Assay type 'Proteomics'

Cells were collected and lysed in urea buffer (9 M Urea, 50 mM Tris pH 8, 150 mM NaCl, 1x Roche protease inhibitor cocktail) followed by short sonification. Samples were cleared by centrifugation and protein amounts were adapted. Protein reduction was performed with dithiothreitol (DTT; 5 mM final) for 25 min at 56°C and protein alkylation by the addition of iodoacetamide (14 mM final) for 30 min at room temperature. Protein mixtures were quenched with DTT and diluted 1:5 with 1 M Tris-Hcl, pH ...

Corpus callosum dissections were lysed in 300 µL STET lysis buffer (1% (v/v) Triton X-100, 150 mM NaCl, 2 mM EDTA, 50 mM TrisHCl pH 7.5) with a Precellys Evolution homogenizer (Bertin, Germany) using 0.5 mL soft tissue homogenization kit CK14 applying two cycles of 30 s with a speed of 6500rpm. After 15 min incubation on ice, samples were centrifuged at 16,000×g for 15 min to remove undissolved material and cell debris. The supernatant was transferred to a fresh protein lobind tube (Eppendorf, ...

Secretome analysis of primary neuronal cultures was performed using the high-performance secretome protein enrichment with click sugars" (hiSPECS) method, described in detail previously (Tüshaus et al, 2020). In brief, neurons were cultured for 48 h (DIV 5-7) in the presence of 50 µM ManNAz (#88904, ThermoFisher), cultivation media was filtered through 0.45 µm spin columns (Sigma-Aldrich, CLS8163). Glycoproteins were enriched using ConA agarose beads (Sigma, C7555) and clicked to magnetic DBCO ...

Samples were prepared by in solution digestions. For details, see the methods part of the accompanying paper.

Primary microglia were isolated from mouse brains (cerebrum) using MACS Technology (Miltenyi Biotec) according to manufacturer´s instructions and as previously described (Daria et al., 2017). Briefly, brain cerebrum was dissected, freed from meninges and dissociated by enzymatic digestion using a Neural Tissue Dissociation Kit P (Miltenyi Biotec) and subsequent mechanical dissociation using 3 fire-polished glass Pasteur pipettes of decreasing diameter. CD11b positive microglia were magnetically ...

After washing the primary cells with 1x PBS, cell-type specific growth media containing serum supplements with 50 µM of ManNAz (Thermo) was added for 48h. Afterwards, conditioned media was collected and filtered through Spin-X 0.45 µM cellulose acetate centrifuge tube filter (#8163, Costar) and stored at -20°C in protein Lobind tubes until further usage. Glycoprotein enrichment was performed using 60 µL Concanavalin A (ConA) bead slurry per sample (Sigma). ConA beads were washed twice with 1 mL ...

LUHMES cell culture LUHMES cells were cultured and differentiated as described previously (Sholz et al., 2011). 0.5 Million undifferentiated LUHMES (unLUHMES) cells were seeded into a Poly-D-Lysine coated 6-well containing growth media (DMEM F12, 1% N2 Supplement, 0.04 µg/mL bFGF) and harvested at day three in vitro. The live cell count was around 1 Million cells using Trypan blue and an automated cell counter (Biorad). For differentiation, 1 Million unLUHMES were seeded into a Poly-D-Lysine ...

The neurons were lysed direct on the plate in RIPA lysis buffer using a cell scraper. The lysate was transferred into a fresh Eppendorf tube and undissolved material was removed by centrifugation for 5 min at 20,000 g and 4°C. A protein assay was performed and 15 µg of protein were subjected to proteolytic digestion with the SP3 protocol. Proteins were reduced by addition of 9 µL of 200 mM dithiothreitol (Biozol, Germany) in 50 mM ammonium bicarbonate and incubation for 30 min at 37°C. Cysteine ...

Primary microglia were isolated from mouse brains (cerebrum) using MACS Technology (Miltenyi Biotec) according to manufacturer´s instructions and as previously described (Daria et al., 2017). Briefly, brain cerebrum was dissected, freed from meninges and dissociated by enzymatic digestion using a Neural Tissue Dissociation Kit P (Miltenyi Biotec) and subsequent mechanical dissociation using 3 fire-polished glass Pasteur pipettes of decreasing diameter. CD11b positive microglia were magnetically ...

2 x 108 wild-type or Tspan15-knockout HEK-293T cells were lysed in 1% digitonin lysis buffer containing protease inhibitor cocktail (Sigma-Aldrich). Lysates were pre-cleared with protein G sepharose prior to immunoprecipitation with Tspan15 mAb 1C12 chemically cross-linked to protein G sepharose with dimethyl pimelimidate (Thermo Fisher Scientific). Five independent immunoprecipitations were carried out for each cell type. Immunoprecipitation samples in non-reducing Laemmli buffer were subjected ...

Microglia isolated by MACS from WT and Myd88-/- mouse pups were seeded at a density of 1×106 cells per 60-mm dish in DMEM/FCS/L929 medium. After 2 DIV, microglia were washed with warm DMEM/pyruvate medium and treated with 20 µg/mL myelin debris (or HEPES control) in 2 mL of TIC medium for 4 h. After treatment, the cells were washed with DMEM/pyruvate medium, and incubated with 4 mL of DMEM containing 0.2% BSA for 16 h. The cells in each dish were washed with 2 mL of cold PBS on ice, and lysed ...

Samples for mass spectrometry were obtained from 8- to 9-week-old, male mice. Mitochondria were immunopurified from cerebellum according to the described protocol with the alteration that the final mitochondrial pellet was washed twice in IB without EDTA and BSA. Sample were lysed in 100 µL SDT lysis buffer (4% w:v SDS, 100 mM DTT in 100 mM Tris-HCl pH 7.6) by heating for 5 min at 95°C and ultrasonication (Vialtweeter: 6 times for 30 s, 100% Amplitude, 50% cycle, max power; Hielscher Ultrasonics). ...

Nine patients per group were treated with either acitretin or vehicle control. Cerebrospinal fluid was collected before (baseline value) and after treatment. A volume of 5 µL of CSF per sample was subjected to proteolytic digestion in 50 mM ammonium bicarbonate with 0.1% sodium deoxycholate (Sigma Aldrich, Germany) as previously described (Pigoni et al., 2016). Briefly, protein disulfide bonds were reduced with dithiothreitol and sulfhydryl residues were alkylated using iodoacetamide. Proteins ...

Cells were harvested and centrifuged 400g for 10 min at 4°C. Cell pellets were resuspended in STE-Buffer (250mM sucrose, 5mM Tris pH 7, 1mM EGTA, PI mix 1:500) and lysed with a 27-gauge needle. Samples were centrifuged 10 min at 800g to remove nuclei, then 10 min at 15.000g to remove mitochondria and finally 1 hour 100.000g. The resulting pellets were washed twice with 100mM Na2CO3 and centrifuged 30 min at 100000g after each wash. Pellets from membrane preparations were dissolved in lysis buffer ...

Post-nuclear supernatants were prepared from testis of wild type and SPPL2c-/- mice (n=5 per genotype). After removal of the tunica albuginea, testicles from two wild type mice were minced with an ultraturrax in 250 mM sucrose, 10 mM HEPES-NaOH, pH 7.4 and 1 mM EDTA (HB, homogenisation buffer) and then further homogenised by eight strokes of a Potter homogeniser. For sedimentation of nuclei, the tissue homogenate was centrifuged at 750 x g for 10 min. The supernatants were collected as post-nuclear ...

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 ...

BV2 cells were cultured in full medium in 10 cm cell culture dishes until they were confluent. MLN4924 (500 nM), CSN5i-3 (1 μM), or solvent control (0.01% DMSO) were added and the culturing continued for 6 h. After the incubation, cells were washed once with PBS, removed from the cell culture plate with a scraper, collected in tubes, and centrifuged in 1.5 ml Eppendorf tubes for 3 min to remove remaining PBS buffer, snap-frozen, and stored at -80 °C until further processing. Thereafter cells were ...

Following HA-immunoprecipitation of C9orf72 from SMCR8 KO cells, proteins were precipitated with 20% TCA and incubated for 20 min on ice. After centrifugation at 20,000 x g, 4°C for 30 min, the supernatant was discarded, 10% cold TCA was added to pellets and centrifuged again. Pellets were washed 3x in cold acetone, centrifuged and then dried in a speed vacuum concentrator. For in-solution tryptic digestion, pellets were resolved in 50 mM ammonium bicarbonate (ABC) pH 8.0 with 10% acetonitrile ...

Pellets of membrane-protected material were lysed with RIPA buffer containing quenchers (50 mM Tris, 150 mM NaCl, 0.1% SDS, 1% Triton X-100, 0.5% sodium deoxycholate, 1x cOmplete Protease Inhibitor Cocktail (Roche), 1x PhosSTOP 956 (Roche), 10 mM sodium ascorbate, 1 mM Trolox and 1 mM sodium azide), sonicated and centrifuged at 10,000x g for 10 min. The supernatant was incubated with Streptavidin-agarose (Sigma-Aldrich) overnight, which was balanced with RIPA buffer containing quenchers. After ...

LCL cells were cultured in lysine- and arginine-free DMEM (GIBCO) supplemented with 2 mM glutamine, 10% dialyzed FBS and antibiotics as well as with 146 mg/ml light (K0, Sigma) or heavy lysine (K8, Cambridge Isotope Laboratories) and 84 mg/ml light (R0, Sigma) or heavy (R10, CambridgeIsotope Laboratories) arginine, respectively. Cell pellets were lysed in 8 M Urea in 50 mM Tris-HCl pH 8.0. Protein concentrations were determined by a BCA assay and protein amounts were adjusted to equal concentrations. ...

Immunoprecipitation: Cells grown in 2-4x15 cm cell culture plates per sample were harvested by scraping on ice and stored at -80. Lysis was performed for 30 min at 4°C with MCLB buffer (50 mM Tris HCl pH 7.5, 150 mM NaCl, 0.5% NP40, 1x PhosStop,1x protease inhibitor) or Glycerol buffer (20 mM Tris pH 7.5, 150 mM NaCl, 10% glycerol, 5 mM EDTA, 0.5% TritonX, 1x PhosStop, inhibitor, 1x protease inhibitor). Samples were cleared from debris by centrifugation (20.000 g for 10 min at 4°C) and Ultrafree®-CL ...

HeLa cells stably expressing CNN2-APEX2 were grown at 37°C in DMEM supplemented with FBS, L-Glutamine, Sodium pyruvate. Cells were differentially treated with 5 µM NMS-873 for 15 min followed by 1 h 1 mM LLOMe (Sigma) and 2 h washout wihout any drugs. Proximity labeling was performed essentially as described before (Korver et al., 2019). Briefly, cells were incubated with 500 µM Biotin-Phenol during the last 30 min and subsequently pulsed by addition of H2O2 for 1 min at room temperature. To stop ...

For diGly proteomics: HeLa cells were cultured in lysine- and arginine-free DMEM supplemented with dialyzed FBS, 2 mM L-glutamine, 1 mM sodium pyruvate, penicillin/streptomycin and light (K0) lysine (38 μg/mL) and arginine (66 μg/ml). Medium and heavy media were the same except the light lysine was replaced with K4 and K8-lysine, respectively. Medium and heavy labeled cells were treated for 1 h with 250 µM LLOMe while light labeled were treated for 1 h with vehicle alone (EtOH). Light and heavy ...

Sample preparation for LC-MS/MS Eight million of Cy3/5-positive autophagosomes (roughly 10ug of proteins) were denatured with 2% sodium deoxycholate, 50 mM Tris-HCl pH 8.5, 2.5 mM TCEP, 10 mM chloroacetamide at 95°C for 10 min. Lysates were prepared with in-StageTip (iST) processing method for LC-MS/MS as previously described by Kulak et al. 2014. Briefly, Proteins were digested overnight at 37°C with 1 volume of 50mM Tris-HCl pH 8.5 containing LysC (Wako Chemicals) at 1:100 (w/w) ratio and Trypsin ...

Samples were essentially prepared as described in Zellner et al. Mol Cell 2021 (DOI: 10.1016/j.molcel.2021.01.009)

APEX2-mediated biotinylation of cells was carried out as described before (Hung et al., 2016). In brief, 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. All steps were carried out at 4°C unless stated otherwise. Cells were washed and suspended in homogenization ...

Cells were incubated with 500 µM Biotin-Phenol during the last 30 min of LLOMe or GPN treatment and subsequently pulsed by addition of H2O2 for 1 min at room temperature. To stop the biotinylation reaction, they were washed 3x with quencher solution (10 mM sodium azide, 10 mM sodium ascorbate, 5 mM Trolox in DPBS) and 3x with PBS. All further steps were performed at 4°C unless indicated otherwise. After cell harvest with 0.25% Trypsin/EDTA (ThermoFisher Scientific), cells were counted and heavy- ...

Frozen cell pellets from 4x15 cm cell culture plates were lysed in Glycerol buffer (20 mM Tris [pH 7.4], 150 mM NaCl, 5 mM EDTA, 0.5 % Triton-X-100, 10 % Glycerol, 1x protease inhibitor, 1x phosphatase inhibitor) for 30 min at 4° C with end-over-end rotation. Lysates were cleared from cell debris by centrifugation prior to adjustment of protein concentrations between the samples and overnight immunoprecipitation at 4° C with pre-equilibrated anti-HA-agarose (Sigma). Agarose beads were washed five ...

HeLa cells stably expressing UBE2QL1-APEX2 were grown in lysine- and arginine-free DMEM supplemented with FBS, L-Glutamine, Sodium pyruvate, heavy arginine (R10) (38 μg/ml) and lysine (K8) (66 μg/ml) or light arginine (R0) (38 μg/ml) and lysine (K0) (66 μg/ml), respectively. Further experiments were conducted as soon as the cells reached a protein labelling with heavy amino acids of at least 95%. Heavy-labeled cells were treated with 250 μM Leu-Leu methyl ester hydrobromide (LLOMe, Sigma) for 3 ...

Cells (4x 15 cm dishes) were harvested and lysed with 3 ml lysis buffer (50 mM Tris, pH 7.5, 150 mM NaCl, 0.5% Nonidet P40 (NP40) and EDTA-free protease inhibitor cocktail tablets). Centrifugation-cleared lysates (13,000 rpm) were filtered through 0.45 µm spin filters (Millipore Ultrafree-CL) and immunoprecipitated with 60 µl anti-HA resin. Resin containing immune complexes were washed five times with lysis buffer followed by five PBS washes, and elution with 150 µl of 250 mg/ml HA peptide in ...

Anti-HA-immunoprecipitation was performed as previously described (Behrends et al, 2010; Jung et al, 2015; Jung et al, 2017; Sowa et al, 2009). Summarily, expression of TAPL-HA and coreTAPL-HA was induced by addition of 4 µg/ml doxycycline for 24 h in HeLa Flp-In T-REx cells. Parental non-transfected HeLa Flp-In T-REx cells were used as negative control. For each sample, 6.4 x 107 cells were harvested, frozen in liquid nitrogen and stored at -80 °C. Cells were lysed in 3 ml MCLB buffer (50 mM ...

Samples were processed and analyszed as described in Behrends et al., Nature 2010.

Blood samples (20 ml) from clinically affected homozygous Npc1 mutation carriers and healthy donors were collected. Negative selection of peripheral blood monocyte-derived macrophages was performed by incubating full blood for 20 min at RT with RosetteSep Human Monocyte Enrichment Cocktail (StemCell Technologies). An equal volume of washing buffer (D-PBS/2% FBS/1 mM EDTA) was added to each sample and layer of macrophages was separated from red blood cells and plasma by centrifugation on a Ficoll ...

Proximity-proteomics-based autophagosome content profiling to identify a role for LC3C in maintaining basal mitochondrial homeostasis. Selected mitochondrial proteins, including MTX1, were targeted by LC3C and p62 through a piecemeal mitophagy pathway. SILAC cells biotinylated using APEX proximity labeling. Cell lysates treated with protease. RIPA soluble and insoluble fractions were subjected to Streptavidin pulldown followed by in gel digestion. 4 lanes were cut from one sample.

Total protein content of CSF samples was measured by Bradford assay (BioRad, Feldkirchen, Germany)and 10μg per sample were proteolysed by the commercially available in-StageTip-NHS kit (PreOmics GmbH, Martinsried, Germany) according to the manufacturer's protocol. Briefly, CSF was reduced and alkylated and incubated for 3 hrs at 37°C with Lys-C and trypsin. Resulting peptides were dried for short term storage at -80°C. Prior to measurement, peptides were resuspended in 2% acetonitrile and 0.5% ...

3-4 months old male and female C57BL/6J mice (n=10 intact controls, n=10 SW-injured, n=5 LPS injected) were sacrificed through cervical dislocation, brains were removed and placed into cold PBS. Biopsy punches (2.5 mm diameter) of the visual cortex of both hemispheres were dissected whereas meninges and white matter were carefully taken off. The contralateral (uninjured) cortices of the SW-injured brains were not considered for proteome analysis (intact: n=20, SW: n=10, LPS: n=10). Samples were ...

8 months old control C57BL/6J (n=10), 17 months aged C57BL/6J (n=4), and 8 months old APP/PS1 mice (n=5) were sacrificed through cervical dislocation, brains were removed and placed into cold 1x PBS. Biopsy punches of the visual cortex of both hemispheres were taken with a tissue puncher (2.5 mm diameter) and meninges and white matter were carefully removed using forceps to have a tissue sample consisting of grey matter only. Each sample was put into a low-protein binding Eppendorf tube, frozen ...

Per sample 10μg of isolated mitochondria were used. SDS was added to a final concentration of 2% for efficient solubilization, prior to tryptic protein digest using a modified FASP protocol (Wiśniewski et al., 2009). Proteomic measurements were performed on a Q-Exactive HF mass spectrometer (Thermo Scientific) online coupled to an Ultimate 3000 nano-RSLC (Dionex). Peptides were separated on a C18 nanoEase MZ HSS T3 column (100Å, 1.8 µm, 75 µm x 250 mm; Waters) in a 95 min non-linear acetonitrile ...

Nuclear extracts of cells expressing Trnp1, FLAGTrnp1, delta1-16Trnp1 or FLAGdelta1-16Trnp1 were obtained by re-suspended cells for 30 min on ice in Tween20 lysis buffer (25 mM HEPES pH 8, 20 mM NaCl, 2 mM EDTA, 1 mM PMSF, 0.5% Tween20, 1X protease inhibitors, cOmplete, Roche), pelleted nuclei by centrifugation, discarding the cytoplasmic fraction (supernatant) and lysing nuclei by sonication with lysis buffer containing 500 mM NaCl. DNAseI (250U; SIGMA) was added to the nuclear pellet and incubated ...

Mice were sacrificed by cervical dislocation (n=4) and brains were subsequently extracted and the injury-site and corresponding area on the contralateral side was removed using a 2.5 mm biopsy punch and the white matter was removed. Samples were homogenized using a (100 μl) dounce (Wheaton #357844) in 100 ul PBS (with protease inhibitor cocktail and Ethylenediaminetetraacetic acid (EDTA)) and directly frozen in liquid nitrogen and stored in -80 °C until tissue protein fractionation. Following ...

Library-Matched Single Shot (LMSS) method Mice were sacrificed by cervical dislocation and brains were subsequently extracted and put into cold phosphate buffered saline (PBS). The ventricular walls were laid bare by removing the dorsal ventricular wall and all tissue above it, as well as the choroid plexus. Brains were then snap-frozen on dry ice and cut into 100 μm sections on a cryostat (Leica CM1000S). The medial (MEZ) and lateral ventricular (SEZ) walls were then manually dissected under a ...

For proteomic analysis, iPSC-derived neural stem cells at day 15 of culture were treated with 3.3 uM Nocodazole (Sigma) or same volume of DMSO (control) before being washed with ice-cold PBS, scrapped and centrifuged for 10 min at 300 g before lysis in Buffer A, containing 50 mM Tris-HCL (pH 7.5), 150 mM NaCl, 1 mM EDTA, 1 mM EGTA, 1% Triton-X100, 0.1% SDS, protease inhibitor (Pierce), at a volume twice that of the pellet. For neurons, day 40 of cultures treated only with DMSO were used. Samples ...

Parental and ITCH KO HeLa cells were cultured in lysine- and arginine-free DMEM supplemented with dialyzed FBS, 2 mM L-glutamine, 1 mM sodium pyruvate, penicillin/streptomycin and light (K0) lysine (38 μg/mL) and arginine (66 μg/ml). Heavy medium was the same except the light lysine was replaced with K8-lysine (L-Lysine, 2HCl U-13C U-15N, Cambridge Isotope Laboratories Inc). All cells were treated for 1 h with 1mM LLOMe (Sigma). Subsequently, cells were processed as described before (Fiskin et ...

Dissection of ventral pial cerebral vessels: Mice were anesthetized with Ketamine (100 mg/kg) and Xylazine (10 mg/kg) and transcardially perfused with 20 ml PBS, followed by 2 ml of 2% Evan’s blue (w/v) prepared in PBS. After brain harvest, pial vessels were collected from the ventral face of the brain with micro forceps under a M205 A dissection microscope (Leica) and snap frozen on dry ice. Lysis of cerebral vessels. Vessels were mixed with 4% (w/v) SDS, 100 mM dithiothreitol, 100 mM Tris–HCl, ...

APEX2-mediated biotinylation of cells was carried out as described before (Hung et al., 2016). In brief, 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. All steps were carried out at 4°C unless stated otherwise. Cells were washed and suspended in homogenization ...

Proteomics: brain tissues coming from both human PFC and the 4 different mouse models were prepared as follows. Tissues were grinded with a biomasher using 350 µL of MeOH:H2O (4:1). Protein pellets were resuspended in 200 µL Laemmli buffer (10% SDS, Tris 1M pH 6.8, glycerol) then centrifuged at 11.135 rpm at 4°C for 5 minutes. Protein concentration was determined using DC assay (BioRad, Hercules, CA, USA) according to the manufacturer’s instructions. 100 µg of protein lysate for each sample were ...

Phosphoproteomics: starting from the protein extracts from the global proteomics experiments, proteases inhibitors (Sigma, P8340) and phosphatases inhibitors (final concentration in Na3VO4 = 1 mM) were added to all samples. Protein concentration was determined using RC-DC assay (BioRad, Hercules, CA, USA) according to the manufacturer’s instructions. 250 µg of proteins for each sample were reduced and alkylated prior to an in-house optimized single-pot, solid-phase-enhanced sample preparation ...