Functional degradation: A mechanism of NLRP1 inflammasome activation by diverse pathogen enzymes

In this study, we find that cleavage results in proteasome-mediated degradation of the amino-terminal domains of NLRP1B, liberating a carboxyl-terminal fragment that is a potent caspase-1 activator. Proteasome-mediated degradation of NLRP1B is both necessary and sufficient for NLRP1B activation. Consistent with our functional degradation model, we identify IpaH7.8, a Shigella flexneri ubiquitin ligase secreted effector, as an enzyme that induces NLRP1B degradation and activation. Our results provide a unified mechanism for NLRP1B activation by diverse pathogen-encoded enzymatic activities.
Source: ScienceNOW - Category: Science Authors: Tags: Immunology, Online Only r-articles Source Type: news

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Gulcin Tezcan1, Ekaterina V. Martynova1, Zarema E. Gilazieva1, Alan McIntyre2, Albert A. Rizvanov1 and Svetlana F. Khaiboullina1,3* 1Institute of Fundamental Medicine and Biology, Kazan Federal University, Kazan, Russia 2Centre for Cancer Sciences, Faculty of Medicine and Health Sciences, University of Nottingham, Nottingham, United Kingdom 3Department of Microbiology and Immunology, University of Nevada, Reno, Reno, NV, United States Inflammation has a crucial role in protection against various pathogens. The inflammasome is an intracellular multiprotein signaling complex that is linked to pathogen sensing and...
Source: Frontiers in Pharmacology - Category: Drugs & Pharmacology Source Type: research
Conclusion Since B. cereus group are highly similar in biochemical as well as genetic profiles, a new biomarker was developed for identifying and distinguishing B. thuringiensis from the closely related group. The performance of XRE was compared with cry2 gene and artificially contaminated samples were also tested. Compared with cry2, XRE gene was observed to be efficiently accurate in the identification of B. thuringiensis. Further, the developed real-time PCR using XRE successfully identified B. thuringiensis and it could be used to quantify cell numbers with the generated standard curve. Author Contributions The expe...
Source: Frontiers in Microbiology - Category: Microbiology Source Type: research
In conclusion, we unraveled the secretome of G. adiacens, an oral bacterium well-documented in infective endocarditis, but also recently shown to be involved in oral infections. Importantly, the secretome of G. adiacens comprised of a large number of putative virulence factors. Of particular importance is the finding that the G. adiacens secretome comprised of a number of “moonlighting” proteins, which in other species are shown to enhance bacterial colonization and virulence through their multifunctional roles (Pavkova et al., 2017; Graf et al., 2019). Thus, our results provide a basis for investigating the ro...
Source: Frontiers in cellular and infection microbiology - Category: Microbiology Source Type: research
Abstract Shigella dysenteriae causing shigellosis is one of the diseases that threaten the health of human society in the developing countries. In Shigella, IpaD gene is one of the key pathogenic genes causing strong mucosal immune system reactions. Anthrax disease is caused by Bacillus anthracis. PA protective antigen is one of the subunits in anthrax toxin complex responsible for the transfer of other subunits into the cytosol of host cells. The 20 kDa subunit of PA (PA20) has the property of immunogenicity. CTxB or B subunit of Vibrio cholerae toxin (CT) is a non-toxic protein and has the function to trans...
Source: Molecular Biology Reports - Category: Molecular Biology Authors: Tags: Mol Biol Rep Source Type: research
Publication date: 5 September 2018Source: Journal of Hazardous Materials, Volume 357Author(s): Hua Fang, Lingxi Han, Houpu Zhang, Zhengnan Long, Lin Cai, Yunlong YuAbstractThe dissemination of antibiotic resistance genes (ARGs), human pathogenic bacteria (HPB), and antibiotic-resistant HPB (ARHPB) from animal feedlot to nearby environment poses a potentially high risk to environmental ecology and public health. Here, a metagenomic analysis was employed to explore the dissemination of ARGs, HPB, and ARHPB from a pig feedlot to surrounding stream and agricultural soils. In total, not detectable (ND)-1,628.4 μg/kg of ant...
Source: Journal of Hazardous Materials - Category: Environmental Health Source Type: research
Abstract INTRODUCTION: The continuous deployments of polio resources, infrastructures and systems for responding to other disease outbreaks in many African countries has led to a number of lessons considered as best practice that need to be documented for strengthening preparedness and response activities in future outbreaks. METHODS: We reviewed and documented the influence of polio best practices in outbreak preparedness and response in Angola, Nigeria and Ethiopia. Data from relevant programmes of the WHO African Region were also analyzed to demonstrate clearly the relative contributions of PEI resources a...
Source: Vaccine - Category: Allergy & Immunology Authors: Tags: Vaccine Source Type: research
Ty21a, the licensed oral live, attenuated bacterial vaccine for Salmonella typhi (the causative agent of typhoid fever), has been engineered to stably express a variety of target LPS (lipopolysaccharides) and protein antigens to protect against shigellosis, anthrax, and plague. Ty21a induces mucosal, humoral, and cellular immunity and can be utilized as a multivalent vaccine vector that is inexpensive to produce. Salmonella species encode inducible acid tolerance, but this genus does not survive well below pH 4. Shigella and enterohemorrhagic E. coli isolates have more effective acid resistance systems than Salmonella and...
Source: NIH OTT Licensing Opportunities - Category: Research Authors: Source Type: research
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