Dataset Information

The Ubiquitin Ligase Smurf1 Functions in Selective Autophagy of Mycobacterium tuberculosis and Anti-tuberculous Host Defense.

ABSTRACT: During antibacterial autophagy, ubiquitination of intracellular bacteria recruits proteins that mediate bacterial delivery to the lysosome for degradation. Smurf1 is an E3 ubiquitin ligase whose role in selective bacterial autophagy is unknown. We show that Smurf1 facilitates selective autophagy of the human pathogen Mycobacterium tuberculosis (Mtb). Smurf1-/- macrophages are defective in recruiting polyubiquitin, the proteasome, the ubiquitin-binding autophagy adaptor NBR1, the autophagy protein LC3, and the lysosomal marker LAMP1 to Mtb-associated structures and are more permissive for Mtb growth. This function of Smurf1 requires both its ubiquitin-ligase and C2 phospholipid-binding domains, and involves K48- rather than K63-linked ubiquitination. Chronically infected Smurf1-/- mice have increased bacterial load, increased lung inflammation, and accelerated mortality. SMURF1 controls Mtb replication in human macrophages and associates with bacteria in lungs of patients with pulmonary tuberculosis. Thus, Smurf1 is required for selective autophagy of Mtb and host defense against tuberculosis infection.

SUBMITTER: Franco LH

PROVIDER: S-EPMC5699477 | biostudies-literature | 2017 Jan

REPOSITORIES: biostudies-literature

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Publications

The Ubiquitin Ligase Smurf1 Functions in Selective Autophagy of Mycobacterium tuberculosis and Anti-tuberculous Host Defense.

Franco Luis H LH Nair Vidhya R VR Scharn Caitlyn R CR Xavier Ramnik J RJ Torrealba Jose R JR Shiloh Michael U MU Levine Beth B

Cell host & microbe 20161222 1

During antibacterial autophagy, ubiquitination of intracellular bacteria recruits proteins that mediate bacterial delivery to the lysosome for degradation. Smurf1 is an E3 ubiquitin ligase whose role in selective bacterial autophagy is unknown. We show that Smurf1 facilitates selective autophagy of the human pathogen Mycobacterium tuberculosis (Mtb). Smurf1<sup>-/-</sup> macrophages are defective in recruiting polyubiquitin, the proteasome, the ubiquitin-binding autophagy adaptor NBR1, the autop ...[more]

PMID: 28017659

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Project description:MyD88 is an adaptor protein in Toll-like receptor and interleukin 1 receptor mediated signaling pathways that plays an essential role in activation of immune responses following pathogen recognition. We investigate that role in the zebrafish embryo model by using a zebrafish mutant line that contains a premature stop condon in the gene encoding MyD88, leading to a truncated protein that lacks domains important for its normal function. We infected these MyD88 mutants and wildtype individuals with S Mycobacterium marinum to compare the resulting immune response by transcriptome profiling on total RNA isolated from single embryos. Autophagy regulator dram1 was identified as one of the MyD88-dependent genes. This microarray study was designed to determine the effect of a truncation of the MyD88 protein on the innate immune response of zebrafish embryos during infection with Mycobacterium marinum. Embryos used in this study are derived from an incross between parents heterozygous for the mutation. Both homozygous mutants and their wildtype siblings were selected by genotyping after being injected with the bacteria or PBS as control. RNA was isolated from single embryos at 4 days post infection (4 dpi) and each treatment group consisted of three embryos: (1) Homozygous mutants mock-injected with PBS/2%PVP 4 dpi, (2) wildtype siblings mock-injected with PBS/2%PVP 4dpi, (3) M. marinum-infected homozygous mutants 4dpi, (4) M. marinum-infected wildtype siblings 4dpi. Embryos were grown at 28.5M-bM-^@M-^S30M-BM-0C in egg water and manually dechorionated at 24 hours post fertilization (hpf). Subsequently, embryos were infected at 28 hpf by micro-injecting 200 colony forming units (CFU) of Mycobacterium marinum Mma20 bacteria into the caudal vein, or were mock-injected with buffer (PBS/2%PVP) as a control. After injections embryos were transferred into fresh egg water and incubated for 4 days at 28M-BM-0C. After the incubation period, single embryos were snap-frozen in liquid nitrogen and RNA was isolated for microarray analysis. The treatment groups were analyzed using a common reference approach.

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Dataset Information

The Ubiquitin Ligase Smurf1 Functions in Selective Autophagy of Mycobacterium tuberculosis and Anti-tuberculous Host Defense.

Publications

The Ubiquitin Ligase Smurf1 Functions in Selective Autophagy of Mycobacterium tuberculosis and Anti-tuberculous Host Defense.

Similar Datasets

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