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Rasouli M, Safari F, Sobhani N, Alavi M, Roudi R. Regulation of Cellular-Signaling Pathways by Mammalian Proteins Containing Bacterial EPIYA or EPIYA-Like Motifs Predicted to be Phosphorylated. DNA Cell Biol 2024; 43:74-84. [PMID: 38153368 DOI: 10.1089/dna.2023.0350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2023] Open
Abstract
The effector proteins of several pathogenic bacteria contain the Glu-Pro-Ile-Tyr-Ala (EPIYA) motif or other similar motifs. The EPIYA motif is delivered into the host cells by type III and IV secretion systems, through which its tyrosine residue undergoes phosphorylation by host kinases. These motifs atypically interact with a wide range of Src homology 2 (SH2) domain-containing mammalian proteins through tyrosine phosphorylation, which leads to the perturbation of multiple signaling cascades, the spread of infection, and improved bacterial colonization. Interestingly, it has been reported that EPIYA (or EPIYA-like) motifs exist in mammalian proteomes and regulate mammalian cellular-signaling pathways, leading to homeostasis and disease pathophysiology. It is possible that pathogenic bacteria have exploited EPIYA (or EPIYA-like) motifs from mammalian proteins and that the mammalian EPIYA (or EPIYA-like) motifs have evolved to have highly specific interactions with SH2 domain-containing proteins. In this review, we focus on the regulation of mammalian cellular-signaling pathways by mammalian proteins containing these motifs.
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Affiliation(s)
- Mohammad Rasouli
- Department of Biology, Faculty of Science, University of Guilan, Rasht, Iran
| | - Fatemeh Safari
- Department of Biology, Faculty of Science, University of Guilan, Rasht, Iran
| | - Navid Sobhani
- Department of Cancer Biology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Mana Alavi
- Department of Biology, Faculty of Science, University of Guilan, Rasht, Iran
| | - Raheleh Roudi
- Molecular Imaging Program at Stanford (MIPS), Department of Radiology, Stanford University, Stanford, California, USA
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Panagi I, Thurston TL. Ready, STAT3, Go! Bacteria in the race for M2 macrophage polarisation. Curr Opin Microbiol 2023; 73:102285. [PMID: 36857844 DOI: 10.1016/j.mib.2023.102285] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Revised: 01/20/2023] [Accepted: 01/25/2023] [Indexed: 03/03/2023]
Abstract
Despite macrophages representing professional immune cells that are integral to the host defences against microbial threats, several intracellular bacteria not only infect, but survive, replicate and often persist in these cells. This is perhaps possible because not all macrophages are the same. Instead, macrophages are loosely divided into two classes: the M1 'classically activated' pro-inflammatory subset and the M2 'alternatively activated' cells that are generally anti-inflammatory and infection-permissive. In this review, we summarise recent findings explaining how several intracellular pathogens, often using secreted effectors, rewire host circuitry in favour of an anti-inflammatory niche. A common theme is the phosphorylation and activation of the signal transducer and activator of transcription-3 (STAT3) transcription factor. We describe and compare the diverse mechanisms employed and reflect how such non-canonical processes may have evolved to circumvent regulation by the host, providing a potent means by which different pathogens manipulate the cells they infect.
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Affiliation(s)
- Ioanna Panagi
- MRC Centre for Molecular Bacteriology and Infection, Department of Infectious Disease, Imperial College London, SW7 2AZ, UK
| | - Teresa Lm Thurston
- MRC Centre for Molecular Bacteriology and Infection, Department of Infectious Disease, Imperial College London, SW7 2AZ, UK.
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3
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Chen C, Dai Y, Yang Y, Zhu Z, Zhang Q, An X, Lai F. Lawsonia intracellularis LI0666 is a new EPIYA effector exported by the Yersinia enterocolitica type III secretion system. Vet Res 2022; 53:39. [PMID: 35659762 PMCID: PMC9167531 DOI: 10.1186/s13567-022-01054-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2022] [Accepted: 03/04/2022] [Indexed: 11/16/2022] Open
Abstract
Lawsonia intracellularis is the causative agent of proliferative enteropathy. While it harbors genes encoding the entire apparatus required for the type III secretion system (T3SS) and the expression of some of these components has been detected during experimental infection, the identification of L. intracellularis T3SS substrates (effector proteins) has been hampered. The Yersinia T3SS and yeast growth inhibition assays are two important heterologous systems used for the characterization of effector proteins. Bacterial EPIYA effectors are a distinct class of bacterial effectors defined by the presence of EPIYA or the EPIYA-related motif. When delivered into host cells via a T3SS or type IV secretion system, these effectors undergo tyrosine phosphorylation of the EPIYA motif, which enables them to manipulate host cell signaling by promiscuously interacting with multiple SH2 domain-containing proteins. A previous study showed that L. intracellularis LI0666 contains two EPIYA motifs and speculated that this protein could be a T3SS effector. In this study, we show that LI0666 is secreted by Yersinia in a T3SS-dependent manner and inhibits yeast growth. LI0666 is phosphorylated at tyrosine residues in porcine intestinal epithelial cells and in human epithelial cells. Like the archetypal EPIYA effector CagA, the EPIYA-containing region is not required for LI0666 association with yeast and mammalian cell membranes. Our results indicate that LI0666 is an authentic bacterial EPIYA effector. Identification of the tyrosine kinases that are responsible for LI0666 phosphorylation and the SH2 domain-containing host proteins that LI0666 interacts with will help to explore the molecular mechanisms of LI0666 in disease development.
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Affiliation(s)
- Cang Chen
- College of Bioscience and Bioengineering, Jiangxi Key Laboratory for Conservation and Utilization of Fungal Resources, Jiangxi Agricultural University, Nanchang, 330045, China
| | - Yimin Dai
- College of Animal Science and Technology, Jiangxi Agricultural University, Nanchang, 330045, China
| | - Yingying Yang
- College of Bioscience and Bioengineering, Jiangxi Key Laboratory for Conservation and Utilization of Fungal Resources, Jiangxi Agricultural University, Nanchang, 330045, China
| | - Zihe Zhu
- College of Bioscience and Bioengineering, Jiangxi Key Laboratory for Conservation and Utilization of Fungal Resources, Jiangxi Agricultural University, Nanchang, 330045, China
| | - Qinghua Zhang
- College of Bioscience and Bioengineering, Jiangxi Key Laboratory for Conservation and Utilization of Fungal Resources, Jiangxi Agricultural University, Nanchang, 330045, China
| | - Xuejiao An
- College of Bioscience and Bioengineering, Jiangxi Key Laboratory for Conservation and Utilization of Fungal Resources, Jiangxi Agricultural University, Nanchang, 330045, China
| | - Fenju Lai
- College of Bioscience and Bioengineering, Jiangxi Key Laboratory for Conservation and Utilization of Fungal Resources, Jiangxi Agricultural University, Nanchang, 330045, China. .,Collaborative Innovation Center of Postharvest Key Technology and Quality Safety of Fruits and Vegetables in Jiangxi Province, Nanchang, Jiangxi, China.
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4
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Fromm K, Dehio C. The Impact of Bartonella VirB/VirD4 Type IV Secretion System Effectors on Eukaryotic Host Cells. Front Microbiol 2022; 12:762582. [PMID: 34975788 PMCID: PMC8714903 DOI: 10.3389/fmicb.2021.762582] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2021] [Accepted: 10/29/2021] [Indexed: 12/14/2022] Open
Abstract
Bartonella spp. are facultative intracellular pathogens that infect a wide range of mammalian hosts including humans. The VirB/VirD4 type IV secretion system (T4SS) is a key virulence factor utilized to translocate Bartonella effector proteins (Beps) into host cells in order to subvert their functions. Crucial for effector translocation is the C-terminal Bep intracellular delivery (BID) domain that together with a positively charged tail sequence forms a bipartite translocation signal. Multiple BID domains also evolved secondary effector functions within host cells. The majority of Beps possess an N-terminal filamentation induced by cAMP (FIC) domain and a central connecting oligonucleotide binding (OB) fold. FIC domains typically mediate AMPylation or related post-translational modifications of target proteins. Some Beps harbor other functional modules, such as tandem-repeated tyrosine-phosphorylation (EPIYA-related) motifs. Within host cells the EPIYA-related motifs are phosphorylated, which facilitates the interaction with host signaling proteins. In this review, we will summarize our current knowledge on the molecular functions of the different domains present in Beps and highlight examples of Bep-dependent host cell modulation.
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Affiliation(s)
- Katja Fromm
- Biozentrum, University of Basel, Basel, Switzerland
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5
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Host Genome-Wide Association Study of Infant Susceptibility to Shigella-Associated Diarrhea. Infect Immun 2021; 89:IAI.00012-21. [PMID: 33649051 PMCID: PMC8316060 DOI: 10.1128/iai.00012-21] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Accepted: 02/22/2021] [Indexed: 12/15/2022] Open
Abstract
Shigella is a leading cause of moderate-to-severe diarrhea globally and the causative agent of shigellosis and bacillary dysentery. Associated with 80 to 165 million cases of diarrhea and >13% of diarrheal deaths, in many regions, Shigella exposure is ubiquitous while infection is heterogenous. To characterize host-genetic susceptibility to Shigella-associated diarrhea, we performed two independent genome-wide association studies (GWAS) including Bangladeshi infants from the PROVIDE and CBC birth cohorts in Dhaka, Bangladesh. Cases were infants with Shigella-associated diarrhea (n = 143) and controls were infants with no Shigella-associated diarrhea in the first 13 months of life (n = 446). Shigella-associated diarrhea was identified via quantitative PCR (qPCR) threshold cycle (CT ) distributions for the ipaH gene, carried by all four Shigella species and enteroinvasive Escherichia coli Host GWAS were performed under an additive genetic model. A joint analysis identified protective loci on chromosomes 11 (rs582240, within the KRT18P59 pseudogene; P = 6.40 × 10-8; odds ratio [OR], 0.43) and 8 (rs12550437, within the lincRNA RP11-115J16.1; P = 1.49 × 10-7; OR, 0.48). Conditional analyses identified two previously suggestive loci, a protective locus on chromosome 7 (rs10266841, within the 3' untranslated region [UTR] of CYTH3; P conditional = 1.48 × 10-7; OR, 0.44) and a risk-associated locus on chromosome 10 (rs2801847, an intronic variant within MPP7; P conditional = 8.37 × 10-8; OR, 5.51). These loci have all been indirectly linked to bacterial type 3 secretion system (T3SS) activity, its components, and bacterial effectors delivered into host cells. Host genetic factors that may affect bacterial T3SS activity and are associated with the host response to Shigella-associated diarrhea may provide insight into vaccine and drug development efforts for Shigella-associated diarrheal disease.
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Keikha M, Karbalaei M. EPIYA motifs of Helicobacter pylori cagA genotypes and gastrointestinal diseases in the Iranian population: a systematic review and meta-analysis. New Microbes New Infect 2021; 41:100865. [PMID: 33912350 PMCID: PMC8066700 DOI: 10.1016/j.nmni.2021.100865] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 03/01/2021] [Accepted: 03/07/2021] [Indexed: 02/08/2023] Open
Abstract
Helicobacter pylori is one of the best risk factors for gastric cancer. Recent studies have examined the relationship between virulence factors, in particular CagA toxin, and the development of gastrointestinal diseases. According to the literature, there is a significant relationship between the polymorphism of cagA-EPIYA motifs and progression to severe clinical outcomes. The main goal of our study was to determine the possible association between cagA genotypes and the risk of severe clinical outcomes in the Iranian population. We investigated these ambiguities using a comprehensive meta-analysis study, in which we evaluated data from 1762 Iranian patients for a potential correlation between all cagA gene genotypes and gastrointestinal diseases. According to statistical analysis, the frequencies of cagA genotypes including ABC, ABCC, AB and ABCCC in the Iranian population were estimated at 80.18%, 22.81%, 5.52% and 2.76%, respectively; the ABD genotype was not detected in these PCR-based studies. There was a significant relationship between cagA genotypes ABCC and ABCCC and severe clinical outcomes of infection such as peptic ulcer and gastric cancer. Overall, it can be concluded that there is a positive correlation with the number of copies of EPIYA-C and the increase of gastric cancer. Therefore, according to our results, it seems that the EPIYA-ABCCC motif has a strong positive relationship with gastric cancer in the Iranian population.
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Affiliation(s)
- M. Keikha
- Department of Microbiology and Virology, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
- Student Research Committee, Mashhad University of Medical Sciences, Mashhad, Iran
| | - M. Karbalaei
- Department of Microbiology and Virology, School of Medicine, Jiroft University of Medical Sciences, Jiroft, Iran
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7
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Mak H, Thurston TLM. Interesting Biochemistries in the Structure and Function of Bacterial Effectors. Front Cell Infect Microbiol 2021; 11:608860. [PMID: 33718265 PMCID: PMC7943720 DOI: 10.3389/fcimb.2021.608860] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Accepted: 01/13/2021] [Indexed: 11/13/2022] Open
Abstract
Bacterial effector proteins, delivered into host cells by specialized multiprotein secretion systems, are a key mediator of bacterial pathogenesis. Following delivery, they modulate a range of host cellular processes and functions. Strong selective pressures have resulted in bacterial effectors evolving unique structures that can mimic host protein biochemical activity or enable novel and distinct biochemistries. Despite the protein structure-function paradigm, effectors from different bacterial species that share biochemical activities, such as the conjugation of ubiquitin to a substrate, do not necessarily share structural or sequence homology to each other or the eukaryotic proteins that carry out the same function. Furthermore, some bacterial effectors have evolved structural variations to known protein folds which enable different or additional biochemical and physiological functions. Despite the overall low occurrence of intrinsically disordered proteins or regions in prokaryotic proteomes compared to eukaryotes proteomes, bacterial effectors appear to have adopted intrinsically disordered regions that mimic the disordered regions of eukaryotic signaling proteins. In this review, we explore examples of the diverse biochemical properties found in bacterial effectors that enable effector-mediated interference of eukaryotic signaling pathways and ultimately support pathogenesis. Despite challenges in the structural and functional characterisation of effectors, recent progress has been made in understanding the often unusual and fascinating ways in which these virulence factors promote pathogenesis. Nevertheless, continued work is essential to reveal the array of remarkable activities displayed by effectors.
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Affiliation(s)
| | - Teresa L. M. Thurston
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, United Kingdom
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Soyfoo DM, Doomah YH, Xu D, Zhang C, Sang HM, Liu YY, Zhang GX, Jiang JX, Xu SF. New genotypes of Helicobacter Pylori VacA d-region identified from global strains. BMC Mol Cell Biol 2021; 22:4. [PMID: 33413074 PMCID: PMC7791883 DOI: 10.1186/s12860-020-00338-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Accepted: 12/16/2020] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND Pathogenesis of Helicobacter Pylori (HP) vacuolating toxin A (vacA) depends on polymorphic diversity within the signal (s), middle (m), intermediate (i), deletion (d) and c-regions. These regions show distinct allelic diversity. The s-region, m-region and the c-region (a 15 bp deletion at the 3'-end region of the p55 domain of the vacA gene) exist as 2 types (s1, s2, m1, m2, c1 and c2), while the i-region has 3 allelic types (i1, i2 and i3). The locus of d-region of the vacA gene has also been classified into 2 genotypes, namely d1 and d2. We investigated the "d-region"/"loop region" through bioinformatics, to predict its properties and relation to disease. One thousand two hundred fifty-nine strains from the NCBI nucleotide database and the dryad database with complete vacA sequences were included in the study. The sequences were aligned using BioEdit and analyzed using Lasergene and BLAST. The secondary structure and physicochemical properties of the region were predicted using PredictProtein. RESULTS We identified 31 highly polymorphic genotypes in the "d-region", with a mean length of 34 amino acids (9 ~ 55 amino acids). We further classified the 31 genotypes into 3 main types, namely K-type (strains starting with the KDKP motif in the "d-region"), Q-type (strains starting with the KNQT motif), and E-type (strains starting with the ESKT motif) respectively. The most common type, K-type, is more prevalent in cancer patients (80.87%) and is associated with the s1i1m1c1 genotypes (P < .01). Incidentally, a new region expressing sequence diversity (2 aa deletion) at the C-terminus of the p55 domain of vacA was identified during bioinformatics analysis. CONCLUSIONS Prediction of secondary structures shows that the "d-region" adopts a loop conformation and is a disordered region.
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Affiliation(s)
- Djaleel Muhammad Soyfoo
- Department of Gastroenterology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Yussriya Hanaa Doomah
- Department of Obstetrics and Gynecology, The Second Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Dong Xu
- Department of Electrical Engineering and Computer Science, Bond Life Sciences Center, University of Missouri, Columbia, MO, USA
| | - Chao Zhang
- Institute for Computational Biomedicine, Weill Cornell Medicine, New York, NY, 10021, USA.,Division of Hematology and Medical Oncology, Department of Medicine, Weill Cornell Medicine, New York, NY, 10021, USA
| | - Huai-Ming Sang
- Department of Gastroenterology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Yan-Yan Liu
- Department of Gastroenterology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Guo-Xin Zhang
- Department of Gastroenterology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Jian-Xia Jiang
- Department of Gastroenterology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China.
| | - Shun-Fu Xu
- Department of Gastroenterology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China.
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Kontizas E, Tastsoglou S, Karamitros T, Karayiannis Y, Kollia P, Hatzigeorgiou AG, Sgouras DN. Impact of Helicobacter pylori Infection and Its Major Virulence Factor CagA on DNA Damage Repair. Microorganisms 2020; 8:microorganisms8122007. [PMID: 33339161 PMCID: PMC7765595 DOI: 10.3390/microorganisms8122007] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Revised: 12/11/2020] [Accepted: 12/14/2020] [Indexed: 01/10/2023] Open
Abstract
Helicobacter pylori infection induces a plethora of DNA damages. Gastric epithelial cells, in order to maintain genomic integrity, require an integrous DNA damage repair (DDR) machinery, which, however, is reported to be modulated by the infection. CagA is a major H. pylori virulence factor, associated with increased risk for gastric carcinogenesis. Its pathogenic activity is partly regulated by phosphorylation on EPIYA motifs. Our aim was to identify effects of H. pylori infection and CagA on DDR, investigating the transcriptome of AGS cells, infected with wild-type, ΔCagA and EPIYA-phosphorylation-defective strains. Upon RNA-Seq-based transcriptomic analysis, we observed that a notable number of DDR genes were found deregulated during the infection, potentially resulting to base excision repair and mismatch repair compromise and an intricate deregulation of nucleotide excision repair, homologous recombination and non-homologous end-joining. Transcriptome observations were further investigated on the protein expression level, utilizing infections of AGS and GES-1 cells. We observed that CagA contributed to the downregulation of Nth Like DNA Glycosylase 1 (NTHL1), MutY DNA Glycosylase (MUTYH), Flap Structure-Specific Endonuclease 1 (FEN1), RAD51 Recombinase, DNA Polymerase Delta Catalytic Subunit (POLD1), and DNA Ligase 1 (LIG1) and, contrary to transcriptome results, Apurinic/Apyrimidinic Endodeoxyribonuclease 1 (APE1) upregulation. Our study accentuates the role of CagA as a significant contributor of H. pylori infection-mediated DDR modulation, potentially disrupting the balance between DNA damage and repair, thus favoring genomic instability and carcinogenesis.
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Affiliation(s)
- Eleftherios Kontizas
- Laboratory of Medical Microbiology, Hellenic Pasteur Institute, 11521 Athens, Greece;
- Department of Genetics and Biotechnology, Faculty of Biology, National and Kapodistrian University of Athens, 15772 Athens, Greece;
- Correspondence: (E.K.); (D.N.S.); Tel.: +30-210-647-8812 (E.K.); +30-210-647-8824 (D.N.S.)
| | - Spyros Tastsoglou
- Department of Electrical and Computer Engineering, University of Thessaly, 38221 Volos, Greece;
- DIANA-Lab, Hellenic Pasteur Institute, 11521 Athens, Greece;
| | - Timokratis Karamitros
- Bioinformatics and Applied Genomics Unit, Hellenic Pasteur Institute, 11521 Athens, Greece;
| | - Yiannis Karayiannis
- Laboratory of Medical Microbiology, Hellenic Pasteur Institute, 11521 Athens, Greece;
- Department of Genetics and Biotechnology, Faculty of Biology, National and Kapodistrian University of Athens, 15772 Athens, Greece;
| | - Panagoula Kollia
- Department of Genetics and Biotechnology, Faculty of Biology, National and Kapodistrian University of Athens, 15772 Athens, Greece;
| | - Artemis G. Hatzigeorgiou
- DIANA-Lab, Hellenic Pasteur Institute, 11521 Athens, Greece;
- DIANA-Lab, Department of Computer Science and Biomedical Informatics, University of Thessaly, 35131 Lamia, Greece
| | - Dionyssios N. Sgouras
- Laboratory of Medical Microbiology, Hellenic Pasteur Institute, 11521 Athens, Greece;
- Correspondence: (E.K.); (D.N.S.); Tel.: +30-210-647-8812 (E.K.); +30-210-647-8824 (D.N.S.)
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Sámano-Sánchez H, Gibson TJ. Mimicry of Short Linear Motifs by Bacterial Pathogens: A Drugging Opportunity. Trends Biochem Sci 2020; 45:526-544. [PMID: 32413327 DOI: 10.1016/j.tibs.2020.03.003] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Revised: 02/25/2020] [Accepted: 03/03/2020] [Indexed: 12/11/2022]
Abstract
Bacterial pathogens have developed complex strategies to successfully survive and proliferate within their hosts. Throughout the infection cycle, direct interaction with host cells occurs. Many bacteria have been found to secrete proteins, such as effectors and toxins, directly into the host cell with the potential to interfere with cell regulatory processes, either enzymatically or through protein-protein interactions (PPIs). Short linear motifs (SLiMs) are abundant peptide modules in cell signaling proteins. Here, we cover the reported examples of eukaryotic-like SLiM mimicry being used by pathogenic bacteria to hijack host cell machinery and discuss how drugs targeting SLiM-regulated cell signaling networks are being evaluated for interference with bacterial infections. This emerging anti-infective opportunity may become an essential contributor to antibiotic replacement strategies.
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Affiliation(s)
- Hugo Sámano-Sánchez
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, Meyerhofstrasse 1, 69117 Heidelberg, Germany; Collaboration for Joint PhD Degree between EMBL and Heidelberg University, Faculty of Biosciences, 69120 Heidelberg, Germany
| | - Toby J Gibson
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, Meyerhofstrasse 1, 69117 Heidelberg, Germany.
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11
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Sorg I, Schmutz C, Lu YY, Fromm K, Siewert LK, Bögli A, Strack K, Harms A, Dehio C. A Bartonella Effector Acts as Signaling Hub for Intrinsic STAT3 Activation to Trigger Anti-inflammatory Responses. Cell Host Microbe 2020; 27:476-485.e7. [PMID: 32101706 DOI: 10.1016/j.chom.2020.01.015] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Revised: 12/13/2019] [Accepted: 01/21/2020] [Indexed: 12/11/2022]
Abstract
Chronically infecting pathogens avoid clearance by the innate immune system by promoting premature transition from an initial pro-inflammatory response toward an anti-inflammatory tissue-repair response. STAT3, a central regulator of inflammation, controls this transition and thus is targeted by numerous chronic pathogens. Here, we show that BepD, an effector of the chronic bacterial pathogen Bartonella henselae targeted to infected host cells, establishes an exceptional pathway for canonical STAT3 activation, thereby impairing secretion of pro-inflammatory TNF-α and stimulating secretion of anti-inflammatory IL-10. Tyrosine phosphorylation of EPIYA-related motifs in BepD facilitates STAT3 binding and activation via c-Abl-dependent phosphorylation of Y705. The tyrosine-phosphorylated scaffold of BepD thus represents a signaling hub for intrinsic STAT3 activation that is independent from canonical STAT3 activation via transmembrane receptor-associated Janus kinases. We anticipate that our findings on a molecular shortcut to STAT3 activation will inspire new treatment options for chronic infections and inflammatory diseases.
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Affiliation(s)
- Isabel Sorg
- Biozentrum, University of Basel, 4056 Basel, Switzerland
| | | | - Yun-Yueh Lu
- Biozentrum, University of Basel, 4056 Basel, Switzerland
| | - Katja Fromm
- Biozentrum, University of Basel, 4056 Basel, Switzerland
| | - Lena K Siewert
- Biozentrum, University of Basel, 4056 Basel, Switzerland
| | | | - Kathrin Strack
- Biozentrum, University of Basel, 4056 Basel, Switzerland
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12
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Zhao R, Liu Z, Xu W, Song L, Ren H, Ou Y, Liu Y, Wang S. Helicobacter pylori infection leads to KLF4 inactivation in gastric cancer through a TET1-mediated DNA methylation mechanism. Cancer Med 2020; 9:2551-2563. [PMID: 32017451 PMCID: PMC7131848 DOI: 10.1002/cam4.2892] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 01/04/2020] [Accepted: 01/14/2020] [Indexed: 12/15/2022] Open
Abstract
Krüppel-like factor 4 (KLF4) has a tumor suppressor role in the progression of gastric cancer (GC), and inhibition or loss of KLF4 expression was identified in GC. The aim of this study was to explore the new molecular mechanism of KLF4 inactivation in gastric cancer. Herein, we report that Helicobacter pylori infection or Cag pathogenicity island protein A (CagA) gene transduction resulted in KLF4 expression downregulation and promoted gastric epithelial cell and gastric cancel cell proliferation, migration, and colony formation. Mechanistically, we found that CagA gene transduction led to DNA methylation of the KLF4 promoter, an effect that was relevant to the significant downregulation of TET1 expression. Causally, knockdown of TET1 expression decreased KLF4 expression, whereas overexpression of TET1 had the opposite effect. Clinically, we found that KLF4 expression and the 5-hmC levels were lower in GC cells with H pylori infection than in GC cells without H pylori infection. Thus, our study not only sheds new light on how H pylori infection promotes the progression of GC but also elucidates a novel mechanism of KLF4 inactivation in GC pathogenesis. During pathogenesis, an alteration in the H pylori/CagA-TET1-KLF4 signaling pathway plays a critical role, suggesting that this pathway may be a prospective target for gastric carcinoma intervention and therapy.
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Affiliation(s)
- Rongrong Zhao
- Department of Physiopathology, Anhui Medical University, Hefei, Anhui, China.,Department of Pathology, First Affiliated Hospital of Anhui Medical University, Hefei, Anhui, China
| | - Zhengxia Liu
- Department of Physiopathology, Anhui Medical University, Hefei, Anhui, China
| | - Wenting Xu
- Department of Physiopathology, Anhui Medical University, Hefei, Anhui, China
| | - Le Song
- Department of Physiopathology, Anhui Medical University, Hefei, Anhui, China
| | - Haifeng Ren
- Department of Physiopathology, Anhui Medical University, Hefei, Anhui, China
| | - Yang Ou
- Department of Physiopathology, Anhui Medical University, Hefei, Anhui, China
| | - Yakun Liu
- Department of Physiopathology, Anhui Medical University, Hefei, Anhui, China
| | - Siying Wang
- Department of Physiopathology, Anhui Medical University, Hefei, Anhui, China
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Patel O, Roy MJ, Murphy JM, Lucet IS. The PEAK family of pseudokinases, their role in cell signalling and cancer. FEBS J 2019; 287:4183-4197. [PMID: 31599110 DOI: 10.1111/febs.15087] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Revised: 09/11/2019] [Accepted: 10/06/2019] [Indexed: 12/20/2022]
Abstract
The study of pseudokinases has uncovered that catalysis-independent functions play a critical role in cell signalling regulation. However, how pseudokinases dynamically assemble and regulate oncogenic signalling pathways remains, in most cases, unclear due to a limited knowledge of the structural determinants that are critical for their functions. Here, we review the recent progress made to unravel the role of the PEAK family of pseudokinases, which comprises SgK269, SgK223 and the recently identified PEAK3, in assembling specific oncogenic signalling pathways that contribute to the progression of several aggressive cancers. We focus on recent structural advances revealing that SgK269 and SgK223 can homo- and heteroassociate via a unique dimerisation domain, comprising conserved regulatory helices directly surrounding the pseudokinase domain, which is also conserved in PEAK3. We also highlight a potential oligomerisation mechanism driven by the pseudokinase domain. While it is likely that homo- or heterodimerisation and oligomerisation mechanisms contribute to the assembly of complex signalling hubs and provide a means to spatially and temporally modulate and diversify signalling outputs, the exact role that these oncogenic scaffolds play in regulating cell migration, invasion and morphology remains unclear. Here, we attempt to link their structural characteristics to their cellular functions by providing a thorough analysis of the signalling transduction pathways they are known to modulate.
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Affiliation(s)
- Onisha Patel
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Australia.,Department of Medical Biology, University of Melbourne, Parkville, Australia
| | - Michael J Roy
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Australia.,Department of Medical Biology, University of Melbourne, Parkville, Australia
| | - James M Murphy
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Australia.,Department of Medical Biology, University of Melbourne, Parkville, Australia
| | - Isabelle S Lucet
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Australia.,Department of Medical Biology, University of Melbourne, Parkville, Australia
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Activity and Functional Importance of Helicobacter pylori Virulence Factors. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1149:35-56. [PMID: 31016624 DOI: 10.1007/5584_2019_358] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Helicobacter pylori is a very successful Gram-negative pathogen colonizing the stomach of humans worldwide. Infections with this bacterium can generate pathologies ranging from chronic gastritis and peptic ulceration to gastric cancer. The best characterized H. pylori virulence factors that cause direct cell damage include an effector protein encoded by the cytotoxin-associated gene A (CagA), a type IV secretion system (T4SS) encoded in the cag-pathogenicity island (cag PAI), vacuolating cytotoxin A (VacA), γ-glutamyl transpeptidase (GGT), high temperature requirement A (HtrA, a serine protease) and cholesterol glycosyl-transferase (CGT). Since these H. pylori factors are either surface-exposed, secreted or translocated, they can directly interact with host cell molecules and are able to hijack cellular functions. Studies on these bacterial factors have progressed substantially in recent years. Here, we review the current status in the characterization of signaling cascades by these factors in vivo and in vitro, which comprise the disruption of cell-to-cell junctions, induction of membrane rearrangements, cytoskeletal dynamics, proliferative, pro-inflammatory, as well as, pro-apoptotic and anti-apoptotic responses or immune evasion. The impact of these signal transduction modules in the pathogenesis of H. pylori infections is discussed.
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15
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Pachathundikandi SK, Gutiérrez-Escobar AJ, Tegtmeyer N. Tailor-Made Detection of Individual Phosphorylated and Non-Phosphorylated EPIYA-Motifs of Helicobacter pylori Oncoprotein CagA. Cancers (Basel) 2019; 11:cancers11081163. [PMID: 31412675 PMCID: PMC6721621 DOI: 10.3390/cancers11081163] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2019] [Revised: 07/25/2019] [Accepted: 08/08/2019] [Indexed: 02/07/2023] Open
Abstract
The gastric pathogen and carcinogen Helicobacter pylori(H. pylori) encodes a type IV secretion system for translocation of the effector protein CagA into host cells. Injected CagA becomes tyrosine-phosphorylated at the five amino acid residue Glutamate-Proline- Isoleucine-Tyrosine-Alanine (EPIYA)-sequence motifs. These phosphorylated EPIYA-sites represent recognition motifs for binding of multiple host factors, which then manipulate signaling pathways to trigger gastric disease. Thus, efficient detection of single phosphorylated EPIYA-motifs in CagA is required. Detection of phospho-CagA is primarily performed using commercial pan-phosphotyrosine antibodies. However, those antibodies were originally generated to recognize many phosphotyrosines in various mammalian proteins and are not optimized for use in bacteria. To address this important limitation, we synthesized 11-mer phospho- and non-phospho-peptides from EPIYA-motifs A, B, and C, and produced three phospho-specific and three non-phospho-specific rabbit polyclonal CagA antibodies. These antibodies specifically recognized the corresponding phosphorylated and non-phosphorylated EPIYA-motifs, while the EPIYA-C antibodies also recognized the related East-Asian EPIYA-D motif. Otherwise, no cross-reactivity of the antibodies among EPIYAs was observed. Western blotting demonstrated that each EPIYA-motif can be predominantly phosphorylated during H. pylori infection. This represents the first complete set of phospho-specific antibodies for an effector protein in bacteria, providing useful tools to gather information for the categorization of CagA phosphorylation, cancer signaling, and gastric disease progression.
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Affiliation(s)
- Suneesh Kumar Pachathundikandi
- Department of Biology, Division of Microbiology, Friedrich Alexander University Erlangen-Nuremberg, Staudtstraße 5, D-91058 Erlangen, Germany
| | - Andrés Julián Gutiérrez-Escobar
- Department of Biology, Division of Microbiology, Friedrich Alexander University Erlangen-Nuremberg, Staudtstraße 5, D-91058 Erlangen, Germany
| | - Nicole Tegtmeyer
- Department of Biology, Division of Microbiology, Friedrich Alexander University Erlangen-Nuremberg, Staudtstraße 5, D-91058 Erlangen, Germany.
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16
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Bie M, Wen J, Wang H, Zhou L, Yang L, Pan Y, Luo J, Liu C, Li M, Wang B. Phylogenetic analysis of clinical strains of Helicobacter pylori isolated from patients with gastric diseases in Tibet. ANNALS OF TRANSLATIONAL MEDICINE 2019; 7:320. [PMID: 31475190 PMCID: PMC6694268 DOI: 10.21037/atm.2019.05.80] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Accepted: 05/28/2019] [Indexed: 08/12/2023]
Abstract
BACKGROUND Helicobacter pylori (H. pylori) is a Gram-negative pathogenic bacterium that causes chronic gastritis and other gastric diseases in humans. In Tibet, China, the infection of H. pylori is an important risk factor that caused gastric cancer. METHODS To understand the characteristics of this pathogen in Tibet, five strains of H. pylori were isolated from three patients' oral cavity or stomach who had either a gastric ulcer or gastritis. We performed genome sequences of these five clinical strains on Illumina Hiseq, and 55,016-63666 SNVs/InDels were identified by comparing to the reference strain of H. pylori 26995. RESULTS The phylogenetic analysis with multi-locus sequence typing (MLST) showed that five Tibetan strains were defined as hpEurope population and their proteins encoded by the cagA gene also presented a western type. Also, the strains that were isolated from the same patients' oral cavity and stomach exhibited homology in molecular evolution. CONCLUSIONS This is the first study to investigate the phylogenetic population structure of the epidemic strains of H. pylori in Tibet, which may improve cognition of Tibetan strains and confirm the homology of the strains from oral cavity and stomach.
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Affiliation(s)
- Mingjiang Bie
- West China School of Basic Medical Sciences and Forensic Medicine, Sichuan University, Chengdu 610041, China
- Medical College of Tibet University, Lhasa 850000, China
- West China Fourth Hospital of Public Health, Sichuan University, Chengdu 610041, China
- Editorial Board of Journal of Sichuan University (Medical Science Edition), Chengdu 610041, China
| | - Jirui Wen
- West China School of Basic Medical Sciences and Forensic Medicine, Sichuan University, Chengdu 610041, China
| | - Hongren Wang
- West China School of Basic Medical Sciences and Forensic Medicine, Sichuan University, Chengdu 610041, China
| | - Linlin Zhou
- West China School of Basic Medical Sciences and Forensic Medicine, Sichuan University, Chengdu 610041, China
| | - Lijun Yang
- Medical College of Tibet University, Lhasa 850000, China
| | - Yongyue Pan
- Medical College of Tibet University, Lhasa 850000, China
| | - Jun Luo
- West China School of Basic Medical Sciences and Forensic Medicine, Sichuan University, Chengdu 610041, China
| | - Chao Liu
- Hospital of Chengdu Office, People’s Government of Tibet Autonomous Region, Chengdu 610041, China
| | - Mingyuan Li
- West China School of Basic Medical Sciences and Forensic Medicine, Sichuan University, Chengdu 610041, China
| | - Baoning Wang
- West China School of Basic Medical Sciences and Forensic Medicine, Sichuan University, Chengdu 610041, China
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17
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O'Rourke RL, Daly RJ. The pseudokinases SgK269 and SgK223: A novel oncogenic alliance in human cancer. Cell Adh Migr 2017; 12:524-528. [PMID: 29105536 DOI: 10.1080/19336918.2017.1394570] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Sugen kinases (SgK)269 (also known as PEAK1), and SgK223, an orthologue of rat pragmin and mouse NACK, are human pseudokinases that are implicated in the progression of several cancers. Both are scaffolding proteins that recruit distinct repertoires of signalling proteins and regulate a variety of biological endpoints including cell migration and invasion. To date, SgK269 and SgK223 have been largely studied as separate signalling entities. However, recent work has demonstrated that SgK269 and SgK223 undergo homo- and heterotypic association that determines signal output and biological response. Further characterization of the mechanism of action of these two pseudokinases will provide novel insights into how they promote cancer progression and may reveal novel therapeutic strategies. Here we review their structure, mechanism and function and roles they play in cancer pathogenesis.
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Affiliation(s)
- Rachelle L O'Rourke
- a Cancer Program, Biomedicine Discovery Institute and Department of Biochemistry and Molecular Biology , Monash University , Melbourne , Victoria , Australia
| | - Roger J Daly
- a Cancer Program, Biomedicine Discovery Institute and Department of Biochemistry and Molecular Biology , Monash University , Melbourne , Victoria , Australia
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18
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Harms A, Segers FHID, Quebatte M, Mistl C, Manfredi P, Körner J, Chomel BB, Kosoy M, Maruyama S, Engel P, Dehio C. Evolutionary Dynamics of Pathoadaptation Revealed by Three Independent Acquisitions of the VirB/D4 Type IV Secretion System in Bartonella. Genome Biol Evol 2017; 9:761-776. [PMID: 28338931 PMCID: PMC5381568 DOI: 10.1093/gbe/evx042] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/03/2017] [Indexed: 12/23/2022] Open
Abstract
The α-proteobacterial genus Bartonella comprises a group of ubiquitous mammalian pathogens that are studied as a model for the evolution of bacterial pathogenesis. Vast abundance of two particular phylogenetic lineages of Bartonella had been linked to enhanced host adaptability enabled by lineage-specific acquisition of a VirB/D4 type IV secretion system (T4SS) and parallel evolution of complex effector repertoires. However, the limited availability of genome sequences from one of those lineages as well as other, remote branches of Bartonella has so far hampered comprehensive understanding of how the VirB/D4 T4SS and its effectors called Beps have shaped Bartonella evolution. Here, we report the discovery of a third repertoire of Beps associated with the VirB/D4 T4SS of B. ancashensis, a novel human pathogen that lacks any signs of host adaptability and is only distantly related to the two species-rich lineages encoding a VirB/D4 T4SS. Furthermore, sequencing of ten new Bartonella isolates from under-sampled lineages enabled combined in silico analyses and wet lab experiments that suggest several parallel layers of functional diversification during evolution of the three Bep repertoires from a single ancestral effector. Our analyses show that the Beps of B. ancashensis share many features with the two other repertoires, but may represent a more ancestral state that has not yet unleashed the adaptive potential of such an effector set. We anticipate that the effectors of B. ancashensis will enable future studies to dissect the evolutionary history of Bartonella effectors and help unraveling the evolutionary forces underlying bacterial host adaptation.
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Affiliation(s)
- Alexander Harms
- Focal Area Infection Biology, Biozentrum, University of Basel, Switzerland
| | | | - Maxime Quebatte
- Focal Area Infection Biology, Biozentrum, University of Basel, Switzerland
| | - Claudia Mistl
- Focal Area Infection Biology, Biozentrum, University of Basel, Switzerland
| | - Pablo Manfredi
- Focal Area Infection Biology, Biozentrum, University of Basel, Switzerland
| | - Jonas Körner
- Focal Area Infection Biology, Biozentrum, University of Basel, Switzerland
| | - Bruno B Chomel
- Department of Population Health and Reproduction, School of Veterinary Medicine, University of California Davis
| | - Michael Kosoy
- Bacterial Diseases Branch, Division of Vector-Borne Disease, Centers for Disease Control and Prevention, Fort Collins, Colorado
| | - Soichi Maruyama
- Laboratory of Veterinary Public Health, Department of Veterinary Medicine, College of Bioresource Sciences, Nihon University, Tokyo, Japan
| | - Philipp Engel
- Department of Fundamental Microbiology, University of Lausanne, Switzerland
| | - Christoph Dehio
- Focal Area Infection Biology, Biozentrum, University of Basel, Switzerland
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19
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Functional Cytotoxin Associated Gene A in Helicobacter pylori Strains and Its Association with Integrity of Cag-pathogenicity Island and Histopathological Changes of Gastric Tissue. ARCHIVES OF CLINICAL INFECTIOUS DISEASES 2017. [DOI: 10.5812/archcid.62955] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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20
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Tegtmeyer N, Neddermann M, Asche CI, Backert S. Subversion of host kinases: a key network in cellular signaling hijacked byHelicobacter pyloriCagA. Mol Microbiol 2017; 105:358-372. [DOI: 10.1111/mmi.13707] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/11/2017] [Indexed: 12/16/2022]
Affiliation(s)
- Nicole Tegtmeyer
- Department of Biology, Division of Microbiology; Friedrich Alexander University Erlangen-Nuremberg; Staudtstr. 5 Erlangen D-91058 Germany
| | - Matthias Neddermann
- Department of Biology, Division of Microbiology; Friedrich Alexander University Erlangen-Nuremberg; Staudtstr. 5 Erlangen D-91058 Germany
| | - Carmen Isabell Asche
- Department of Biology, Division of Microbiology; Friedrich Alexander University Erlangen-Nuremberg; Staudtstr. 5 Erlangen D-91058 Germany
| | - Steffen Backert
- Department of Biology, Division of Microbiology; Friedrich Alexander University Erlangen-Nuremberg; Staudtstr. 5 Erlangen D-91058 Germany
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21
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Nishikawa H, Hatakeyama M. Sequence Polymorphism and Intrinsic Structural Disorder as Related to Pathobiological Performance of the Helicobacter pylori CagA Oncoprotein. Toxins (Basel) 2017; 9:toxins9040136. [PMID: 28406453 PMCID: PMC5408210 DOI: 10.3390/toxins9040136] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Revised: 04/08/2017] [Accepted: 04/10/2017] [Indexed: 12/12/2022] Open
Abstract
CagA, an oncogenic virulence factor produced by Helicobacter pylori, is causally associated with the development of gastrointestinal diseases such as chronic gastritis, peptic ulcers, and gastric cancer. Upon delivery into gastric epithelial cells via bacterial type IV secretion, CagA interacts with a number of host proteins through the intrinsically disordered C-terminal tail, which contains two repeatable protein-binding motifs, the Glu-Pro-Ile-Tyr-Ala (EPIYA) motif and the CagA multimerization (CM) motif. The EPIYA motif, upon phosphorylation by host kinases, binds and deregulates Src homology 2 domain-containing protein tyrosine phosphatase 2 (SHP2), a bona fide oncoprotein, inducing pro-oncogenic mitogenic signaling and abnormal cell morphology. Through the CM motif, CagA inhibits the kinase activity of polarity regulator partitioning-defective 1b (PAR1b), causing junctional and polarity defects while inducing actin cytoskeletal rearrangements. The magnitude of the pathobiological action of individual CagA has been linked to the tandem repeat polymorphisms of these two binding motifs, yet the molecular mechanisms by which they affect disease outcome remain unclear. Recent studies using quantitative techniques have provided new insights into how the sequence polymorphisms in the structurally disordered C-terminal region determine the degree of pro-oncogenic action of CagA in the gastric epithelium.
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Affiliation(s)
- Hiroko Nishikawa
- Division of Microbiology, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
- CREST, Japan Science and Technology Agency, Saitama 332-0012, Japan.
- Max Planck-The University of Tokyo Center for Integrative Inflammology, Tokyo 113-0033, Japan.
| | - Masanori Hatakeyama
- Division of Microbiology, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
- CREST, Japan Science and Technology Agency, Saitama 332-0012, Japan.
- Max Planck-The University of Tokyo Center for Integrative Inflammology, Tokyo 113-0033, Japan.
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22
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Price C, Merchant M, Jones S, Best A, Von Dwingelo J, Lawrenz MB, Alam N, Schueler-Furman O, Kwaik YA. Host FIH-Mediated Asparaginyl Hydroxylation of Translocated Legionella pneumophila Effectors. Front Cell Infect Microbiol 2017; 7:54. [PMID: 28321389 PMCID: PMC5337513 DOI: 10.3389/fcimb.2017.00054] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Accepted: 02/13/2017] [Indexed: 01/15/2023] Open
Abstract
FIH-mediated post-translational modification through asparaginyl hydroxylation of eukaryotic proteins impacts regulation of protein-protein interaction. We have identified the FIH recognition motif in 11 Legionella pneumophila translocated effectors, YopM of Yersinia, IpaH4.5 of Shigella and an ankyrin protein of Rickettsia. Mass spectrometry analyses of the AnkB and AnkH effectors of L. pneumophila confirm their asparaginyl hydroxylation. Consistent with localization of the AnkB effector to the Legionella-containing vacuole (LCV) membrane and its modification by FIH, our data show that FIH and its two interacting proteins, Mint3 and MT1-MMP are acquired by the LCV in a Dot/Icm type IV secretion-dependent manner. Chemical inhibition or RNAi-mediated knockdown of FIH promotes LCV-lysosomes fusion, diminishes decoration of the LCV with polyubiquitinated proteins, and abolishes intra-vacuolar replication of L. pneumophila. These data show acquisition of the host FIH by a pathogen-containing vacuole and that asparaginyl-hydroxylation of translocated effectors is indispensable for their function.
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Affiliation(s)
- Christopher Price
- Department of Microbiology and Immunology, College of Medicine, University of Louisville Louisville, KY, USA
| | - Michael Merchant
- Department of Medicine-Renal, College of Medicine, University of Louisville Louisville, KY, USA
| | - Snake Jones
- Department of Microbiology and Immunology, College of Medicine, University of Louisville Louisville, KY, USA
| | - Ashley Best
- Department of Microbiology and Immunology, College of Medicine, University of Louisville Louisville, KY, USA
| | - Juanita Von Dwingelo
- Department of Microbiology and Immunology, College of Medicine, University of Louisville Louisville, KY, USA
| | - Matthew B Lawrenz
- Department of Microbiology and Immunology, College of Medicine, University of LouisvilleLouisville, KY, USA; Center for Predictive Medicine, College of Medicine, University of LouisvilleLouisville, KY, USA
| | - Nawsad Alam
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada (IMRIC), Faculty of Medicine, Hadassah Medical School, The Hebrew University of Jerusalem Jerusalem, Israel
| | - Ora Schueler-Furman
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada (IMRIC), Faculty of Medicine, Hadassah Medical School, The Hebrew University of Jerusalem Jerusalem, Israel
| | - Yousef A Kwaik
- Department of Microbiology and Immunology, College of Medicine, University of LouisvilleLouisville, KY, USA; Center for Predictive Medicine, College of Medicine, University of LouisvilleLouisville, KY, USA
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23
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Jiménez-Guerrero I, Pérez-Montaño F, Medina C, Ollero FJ, López-Baena FJ. The Sinorhizobium (Ensifer) fredii HH103 Nodulation Outer Protein NopI Is a Determinant for Efficient Nodulation of Soybean and Cowpea Plants. Appl Environ Microbiol 2017; 83:e02770-16. [PMID: 27986730 PMCID: PMC5311403 DOI: 10.1128/aem.02770-16] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Accepted: 12/13/2016] [Indexed: 12/12/2022] Open
Abstract
The type III secretion system (T3SS) is a specialized secretion apparatus that is commonly used by many plant and animal pathogenic bacteria to deliver proteins, termed effectors, to the interior of the host cells. These effectors suppress host defenses and interfere with signal transduction pathways to promote infection. Some rhizobial strains possess a functional T3SS, which is involved in the suppression of host defense responses, host range determination, and symbiotic efficiency. The analysis of the genome of the broad-host-range rhizobial strain Sinorhizobium fredii HH103 identified eight genes that code for putative T3SS effectors. Three of these effectors, NopL, NopP, and NopI, are Rhizobium specific. In this work, we demonstrate that NopI, whose amino acid sequence shows a certain similarity with NopP, is secreted through the S. fredii HH103 T3SS in response to flavonoids. We also determined that NopL can be considered an effector since it is directly secreted to the interior of the host cell as demonstrated by adenylate cyclase assays. Finally, the symbiotic phenotype of single, double, and triple nopI, nopL, and nopP mutants in soybean and cowpea was assayed, showing that NopI plays an important role in determining the number of nodules formed in both legumes and that the absence of both NopL and NopP is highly detrimental for symbiosis.IMPORTANCE The paper is focused on three Rhizobium-specific T3SS effectors of Sinorhizobium fredii HH103, NopL, NopP, and NopI. We demonstrate that S. fredii HH103 is able to secrete through the T3SS in response to flavonoids the nodulation outer protein NopI. Additionally, we determined that NopL can be considered an effector since it is secreted to the interior of the host cell as demonstrated by adenylate cyclase assays. Finally, nodulation assays of soybean and cowpea indicated that NopI is important for the determination of the number of nodules formed and that the absence of both NopL and NopP negatively affected nodulation.
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Affiliation(s)
- Irene Jiménez-Guerrero
- Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla, Seville, Spain
| | | | - Carlos Medina
- Centro Andaluz de Biología del Desarrollo, Universidad Pablo de Olavide, Consejo Superior de Investigaciones Científicas, Junta de Andalucía, Seville, Spain
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HATAKEYAMA M. Structure and function of Helicobacter pylori CagA, the first-identified bacterial protein involved in human cancer. PROCEEDINGS OF THE JAPAN ACADEMY. SERIES B, PHYSICAL AND BIOLOGICAL SCIENCES 2017; 93:196-219. [PMID: 28413197 PMCID: PMC5489429 DOI: 10.2183/pjab.93.013] [Citation(s) in RCA: 124] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Chronic infection with Helicobacter pylori cagA-positive strains is the strongest risk factor of gastric cancer. The cagA gene-encoded CagA protein is delivered into gastric epithelial cells via bacterial type IV secretion, where it undergoes tyrosine phosphorylation at the Glu-Pro-Ile-Tyr-Ala (EPIYA) motifs. Delivered CagA then acts as a non-physiological scaffold/hub protein by interacting with multiple host signaling molecules, most notably the pro-oncogenic phosphatase SHP2 and the polarity-regulating kinase PAR1/MARK, in both tyrosine phosphorylation-dependent and -independent manners. CagA-mediated manipulation of intracellular signaling promotes neoplastic transformation of gastric epithelial cells. Transgenic expression of CagA in experimental animals has confirmed the oncogenic potential of the bacterial protein. Structural polymorphism of CagA influences its scaffold function, which may underlie the geographic difference in the incidence of gastric cancer. Since CagA is no longer required for the maintenance of established gastric cancer cells, studying the role of CagA during neoplastic transformation will provide an excellent opportunity to understand molecular processes underlying "Hit-and-Run" carcinogenesis.
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Affiliation(s)
- Masanori HATAKEYAMA
- Department of Microbiology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
- Correspondence should be addressed: M. Hatakeyama, Division of Microbiology, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan (e-mail: )
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25
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Lind J, Backert S, Hoffmann R, Eichler J, Yamaoka Y, Perez-Perez GI, Torres J, Sticht H, Tegtmeyer N. Systematic analysis of phosphotyrosine antibodies recognizing single phosphorylated EPIYA-motifs in CagA of East Asian-type Helicobacter pylori strains. BMC Microbiol 2016; 16:201. [PMID: 27590005 PMCID: PMC5009636 DOI: 10.1186/s12866-016-0820-6] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Accepted: 05/19/2016] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Highly virulent strains of the gastric pathogen Helicobacter pylori encode a type IV secretion system (T4SS) that delivers the effector protein CagA into gastric epithelial cells. Translocated CagA undergoes tyrosine phosphorylation by members of the oncogenic c-Src and c-Abl host kinases at EPIYA-sequence motifs A, B and D in East Asian-type strains. These phosphorylated EPIYA-motifs serve as recognition sites for various SH2-domains containing human proteins, mediating interactions of CagA with host signaling factors to manipulate signal transduction pathways. Recognition of phospho-CagA is mainly based on the use of commercial pan-phosphotyrosine antibodies that were originally designed to detect phosphotyrosines in mammalian proteins. Specific anti-phospho-EPIYA antibodies for each of the three sites in CagA are not forthcoming. RESULTS This study was designed to systematically analyze the detection preferences of each phosphorylated East Asian CagA EPIYA-motif by pan-phosphotyrosine antibodies and to determine a minimal recognition sequence. We synthesized phospho- and non-phosphopeptides derived from each predominant EPIYA-site, and determined the recognition patterns by seven different pan-phosphotyrosine antibodies using Western blotting, and also investigated representative East Asian H. pylori isolates during infection. The results indicate that a total of only 9-11 amino acids containing the phosphorylated East Asian EPIYA-types are required and sufficient to detect the phosphopeptides with high specificity. However, the sequence recognition by the different antibodies was found to bear high variability. From the seven antibodies used, only four recognized all three phosphorylated EPIYA-motifs A, B and D similarly well. Two of the phosphotyrosine antibodies preferentially bound primarily to the phosphorylated motif A and D, while the seventh antibody failed to react with any of the phosphorylated EPIYA-motifs. Control experiments confirmed that none of the antibodies reacted with non-phospho-CagA peptides and in accordance were able to recognize phosphotyrosine proteins in human cells. CONCLUSIONS The results of this study disclose the various binding preferences of commercial anti-phosphotyrosine antibodies for phospho-EPIYA-motifs, and are valuable in the application for further characterization of CagA phosphorylation events during infection with H. pylori and risk prediction for gastric disease development.
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Affiliation(s)
- Judith Lind
- Department of Biology, Division of Microbiology, Friedrich Alexander University Erlangen-Nuremberg, Staudtstr. 5, D-91058, Erlangen, Germany
| | - Steffen Backert
- Department of Biology, Division of Microbiology, Friedrich Alexander University Erlangen-Nuremberg, Staudtstr. 5, D-91058, Erlangen, Germany
| | - Rebecca Hoffmann
- Department of Chemistry and Pharmacy, Friedrich Alexander University Erlangen-Nuremberg, Schuhstraße 19, D-91052, Erlangen, Germany
| | - Jutta Eichler
- Department of Chemistry and Pharmacy, Friedrich Alexander University Erlangen-Nuremberg, Schuhstraße 19, D-91052, Erlangen, Germany
| | - Yoshio Yamaoka
- Department of Environmental and Preventive Medicine, Oita University Faculty of Medicine, Yufu, Japan
| | - Guillermo I Perez-Perez
- Department of Medicine and Microbiology, New York University, Langone Medical Centre, New York, USA
| | - Javier Torres
- Unidad de Investigación en Enfermedades Infecciosas, Hospital de Pediatría del Instituto Mexicano del Seguro Social, Mexico City, México
| | - Heinrich Sticht
- Bioinformatics, Institute for Biochemistry, Friedrich Alexander University Erlangen-Nuremberg, Fahrstrasse 17, D-91054, Erlangen, Germany
| | - Nicole Tegtmeyer
- Department of Biology, Division of Microbiology, Friedrich Alexander University Erlangen-Nuremberg, Staudtstr. 5, D-91058, Erlangen, Germany.
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Popa CM, Tabuchi M, Valls M. Modification of Bacterial Effector Proteins Inside Eukaryotic Host Cells. Front Cell Infect Microbiol 2016; 6:73. [PMID: 27489796 PMCID: PMC4951486 DOI: 10.3389/fcimb.2016.00073] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Accepted: 06/27/2016] [Indexed: 12/16/2022] Open
Abstract
Pathogenic bacteria manipulate their hosts by delivering a number of virulence proteins -called effectors- directly into the plant or animal cells. Recent findings have shown that such effectors can suffer covalent modifications inside the eukaryotic cells. Here, we summarize the recent reports where effector modifications by the eukaryotic machinery have been described. We restrict our focus on proteins secreted by the type III or type IV systems, excluding other bacterial toxins. We describe the known examples of effectors whose enzymatic activity is triggered by interaction with plant and animal cell factors, including GTPases, E2-Ubiquitin conjugates, cyclophilin and thioredoxins. We focus on the structural interactions with these factors and their influence on effector function. We also review the described examples of host-mediated post-translational effector modifications which are required for proper subcellular location and function. These host-specific covalent modifications include phosphorylation, ubiquitination, SUMOylation, and lipidations such as prenylation, fatty acylation and phospholipid binding.
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Affiliation(s)
- Crina M Popa
- Department of Genetics, Centre for Research in Agricultural Genomics (CSIC-IRTA-UAB), Universitat de Barcelona Barcelona, Spain
| | - Mitsuaki Tabuchi
- Department of Applied Biological Science, Faculty of Agriculture, Kagawa University Kagawa, Japan
| | - Marc Valls
- Department of Genetics, Centre for Research in Agricultural Genomics (CSIC-IRTA-UAB), Universitat de Barcelona Barcelona, Spain
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Gonzalez-Rivera C, Bhatty M, Christie PJ. Mechanism and Function of Type IV Secretion During Infection of the Human Host. Microbiol Spectr 2016; 4:10.1128/microbiolspec.VMBF-0024-2015. [PMID: 27337453 PMCID: PMC4920089 DOI: 10.1128/microbiolspec.vmbf-0024-2015] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2015] [Indexed: 02/07/2023] Open
Abstract
Bacterial pathogens employ type IV secretion systems (T4SSs) for various purposes to aid in survival and proliferation in eukaryotic hosts. One large T4SS subfamily, the conjugation systems, confers a selective advantage to the invading pathogen in clinical settings through dissemination of antibiotic resistance genes and virulence traits. Besides their intrinsic importance as principle contributors to the emergence of multiply drug-resistant "superbugs," detailed studies of these highly tractable systems have generated important new insights into the mode of action and architectures of paradigmatic T4SSs as a foundation for future efforts aimed at suppressing T4SS machine function. Over the past decade, extensive work on the second large T4SS subfamily, the effector translocators, has identified a myriad of mechanisms employed by pathogens to subvert, subdue, or bypass cellular processes and signaling pathways of the host cell. An overarching theme in the evolution of many effectors is that of molecular mimicry. These effectors carry domains similar to those of eukaryotic proteins and exert their effects through stealthy interdigitation of cellular pathways, often with the outcome not of inducing irreversible cell damage but rather of reversibly modulating cellular functions. This article summarizes the major developments for the actively studied pathogens with an emphasis on the structural and functional diversity of the T4SSs and the emerging common themes surrounding effector function in the human host.
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Affiliation(s)
- Christian Gonzalez-Rivera
- Department of Microbiology and Molecular Genetics, University of Texas Medical School at Houston, 6431 Fannin St, Houston, Texas 77030, Phone: 713-500-5440 (P. J. Christie); 713-500-5441 (C. Gonzalez-Rivera, M. Bhatty)
| | - Minny Bhatty
- Department of Microbiology and Molecular Genetics, University of Texas Medical School at Houston, 6431 Fannin St, Houston, Texas 77030, Phone: 713-500-5440 (P. J. Christie); 713-500-5441 (C. Gonzalez-Rivera, M. Bhatty)
| | - Peter J. Christie
- Department of Microbiology and Molecular Genetics, University of Texas Medical School at Houston, 6431 Fannin St, Houston, Texas 77030, Phone: 713-500-5440 (P. J. Christie); 713-500-5441 (C. Gonzalez-Rivera, M. Bhatty)
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Role of Regulatory T-cells in Different Clinical Expressions of Helicobacter pylori Infection. Arch Med Res 2016; 47:245-54. [DOI: 10.1016/j.arcmed.2016.07.013] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Accepted: 07/22/2016] [Indexed: 12/15/2022]
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Ge YY, Xiang QW, Wagner C, Zhang D, Xie ZP, Staehelin C. The type 3 effector NopL of Sinorhizobium sp. strain NGR234 is a mitogen-activated protein kinase substrate. JOURNAL OF EXPERIMENTAL BOTANY 2016; 67:2483-94. [PMID: 26931172 DOI: 10.1093/jxb/erw065] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Pathogenic bacteria utilize type 3 secretion systems to inject type 3 effectors (T3Es) into host cells, thereby subverting host defense reactions. Similarly, T3Es of symbiotic nitrogen-fixing rhizobia can affect nodule formation on roots of legumes. Previous work showed that NopL (nodulation outer protein L) of Sinorhizobium(Ensifer) sp. strain NGR234 is multiply phosphorylated in eukaryotic cells and that this T3E suppresses responses mediated by mitogen-activated protein (MAP) kinase signaling in yeast (mating pheromone signaling) and plant cells (expression of pathogenesis-related defense proteins). Here, we show that NopL is a MAP kinase substrate. Microscopic observations of fluorescent fusion proteins and bimolecular fluorescence complementation analysis in onion cells indicated that NopL is targeted to the nucleus and forms a complex with SIPK (salicylic acid-induced protein kinase), a MAP kinase of tobacco. In vitro experiments demonstrated that NopL is phosphorylatyed by SIPK. At least nine distinct spots were observed after two-dimensional gel electrophoresis, indicating that NopL can be hyperphosphorylated by MAP kinases. Senescence symptoms in nodules of beans (Phaseolus vulgaris cv. Tendergreen) were analyzed to determine the symbiotic effector activity of different NopL variants with serine to alanine substitutions at identified and predicted phosphorylation sites (serine-proline motif). NopL variants with six or eight serine to alanine substitutions were partially active, whereas NopL forms with 10 or 12 substituted serine residues were inactive. In conclusion, our findings provide evidence that NopL interacts with MAP kinases and reveals the importance of serine-proline motifs for effector activity during symbiosis.
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Affiliation(s)
- Ying-Ying Ge
- State Key Laboratory of Biocontrol and Guangdong Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Qi-Wang Xiang
- State Key Laboratory of Biocontrol and Guangdong Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Christian Wagner
- State Key Laboratory of Biocontrol and Guangdong Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Di Zhang
- State Key Laboratory of Biocontrol and Guangdong Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Zhi-Ping Xie
- State Key Laboratory of Biocontrol and Guangdong Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, Guangzhou, China Shenzhen Research and Development Center of State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Baoan, Shenzhen, China
| | - Christian Staehelin
- State Key Laboratory of Biocontrol and Guangdong Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, Guangzhou, China Shenzhen Research and Development Center of State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Baoan, Shenzhen, China
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Dramatic increase in SHP2 binding activity of Helicobacter pylori Western CagA by EPIYA-C duplication: its implications in gastric carcinogenesis. Sci Rep 2015; 5:15749. [PMID: 26507409 PMCID: PMC4623810 DOI: 10.1038/srep15749] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2015] [Accepted: 10/01/2015] [Indexed: 12/13/2022] Open
Abstract
Infection with cagA-positive Helicobacter pylori is critically associated with the development of gastric cancer. The cagA-encoded CagA is delivered into gastric epithelial cells via type IV secretion, where it interacts with and thereby deregulates the pro-oncogenic phosphatase SHP2. East Asian CagA and Western CagA are two major CagA species produced by H. pylori circulating in East Asian countries and in the rest of the world, respectively. The SHP2 binding site of Western CagA, termed the EPIYA-C segment, variably duplicates and infection with H. pylori carrying Western CagA with multiple EPIYA-C segments is a distinct risk factor of gastric cancer. Here we show that duplication of EPIYA-C from one to two or more increases SHP2 binding of Western CagA by more than one hundredfold. Based on the decisive difference in SHP2 binding, Western CagA can be divided into two types: type I CagA carrying a single EPIYA-C segment and type II CagA carrying multiple EPIYA-C segments. Gastric epithelial cells expressing type II CagA acquire the ability to invade extracellular matrices, a malignant cellular trait associated with deregulated SHP2. A big leap in SHP2 binding activity may therefore provide molecular basis that makes type II Western CagA a distinct gastric cancer risk.
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Via A, Uyar B, Brun C, Zanzoni A. How pathogens use linear motifs to perturb host cell networks. Trends Biochem Sci 2014; 40:36-48. [PMID: 25475989 DOI: 10.1016/j.tibs.2014.11.001] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2014] [Revised: 11/03/2014] [Accepted: 11/03/2014] [Indexed: 12/31/2022]
Abstract
Molecular mimicry is one of the powerful stratagems that pathogens employ to colonise their hosts and take advantage of host cell functions to guarantee their replication and dissemination. In particular, several viruses have evolved the ability to interact with host cell components through protein short linear motifs (SLiMs) that mimic host SLiMs, thus facilitating their internalisation and the manipulation of a wide range of cellular networks. Here we present convincing evidence from the literature that motif mimicry also represents an effective, widespread hijacking strategy in prokaryotic and eukaryotic parasites. Further insights into host motif mimicry would be of great help in the elucidation of the molecular mechanisms behind host cell invasion and the development of anti-infective therapeutic strategies.
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Affiliation(s)
- Allegra Via
- Department of Physics, Sapienza University, 00185 Rome, Italy
| | - Bora Uyar
- Structural and Computational Biology, European Molecular Biology Laboratory, 69117 Heidelberg, Germany
| | - Christine Brun
- Inserm, UMR1090 TAGC, Marseille F-13288, France; Aix-Marseille Université, UMR1090 TAGC, Marseille F-13288, France; CNRS, Marseille F-13402, France
| | - Andreas Zanzoni
- Inserm, UMR1090 TAGC, Marseille F-13288, France; Aix-Marseille Université, UMR1090 TAGC, Marseille F-13288, France.
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Helicobacter pylori CagA and gastric cancer: a paradigm for hit-and-run carcinogenesis. Cell Host Microbe 2014; 15:306-16. [PMID: 24629337 DOI: 10.1016/j.chom.2014.02.008] [Citation(s) in RCA: 351] [Impact Index Per Article: 35.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Helicobacter pylori is a gastric bacterial pathogen that is etiologically linked to human gastric cancer. The cytotoxin-associated gene A (CagA) protein of H. pylori, which is delivered into gastric epithelial cells via bacterial type IV secretion, is an oncoprotein that can induce malignant neoplasms in mammals. Upon delivery, CagA perturbs multiple host signaling pathways by acting as an extrinsic scaffold or hub protein. On one hand, signals aberrantly raised by CagA are integrated into a direct oncogenic insult, whereas on the other hand, they engender genetic instability. Despite its decisive role in the development of gastric cancer, CagA is not required for the maintenance of a neoplastic phenotype in established cancer cells. Therefore, CagA-conducted gastric carcinogenesis progresses through a hit-and-run mechanism in which pro-oncogenic actions of CagA are successively taken over by a series of genetic and/or epigenetic alterations compiled in cancer-predisposing cells during long-standing infection with cagA-positive H. pylori.
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The Haemophilus ducreyi LspA1 protein inhibits phagocytosis by using a new mechanism involving activation of C-terminal Src kinase. mBio 2014; 5:e01178-14. [PMID: 24902122 PMCID: PMC4030455 DOI: 10.1128/mbio.01178-14] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Haemophilus ducreyi causes chancroid, a sexually transmitted infection. A primary means by which this pathogen causes disease involves eluding phagocytosis; however, the molecular basis for this escape mechanism has been poorly understood. Here, we report that the LspA virulence factors of H. ducreyi inhibit phagocytosis by stimulating the catalytic activity of C-terminal Src kinase (Csk), which itself inhibits Src family protein tyrosine kinases (SFKs) that promote phagocytosis. Inhibitory activity could be localized to a 37-kDa domain (designated YL2) of the 456-kDa LspA1 protein. The YL2 domain impaired ingestion of IgG-opsonized targets and decreased levels of active SFKs when expressed in mammalian cells. YL2 contains tyrosine residues in two EPIYG motifs that are phosphorylated in mammalian cells. These tyrosine residues were essential for YL2-based inhibition of phagocytosis. Csk was identified as the predominant mammalian protein interacting with YL2, and a dominant-negative Csk rescued phagocytosis in the presence of YL2. Purified Csk phosphorylated the tyrosines in the YL2 EPIYG motifs. Phosphorylated YL2 increased Csk catalytic activity, resulting in positive feedback, such that YL2 can be phosphorylated by the same kinase that it activates. Finally, we found that the Helicobacter pylori CagA protein also inhibited phagocytosis in a Csk-dependent manner, raising the possibility that this may be a general mechanism among diverse bacteria. Harnessing Csk to subvert the Fcγ receptor (FcγR)-mediated phagocytic pathway represents a new bacterial mechanism for circumventing a crucial component of the innate immune response and may potentially affect other SFK-involved cellular pathways. Phagocytosis is a critical component of the immune system that enables pathogens to be contained and cleared. A number of bacterial pathogens have developed specific strategies to either physically evade phagocytosis or block the intracellular signaling required for phagocytic activity. Haemophilus ducreyi, a sexually transmitted pathogen, secretes a 4,153-amino-acid (aa) protein (LspA1) that effectively inhibits FcγR-mediated phagocytic activity. In this study, we show that a 294-aa domain within this bacterial protein binds to C-terminal Src kinase (Csk) and stimulates its catalytic activity, resulting in a significant attenuation of Src kinase activity and consequent inhibition of phagocytosis. The ability to inhibit phagocytosis via Csk is not unique to H. ducreyi, because we found that the Helicobacter pylori CagA protein also inhibits phagocytosis in a Csk-dependent manner. Harnessing Csk to subvert the FcγR-mediated phagocytic pathway represents a new bacterial effector mechanism for circumventing the innate immune response.
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Lind J, Backert S, Pfleiderer K, Berg DE, Yamaoka Y, Sticht H, Tegtmeyer N. Systematic analysis of phosphotyrosine antibodies recognizing single phosphorylated EPIYA-motifs in CagA of Western-type Helicobacter pylori strains. PLoS One 2014; 9:e96488. [PMID: 24800748 PMCID: PMC4011759 DOI: 10.1371/journal.pone.0096488] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2013] [Accepted: 04/09/2014] [Indexed: 12/14/2022] Open
Abstract
The clinical outcome of Helicobacter pylori infections is determined by multiple host-pathogen interactions that may develop to chronic gastritis, and sometimes peptic ulcers or gastric cancer. Highly virulent strains encode a type IV secretion system (T4SS) that delivers the effector protein CagA into gastric epithelial cells. Translocated CagA undergoes tyrosine phosphorylation at EPIYA-sequence motifs, called A, B and C in Western-type strains, by members of the oncogenic Src and Abl host kinases. Phosphorylated EPIYA-motifs mediate interactions of CagA with host signaling factors--in particular various SH2-domain containing human proteins--thereby hijacking multiple downstream signaling cascades. Observations of tyrosine-phosphorylated CagA are mainly based on the use of commercial phosphotyrosine antibodies, which originally were selected to detect phosphotyrosines in mammalian proteins. Systematic studies of phosphorylated EPIYA-motif detection by the different antibodies would be very useful, but are not yet available. To address this issue, we synthesized phospho- and non-phosphopeptides representing each predominant Western CagA EPIYA-motif, and determined the recognition patterns of seven different phosphotyrosine antibodies in Western blots, and also performed infection studies with diverse representative Western H. pylori strains. Our results show that a total of 9-11 amino acids containing the phosphorylated EPIYA-motifs are necessary and sufficient for specific detection by these antibodies, but revealed great variability in sequence recognition. Three of the antibodies recognized phosphorylated EPIYA-motifs A, B and C similarly well; whereas preferential binding to phosphorylated motif A and motifs A and C was found with two and one antibodies, respectively, and the seventh anti-phosphotyrosine antibody did not recognize any phosphorylated EPIYA-motif. Controls showed that none of the antibodies recognized the corresponding non-phospho CagA peptides, and that all of them recognized phosphotyrosines in mammalian proteins. These data are valuable in judicious application of commercial anti-phosphotyrosine antibodies and in characterization of CagA phosphorylation during infection and disease development.
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Affiliation(s)
- Judith Lind
- Friedrich Alexander University Erlangen-Nuremberg, Department of Biology, Division of Microbiology, Erlangen, Germany
| | - Steffen Backert
- Friedrich Alexander University Erlangen-Nuremberg, Department of Biology, Division of Microbiology, Erlangen, Germany
| | - Klaus Pfleiderer
- Friedrich Alexander University Erlangen-Nuremberg, Department of Biology, Division of Microbiology, Erlangen, Germany
| | - Douglas E. Berg
- Division of Infectious Disease, Department of Medicine, University of California San Diego, La Jolla, California, United States of America
| | - Yoshio Yamaoka
- Oita University Faculty of Medicine, Department Environmental and Preventive Medicine, Yufu, Japan
| | - Heinrich Sticht
- Friedrich Alexander University Erlangen-Nuremberg, Bioinformatics, Institute for Biochemistry, Erlangen, Germany
| | - Nicole Tegtmeyer
- Friedrich Alexander University Erlangen-Nuremberg, Department of Biology, Division of Microbiology, Erlangen, Germany
- * E-mail:
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Ruhanen H, Hurley D, Ghosh A, O'Brien KT, Johnston CR, Shields DC. Potential of known and short prokaryotic protein motifs as a basis for novel peptide-based antibacterial therapeutics: a computational survey. Front Microbiol 2014; 5:4. [PMID: 24478765 PMCID: PMC3896991 DOI: 10.3389/fmicb.2014.00004] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2013] [Accepted: 01/05/2014] [Indexed: 11/13/2022] Open
Abstract
Short linear motifs (SLiMs) are functional stretches of protein sequence that are of crucial importance for numerous biological processes by mediating protein-protein interactions. These motifs often comprise peptides of less than 10 amino acids that modulate protein-protein interactions. While well-characterized in eukaryotic intracellular signaling, their role in prokaryotic signaling is less well-understood. We surveyed the distribution of known motifs in prokaryotic extracellular and virulence proteins across a range of bacterial species and conducted searches for novel motifs in virulence proteins. Many known motifs in virulence effector proteins mimic eukaryotic motifs and enable the pathogen to control the intracellular processes of their hosts. Novel motifs were detected by finding those that had evolved independently in three or more unrelated virulence proteins. The search returned several significantly over-represented linear motifs of which some were known motifs and others are novel candidates with potential roles in bacterial pathogenesis. A putative C-terminal G[AG].$ motif found in type IV secretion system proteins was among the most significant detected. A KK$ motif that has been previously identified in a plasminogen-binding protein, was demonstrated to be enriched across a number of adhesion and lipoproteins. While there is some potential to develop peptide drugs against bacterial infection based on bacterial peptides that mimic host components, this could have unwanted effects on host signaling. Thus, novel SLiMs in virulence factors that do not mimic host components but are crucial for bacterial pathogenesis, such as the type IV secretion system, may be more useful to develop as leads for anti-microbial peptides or drugs.
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Affiliation(s)
- Heini Ruhanen
- Complex and Adaptive Systems Laboratory, University College Dublin Dublin, Ireland ; Conway Institute of Biomolecular and Biomedical Science, University College Dublin Dublin, Ireland ; School of Medicine and Medical Science, University College Dublin Dublin, Ireland
| | - Daniel Hurley
- Complex and Adaptive Systems Laboratory, University College Dublin Dublin, Ireland ; Conway Institute of Biomolecular and Biomedical Science, University College Dublin Dublin, Ireland ; School of Medicine and Medical Science, University College Dublin Dublin, Ireland
| | - Ambarnil Ghosh
- Crystallography and Molecular Biology Department, Saha Institute of Nuclear Physics Kolkata, India
| | - Kevin T O'Brien
- Complex and Adaptive Systems Laboratory, University College Dublin Dublin, Ireland ; Conway Institute of Biomolecular and Biomedical Science, University College Dublin Dublin, Ireland ; School of Medicine and Medical Science, University College Dublin Dublin, Ireland
| | | | - Denis C Shields
- Complex and Adaptive Systems Laboratory, University College Dublin Dublin, Ireland ; Conway Institute of Biomolecular and Biomedical Science, University College Dublin Dublin, Ireland ; School of Medicine and Medical Science, University College Dublin Dublin, Ireland
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H. pylori virulence factors: influence on immune system and pathology. Mediators Inflamm 2014; 2014:426309. [PMID: 24587595 PMCID: PMC3918698 DOI: 10.1155/2014/426309] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2013] [Accepted: 12/19/2013] [Indexed: 02/07/2023] Open
Abstract
Helicobacter pylori is the most widespread chronic bacterial agent in humans and is well recognized for its association with ulcer disease and gastric cancer, with both representing major global health and socioeconomic issues. Given the high level of adaptation and the coevolution of this bacterium with its human host, a thorough and multidirectional view of the specific microbiological characteristics of this infection as well as the host physiology is needed in order to develop novel means of prevention of therapy. This review aims to pinpoint some of these potentially important angles, which have to be considered mutually when studying H. pylori's pathogenicity. The host's biological changes due to the virulence factors are a valuable pillar of H. pylori research as are the mechanisms by which bacteria provoke these changes. In this context, necessary adhesion molecules and significant virulence factors of H. pylori are discussed. Moreover, metabolism of the bacteria, one of the most important aspects for a better understanding of bacterial physiology and consequently possible therapeutic and prophylactic strategies, is addressed. On the other hand, we discuss the recent experimental proofs of the "hygiene hypothesis" in correlation with Helicobacter's infection, which adds another aspect of complexity to this infection.
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Majazki J, Wüppenhorst N, Hartelt K, Birtles R, von Loewenich FD. Anaplasma phagocytophilum strains from voles and shrews exhibit specific ankA gene sequences. BMC Vet Res 2013; 9:235. [PMID: 24283328 PMCID: PMC4220824 DOI: 10.1186/1746-6148-9-235] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2013] [Accepted: 11/25/2013] [Indexed: 12/31/2022] Open
Abstract
Background Anaplasma phagocytophilum is a Gram-negative bacterium that replicates obligate intracellularly in neutrophils. It is transmitted by Ixodes spp. ticks and causes acute febrile disease in humans, dogs, horses, cats, and livestock. Because A. phagocytophilum is not transmitted transovarially in Ixodes spp., it is thought to depend on reservoir hosts to complete its life cycle. In Europe, A. phagocytophilum was detected in roe deer, red deer, wild boars, and small mammals. In contrast to roe deer, red deer and wild boars have been considered as reservoir hosts for granulocytic anaplasmosis in humans, dogs, and horses according to groESL- and ankA-based genotyping. A. phagocytophilum variants infecting small mammals in Europe have not been characterized extensively to date. Results We amplified the total ankA open reading frames of 27 strains from voles and shrews. The analysis revealed that they harboured A. phagocytophilum strains that belonged to a distinct newly described ankA gene cluster. Further, we provide evidence that the heterogeneity of ankA gene sequences might have arisen via recombination. Conclusions Based on ankA-based genotyping voles and shrews are unlikely reservoir hosts for granulocytic anaplasmosis in humans, dogs, horses, and livestock in Europe.
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Affiliation(s)
- Juliana Majazki
- Institute of Medical Microbiology and Hygiene, University of Freiburg, Hermann-Herder-Strasse 11, Freiburg D-79104, Germany.
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Woon AP, Tohidpour A, Alonso H, Saijo-Hamano Y, Kwok T, Roujeinikova A. Conformational analysis of isolated domains of Helicobacter pylori CagA. PLoS One 2013; 8:e79367. [PMID: 24223932 PMCID: PMC3815135 DOI: 10.1371/journal.pone.0079367] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2013] [Accepted: 09/26/2013] [Indexed: 01/25/2023] Open
Abstract
The CagA protein of Helicobacter pylori is associated with increased virulence and gastric cancer risk. CagA is translocated into the host cell by a H. pylori type IV secretion system via mechanisms that are poorly understood. Translocated CagA interacts with numerous host factors, altering a variety of host signalling pathways. The recently determined crystal structure of C-terminally-truncated CagA indicated the presence of two domains: the smaller, flexible N-terminal domain and the larger, middle domain. In this study, we have investigated the conformation, oligomeric state and stability of the N-terminal, middle and glutamate-proline-isoleucine-tyrosine-alanine (EPIYA)-repeats domains. All three domains are monomeric, suggesting that the multimerisation of CagA observed in infected cells is likely to be mediated not by CagA itself but by its interacting partners. The middle and the C-terminal domains, but not the N-terminal domain, are capable of refolding spontaneously upon heat denaturation, lending support to the hypothesis that unfolded CagA is threaded C-terminus first through the type IV secretion channel with its N-terminal domain, which likely requires interactions with other domains to refold, being threaded last. Our findings also revealed that the C-terminal EPIYA-repeats domain of CagA exists in an intrinsically disordered premolten globule state with regions in PPII conformation - a feature that is shared by many scaffold proteins that bind multiple protein components of signalling pathways. Taken together, these results provide a deeper understanding of the physicochemical properties of CagA that underpin its complex cellular and oncogenic functions.
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Affiliation(s)
- Amanda P. Woon
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria, Australia
| | | | - Hernan Alonso
- Department of Microbiology, Monash University, Clayton, Victoria, Australia
| | - Yumiko Saijo-Hamano
- Graduate School of Frontier Biosciences, Osaka University, Suita, Osaka, Japan
| | - Terry Kwok
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria, Australia
- Department of Microbiology, Monash University, Clayton, Victoria, Australia
| | - Anna Roujeinikova
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria, Australia
- Department of Microbiology, Monash University, Clayton, Victoria, Australia
- * E-mail:
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Salama NR, Hartung ML, Müller A. Life in the human stomach: persistence strategies of the bacterial pathogen Helicobacter pylori. Nat Rev Microbiol 2013; 11:385-99. [PMID: 23652324 DOI: 10.1038/nrmicro3016] [Citation(s) in RCA: 439] [Impact Index Per Article: 39.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The bacterial pathogen Helicobacter pylori has co-evolved with humans and colonizes approximately 50% of the human population, but only causes overt gastric disease in a subset of infected hosts. In this Review, we discuss the pathogenesis of H. pylori and the mechanisms it uses to promote persistent colonization of the gastric mucosa, with a focus on recent insights into the role of the virulence factors vacuolating cytotoxin (VacA), cytotoxin-associated gene A (CagA) and CagL. We also describe the immunobiology of H. pylori infection and highlight how this bacterium manipulates the innate and adaptive immune systems of the host to promote its own persistence.
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Affiliation(s)
- Nina R Salama
- Division of Human Biology, Fred Hutchinson Cancer Research Center, 1100 Fairview Avenue North, Mailstop C3-168, Seattle, Washington 981091024, USA.
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