Drug-specific signatures of the glycopeptide antibiotics dalbavancin, vancomycin and chlorobiphenyl-vancomycin in Streptomyces coelicolor
Ontology highlight
ABSTRACT: We used transcriptome profiling by RNAseq to identify the gene expression signatures elucidated in S. coelicolor in response to the three different glycopeptide compounds that share high degree of structural similarities and the same primary mode of action: dalbavancin, vancomycin and chlorobiphenyl-vancomycin.
Project description:The pioneer interactions between incoming viral RNA genomes and host proteins are crucial to infection and immune response. Until now, the ability to study these events was lacking. We developed VIR-CLASP (VIRal Cross-Linking And Solid-phase Purification) to characterize the earliest interactions between viral RNA and cellular proteins. We investigated the infection of human cells using Chikungunya virus (CHIKV) and Influenza A virus and identified hundreds of direct RNA-protein interactions. Here, we validate the biological impact of three protein classes that bind CHIKV RNA within minutes of infection. We find CHIKV RNA binds and hijacks the lipid-modifying enzyme FASN for pro-viral activity. We show that CHIKV genomes are N6-methyladenosine modified and that YTHDF1 binds and suppresses its replication. Finally, we find that the innate immune DNA sensor IFI16 associates with CHIKV RNA, reducing viral replication and maturation. Our findings have direct applicability to the investigation of potentially all RNA viruses.
Project description:Background: Microorganisms are the major cause of food spoilage during storage, processing and distribution. Pseudomonas fluorescens is a typical spoilage bacterium that contributes to a large extent to the spoilage process of proteinaceous food. RpoS is considered an important global regulator involved in stress survival and virulence in many pathogens. Our previous work revealed that RpoS contributed to the spoilage activities of P. fluorescens by regulating resistance to different stress conditions, extracellular acylated homoserine lactone (AHL) levels, extracellular protease and total volatile basic nitrogen (TVB-N) production. However, RpoS-dependent genes in P. fluorescens remained undefined. Results: RNA-seq transcriptomics analysis combined with quantitative proteomics analysis basing on multiplexed isobaric tandem mass tag (TMT) labeling was performed for the P. fluorescens wild-type strain UK4 and its derivative carrying a rpoS mutation. A total of 375 differentially expressed genes (DEGs) and 212 differentially expressed proteins (DEPs) were identified in these two backgrounds. The DGEs were further verified by qRT-PCR tests, and the genes directly regulated by RpoS were confirmed by 5’-RACE-PCR sequencing. The combining transcriptome and proteome analysis revealed a role of this regulator in several cellular processes, including polysaccharide metabolism, intracellular secretion and extracellular structures, cell well biogenesis, stress responses, ammonia and biogenic amine production, which may contribute to biofilm formation, stress resistance and spoilage activities of P. fluorescens. Moreover, in this work we indeed observed that RpoS contributed to the production of the macrocolony biofilm’s matrix.
Project description:Extremophilic archaea employ diverse chemical RNA modifications, providing a rich source of new enzymes for biotechnologically valuable RNA manipulations. Our understanding of the modified nucleoside profiles in Archaea, as well as the functions and dynamic regulation of specific RNA modifications is far from complete. Here, we established an extensive profile of nucleoside modifications in thermophilic and mesophilic Archaea through highly sensitive LC-MS/MS analysis and rigorous non-coding RNA depletion, identifying - with high confidence - at least four previously unannotated modifications in archaeal mRNAs. Nucleoside quantification analysis conducted on total, large, small, and mRNA-enriched subfractions of the model hyperthermophilic archaeon Thermococcus kodakarensis revealed a series of modifications whose abundance is dynamically responsive to growth temperatures, implying that specific RNA modifications are fitness relevant under specific growth conditions. To predict the RNA-modifying enzymes most likely to generate the new and dynamic RNA modifications, we leveraged a bioinformatics analysis of open-access databases to annotate likely functional domains of archaeal proteins. Putative enzyme activities were confirmed in vitro and in vivo by assessing the presence of the target RNA modification in genetic deletion strains of T. kodakarensis. Our approach led to the discovery of a methyltransferase-encoded gene responsible for m7G modification in the P-loop of 23S rRNA peptidyl transferase center. This novel finding validates an effective platform for discovering RNA-modifying enzymes through LC-MS/MS analysis that will accelerate efforts of the community towards uncovering the complex and dynamic roles of RNA modifications.
Project description:mRNA synthesis, processing, and destruction involve a complex series of molecular steps that are incompletely understood. Because the RNA intermediates in each of these steps have finite lifetimes, extensive mechanistic and dynamical information is encoded in total cellular RNA. Here we report the development of SnapShot-Seq, a set of computational methods that allow the determination of in vivo rates of pre-mRNA synthesis, splicing, intron degradation, and mRNA decay from a single RNA-Seq snapshot of total cellular RNA. SnapShot-Seq can detect in vivo changes in the rates of specific steps of splicing, and it provides genome-wide estimates of pre-mRNA synthesis rates comparable to those obtained via labeling of newly synthesized RNA. We used SnapShot-Seq to investigate the origins of the intrinsic bimodality of metazoan gene expression levels, and our results suggest that this bimodality is partly due to spillover of transcriptional activation from highly expressed genes to their poorly expressed neighbors. SnapShot-Seq dramatically expands the information obtainable from a standard RNA-Seq experiment. These data are total RNA-Seq data, from RNA sequencing of rRNA-depleted total cellular RNA -- except the LCL 4SU data, which derive from 4SU-labeled RNA. Please see the associated paper for more details.
Project description:In this study, we make used of mRNA-seq and its ability to reliably quantify isoforms, integrating this data with ribosome profiling and LC-MS/MS, to assign ribosome footprints and peptides at the isoform level. We leverage the principle that most cell types, and even tissues, predominantly express a single principal isoform to set isoform-level mRNA-seq quantifications as priors to guide and improve allocation of footprints or peptides to isoforms. Through tightly integrated mRNAseq, ribosome footprinting and/or LC-MS/MS proteomics we demonstrate that a principal isoform can be identified in over 80% of gene products in homogenous HEK293 cell culture and over 70% of proteins detected in complex human brain tissue. Defining isoforms in experiments with matched RNA-seq and translatomic/proteomic data increases the functional relevance of such datasets and will further broaden our understanding of multi-level control of gene expression. In this PRIDE submission you will find the raw files for the HEK293 cell proteomics. Files for the human brain proteomics can be found at PXD005445. We have also uploaded a zip file that contains the input files for our HEK293 cell analysis, and the isoform level output files – there is a separate folder within the zip files for these. The data used to create the manuscript figures is in the Rdata file. Code for assigning peptides and footprints to isoforms can be found on Github here: https://github.com/rkitchen/EMpire
Project description:As a newly identified mRNA modification, the regulation of ac4C remains largely unexplored. RNA-binding proteins (RBPs) that specifically binds to ac4C modification and mediate downstream cellular activities (readers) have not been reported yet. We synthesized acetylated and non-acetylated RNA probes by in vitro transcription. The sequences of the probes were segments of FUS and 18s rRNA, which contain ac4C sites as reported. A biotin-RNA pulldown assay and mass spectrometry were performed with HEK 293T cell lysates.
Project description:Efficient microbial conversion of lignocellulosic hydrolysates to biofuels is a key barrier to the economically viable deployment of lignocellulosic biofuels. A chief contributor to this barrier is the impact on microbial processes and energy metabolism of lignocellulose-derived inhibitors, including phenolic carboxylates, phenolic amides (for ammonia-pretreated biomass), phenolic aldehydes, and furfurals. To understand the bacterial pathways induced by inhibitors present in ammonia-pretreated biomass hydrolysates, which are less well studied than acid-pretreated biomass hydrolysates, we developed and exploited synthetic mimics of ammonia-pretreated corn stover hydrolysate (ACSH). To determine regulatory responses to the inhibitors normally present in ACSH, we measured transcript and protein levels in an Escherichia coli ethanologen using RNA-seq and quantitative proteomics during fermentation to ethanol of synthetic hydrolysates containing or lacking the inhibitors. Our study identified four major regulators mediating these responses, the MarA/SoxS/Rob network, AaeR, FrmR, and YqhC. Induction of these regulons was correlated with a reduced rate of ethanol production, buildup of pyruvate, depletion of ATP and NAD(P)H, and an inhibition of xylose conversion. The aromatic aldehyde inhibitor 5M-bM-^@M-^Qhydroxymethylfurfural appeared to be reduced to its alcohol form by the ethanologen during fermentation, whereas phenolic acid and amide inhibitors were not metabolized. Together, our findings establish that the major regulatory responses to lignocellulose-derived inhibitors are mediated by transcriptional rather than translational regulators, suggest that energy consumed for inhibitor efflux and detoxification may limit biofuel production, and identify a network of regulators for future synthetic biology efforts. E.coli ethanologen strain GLBRCE1 was grown in 3 media, AFEX corn stover hydrolysate (ACSH), synthetic hydrolysate (SynH) and syntetic hydrolysate with added lignotoxins (SynH_LT). Fermentations were carried out in 3 L bioreactors (Applikon Biotechnology) containing 2.45 L of ACSH or SynH media, and cultures were diluted into ACSH or SynH with initial OD at 0.2, grown anaerobically overnight, and then inoculated into bioreactors to a starting OD600 of 0.2. 3 biological replicates (independent cultures) were grown in each medium. RNA samples were obtained at 4 time points, corresponding to exponential (Exp), transitional (Trans), stationary (Stat1) and late stationary (Stat2) growth phases.
Project description:Histone H3K4 methylation is connected to gene transcription from yeast to humans, but its mechanistic role in transcription and chromatin dynamics remains poorly understood. Here, we investigated the functions for Set1 and Jhd2, the sole H3K4 methyltransferase and H3K4 demethylase, respectively, in S. cerevisiae. Our data show that Set1 and Jhd2 predominantly co-regulate transcription. To further understand the role for H3K4 methylation, we overexpressed Flag epitope-tagged SET1-G990E (a dominant hyperactive allele of SET1) in yeast using the constitutive ADH1 promoter (ADH1p). As a control, we also overexpressed Flag epitope-tagged wild type SET1 in yeast. Analysis of gene expression in set1-null, jhd2-null and wild type SET1 or hypeactive SET1-G990E overexpressing mutants together revealed that the transcriptional regulation at a sub-set of genes, inclduing those governing glycogen metabolism and ribosome biogenesis, is highly sensitive to any change (i.e., loss or gain) in H3K4 methylation levels. Overall, we find combined activities of Set1 and Jhd2 via dynamic modulation of H3K4 methylation contribute to positive or negative transcriptional regulation at shared target genes. Gene expression changes were generated from five different yeast strains representing wild type control, set1 null and jhd2 null mutants, and wild type SET1 or dominant hyperacive SET1-G990E overexpressing mutants. Three independent biological samples were grown for each strain, total RNA was isolated, libraries were prepared, sequenced, and analyzed separately.
Project description:Novel anti-infective agents targeting Staphylococcus aureus and capable of increasing S. aureus susceptibility towards antibiotics are needed. One alternative approach is targeting the bacterial quorum sensing (QS) system. QS is a process by which bacteria produce and detect signal molecules and thereby coordinate their behaviour, virulence and biofilm formation in a cell-density-dependent manner. Hamamelitannin (HAM) was previously suggested to target the S. aureus QS system, thereby increasing the susceptibility of S. aureus biofilms towards vancomycin. However, mechanistic insights are still lacking. For this reason, we evaluated the effect of Hamamelitannin, vancomycin and combination treatment of Hamamelitannin and vancomycin on gene expression in S. aureus Mu50 biofilms.
Project description:Using bottom-up oligonucleotide LC-MS/MS in combination with stable isotope labeling, chemical derivatization, and bioinformatics variable modification search, a total of 25 modifications were mapped to the sequences of 16S and 23S RNA in B. subtilis. 10 modification sites, previously identified by others using alternative methods were independently confirmed using targeted MS/MS data analysis. Modification types, namely base/ribose methylation, pseudouridines and dihydrouridine, and modification positions are fully consistent with prior experimental evidence and agree well with modifications that were annotated in E. coli and other bacteria species.