this, we stimulated cultured hUC-MSCs with inflammatory monkey serum (serum isolated at day 1 following toxin challenge). After a 30-min stimulation, the cells were collected for microarray gene expression analysis. A whole human genome oligo microarray analysis was performed to reveal the altered gene expression profiles of the hUC-MSCs
Project description:Transcriptional profiling of DW2 E. coli cells in exponential growth phase that have a chromosomal deletion of the rnpb gene (which encodes the catalytic subunit of Ribonuclease P). We compared the test strain DW2/pFLP-Bs that expresses Bacillus subtilis rnpb from plasmid pFLP-Bs to reference strain DW2/pFLP-Ec, which expresses E. coli rnpb from plasmid pFLP-Ec. Two-strain experiment, wildtype proxy strain DW2/pFLP-Ec (reference) vs DW2/pFLP-Bs RT-10-2 (test) on each array. Biological replicates: 1 reference, 2 test. Four slides plus one dyeflip slide
Project description:An early hallmark of Toxoplasma infection is the rapid control of the parasite population by a potent multifaceted innate immune response that engages resident and homing immune cells along with pro- and counter-inflammatory cytokines. In this context, IFN-γ activates a variety of Toxoplasma-targeting activities in immune and non-immune cells, but can also contribute to host immune pathology. Toxoplasma has evolved mechanisms to timely counteract the host IFN-γ defenses by interfering with the transcription of IFN-γ-stimulated genes. We now have identified TgIST as a critical molecular switch that is secreted by intracellular parasites and traffics to the host cell nucleus where it inhibits STAT1-dependent proinflammatory gene expression. We show that TgIST not only sequesters STAT1 on dedicated loci but also promotes shaping of a nonpermissive chromatin through its capacity to recruit the NuRD transcriptional repressor. We found that during mice acute infection, TgIST-deficient parasites are rapidly eliminated by the homing Gr1(+) inflammatory monocytes thus highlighting the protective role of TgIST against IFN-γ-mediated killing. By uncovering TgIST functions, this study brings novel evidence on how Toxoplasma has devised a molecular weapon of choice to take control over a ubiquitous immune gene expression mechanism in metazoans, as a way to promote long-term parasitism. HFF, 2fTGH (STAT1+/+) and U3A (STAT1-/-) human cells were left uninfected or infected for 24 hours with 76KGFP and 76KGFPΔTgIST Toxoplasma strains and stimulated with 100 U/ml IFN-γ for 6 hours before gene expression was measured. Three independent experiments were performed for each condition.