The bromodomain and extra-terminal (BET) family proteins, which are involved in chromatin function, have been shown to be promising drug targets in several pathological conditions, including cancer and inflammation. There is considerable interest in the development of BET inhibitors with novel scaffolds to modulate the epigenesis of such diseases. Here, high-resolution crystal structures of the purine class of FDA-approved drugs (theophylline, doxophylline and acyclovir) and non-FDA-approved compounds (3-methyl-7-propylxanthine and theobromine) complexed with hBRD2 bromodomains BD1 and BD2 are reported. Remarkably, a new binding site is exhibited by stacking the compounds against the WPF shelf of BD1 and BD2. This serendipitous binding, in addition to the known acetyl-lysine binding site, sufficiently anchors the ligands in the solvent-exposed region. In addition, slight variations in the lipophilicity of these molecules significantly affected the in vitro binding affinity and selectivity towards BD1 compared with BD2. This idiosyncratic binding provides a new structural framework to link these sites for the development of next-generation inhibitors of the BET family.
GO analysis of proteins with at least a 1.5-fold increase in expression in the presence of AG-636 compared to DMSO
SWPs are the major virulence component of microsporidian spores. In microsporidia, SWPs can be found either in exospore or endospore to serve as a putative virulence factor for host cell invasion. SWP5 is a vital protein that involves in exospore localization and supports the structural integrity of the spore wall and this action potentially modulates the course of infection in N. bombycis. Here we report recombinant SWP5 purification using Ni-NTA IMAC and SEC. GFC analysis reveals SWP5 to be a monomer which correlates with the predicted theoretical weight and overlaps with ovalbumin peak in the chromatogram. The raised polyclonal anti-SWP5 antibodies was confirmed using blotting and enterokinase cleavage experiments. The resultant fusion SWP5 and SWP5 in infected silkworm samples positively reacts to anti-SWP5 antibodies is shown in ELISA. Immunoassays and Bioinformatic analysis reveal SWP5 is found to be localized on exospore and this action could indicate the probable role of SWP5 in host pathogen interactions during spore germination and its contribution to microsporidian pathogenesis. This study will support development of a field-based diagnostic kit for the detection N. bombycis NIK-1S infecting silkworms. The analysis will also be useful for the formulation of drugs against microsporidia and pebrine disease.
Profilin is a multi-ligand binding protein, which is a key regulator of actin dynamics and involved in regulating several cellular functions. It is present in all eukaryotes, including trypanosomatids such as Leishmania. However, not much is known about its functions in these organisms. Our earlier studies have shown that Leishmania parasites express a single homologue of profilin (LdPfn) that binds actin, phosphoinositides and poly- L- proline motives, and depletion of its intracellular pool to 50%of normal levels affects the cell growth and intracellular trafficking. Here, we show, employing affinity pull-down and mass spectroscopy, that LdPfn interacted with a large number of proteins, including those involved in mRNA processing and protein translation initiation, such as eIF4A1. Further, we reveal, using mRNA Seq analysis, that depletion of LdPfn in Leishmania cells (LdPfn+/-) resulted in significantly reduced expression of genes which encode proteins involved in cell cycle regulation, mRNA translation initiation, nucleosides and amino acids transport. In addition, we show that in LdPfn+/- cells, cellular levels of eIF4A1 protein were significantly decreased, and during their cell division cycle, G1-to-S phase progression was delayed and orientation of mitotic spindle altered. These changes were, however, reversed to normal by episomal expression of GFP-LdPfn in LdPfn+/- cells. Taken together, our results indicate that profilin is involved in regulation of G1-to-S phase progression and mitotic spindle orientation in Leishmania cell cycle, perhaps through its interaction with elF4A1 protein.
Mutations in MEK1/2 have been described as a resistance mechanism to BRAF/MEK inhibitor treatment. We report the discovery of a novel ATP-competitive MEK1/2 inhibitor with efficacy in wildtype (WT) and mutant MEK12 models. Starting from a HTS hit, we obtained selective, cellularly active compounds that showed equipotent inhibition of WT MEK1/2 and a panel of MEK1/2 mutant cell lines. Using a structure-based approach, the optimization addressed the liabilities by systematic analysis of molecular matched pairs (MMPs) and ligand conformation. Addition of only three heavy atoms to early tool compound 6 removed Cyp3A4 liabilities and increased the cellular potency by 100-fold, while reducing log P by 5 units. Profiling of MAP855, compound 30, in pharmacokinetic-pharmacodynamic and efficacy studies in BRAF-mutant models showed comparable efficacy to clinical MEK1/2 inhibitors. Compound 30 is a novel highly potent and selective MEK1/2 kinase inhibitor with equipotent inhibition of WT and mutant MEK1/2, whose drug-like properties allow further investigation in the mutant MEK setting upon BRAF/MEK therapy.
We report a de novo -assembled draft genome sequence of the Indian Staphylococcus aureus sequence type 88 (ST88) strain LVP-7, isolated from an ocular infection. The genome harbors a Panton-Valentine leukocidin phage, a type V staphylococcal cassette chromosome mec element, the delta-hemolysin-converting Newman phage ΦNM3, and the pathogenicity island SaPI3, encoding the superantigen enterotoxin B.
Whether PI information is available from Responsible Party. (XLSX 1495 kb)
Agents targeting metabolic pathways form the backbone of standard oncology treatments, though a better understanding of differential metabolic dependencies could instruct more rationale-based therapeutic approaches. We performed a chemical biology screen that revealed a strong enrichment in sensitivity to a novel dihydroorotate dehydrogenase (DHODH) inhibitor, AG-636, in cancer cell lines of hematologic versus solid tumor origin. Differential AG-636 activity translated to the in vivo setting, with complete tumor regression observed in a lymphoma model. Dissection of the relationship between uridine availability and response to AG-636 revealed a divergent ability of lymphoma and solid tumor cell lines to survive and grow in the setting of depleted extracellular uridine and DHODH inhibition. Metabolic characterization paired with unbiased functional genomic and proteomic screens pointed to adaptive mechanisms to cope with nucleotide stress as contributing to response to AG-636. These findings support targeting of DHODH in lymphoma and other hematologic malignancies and suggest combination strategies aimed at interfering with DNA-damage response pathways.
Profilins are the key regulators of actin dynamics in all eukaryotic cells. However, little information is available on their biochemical properties and functions in kinetoplastids, such as Trypanosoma and Leishmania. We show here that Leishmania parasites express only one homolog of profilin (LdPfn), which catalyzes nucleotide exchange on G-actin and promotes actin polymerization at its low concentrations. However, at high concentrations, it strongly inhibits the polymerization process by sequestering actin monomers. We further demonstrate that LdPfn binds to actin in Leishmania promastigotes, by both immunofluorescence microscopy and IgG affinity chromatography. Further, we reveal that this protein besides binding to poly-null-proline motifs, also binds more efficiently to PI(3,5)P2, which is found on early or late endosomes or lysosomes, than to PI(4,5)P2 and PI(3,4,5)P3. Additionally, we show that heterozygous mutants of profilin display significantly slower growth and intracellular vesicle trafficking activity, which is reversed on episomal gene complementation. Together, these findings suggest that profilin regulates intracellular vesicle trafficking in Leishmania perhaps through its binding to polyphosphoinositides.
Processing of PI names to identify ambiguities. An overview of Additional file 17: Table S15 to Additional file 20: Table S18. (ODS 22 kb)
Small molecule potent IRAK4 inhibitors from a novel bicyclic heterocycle class were designed and synthesized based on hits identified from Aurigene's compound library. The advanced lead compound, CA-4948, demonstrated good cellular activity in ABC DLBCL and AML cell lines. Inhibition of TLR signaling leading to decreased IL-6 levels was also observed in whole blood assays. CA-4948 demonstrated moderate to high selectivity in a panel of 329 kinases as well as exhibited desirable ADME and PK profiles including good oral bioavailability in mice, rat, and dog and showed >90% tumor growth inhibition in relevant tumor models with excellent correlation with in vivo PD modulation. CA-4948 was well tolerated in toxicity studies in both mouse and dog at efficacious exposure. The overall profile of CA-4948 prompted us to select it as a clinical candidate for evaluation in patients with relapsed or refractory hematologic malignancies including non-Hodgkin lymphoma and acute myeloid leukemia.
Aedes spp. mosquitoes are a major health concern as they transmit several viral pathogens resulting in millions of deaths annually around the world. This is compounded by the emergence of insecticide-resistant strains and global warming, which could expose more than half of the world's population to Aedes-borne diseases in the future. Therefore, a comprehensive understanding of vector biology and the genomic basis of phenotypes such as insecticide resistance in natural populations are of paramount importance. Here, we sequenced the genome of Aedes aegypti mosquitos sampled from dengue-endemic areas and investigated the genetic variations between the previously reported laboratory-reared strain and our field isolates. The mosquito genomic DNA was used for paired-end sequencing using the Illumina platform. The reads were used for template-based assembly and mapped to the Aedes aegypti reference genome. Stringent parameters and multiple variant calling methods were used to identify unique single nucleotide variants (SNVs) and insertions-deletions (indels) and mapped to the Aedes chromosomes to create a draft consensus genome. Gene Ontology analyses was performed on the variant-enriched genes while two gene families involved in insecticide resistance were used for comparative sequence and phylogenetic analyses. Comparative sequence variant analyses showed that the majority of the high-quality variants in our samples mapped to non-coding regions of the genome, while gene ontology analyses of genic variants revealed enrichment of terms relevant to drug binding and insecticide resistance. Importantly, one mutation implicated in pyrethroid resistance was found in one Aedes sample. This is the first report of genome sequences of A. aegypti field isolates from India which reveals variants specific to the wild population. This is a useful resource which will facilitate development of robust integrated vector control strategies for management of Aedes-borne diseases through genetic manipulation of local mosquito populations.
ObjectiveThis study's primary goal is unraveling the mechanism of action of bioactives of Curcuma longa L. at the molecular level using protein-protein interaction network.ResultsWe used target proteins to create protein-protein interaction network (PPIN) and identified significant node and edge attributes of PPIN. We identified the cluster of proteins in the PPIN, which were used to identify enriched pathways. We identified closeness centrality and jaccard score as most important node and edge attribute of the PPIN respectively. The enriched pathways of various clusters were overlapped suggesting synergistic mechanism of action. The three pathways found to be common among three clusters were Gonadotropin-releasing hormone receptor pathway, Endothelin signaling pathway, and Inflammation mediated by chemokine and cytokine signaling pathway.
Processing of PI names to identify ambiguities—step 2. (XLSX 1406 kb)
BACKGROUND:Clinical trial registries have been established as a form of public accountability. Sponsors ought to register their trials promptly and accurately, but this is not always done. Some of the problems include non-registration of trials, registration of trials with incomplete information, and non-reporting of trial results on time. In this study we enumerate or quantify some quality issues with respect to Principal Investigator (PI) and Responsible Party data.METHODS:We analyzed interventional trials registered with ClinicalTrials.gov. Using certain selection criteria, we started with 112,013 records, and then applied further filters. The trial had to (a) start between 1 January 2005 and 31 December 2014, (b) include a "drug" or "biological" in the "intervention" field, (c) be registered with an American authority, and (d) list a real person's name as investigator and also his or her role in the study.RESULTS:We identified four categories of errors in the ClinicalTrials.gov records. First, some data were missing. The name of the investigator, or his or her role, was missing in 12% of 35,121 trials. In examining 71,359 pairs of names and roles, 17% of the "names" were found to be not those of real persons, but instead junk information. Second, there were variations in a large number of names. We identified 19 categories of variants. We determined that 13% of the names had variants that could not be resolved using a program. Third, some trials listed many PIs each, although only one such person holds overall responsibility for the trial and therefore not more than one person should be listed as PI. Fourth, in examining whether the PI's name was available as part of the Responsible Party tag, we found that in 1221 (3.5%) of 35,121 trials, the Responsible Party tag is absent.CONCLUSIONS:We have outlined four categories of problems with data hosted by ClinicalTrials.gov and have quantified three of them. We also suggest how these errors could be prevented in future. It is important to carry out various kinds of audits of trial registries, in order to identify lacunae in the records, that they be addressed.