Journal: Current biology : CB
Article Title: Force-induced dephosphorylation activates the cochaperone BAG3 to coordinate protein homeostasis and membrane traffic.
doi: 10.1016/j.cub.2024.07.088
Figure Lengend Snippet: Figure 3. BAG3 interacts with RAB GTPases in a dephosphorylation- dependent manner (A) Phosphosite mutant variants of BAG3 were transiently expressed in A7r5 cells as FLAG-epitope tagged proteins followed by anti-FLAG immunopre- cipitation and mass spectrometry. (B) HSC70 was detected in complexes of wild-type BAG3, and BAG3-T285A/ S289A and BAG3-T285D/S289D mutant variants by interaction proteomics. HSPB1 was significantly more abundant (LIMMA-moderated t test p value < 0.05) in pull-downs with the dephosphorylation-mimicking BAG3- T285A/S289A. Heatmap shows protein abundance as log2-transformed mean intensity compared to mean background intensity (FLAG-BAG3- construct/empty). See Data S1A for more information. (C) Principal-component analysis based on label-free quantification (LFQ) in- tensities of 42 proteins identified as differentially abundant (ANOVA p value < 0.05 with Tukey’s post hoc test FDR < 0.05). Empty, empty vector transfected controls (black); WT, wild-type BAG3 (green); DD, BAG3-T285D/ S289D (blue); AA, BAG3-T285A/S289A (red). See Data S1B for more infor- mation. (D) Gene Ontology (GO) terms enriched among proteins identified as BAG3 interactors. GO terms were selected from significantly enriched categories (FDR-corrected p value < 0.05). For GO-term identifier numbers, see Data S1C. (E) Volcano plot visualizing the log2 transformed ratio of mean protein abundance in pull-downs with BAG3-T285A/S289A compared to BAG3- T285D/S289D (log2 (AA/DD)), plotted against log10 (LIMMA-moderated t
Article Snippet: REAGENT or RESOURCE SOURCE IDENTIFIER Antibodies Rabbit polyclonal anti-BAG3 Proteintech Cat#: 10599-1-AP; RRID: AB_2062602 Rabbit polyclonal anti-BAG3 Arndt et al.12 N/A Rabbit polyclonal anti-BAG3-pS136 This paper N/A Rabbit polyclonal anti-HSC70 Ulbricht et al.9 N/A Rabbit polyclonal anti-HSPB1 Enzo Cat#: ADI-SPA-801; RRID: AB_10615795 Rabbit polyclonal anti-HSPB8 St John s Lab Cat#: STJ24102 Rabbit polyclonal anti-LC3B Novus Biologicals Cat#: NB100-2220; RRID: AB_10003146 Rabbit polyclonal anti-RAB2A Proteintech Cat#: 15420-1-AP; RRID: AB_2176874 Rabbit polyclonal anti-RAB7A T. Watts (University of Toronto, Canada) N/A Rabbit polyclonal anti-RAB11A Abcam Cat#: Ab128913; RRID: AB_11140633 Rabbit polyclonal anti-RAB11B Proteintech Cat#: 19742-1-AP; RRID: AB_10642010 Guinea pig polyclonal anti-SQSTM1/p62 Progen Cat#: GP62-C; RRID: AB_2687531 Rabbit polyclonal anti-SYNPO2 Linnemann et al.87 N/A Mouse monoclonal anti-T7 Sigma-Aldrich Cat#: 69522 Mouse monoclonal anti-g-tubulin Sigma-Aldrich Cat#: T5326; RRID: AB_532292 Rabbit polyclonal anti-ubiquitin-pS65 Cell Signaling Cat#: 62802; RRID: AB_2799632 Bacterial and virus strains Escherichia coli BL21(DE3) Thermo Fisher Cat#: ECO114 Biological samples Human vastus lateralis muscle biopsies This paper N/A Chemicals, peptides, and recombinant proteins Cell lysis buffer Cell Signaling Technology Cat#: 9803 Protease-Inhibitor-Cocktail Thermo Fisher Cat#: 78429 Complete protease inhibitor Roche Cat#: 4693132001 PhosSTOP phosphatase inhibitor Roche Cat#: 4906837001 RIPA buffer Thermo Fisher Cat#: 89901 Protease inhibitor cocktail Sigma-Aldrich Cat#: P8340 Phosphatase inhibitor cocktail Sigma-Aldrich Cat#: P5726 M2-agarose Sigma-Aldrich Cat#: A2220 Cycloheximide Roth Cat#: 8682.1 Anti-FLAG magnetic beads Thermo Fisher Cat#: A36797 SDS, proteomics grade VWR Cat#: M112 Bafilomycin A1 Santa Cruz Biotechnology Cat#: sc-201550A Fluoromount-G Thermo Fisher Cat#: 00-4958-02 Ni-NTA-agarose Qiagen Cat#: 30210 GDP Merck Cat#: 20-177 GTP-g-S Merck Cat#: 20-176 Protein G sepharose Sigma-Aldrich Cat#: GE17-0618-01 (Continued on next page) Current Biology 34, 1–14.e1–e9, September 23, 2024 e1 Article
Techniques: De-Phosphorylation Assay, Phospho-proteomics, Mutagenesis, FLAG-tag, Mass Spectrometry, Quantitative Proteomics, Transformation Assay, Construct, Plasmid Preparation, Transfection