Publication Date:
2014-06-12
Description:
Cytosolic inflammasome complexes mediated by a pattern recognition receptor (PRR) defend against pathogen infection by activating caspase 1. Pyrin, a candidate PRR, can bind to the inflammasome adaptor ASC to form a caspase 1-activating complex. Mutations in the Pyrin-encoding gene, MEFV, cause a human autoinflammatory disease known as familial Mediterranean fever. Despite important roles in immunity and disease, the physiological function of Pyrin remains unknown. Here we show that Pyrin mediates caspase 1 inflammasome activation in response to Rho-glucosylation activity of cytotoxin TcdB, a major virulence factor of Clostridium difficile, which causes most cases of nosocomial diarrhoea. The glucosyltransferase-inactive TcdB mutant loses the inflammasome-stimulating activity. Other Rho-inactivating toxins, including FIC-domain adenylyltransferases (Vibrio parahaemolyticus VopS and Histophilus somni IbpA) and Clostridium botulinum ADP-ribosylating C3 toxin, can also biochemically activate the Pyrin inflammasome in their enzymatic activity-dependent manner. These toxins all target the Rho subfamily and modify a switch-I residue. We further demonstrate that Burkholderia cenocepacia inactivates RHOA by deamidating Asn 41, also in the switch-I region, and thereby triggers Pyrin inflammasome activation, both of which require the bacterial type VI secretion system (T6SS). Loss of the Pyrin inflammasome causes elevated intra-macrophage growth of B. cenocepacia and diminished lung inflammation in mice. Thus, Pyrin functions to sense pathogen modification and inactivation of Rho GTPases, representing a new paradigm in mammalian innate immunity.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Xu, Hao -- Yang, Jieling -- Gao, Wenqing -- Li, Lin -- Li, Peng -- Zhang, Li -- Gong, Yi-Nan -- Peng, Xiaolan -- Xi, Jianzhong Jeff -- Chen, She -- Wang, Fengchao -- Shao, Feng -- Howard Hughes Medical Institute/ -- England -- Nature. 2014 Sep 11;513(7517):237-41. doi: 10.1038/nature13449. Epub 2014 Jun 11.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉1] National Institute of Biological Sciences, Beijing 102206, China [2]. ; 1] National Institute of Biological Sciences, Beijing 102206, China [2] National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China [3]. ; National Institute of Biological Sciences, Beijing 102206, China. ; Department of Biomedical Engineering, College of Engineering, Peking University, Beijing 100871, China. ; 1] National Institute of Biological Sciences, Beijing 102206, China [2] National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China [3] National Institute of Biological Sciences, Beijing, Collaborative Innovation Center for Cancer Medicine, Beijing 102206, China.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/24919149" target="_blank"〉PubMed〈/a〉
Keywords:
Animals
;
Bacterial Proteins/genetics/metabolism
;
Bacterial Toxins/genetics/metabolism
;
Burkholderia cenocepacia/metabolism
;
Caspase 1/metabolism
;
Cell Line
;
Clostridium difficile/metabolism
;
Cytoskeletal Proteins/genetics/*metabolism
;
Humans
;
Immunity, Innate/genetics/*immunology
;
Inflammasomes/*metabolism
;
Mice
;
Mice, Inbred Strains
;
Mutation
;
Protein Binding
;
Receptors, Pattern Recognition/metabolism
;
U937 Cells
;
rho GTP-Binding Proteins/*metabolism
Print ISSN:
0028-0836
Electronic ISSN:
1476-4687
Topics:
Biology
,
Chemistry and Pharmacology
,
Medicine
,
Natural Sciences in General
,
Physics
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