Mass-spectrometry proteomics data of Legionella effector
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo Sapiens
SUBMITTER: 
Taotao Chen
PROVIDER: PXD070394 | iProX | Thu Nov 06 00:00:00 GMT 2025
REPOSITORIES: iProX
Similar Datasets
Project description:Upon infection of host cells Legionella pneumophila releases a multitude of effector enzymes into the hosts cytoplasm that hijack a plethora of cellular activities, including the hosts ubiquitination pathways. Effectors belonging to the SidE-family are involved in non-canonical serine phosphoribosyl ubiquitination of host substrate proteins contributing to the formation of a Legionella-containing vacuole which is crucial in the onset of legionnaires disease. This dynamic process is reversed by effectors called Dups that hydrolyse the phosphodiester in the phosphoribosyl ubiquitinated protein. We installed reactive warheads on chemically prepared ribosylated ubiquitin to generate a set of probes targetting these Legionella enzymes. In vitro tests on recombinant DupA revealed that a vinyl sulfonate warhead was most efficient in covalent complex formation. Mutagenesis and x-ray crystallography approaches were used to identify the site of covalent crosslinking to be an allosteric cysteine residue and subsequent application of this probe highlight the potential to selective enrich Dup enzymes from Legionella infected cell lysates.
2025-05-06 | PXD049797 | Pride
Project description:Legionella pneumophila is an intracellular pathogen that uses a type IV secretion system called Dot/Icm to translocate over 330 effector proteins into the infected cells. To explore the collective impact of Dot/Icm effectors on host cell processes, we created a library of 14 L. pneumophila genomic mutant strains lacking effector-rich regions (a total of 85 effector genes deleted) and used the multi-deletion mutants to interrogate host-pathogen interactions. We then performed bulk mRNAseq profilling of PMA-differentiated THP1 macrophages after infection with WT, Dot/Icm-deficient mutant, or genomic mutant strains of Legionella pneumophila 130b (18h post-infection, MOI 10).
2026-02-28 | E-MTAB-16655 | biostudies-arrayexpress
Project description:Legionella pneumophila (LP) secretes more than 300 effectors into the host cytosol to facilitate intracellular replication. One of these effectors, SidH does not have sequence similarityto proteins of known function and is toxic when overexpressed in host cells. In order to understand the mechanism and function, it is important to know what host factors, SidH interacts with in human cells. Using quantitative proteomics, we uncovered multiple host proteins as potential targets of SidH.
2023-10-02 | PXD044950 | Pride
Project description:This SuperSeries is composed of the following subset Series: GSE26473: Secreted bacterial effectors that inhibit host protein synthesis are critical for induction of the innate immune response to virulent Legionella pneumophila [exp1] GSE26490: Secreted bacterial effectors that inhibit host protein synthesis are critical for induction of the innate immune response to virulent Legionella pneumophila [exp2] Refer to individual Series
2011-01-08 | E-GEOD-26491 | biostudies-arrayexpress
Project description:Legionella pneumophila utilises a type IVB secretion system (T4SS) to translocate over 300 effectors into host cells, hijacking cellular processes, including those within the mitochondrion. Currently, no Legionella effectors have been identified at the mitochondrial outer membrane, a critical interface between the organelle and rest of the cell. We screened the Legionella effector repertoire for features of mitochondrial tail-anchored (TA) proteins and identified four putative TA effectors. Among them, Lpg1625 was confirmed to localize to the mitochondrial outer membrane and shown to interact with all three isoforms of protein phosphatase 1 (PP1) through an RVxF motif. Importantly, PP1 remains catalytically active upon interaction with Lpg1625, leading to dephosphorylation of specific mitochondrial outer membrane proteins. Altering the TA signature to direct Lpg1625 to the ER led to ER-recruitment of PP1 and subsequent dephosphorylation of ER resident proteins indicating that Lpg1625 controls PP1 localisation and not substrate specificity. This study uncovers a novel pathogen-mediated strategy to modulate PP1 and manipulate the host phosphoproteome.
2025-06-03 | PXD057005 | Pride
Project description:Legionella pneumophila is the causative agent of Legionnaires’ disease, an acute pulmonary infection. L. pneumophila is able to infect and multiply in both phagocytic protozoan, such as Acanthamoeba castellanii, and mammalian professional phagocytes. The best-known virulence determinant used by L. pneumophila to infect host cells is a Type IVb translocation system named Icm/Dot, which is used to modify the host cell functions to the benefit of the bacteria. To date the Icm/Dot systeme is known to translocate more than 100 effectors. While the transcriptional response of Legionella to the intracellular environement of A. castelannii as already been investigated, much less is known of how Legionella reacts transcriptionnally inside human macrophages. In this study, the transcriptome of L. pneumophila was monitored during exponential and post-exponential phase in rich AYE broth and during infection of human cultured macrophages by using microarray and a RNA amplification procedure called SCOTS to allow for the study of conditions of low bacterial loads. Among the genes induced intracellularly are those involved in amino acid synthesis pathway leading to L-arginine, L-histidne and L-proline as well as many transport system involved in amino acid and iron uptake. The Icm/Dot systems is not differentially expressed inside cells compare to the E phase control but the effectors are strongly induced. The intracellular transcriptome was further used to identify putative new Icm/Dot effectors and translocation was show to occur for 3 of them. This study provides a comprehensive view of how L. pneumophila react to the human macrophages intracellular environment.
2011-01-01 | GSE23029 | GEO
Project description:Legionella pneumophila is an intracellular bacterial pathogen that encodes almost 300 effector proteins, many of which target various aspects of its eukaryotic host. While the physiological roles of many effectors are not understood, the focused study of individual effectors provides insight into their often novel and unique biochemistries. Here, we characterize the function of one effector, SidL, who was reported to inhibit host translation. We find that SidL blocks the nutrient-responsive translation regulator mTORC1, suggesting that translation inhibition is a downstream consequence of SidL activity. We use computational analyses that classify SidL as a member of a phosphotransferase and oxidoreductase superfamily, including a recently described protein-modifying adenylyltransferase; however, SidL does not adenylate proteins. Instead we use in vitro biochemistry to discover that SidL adenylates the glycolysis intermediate 3-phosphoglycerate (3PG), producing the novel metabolite 2-AMP-3PG. In cells, SidL disrupts glycolysis with a notable loss of 3PG and downstream intermediates. We propose that SidL expression consumes 3PG, causing metabolic perturbations that inactivate mTORC1, consequentially inhibiting translation. To our knowledge, this is the first report of a bacterial effector uniquely modifying an intermediate in a conserved metabolic pathway and suggests a novel mechanism by which bacteria modulate host metabolism.
2026-07-24 | PXD068090 | Pride
Project description:Research article on Legionella pneumophila effectors.
| PRJEB62121 | ENA
Project description:Legionella pneumophila, the causative agent of Legionnaire’s disease, uses its type IV secretion system to translocate over 300 effector proteins into host cells. These effectors subvert host cell signaling pathways to ensure bacterial proliferation. Despite their importance for pathogenesis, the roles of most of the effectors are yet to be characterized. Key to understanding the function of effectors is the identification of host proteins they bind during infection. We previously developed a novel tandem-affinity purification (TAP) approach using hexahistidine and BirA-specific biotinylation tags for isolating translocated effector complexes from infected cells whose composition were subsequently deciphered by mass spectrometry. Here we further advanced the workflow for the TAP approach and determined the infection-dependent interactomes of the effectors SidM and LidA, which were previously reported to promiscuously bind multiple Rab GTPases in vitro. In this study we defined a stringent subset of Rab GTPases targeted by SidM and LidA during infection, comprising of Rab1A, 1B, 6 and 10; in addition, LidA targets Rab14 and 18. Taken together, this study illustrates the power of this approach to profile the intracellular interactomes of bacterial effectors during infection.
2016-02-11 | PXD003573 | Pride
Project description:The intracellular bacterial pathogen Legionella pneumophila causes an inflammatory pneumonia called Legionnaires’ Disease. For virulence, L. pneumophila requires a Dot/Icm type IV secretion system that translocates bacterial effectors to the host cytosol. L. pneumophila lacking the Dot/Icm system is recognized by Toll-like receptors (TLRs), leading to a canonical NF-κB-dependent transcriptional response. In addition, L. pneumophila expressing a functional Dot/Icm system potently induces unique transcriptional targets, including proinflammatory genes such as Il23a and Csf2. Here we demonstrate that this Dot/Icm-dependent response, which we term the effector-triggered response (ETR), requires five translocated bacterial effectors that inhibit host protein synthesis. Upon infection of macrophages with virulent L. pneumophila, these five effectors caused a global decrease in host translation, thereby preventing synthesis of IκB, an inhibitor of the NF-κB transcription factor. Thus, macrophages infected with wildtype L. pneumophila exhibited prolonged activation of NF-κB, which was associated with transcription of ETR target genes such as Il23a and Csf2. L. pneumophila mutants lacking the five effectors still activated TLRs and NF-κB, but because the mutants permitted normal IκB synthesis, NF-κB activation was more transient and was not sufficient to fully induce the ETR. L. pneumophila mutants expressing enzymatically inactive effectors were also unable to fully induce the ETR, whereas multiple compounds or bacterial toxins that inhibit host protein synthesis via distinct mechanisms recapitulated the ETR when administered with TLR ligands. Previous studies have demonstrated that the host response to bacterial infection is induced primarily by specific microbial molecules that activate TLRs or cytosolic pattern recognition receptors. Our results add to this model by providing a striking illustration of how the host immune response to a virulent pathogen can also be shaped by pathogen-encoded activities, such as inhibition of host protein synthesis. Three-condition experiment: macrophages left uninfected (negative control), or infected with wildtype Legionella pneumophila, or the mutant Δ5, which lacks five bacterial effectors involved in inhibition of host protein synthesis (lgt1, lgt2, lgt3, sidI, sidL) (two experimental conditions). Biological replicates: two, independently infected, harvested, and hybridized to arrays. One technical replicate per array.
2011-01-08 | E-GEOD-26490 | biostudies-arrayexpress