TBK1/ALS

Samples were lysed with lysis buffer (2% SDS, 50mM Tris-HCl pH 8.5, 10mM TCEP, 40mM chloroacetamide and protease inhibitor cocktail tablet [EDTA-free, Roche]). Samples were incubated for 5 minutes at 95°C before sonication with Sonic Vibra Cell at 1s ON/ 1s OFF pulse for 30s at a maximal amplitude of 30% to shear genomic DNA. After sonication, samples were incubated for 10min at 95°C. Proteins were precipitated using 3 volumes of ice-cold methanol, 1 volume Chloroform and 2.5 volumes ddH2O. After ...

Proximity labeling: Cells were supplemented with 500 µM biotin-phenol (IrisBiotech) for 30 min at 37°C before addition of 1 mM H2O2 at room temperature. Cells were then first washed with quencher solution (1 mM sodium azide, 10 mM sodium ascorbate and 5 mM Trolox in DPBS), then with DPBS, scraped and harvested. Proteinase K digest: All steps were carried out at 4°C unless stated otherwise. Cells were washed and suspended in homogenization buffer I (10 mM KCl, 1.5 mM MgCl2, 10 mM HEPES-KOH and 1 ...

To determine how the mutant TBK1-E696K protein impacts autophagosomes, we performed autophagosome content profiling using protease protection coupled APEX2 proximity proteomics of autophagosomes of homozygous TBK1-E696K knockin and wiltype mouse embryonic fibroblasts (MEFs) transfected with a APEX2-LC3 as previously described in Zellner et al. 2021 Molecular Cell.

While deleterious mutations are responsible for the vast majority of TBK1-linked ALS/FTD cases, the ALS/FTD causing missense mutation p.E696K leads to a selective loss of TBK1/optineurin binding. Knock-in of this specific missense mutation causes progressive autophagolysosomal dysfunction and an ALS/FTD-like phenotype in mice, while, as opposed to TBK1 deletion, RIPK/TNF-α-dependent necroptosis or overt inflammation are absent. Our results highlight the role of autophagolysosomal dysfunction as ...