Project description:RNA-binding proteins (RBPs) are essential modulators of transcription and translation and are often dysregulated in cancer. Here we systematically interrogated RBP vulnerabilities in acute myeloid leukemia (AML) by performing a comprehensive CRISPR/Cas9 screen, targeting the RNA-binding domains of all classical RBPs. Our screen revealed RBPs that are exclusively required for leukemia survival, including the splicing factor RBM39. Proteomics analysis identified a network of RBP’s interacting with RBM39 crucial for maintaining RNA splicing and survival in AML. Mechanistically, RBM39 suppression led to altered splicing of genes involved in essential oncogenic pathways. Selective targeting of RBM39 via ubiquitin-mediated pharmacologic degradation induced broad anti-leukemic effects in vitro and potent single agent activity in vivo. The effects of RBM39 loss on alteration of splicing further resulted in preferential lethality of AML cells bearing spliceosomal gene mutations, thereby providing a strategy for treating AML patients bearing RBP splicing mutations.
Project description:Entomopathogenic nematodes (EPNs) are unique parasitic nematodes due to their symbiosis with entomopathogenic bacteria and their ability to kill insect hosts quickly after infection. Although it has been widely believed that EPNs rely on their bacterial partners for killing insect hosts, compelling evidence from previous studies challenges this model. We developed an improved method of activating millions of Steinernema carpocapsae infective juveniles (IJs) in vitro to harvest excreted/secreted (ES) proteins for bioactivity tests and proteomics analysis. We found that a low dose of the ES proteins from early activated nematodes is lethal to Drosophila melanogaster adults within 2-6 hours. We analyzed the protein composition of this venom using mass spectrometry and identified 472 proteins. Many of these venom proteins share high homology with those of vertebrate-parasitic nematodes. Among many different families of proteins found in the venom, proteases and protease inhibitors are especially abundant. Some toxin-related proteins such as Shk domain-containing proteins were also detected. We further analyzed the transcriptomes of individual non-activated IJs and nematodes that were activated in vitro and in vivo, which revealed a dramatic shift in gene expression during IJ activation. By comparing the whole transcriptomes and the genes encoding venom proteins between the in vitro and in vivo activated nematodes, we confirmed that the in vitro activation is a good approximation of the in vivo process. In summary, our findings strongly support a new model that S. carpocapsae and likely other Steinernema EPNs have a more active role in contributing to the pathogenicity of the nematode-bacterium complex than simply relying on their symbiotic bacteria. Furthermore, we propose that EPNs are a good model system for investigating vertebrate- and human-parasitic nematodes, especially regarding the function of ES products.
Project description:Chromatin insulators are DNA-protein complexes situated throughout the genome that contribute to higher order organization and demarcation into distinct transcriptional domains. Mounting evidence in different species implicates RNA and RNA-binding proteins as regulators of chromatin insulator activities. Here we identify the Drosophila hnRNP M homolog Rumpelstiltskin (Rump) as an antagonist of gypsy chromatin insulator enhancer-blocking and barrier activities. Despite ubiquitous expression of Rump, improvement of barrier activity is detected only in tissue outside of the central nervous system (CNS) when Rump levels are reduced. Furthermore, rump mutants restore insulator complex localization in an otherwise compromised genetic background only in non-CNS tissues. Rump associates physically with core gypsy insulator proteins, and ChIP-Seq analysis of Rump demonstrates extensive colocalization with a subset of gypsy insulator sites across the genome. The genome-wide binding profile and tissue-specificity of Rump contrast with that of Shep, a recently identified RNA-binding protein that antagonizes gypsy insulator activity exclusively in the CNS. Our findings indicate parallel roles for RNA-binding proteins in mediating tissue-specific regulation of chromatin insulator activity. ChIP-seq of Rump, Mod(mdg4)2.2, Shep, Su(Hw), and CP190 in Drosophila Kc167 cells
Project description:Chromatin insulators are DNA-protein complexes situated throughout the genome that contribute to higher order organization and demarcation into distinct transcriptional domains. Mounting evidence in different species implicates RNA and RNA-binding proteins as regulators of chromatin insulator activities. Here we identify the Drosophila hnRNP M homolog Rumpelstiltskin (Rump) as an antagonist of gypsy chromatin insulator enhancer-blocking and barrier activities. Despite ubiquitous expression of Rump, improvement of barrier activity is detected only in tissue outside of the central nervous system (CNS) when Rump levels are reduced. Furthermore, rump mutants restore insulator complex localization in an otherwise compromised genetic background only in non-CNS tissues. Rump associates physically with core gypsy insulator proteins, and ChIP-Seq analysis of Rump demonstrates extensive colocalization with a subset of gypsy insulator sites across the genome. The genome-wide binding profile and tissue-specificity of Rump contrast with that of Shep, a recently identified RNA-binding protein that antagonizes gypsy insulator activity exclusively in the CNS. Our findings indicate parallel roles for RNA-binding proteins in mediating tissue-specific regulation of chromatin insulator activity.
Project description:Toad venom is a traditional Chinese medicine with high medicinal value. The existing quality evaluation standards of it has obvious limitation for lack of protein study. Thus, it’s necessary to screen suitable biomarkers and establish appropriate quality evaluation method for the characteristics of toad venom’s proteins, guaranteeing the safety and efficacy in clinical applications. The sodium dodecyl sulfate-polyacrylamide gel electrophoresis, high-performance liquid chromatography and cytotoxicity assay were used to analyze protein components difference between toad venom of different areas. Functional proteins were screened as potential biomarkers by tandem mass tags proteomic and bioinformatic analysis. The results showed that the composition of different toad venom was similar. The protein content of Lianyungang’s toad venom was higher and the alcohol-soluble substance was lower, which suggested that they had no correlation. Simultaneously, the protein component was verified to have strong cytotoxicity. Proteomics analysis showed that 13 antimicrobial proteins, 4 anti-inflammatory and analgesic proteins, and 20 antitumor proteins were screened in the extracellular differentially expressed proteins. A candidate list of functional proteins that could be used as potential biomarkers was presented. Moreover, the antimicrobial activity of Lysozyme C-1 and the anti-inflammatory and analgesic activity of Neuropeptide B were identified as biomarkers for toad venom protein in future. The biomarkers can form the basis for the quality studies of toad venom’s proteins, helping construct and improve the safe, scientific and comprehensive quality evaluation method.
Project description:A large swath of the human proteome is dedicated to RNA homeostasis, but most RNA-binding proteins lack chemical probes1,2. Here, phenotypic screening led to the discovery of electrophilic small molecules that swiftly (within 4 h) and stereospecifically decrease transcripts encoding the androgen receptor (AR) and its major V7 splice variant in human prostate cancer cells. We show by chemical proteomics that these compounds covalently engage cysteine-145 on the RNA-binding protein NONO. Transcriptomics and proteomics profiling revealed that covalent NONO ligands suppress a discrete set of transcripts and proteins, including multiple oncogenic transcription factors, and impair the proliferation of cancer cells. These effects were not observed following genetic disruption of NONO, which instead blocked ligand activity. The covalent ligands promote accumulation of NONO in nuclear foci and at the first 5 splice site of immature transcripts, pointing to a trapping mechanism that may prevent compensatory action by the related protein PSPC1, which was found to increase in cancer cells following genetic or chemical perturbation of NONO. These findings, taken together, designate NONO as a druggable RNA-binding protein that can be co-opted by covalent small molecules to suppress pro-tumorigenic transcriptional networks.
Project description:Mucuna pruriens extract MPE pretreatment may have a direct protective effect on heart (other than immunological neutralization of the venom neurotoxin and phospholipase A2 by the anti-MPE antibodies) that renders the heart more resistant to the toxic action of the venom The direct protective effect probably involves functional changes to the cardiac tissue that enable the heart to resist the reduction of contractility and rate induced by the cobra venom.To explore the possibility of the direct action of MPE pretreatment on heart and to understand the molecular events involved in the protection of MPE pretreatment against the lethal action of Naja sputatrix venom, gene expression studies were carried out using microarray analysis. Rats were divided into four groups (n=6): negative control (abbreviated as ‘negative’ group), MPE pretreated group (abbreviated as ‘MPE’ group), N. sputatrix venom-challenge group (abbreviated as ‘NS’ group) and N. sputatrix venom-challenge to MPE pretreated animals group (abbreviated as ‘MPE-NS’ group). In the ‘MPE’ group, rats were injected with MPE at a dose of 21 mg/kg (i.p.), on day 0, 7 and 14, and sacrificed on day 21. In the ‘negative’ group (the untreated, control group), rats were injected with saline of the same volume and sacrificed also on day 21. Hearts were then harvested immediately. In the N. sputatrix venom-challenge group (‘NS’ group), untreated rats were challenged with 1.5 LD50 (1.25 ?g/g) of N. sputatrix venom whereas in the venom challenge to MPE pretreated animals group (the ‘MPE-NS’ group), MPE pretreated rats were challenged with 1.5 LD50 (1.25 ?g/g) of N. sputatrix venom, both on day 21. For the ‘NS’ and ‘MPE-NS’ group, the rats were observed for 24 h after venom challenged and hearts were harvested as soon as death occurred or 24 h after the venom injection, whichever occurred first.
Project description:Background The generalist dipteran pupal parasitoid Nasonia vitripennis injects 79 venom peptides into the host before egg laying. This venom induces several important changes in the host, including developmental arrest, immunosuppression, and alterations to normal metabolism. It is hoped that diverse and potent bioactivities of N. vitripennis venom provide an opportunity for the design of novel acting drugs. However, currently very little is known about the individual functions of N. vitripennis venom peptides and less than half can be bioinformatically annotated. The paucity of annotation information complicates the design of studies that seek to better understand the potential mechanisms underlying the envenomation response. Although the RNA interference system of N. vitripennis provides an opportunity to functionally characterise venom encoding genes, with 79 candidates this represents a daunting task. For this reason we were interested in determining the expression levels of venom encoding genes in the venom gland, such that this information could be used to rank candidate venoms. To do this we carried out deep sequencing of the transcriptome of the venom gland and neighbouring ovary tissue and used RNA-seq to measure expression from the 79 venom encoding genes. The generation of a specific venom gland transcriptome dataset also provides further opportunities to investigate novel features of this highly specialised organ. Results High throughput sequencing and RNA-seq revealed that the highest expressed venom encoding gene in the venom gland was a serine protease called Nasvi2EG007167, which has previously been implicated in the apoptotic activity of N. vitripennis venom. As expected the RNA-seq confirmed that the N. vitripennis venom encoding genes are almost exclusively expressed in the venom gland relative to the neighbouring ovary tissue. Novel peptides appear to perform key roles in N. vitripennis venom function as only four of the highest 15 expressed venom encoding genes are bioinformatically annotationed. The high throughput sequencing data also provided evidence for the existence of an additional 471 novel genes in the Nasonia genome that are expressed in the venom gland and ovary. Finally, metagenomic analysis of venom gland transcripts identified viral transcripts that may play an important part in the N. vitripennis venom function. Conclusions The expression level information provided here for the 79 venom encoding genes provides an unbiased dataset that can be used by the N. vitripennis community to identify high value candidates for further functional characterisation. These candidates represent bioactive peptides that have value in drug development pipelines.
Project description:Parkinson disease (PD) is a neurodegenerative disease characterized by the accumulation of alpha-synuclein (SNCA) and other proteins in aggregates termed âLewy Bodiesâ within neurons. PD has both genetic and environmental risk factors, and while processes leading to aberrant protein aggregation are unknown, past work points to abnormal levels of SNCA and other proteins. Although several genome-wide studies have been performed for PD, these have focused on DNA sequence variants by genome-wide association studies (GWAS) and on RNA levels (microarray transcriptomics), while genome-wide proteomics analysis has been lacking. After appropriate filters, proteomics identified 3,558 unique proteins and 283 of these (7.9%) were significantly different between PD and controls (q-value<0.05). RNA-sequencing identified 17,580 protein-coding genes and 1,095 of these (6.2%) were significantly different (FDR p-value<0.05), but only 166 of the FDR significant protein-coding genes (0.94%) were present among the 3,558 proteins characterized. Of these 166, eight genes (4.8%) were significant in both studies, with the same direction of effect. Functional enrichment analysis of the proteomics results strongly supports mitochondrial-related pathways, while comparable analysis of the RNA-sequencing results implicates protein folding pathways and metallothioneins. Ten of the implicated genes or proteins co-localized to GWAS loci. Evidence implicating SNCA was stronger in proteomics than in RNA-sequencing analyses. Notably, differentially expressed protein-coding genes were more likely to not be characterized in the proteomics analysis, which lessens the ability to compare across platforms. Combining multiple genome-wide platforms offers novel insights into the pathological processes responsible for this disease by identifying pathways implicated across methodologies. The study consists of mRNA-Seq (29 PD, 44 neurologically normal controls) and three-stage Mass Spectrometry Tandem Mass Tag Proteomics (12 PD, 12 neurologically normal controls) performed in post-mortem BA9 brain tissue. The proteomics samples are a subset of the RNA-Seq samples.