Publication Date:
2014-02-21
Description:
Crohn's disease is a debilitating inflammatory bowel disease (IBD) that can involve the entire digestive tract. A single-nucleotide polymorphism (SNP) encoding a missense variant in the autophagy gene ATG16L1 (rs2241880, Thr300Ala) is strongly associated with the incidence of Crohn's disease. Numerous studies have demonstrated the effect of ATG16L1 deletion or deficiency; however, the molecular consequences of the Thr300Ala (T300A) variant remains unknown. Here we show that amino acids 296-299 constitute a caspase cleavage motif in ATG16L1 and that the T300A variant (T316A in mice) significantly increases ATG16L1 sensitization to caspase-3-mediated processing. We observed that death-receptor activation or starvation-induced metabolic stress in human and murine macrophages increased degradation of the T300A or T316A variants of ATG16L1, respectively, resulting in diminished autophagy. Knock-in mice harbouring the T316A variant showed defective clearance of the ileal pathogen Yersinia enterocolitica and an elevated inflammatory cytokine response. In turn, deletion of the caspase-3-encoding gene, Casp3, or elimination of the caspase cleavage site by site-directed mutagenesis rescued starvation-induced autophagy and pathogen clearance, respectively. These findings demonstrate that caspase 3 activation in the presence of a common risk allele leads to accelerated degradation of ATG16L1, placing cellular stress, apoptotic stimuli and impaired autophagy in a unified pathway that predisposes to Crohn's disease.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Murthy, Aditya -- Li, Yun -- Peng, Ivan -- Reichelt, Mike -- Katakam, Anand Kumar -- Noubade, Rajkumar -- Roose-Girma, Merone -- DeVoss, Jason -- Diehl, Lauri -- Graham, Robert R -- van Lookeren Campagne, Menno -- England -- Nature. 2014 Feb 27;506(7489):456-62. doi: 10.1038/nature13044. Epub 2014 Feb 19.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Immunology, Genentech, Inc., 1 DNA Way, South San Francisco, California 94080, USA. ; Department of Pathology, Genentech, Inc., 1 DNA Way, South San Francisco, California 94080, USA. ; Department of Molecular Biology, Genentech, Inc., 1 DNA Way, South San Francisco, California 94080, USA. ; ITGR Human Genetics, Genentech, Inc., 1 DNA Way, South San Francisco, California 94080, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/24553140" target="_blank"〉PubMed〈/a〉
Keywords:
Amino Acid Motifs
;
Animals
;
Autophagy/genetics
;
Carrier Proteins/chemistry/*genetics/*metabolism
;
Caspase 3/deficiency/genetics/*metabolism
;
Cell Line
;
Cells, Cultured
;
Crohn Disease/*genetics/pathology
;
Cytokines/immunology
;
Enzyme Activation
;
Female
;
Food Deprivation
;
Humans
;
Macrophages/immunology/metabolism
;
Male
;
Mice
;
Mice, Inbred C57BL
;
Mutagenesis, Site-Directed
;
Polymorphism, Single Nucleotide/*genetics
;
*Proteolysis
;
Stress, Physiological
;
Yersinia enterocolitica/immunology
Print ISSN:
0028-0836
Electronic ISSN:
1476-4687
Topics:
Biology
,
Chemistry and Pharmacology
,
Medicine
,
Natural Sciences in General
,
Physics
