Identification of the endogenous insoluble host targets of the Salmonella effectors SSeK3
Ontology highlight
ABSTRACT:
INSTRUMENT(S): Orbitrap Fusion Lumos
ORGANISM(S): Mus Musculus (mouse)
SUBMITTER: 
Nichollas Scott
LAB HEAD: Elizabeth L Hartland
PROVIDER: PXD015082 | Pride | 2020-07-28
REPOSITORIES: Pride
Similar Datasets
Project description:Strains of Salmonella utilise two distinct type three secretion systems to deliver effector proteins directly into host cells. The Salmonella effectors SseK1 and SseK3 are arginine glycosyltransferases that modify mammalian death domain containing proteins with N-acetyl glucosamine (GlcNAc) when overexpressed ectopically or as recombinant protein fusions. Here, we combined Arg-GlcNAc glycopeptide immunoprecipitation and mass spectrometry to identify host proteins GlcNAcylated by endogenous levels of SseK1 and SseK3 during Salmonella infection. We observed that SseK1 modified the mammalian signaling protein TRADD, but not FADD as previously reported. Overexpression of SseK1 greatly broadened substrate specificity, while ectopic co-expression of SseK1 and TRADD increased the range of modified arginine residues within the death domain of TRADD. In contrast, endogenous levels of SseK3 resulted in modification of the death domains of receptors of the mammalian TNF superfamily, TNFR1 and TRAILR, at residues Arg376 and Arg293 respectively. Structural studies on SseK3 showed that the enzyme displays a classic GT-A glycosyltransferase fold and binds UDP-GlcNAc in a narrow and deep cleft with the GlcNAc facing the surface. Together our data suggests that Salmonellae carrying sseK1 and sseK3 employ the glycosyltransferase effectors to antagonise different components of death receptor signaling.
2019-03-27 | PXD010769 | Pride
Project description:Many Gram-negative bacterial pathogens interact with mammalian cells by using type III secretion systems (T3SS) to inject virulence proteins directly into infected host cells. A subset of these injected protein ‘effectors’ are enzymes that modify the structure and inhibit the function of human proteins by catalyzing the addition of unusual post-translational modifications. T3SS effectors play essential roles in bacterial virulence and their modes of action have provided great insight into the functions and the components of the innate immune system. The E. coli and Citrobacter rodentium NleB effectors, as well as the Salmonella enterica SseK effectors are glycosyltransferases that modify host protein substrates with N-acetyl glucosamine (GlcNAc) on arginine residues. Arginine glycosylation is unusual because it occurs on the guanidinium groups of arginines, which are poor nucleophiles. This post-translational modification disrupts the normal functioning of host immune response proteins. T3SS effectors are chaperoned in the bacterium to keep the effectors partially unfolded and competent for secretion, as well as for targeting the effectors to the T3SS sorting platform. The chaperones are then stripped from their effector substrates at the sorting platform and the effectors are secreted in an unfolded conformation. T3SS effectors are thought to be inactive within the bacterium and fold into their active conformations after they are injected into host cells. While performing mass spectrometry experiments to identify glycosylation substrates of NleB orthologs, we unexpectedly observed that the E. coli glutathione synthetase (GshB) is glycosylated on an arginine residue (R256) by NleB. NleB glycosyltransferase activity is essential to C. rodentium survival in oxidative stress conditions because glycosylation of GshB results in enhanced glutathione production. These data represent, to our knowledge, the first intra-bacterial activity for a T3SS effector and show that effector activities thought to be restricted to host cell compartments additionally play important roles in regulating bacterial physiology.
2020-01-14 | PXD015752 | Pride
Project description:Characterisation of glycosylation events within the key adhesin MIC2 of Toxoplasma gondii and the confirmation of tgPOFUT2 as being responsible for Fucosylation of MIC2
2018-12-04 | PXD011440 | Pride
Project description:Characterisation of glycosylation events within the key adhesin MIC2 of Toxoplasma gondii and the confirmation of tgPOFUT2 as being responsible for Fucosylation of MIC2
2018-12-04 | PXD010714 | Pride
Project description:The inhibition of host innate immunity pathways is essential for the survival of attaching and effacing (A/E) pathogens such as enteropathogenic Escherichia coli (EPEC) and Citrobacter rodentium during mammalian infections. To subvert these pathways, A/E pathogens utilize a type III secretion system (T3SS) to introduce effectors that target key signaling pathways thereby suppressing the anti-microbial response. One effector used by A/E pathogens is the arginine glycosyltransferase NleB1 (NleBCR in C. rodentium) that modifies conserved arginine residues with N-acetylglucosamine (GlcNAc) in death-domain containing host proteins thereby blocking extrinsic apoptosis signaling. When expressed ectopically, NleB1 modifies the host proteins, FADD, TRADD and RIPK1. However, the true repertoire of arginine-GlcNAcylation during infection with endogenous levels of NleB delivered by the pathogen is unknown. Here we explored the effects of arginine-GlcNAcylation by NleB on the global host proteome. Utilizing an affinity proteomic approach for Arginine-GlcNAcylated glycopeptide, we compared the global repertoire of arginine-GlcNAcylation during ectopic expression of NleB, EPEC infection in vitro or C. rodentium infection in vivo. When NleB was overexpressed, multiple host proteins were arginine-GlcNAcylated. However, when endogenous levels of NleB were delivered during EPEC and C. rodentium infection, R117of FADD was rapidly and preferentially modified. The arginine-GlcNAcylation modification of FADD was extremely stable and insensitive to environmental or host cell degradation. Despite its stability and effect on the inhibition of apoptosis, arginine-GlcNAcylation did not illicit any proteomic changes, even in response to prolonged expression of NleB. Thus, under wild type levels of expression, NleB1/NleBCR antagonizes death-receptor-induced apoptosis of infected cells by modifying FADD in an irreversible and silent manner.
2017-09-11 | PXD006810 | Pride
Project description:This SuperSeries is composed of the following subset Series: GSE3101: Chitin oligosaccharide induction GSE3102: Crab shell attachment GSE3103: Chitin sensor Abstract: Chitin, an insoluble polymer of GlcNAc, is an abundant source of carbon, nitrogen, and energy for marine microorganisms. Microarray expression profiling and mutational studies of Vibrio cholerae growing on a natural chitin surface, or with the soluble chitin oligosaccharides (GlcNAc)(2-6), GlcNAc, or the glucosamine dimer (GlcN)2 identified three sets of differentially regulated genes. We show that (i) ChiS, a sensor histidine kinase, regulates expression of the (GlcNAc)(2-6) gene set, including a (GlcNAc)2 catabolic operon, two extracellular chitinases, a chitoporin, and a PilA-containing type IV pilus, designated ChiRP (chitin-regulated pilus) that confers a significant growth advantage to V. cholerae on a chitin surface; (ii) GlcNAc causes the coordinate expression of genes involved with chitin chemotaxis and adherence and with the transport and assimilation of GlcNAc; (iii) (GlcN)2 induces genes required for the transport and catabolism of nonacetylated chitin residues; and (iv) the constitutively expressed MSHA pilus facilitates adhesion to the chitin surface independent of surface chemistry. Collectively, these results provide a global portrait of a complex, multistage V. cholerae program for the efficient utilization of chitin. Refer to individual Series
2006-03-07 | E-GEOD-4388 | biostudies-arrayexpress
Project description:Salmonella enterica is an important foodborne pathogen that utilizes secreted effector proteins to manipulate host pathways to facilitate survival and dissemination. Different S. enterica serovars cause disease syndromes ranging from self-limited gastroenteritis to typhoid fever and vary in their repertoire of effectors. We leveraged this natural diversity to identify stm2585, here designated sarA (Salmonella anti-inflammatory response activator), as a Salmonella effector secreted primary by the SPI-2 type III secretion system. SarA is necessary and sufficient to induce STAT3 phosphorylation and IL-10 production, contributing to intracellular replication in vitro and bacterial load at systemic sites in mice. These results demonstrate that Salmonella has evolved effector mechanisms for regulating a host anti-inflammatory signaling pathway important in infection, autoimmunity, and cancer.
2018-06-01 | GSE104354 | GEO
Project description:Abstract: Chitin, an insoluble polymer of GlcNAc, is an abundant source of carbon, nitrogen, and energy for marine microorganisms. Microarray expression profiling and mutational studies of Vibrio cholerae growing on a natural chitin surface, or with the soluble chitin oligosaccharides (GlcNAc)(2-6), GlcNAc, or the glucosamine dimer (GlcN)2 identified three sets of differentially regulated genes. We show that (i) ChiS, a sensor histidine kinase, regulates expression of the (GlcNAc)(2-6) gene set, including a (GlcNAc)2 catabolic operon, two extracellular chitinases, a chitoporin, and a PilA-containing type IV pilus, designated ChiRP (chitin-regulated pilus) that confers a significant growth advantage to V. cholerae on a chitin surface; (ii) GlcNAc causes the coordinate expression of genes involved with chitin chemotaxis and adherence and with the transport and assimilation of GlcNAc; (iii) (GlcN)2 induces genes required for the transport and catabolism of nonacetylated chitin residues; and (iv) the constitutively expressed MSHA pilus facilitates adhesion to the chitin surface independent of surface chemistry. Collectively, these results provide a global portrait of a complex, multistage V. cholerae program for the efficient utilization of chitin. This SuperSeries is composed of the SubSeries listed below.
2006-03-08 | GSE4388 | GEO
Project description:Investigation of whole genome gene expression level changes in a Salmonella enterica serovar Typhimurium UK1 delta-iacP mutant, compared to the wild-type strain. IacP is resoponsible for the secretion of virulence effector proteins via the type III secretion system, thereby contributing the virulence of S. Typhimurium. The mutants analyzed in this study are further described in Kim et al. 2011. Role of Salmonella Pathogenicity Island 1 Protein IacP in Salmonella enterica Serovar Typhimurium Pathogenesis. Infection and Immunity 79(4):1440-1450 (PMID 21263021). A chip study using total RNA recovered from two separate wild-type cultures of Salmonella enterica serovar Typhimurium UK1 and two separate cultures of a mutant strain, Salmonella enterica serovar Typhimurium UK1 delta-iacP. Each chip measures the expression level of 4,302 genes from Salmonella enterica serovar Typhimurium.
2012-04-29 | E-GEOD-34663 | biostudies-arrayexpress
Project description:Single-celled organisms have different strategies to sense and utilize nutrients in their ever-changing environments. The opportunistic fungal pathogen Candida albicans is a common member of the human microbiota, especially that of the gastrointestinal (GI) tract. An important question concerns how C. albicans gained a competitive advantage over other microbes to become a successful commensal and opportunistic pathogen. Here, we report that C. albicans uses N-acetylglucosamine (GlcNAc), an abundant carbon source present in the GI tract, as a signal for nutrient availability. When placed in water, C. albicans cells normally enter the G0 phase and remain viable for weeks. However, they quickly lose viability when cultured in water containing only GlcNAc. We term this phenomenon GlcNAc-induced cell death (GICD). GlcNAc triggers the upregulation of ribosomalbiogenesis genes, alterations of mitochondrial metabolism, and the accumulation of reactive oxygen species (ROS), followed by rapid cell death via both apoptotic and necrotic mechanisms. Multiple pathways, including the conserved cyclic AMP (cAMP) signaling and GlcNAc catabolic pathways, are involved in GICD. GlcNAc acts as a signaling molecule to regulate multiple cellular programs in a coordinated manner and therefore maximizes the efficiency of nutrient use. This adaptive behavior allows C. albicans’ more efficient colonization of the gut. Expression profiles of Candida alibcans in three different 5 hours) were determined by high throughput sequencing technology.
2015-08-22 | E-GEOD-64659 | biostudies-arrayexpress