Journal: eLife

Article Title: A bidirectional switch in the Shank3 phosphorylation state biases synapses toward up- or downscaling

doi: 10.7554/elife.74277

Figure Lengend Snippet: Figure 2. Neuronal activity bidirectionally modulates the phosphorylation state of Shank3. (A) The experiment protocol for extraction of Shank3 from rat cultured neocortical neurons for further quantitative mass spectrometry (MS) or Western blot analyses. (B) Volcano plot of quantitative MS data showing Shank3 residues that were differentially phosphorylated in tetrodotoxin (TTX)-treated samples compared to untreated controls. The log2 values of fold changes, if below zero, indicated hypophosphorylation (paired t-test: S1586, adjusted p=0.034142, S1614/5, 0.014444). (C) Top: diagram showing the location of S1586 and S1615 within the rat Shank3 protein. Functional domains: ANK = ankyrin repeat; SH3 = SRC homology 3; PDZ = PSD-95/Disc Large/ZO-1; Pro-rich = proline rich; SAM = sterile alpha motif. Bottom: homology comparison of sequences flanking rat S1586 and S1615 (matching mouse S1539) across species (human Shank3: NP_001358973.1; rat Shank3: NP_067708.2; mouse Shank3: UniprotKB: Q4ACU6.3). Phosphosites of interest are labeled in red; the only residue not conserved is shown in blue. (D, E) Representative Western blot using an antibody specific for phosphorylated S1615, showing changes in Shank3 phosphorylation after 10 min (D) or 24 hr (E) treatment with TTX or picrotoxin (PTX). (F) Quantification of the fold change of Shank3 S1615 phosphorylation in (D). Dashed line indicates the baseline untreated control (one-sample t-test: TTX, ***p=0.0005, PTX, **p=0.0035, n = 5 and 10 biological replicates, respectively). (G) Quantification of the fold change of Shank3 S1615 phosphorylation in (E) (one-sample t-test: TTX, ****p<0.0001, PTX, p = 0.6336, n = 7 and 7 biological replicates, respectively). Solid colored horizontal

Article Snippet: DOI: https://doi.org/10.7554/eLife.74277 19 of 31 Reagent type (species) or resource Designation Source or reference Identifiers Additional information Recombinant DNA reagent pAAV- CMV- PI- EGFP- WPRE- bGH Gift from James M. Wilson Addgene# 105530; RRID:Addgene_105530 Commercial assay or kit Lipofectamine 2000 Thermo Fisher Scientific Cat# 11668- 027 Commercial assay or kit Gibson Assembly Master Mix New England Biolabs Cat# E2611S Commercial assay or kit Lambda protein phosphatase New England Biolabs Cat# P0753S Commercial assay or kit BCA Protein Assay Kit Thermo Fisher Scientific Cat# 23227 Commercial assay or kit Protein- G Magnetic Beads Thermo Fisher Scientific Cat# 88847 Commercial assay or kit SimplyBlue SafeStain Thermo Fisher Scientific Cat# LC6060 Commercial assay or kit PP2A Immunoprecipitation Phosphatase Assay Kit Millipore Cat# 17- 313 Commercial assay or kit Ni- NTA Superflow Agarose Beads QIAGEN Cat# 30410 Chemical compound, drug Tetrodotoxin Tocris Cat# 1069 Chemical compound, drug Bicuculline methobromide Tocris Cat# 0109 Chemical compound, drug Picrotoxin Sigma- Aldrich Cat# P1675 Chemical compound, drug Okadaic acid Santa Cruz Cat# sc- 3513 Chemical compound, drug Tautomycetin Tocris Cat# 2305 Chemical compound, drug Fostriecin Tocris Cat# 1840 Chemical compound, drug KN62 Tocris Cat# 1277 Chemical compound, drug KN93 Tocris Cat# 1278 Chemical compound, drug H89 Tocris Cat# 2910 Chemical compound, drug Sequencing- grade trypsin Promega Cat# V5111 Chemical compound, drug Tandem Mass Tag (TMT) 10plex Thermo Fisher Scientific Cat# 90110 Software, algorithm Image Lab Software Bio- Rad RRID:SCR_014210 https://www.bio-rad.com/en-us/product/imagelab-software?ID=KRE6P5E8Z&source_wt= imagelabsoftware_surl Software, algorithm ZEN Black Zeiss RRID:SCR_018163 https://www.zeiss.com Software, algorithm Metamorph Molecular Devices RRID:SCR_002368 http://www.moleculardevices.com/Products/Software/ Meta-Imaging-Series/MetaMorph.html Software, algorithm Fiji Fiji RRID:SCR_002285 http://fiji.sc Software, algorithm GraphPad Prism GraphPad RRID:SCR_002798 http://www.graphpad.com/ Software, algorithm IGOR pro Wavemetrics RRID:SCR_000325 https://www.wavemetrics. com/products/igorpro/igorpro.htm Software, algorithm Spectrum mill v.7.00.208 Agilent Technologies Software, algorithm R v 4.0 The R Foundation RRID:SCR_001905 https://www.R-project.org/ Continued Continued on next page Wu, Tatavarty, Jean Beltran, et al. eLife 2022;11:e74277.

Techniques: Activity Assay, Phospho-proteomics, Extraction, Cell Culture, Mass Spectrometry, Western Blot, Functional Assay, Sterility, Comparison, Labeling, Residue, Control

Journal: eLife

Article Title: A bidirectional switch in the Shank3 phosphorylation state biases synapses toward up- or downscaling

doi: 10.7554/elife.74277

Figure Lengend Snippet: Figure 3. Phosphorylation state modulates activity-dependent changes in the synaptic enrichment of Shank3. (A) Representative images of synaptic puncta colocalized with surface GluA2 (sGluA2) and Shank3 in neuron dendrites ± tetrodotoxin (TTX) (scale bar = 5 µm). (B) Quantification of synaptic sGluA2 intensity changes induced by scaling up and down protocols (number of neurons: untreated, n = 77, TTX, n = 40, picrotoxin [PTX], n = 29; Kruskal–Wallis test with post-hoc Dunn’s multiple comparison tests: Un vs. TTX, **p=0.0034, Un vs. PTX, *p=0.0408, TTX vs. PTX, ****p<0.0001). (C) Quantification of synaptic Shank3 intensity during scaling up and down protocols (Kruskal–Wallis test with post-hoc Dunn’s tests: Un vs. TTX, *p=0.0155, Un vs. PTX, *p=0.0205, TTX vs. PTX, ****p<0.0001). (D) Representative images of synaptic localization of wild-type Shank3 and Shank3 phospho-mutants (scale bar = 5 µm). (E) Quantification of synaptic intensity of Shank3 phospho-mutants (number of neurons: WT, n = 33, AA, n = 30, DD, n = 24; Kruskal–Wallis test with post-hoc Dunn’s tests: WT vs. AA, p>0.9999, WT vs. DD, *p=0.0395, AA vs. DD, **p=0.0039). (F) Quantification of the density of synaptic puncta containing Shank3 phospho-mutants (number of neurons: WT, n = 32, AA, n = 30, DD, n = 24; Kruskal–Wallis test: p=0.2814). For imaging experiments here and below, each data point represents a single pyramidal neuron, and data were collected from at least four independent experiments. Also see Figure 3—source data 1.

Article Snippet: DOI: https://doi.org/10.7554/eLife.74277 19 of 31 Reagent type (species) or resource Designation Source or reference Identifiers Additional information Recombinant DNA reagent pAAV- CMV- PI- EGFP- WPRE- bGH Gift from James M. Wilson Addgene# 105530; RRID:Addgene_105530 Commercial assay or kit Lipofectamine 2000 Thermo Fisher Scientific Cat# 11668- 027 Commercial assay or kit Gibson Assembly Master Mix New England Biolabs Cat# E2611S Commercial assay or kit Lambda protein phosphatase New England Biolabs Cat# P0753S Commercial assay or kit BCA Protein Assay Kit Thermo Fisher Scientific Cat# 23227 Commercial assay or kit Protein- G Magnetic Beads Thermo Fisher Scientific Cat# 88847 Commercial assay or kit SimplyBlue SafeStain Thermo Fisher Scientific Cat# LC6060 Commercial assay or kit PP2A Immunoprecipitation Phosphatase Assay Kit Millipore Cat# 17- 313 Commercial assay or kit Ni- NTA Superflow Agarose Beads QIAGEN Cat# 30410 Chemical compound, drug Tetrodotoxin Tocris Cat# 1069 Chemical compound, drug Bicuculline methobromide Tocris Cat# 0109 Chemical compound, drug Picrotoxin Sigma- Aldrich Cat# P1675 Chemical compound, drug Okadaic acid Santa Cruz Cat# sc- 3513 Chemical compound, drug Tautomycetin Tocris Cat# 2305 Chemical compound, drug Fostriecin Tocris Cat# 1840 Chemical compound, drug KN62 Tocris Cat# 1277 Chemical compound, drug KN93 Tocris Cat# 1278 Chemical compound, drug H89 Tocris Cat# 2910 Chemical compound, drug Sequencing- grade trypsin Promega Cat# V5111 Chemical compound, drug Tandem Mass Tag (TMT) 10plex Thermo Fisher Scientific Cat# 90110 Software, algorithm Image Lab Software Bio- Rad RRID:SCR_014210 https://www.bio-rad.com/en-us/product/imagelab-software?ID=KRE6P5E8Z&source_wt= imagelabsoftware_surl Software, algorithm ZEN Black Zeiss RRID:SCR_018163 https://www.zeiss.com Software, algorithm Metamorph Molecular Devices RRID:SCR_002368 http://www.moleculardevices.com/Products/Software/ Meta-Imaging-Series/MetaMorph.html Software, algorithm Fiji Fiji RRID:SCR_002285 http://fiji.sc Software, algorithm GraphPad Prism GraphPad RRID:SCR_002798 http://www.graphpad.com/ Software, algorithm IGOR pro Wavemetrics RRID:SCR_000325 https://www.wavemetrics. com/products/igorpro/igorpro.htm Software, algorithm Spectrum mill v.7.00.208 Agilent Technologies Software, algorithm R v 4.0 The R Foundation RRID:SCR_001905 https://www.R-project.org/ Continued Continued on next page Wu, Tatavarty, Jean Beltran, et al. eLife 2022;11:e74277.

Techniques: Phospho-proteomics, Activity Assay, Comparison, Imaging

Journal: eLife

Article Title: A bidirectional switch in the Shank3 phosphorylation state biases synapses toward up- or downscaling

doi: 10.7554/elife.74277

Figure Lengend Snippet: Figure 4. Increased PP2A activity maintains tetrodotoxin (TTX)-induced Shank3 hypophosphorylation. (A) Diagram showing the potential roles of kinases and phosphatases in regulating activity-dependent Shank3 phosphorylation. (B) Representative Western blot showing the impacts of inhibiting CAMKII (KN62, KN93) or PKA (H89) on Shank3 phosphorylation at baseline and upon TTX treatment. (C) Quantification of S1615 phosphorylation in (B) (two-way ANOVA with post-hoc Tukey’s test: DMSO vs. KN62, p>0.9999, DMSO vs. KN93, p=0.8148, DMSO vs. H89, p=0.9112, DMSO vs. picrotoxin (PTX), *p=0.0406, PTX vs. PTX/KN62, **p=0.0040, PTX vs. PTX/KN93, ****p<0.0001, PTX vs. PTX/H89, ****p<0.0001, n = 5 biological replicates). Dashed line indicates the DMSO control. (D) Quantification of PP2A activity after 1 hr TTX treatment (Un, n = 5, TTX, n = 5; paired t-test: **p=0.0018). (E) Quantification of PP2A activity after 24 hr TTX treatment (Un, n = 7, TTX, n = 7; paired t-test: *p=0.0129). (F, G) Western blot analyses showing changes in S1615 phosphorylation after 1 hr (F) or 24 hr (G) TTX treatment, with inhibition of PP2A by okadaic acid (OKA, 50 nM) during the

Article Snippet: DOI: https://doi.org/10.7554/eLife.74277 19 of 31 Reagent type (species) or resource Designation Source or reference Identifiers Additional information Recombinant DNA reagent pAAV- CMV- PI- EGFP- WPRE- bGH Gift from James M. Wilson Addgene# 105530; RRID:Addgene_105530 Commercial assay or kit Lipofectamine 2000 Thermo Fisher Scientific Cat# 11668- 027 Commercial assay or kit Gibson Assembly Master Mix New England Biolabs Cat# E2611S Commercial assay or kit Lambda protein phosphatase New England Biolabs Cat# P0753S Commercial assay or kit BCA Protein Assay Kit Thermo Fisher Scientific Cat# 23227 Commercial assay or kit Protein- G Magnetic Beads Thermo Fisher Scientific Cat# 88847 Commercial assay or kit SimplyBlue SafeStain Thermo Fisher Scientific Cat# LC6060 Commercial assay or kit PP2A Immunoprecipitation Phosphatase Assay Kit Millipore Cat# 17- 313 Commercial assay or kit Ni- NTA Superflow Agarose Beads QIAGEN Cat# 30410 Chemical compound, drug Tetrodotoxin Tocris Cat# 1069 Chemical compound, drug Bicuculline methobromide Tocris Cat# 0109 Chemical compound, drug Picrotoxin Sigma- Aldrich Cat# P1675 Chemical compound, drug Okadaic acid Santa Cruz Cat# sc- 3513 Chemical compound, drug Tautomycetin Tocris Cat# 2305 Chemical compound, drug Fostriecin Tocris Cat# 1840 Chemical compound, drug KN62 Tocris Cat# 1277 Chemical compound, drug KN93 Tocris Cat# 1278 Chemical compound, drug H89 Tocris Cat# 2910 Chemical compound, drug Sequencing- grade trypsin Promega Cat# V5111 Chemical compound, drug Tandem Mass Tag (TMT) 10plex Thermo Fisher Scientific Cat# 90110 Software, algorithm Image Lab Software Bio- Rad RRID:SCR_014210 https://www.bio-rad.com/en-us/product/imagelab-software?ID=KRE6P5E8Z&source_wt= imagelabsoftware_surl Software, algorithm ZEN Black Zeiss RRID:SCR_018163 https://www.zeiss.com Software, algorithm Metamorph Molecular Devices RRID:SCR_002368 http://www.moleculardevices.com/Products/Software/ Meta-Imaging-Series/MetaMorph.html Software, algorithm Fiji Fiji RRID:SCR_002285 http://fiji.sc Software, algorithm GraphPad Prism GraphPad RRID:SCR_002798 http://www.graphpad.com/ Software, algorithm IGOR pro Wavemetrics RRID:SCR_000325 https://www.wavemetrics. com/products/igorpro/igorpro.htm Software, algorithm Spectrum mill v.7.00.208 Agilent Technologies Software, algorithm R v 4.0 The R Foundation RRID:SCR_001905 https://www.R-project.org/ Continued Continued on next page Wu, Tatavarty, Jean Beltran, et al. eLife 2022;11:e74277.

Techniques: Activity Assay, Phospho-proteomics, Western Blot, Control, Inhibition

Journal: eLife

Article Title: A bidirectional switch in the Shank3 phosphorylation state biases synapses toward up- or downscaling

doi: 10.7554/elife.74277

Figure Lengend Snippet: Figure 5. PP2A activity is required for tetrodotoxin (TTX)-induced synaptic enrichment of Shank3. (A) Representative images of synaptic enrichment of endogenous Shank3 upon treatment with TTX and PP2A inhibitor fostriecin (FST) (scale bar = 10 µm). (B) Quantification of synaptic Shank3 intensity in (A) (number of neurons: DMSO, n = 26, FST, n = 28, TTX, n = 28, TTX/FST, n = 29; Kruskal–Wallis test with post-hoc Dunn’s tests: DMSO vs. FST, p>0.9999, DMSO vs. TTX, ***p=0.0002, FST vs. TTX/FST, p=0.1259, TTX vs. TTX/FST, p=0.1292). (C) Quantification of density of synapses containing Shank3 in (A) (Kruskal–Wallis test with post-hoc Dunn’s tests: DMSO vs. FST, p=0.9458, DMSO vs. TTX, **p=0.0051, FST vs. TTX/FST, p=0.2446, TTX vs. TTX/FST, *p=0.0273). (D) Representative images of synaptic enrichment of endogenous Shank3 upon treatment with TTX and PP1 inhibitor tautomycetin (TAUT) (scale bar = 10 µm). (E) Quantification of synaptic Shank3 intensity in (D) (number of neurons: DMSO, n = 26, TAUT, n = 21, TTX, n = 28, TTX/ TAUT, n = 32; Kruskal–Wallis test with post-hoc Dunn’s tests: DMSO vs. TAUT, *p=0.0315, DMSO vs. TTX, ***p=0.0006, TAUT vs. TTX/TAUT, ***p=0.0002, TTX vs. TTX/TAUT, *p=0.0392). (F) Quantification of density of synapses containing Shank3 in (D) (Kruskal–Wallis test with post-hoc Dunn’s tests: DMSO vs. TAUT, p=0.2450, DMSO vs. TTX, *p=0.0116, TAUT vs. TTX/TAUT, p=0.6552, TTX vs. TTX/TAUT, ***p=0.0007). Also see Figure 5—figure supplement 1 and Figure 5—source data 1.

Article Snippet: DOI: https://doi.org/10.7554/eLife.74277 19 of 31 Reagent type (species) or resource Designation Source or reference Identifiers Additional information Recombinant DNA reagent pAAV- CMV- PI- EGFP- WPRE- bGH Gift from James M. Wilson Addgene# 105530; RRID:Addgene_105530 Commercial assay or kit Lipofectamine 2000 Thermo Fisher Scientific Cat# 11668- 027 Commercial assay or kit Gibson Assembly Master Mix New England Biolabs Cat# E2611S Commercial assay or kit Lambda protein phosphatase New England Biolabs Cat# P0753S Commercial assay or kit BCA Protein Assay Kit Thermo Fisher Scientific Cat# 23227 Commercial assay or kit Protein- G Magnetic Beads Thermo Fisher Scientific Cat# 88847 Commercial assay or kit SimplyBlue SafeStain Thermo Fisher Scientific Cat# LC6060 Commercial assay or kit PP2A Immunoprecipitation Phosphatase Assay Kit Millipore Cat# 17- 313 Commercial assay or kit Ni- NTA Superflow Agarose Beads QIAGEN Cat# 30410 Chemical compound, drug Tetrodotoxin Tocris Cat# 1069 Chemical compound, drug Bicuculline methobromide Tocris Cat# 0109 Chemical compound, drug Picrotoxin Sigma- Aldrich Cat# P1675 Chemical compound, drug Okadaic acid Santa Cruz Cat# sc- 3513 Chemical compound, drug Tautomycetin Tocris Cat# 2305 Chemical compound, drug Fostriecin Tocris Cat# 1840 Chemical compound, drug KN62 Tocris Cat# 1277 Chemical compound, drug KN93 Tocris Cat# 1278 Chemical compound, drug H89 Tocris Cat# 2910 Chemical compound, drug Sequencing- grade trypsin Promega Cat# V5111 Chemical compound, drug Tandem Mass Tag (TMT) 10plex Thermo Fisher Scientific Cat# 90110 Software, algorithm Image Lab Software Bio- Rad RRID:SCR_014210 https://www.bio-rad.com/en-us/product/imagelab-software?ID=KRE6P5E8Z&source_wt= imagelabsoftware_surl Software, algorithm ZEN Black Zeiss RRID:SCR_018163 https://www.zeiss.com Software, algorithm Metamorph Molecular Devices RRID:SCR_002368 http://www.moleculardevices.com/Products/Software/ Meta-Imaging-Series/MetaMorph.html Software, algorithm Fiji Fiji RRID:SCR_002285 http://fiji.sc Software, algorithm GraphPad Prism GraphPad RRID:SCR_002798 http://www.graphpad.com/ Software, algorithm IGOR pro Wavemetrics RRID:SCR_000325 https://www.wavemetrics. com/products/igorpro/igorpro.htm Software, algorithm Spectrum mill v.7.00.208 Agilent Technologies Software, algorithm R v 4.0 The R Foundation RRID:SCR_001905 https://www.R-project.org/ Continued Continued on next page Wu, Tatavarty, Jean Beltran, et al. eLife 2022;11:e74277.

Techniques: Activity Assay

Journal: eLife

Article Title: A bidirectional switch in the Shank3 phosphorylation state biases synapses toward up- or downscaling

doi: 10.7554/elife.74277

Figure Lengend Snippet: Figure 6. Changes in the phosphorylation state of Shank3 are crucial for bidirectional synaptic scaling. (A, B) Representative miniature excitatory postsynaptic current (mEPSC) recordings from neurons overexpressing Shank3 WT (A) or DD mutant (B) during scaling up. (C) Quantification of average mEPSC amplitude in (A) (WT, n = 8, WT + tetrodotoxin [TTX], n = 9; unpaired two-tailed t-test: **p=0.0074). (D) Quantification of average mEPSC amplitude in (B) (number of neurons: DD, n = 12, DD + TTX, n = 14; unpaired two-tailed t-test: p=0.5708). (E, F) Representative traces of mEPSCs recorded from neurons overexpressing Shank3 WT (E) or AA mutant (F) during scaling down. (G) Quantification of average mEPSC amplitude in (E) (number of neurons: WT, n = 8, WT + bicuculline [BIC], n = 8; Mann–Whitney test: *p=0.0148). (H) Quantification of average mEPSC amplitude in (F) (AA, n = 9, AA + BIC, n = 14; unpaired two-tailed t-test: p=0.8612). Also see Figure 6—figure supplement 1, Figure 6—figure supplement 2, and Figure 6—source data 1.

Article Snippet: DOI: https://doi.org/10.7554/eLife.74277 19 of 31 Reagent type (species) or resource Designation Source or reference Identifiers Additional information Recombinant DNA reagent pAAV- CMV- PI- EGFP- WPRE- bGH Gift from James M. Wilson Addgene# 105530; RRID:Addgene_105530 Commercial assay or kit Lipofectamine 2000 Thermo Fisher Scientific Cat# 11668- 027 Commercial assay or kit Gibson Assembly Master Mix New England Biolabs Cat# E2611S Commercial assay or kit Lambda protein phosphatase New England Biolabs Cat# P0753S Commercial assay or kit BCA Protein Assay Kit Thermo Fisher Scientific Cat# 23227 Commercial assay or kit Protein- G Magnetic Beads Thermo Fisher Scientific Cat# 88847 Commercial assay or kit SimplyBlue SafeStain Thermo Fisher Scientific Cat# LC6060 Commercial assay or kit PP2A Immunoprecipitation Phosphatase Assay Kit Millipore Cat# 17- 313 Commercial assay or kit Ni- NTA Superflow Agarose Beads QIAGEN Cat# 30410 Chemical compound, drug Tetrodotoxin Tocris Cat# 1069 Chemical compound, drug Bicuculline methobromide Tocris Cat# 0109 Chemical compound, drug Picrotoxin Sigma- Aldrich Cat# P1675 Chemical compound, drug Okadaic acid Santa Cruz Cat# sc- 3513 Chemical compound, drug Tautomycetin Tocris Cat# 2305 Chemical compound, drug Fostriecin Tocris Cat# 1840 Chemical compound, drug KN62 Tocris Cat# 1277 Chemical compound, drug KN93 Tocris Cat# 1278 Chemical compound, drug H89 Tocris Cat# 2910 Chemical compound, drug Sequencing- grade trypsin Promega Cat# V5111 Chemical compound, drug Tandem Mass Tag (TMT) 10plex Thermo Fisher Scientific Cat# 90110 Software, algorithm Image Lab Software Bio- Rad RRID:SCR_014210 https://www.bio-rad.com/en-us/product/imagelab-software?ID=KRE6P5E8Z&source_wt= imagelabsoftware_surl Software, algorithm ZEN Black Zeiss RRID:SCR_018163 https://www.zeiss.com Software, algorithm Metamorph Molecular Devices RRID:SCR_002368 http://www.moleculardevices.com/Products/Software/ Meta-Imaging-Series/MetaMorph.html Software, algorithm Fiji Fiji RRID:SCR_002285 http://fiji.sc Software, algorithm GraphPad Prism GraphPad RRID:SCR_002798 http://www.graphpad.com/ Software, algorithm IGOR pro Wavemetrics RRID:SCR_000325 https://www.wavemetrics. com/products/igorpro/igorpro.htm Software, algorithm Spectrum mill v.7.00.208 Agilent Technologies Software, algorithm R v 4.0 The R Foundation RRID:SCR_001905 https://www.R-project.org/ Continued Continued on next page Wu, Tatavarty, Jean Beltran, et al. eLife 2022;11:e74277.

Techniques: Phospho-proteomics, Mutagenesis, Two Tailed Test, MANN-WHITNEY

Journal: eLife

Article Title: A bidirectional switch in the Shank3 phosphorylation state biases synapses toward up- or downscaling

doi: 10.7554/elife.74277

Figure Lengend Snippet: Figure 7. Brief PP2A inactivation reverses scaling up. (A) Representative images showing the effects of 1 hr fostriecin (FST) treatment on synaptic sGluA2 intensity in neurons expressing Shank3 WT or AA, after 24 hr of tetrodotoxin (TTX) to scale up synaptic strengths (scale bar = 10 µm). (B) Quantification of synaptic sGluA2 intensity in (A) (number of cells: WT/TTX, n = 22, WT/TTX/FST, n = 23, AA/TTX, n = 26, AA/TTX/FST, n = 25; Mann–Whitney test: WT/TTX vs. WT/TTX/FST, ***p=0.0007, AA/TTX vs. AA/TTX/FST, p=0.3739). (C) Quantification of synaptic Shank3 intensity in (A) (Mann–Whitney test: WT/TTX vs. WT/TTX/FST, **p=0.0090, AA/TTX vs. AA/TTX/FST, p=0.7296). (D) Quantification of the density of puncta containing sGluA2 and Shank3 (Mann–Whitney test: WT/TTX vs. WT/TTX/FST, **p=0.0016, AA/TTX vs. AA/TTX/FST, p=0.7017). Each data point indicates a cell, and the total number (n) was pooled from five independent experiments. Also see Figure 7—source data 1.

Article Snippet: DOI: https://doi.org/10.7554/eLife.74277 19 of 31 Reagent type (species) or resource Designation Source or reference Identifiers Additional information Recombinant DNA reagent pAAV- CMV- PI- EGFP- WPRE- bGH Gift from James M. Wilson Addgene# 105530; RRID:Addgene_105530 Commercial assay or kit Lipofectamine 2000 Thermo Fisher Scientific Cat# 11668- 027 Commercial assay or kit Gibson Assembly Master Mix New England Biolabs Cat# E2611S Commercial assay or kit Lambda protein phosphatase New England Biolabs Cat# P0753S Commercial assay or kit BCA Protein Assay Kit Thermo Fisher Scientific Cat# 23227 Commercial assay or kit Protein- G Magnetic Beads Thermo Fisher Scientific Cat# 88847 Commercial assay or kit SimplyBlue SafeStain Thermo Fisher Scientific Cat# LC6060 Commercial assay or kit PP2A Immunoprecipitation Phosphatase Assay Kit Millipore Cat# 17- 313 Commercial assay or kit Ni- NTA Superflow Agarose Beads QIAGEN Cat# 30410 Chemical compound, drug Tetrodotoxin Tocris Cat# 1069 Chemical compound, drug Bicuculline methobromide Tocris Cat# 0109 Chemical compound, drug Picrotoxin Sigma- Aldrich Cat# P1675 Chemical compound, drug Okadaic acid Santa Cruz Cat# sc- 3513 Chemical compound, drug Tautomycetin Tocris Cat# 2305 Chemical compound, drug Fostriecin Tocris Cat# 1840 Chemical compound, drug KN62 Tocris Cat# 1277 Chemical compound, drug KN93 Tocris Cat# 1278 Chemical compound, drug H89 Tocris Cat# 2910 Chemical compound, drug Sequencing- grade trypsin Promega Cat# V5111 Chemical compound, drug Tandem Mass Tag (TMT) 10plex Thermo Fisher Scientific Cat# 90110 Software, algorithm Image Lab Software Bio- Rad RRID:SCR_014210 https://www.bio-rad.com/en-us/product/imagelab-software?ID=KRE6P5E8Z&source_wt= imagelabsoftware_surl Software, algorithm ZEN Black Zeiss RRID:SCR_018163 https://www.zeiss.com Software, algorithm Metamorph Molecular Devices RRID:SCR_002368 http://www.moleculardevices.com/Products/Software/ Meta-Imaging-Series/MetaMorph.html Software, algorithm Fiji Fiji RRID:SCR_002285 http://fiji.sc Software, algorithm GraphPad Prism GraphPad RRID:SCR_002798 http://www.graphpad.com/ Software, algorithm IGOR pro Wavemetrics RRID:SCR_000325 https://www.wavemetrics. com/products/igorpro/igorpro.htm Software, algorithm Spectrum mill v.7.00.208 Agilent Technologies Software, algorithm R v 4.0 The R Foundation RRID:SCR_001905 https://www.R-project.org/ Continued Continued on next page Wu, Tatavarty, Jean Beltran, et al. eLife 2022;11:e74277.

Techniques: Expressing, MANN-WHITNEY

Journal: Neuron

Article Title: Glutamate-Releasing SWELL1 Channel in Astrocytes Modulates Synaptic Transmission and Promotes Brain Damage in Stroke

doi: 10.1016/j.neuron.2019.03.029

Figure Lengend Snippet: KEY RESOURCES TABLE

Article Snippet: ​ REAGENT or RESOURCE SOURCE IDENTIFIER Antibodies Mouse anti-NeuN (clone A60) Millipore Cat# MAB377; RRID: AB_4339490 Mouse anti-GFAP (clone GA5) Thermo Fisher Scientific Cat# 14–9892-82;RRID: AB_4339490 Rabbit anti-Swell1 This paper N/A Rabbit anti-GAPDH (clone {"type":"entrez-protein","attrs":{"text":"EPR16891","term_id":"523382963","term_text":"EPR16891"}} EPR16891 ) Abcam Cat# ab181602; RRID: AB_21135 Alexa Fluor 546 Goat anti-mouse Thermo Fisher Scientific Cat# A11018; RRID: AB_1944229 Alexa Fluor 488 Goat anti-mouse Thermo Fisher Scientific Cat# A11017; RRID: AB_2107298 Cy3-conjugated Streptavidin Jackson ImmunoResearch Cat# 016–160-084; RRID: AB_130355 TSA Plus Fluorescein Evaluation Kit PerkinElmer Cat #NEL741; RRID: AB_2490275 RNAscope Multiplex Fluorescent Reagent Kit v.2 Advanced Cell Diagnostics Cat# 323100 Chemicals, Peptides, and Recombinant Proteins TTX Tocris Cat# 1069 DL-APV Sigma-Aldrich Cat# A8054 DNQX Sigma-Aldrich Cat# D0540 Picrotoxin Sigma-Aldrich Cat# P1675 Bicuculine Sigma-Aldrich Cat# 14340 DCPIB Tocris Cat# 1540 D-serine Sigma-Aldrich Cat# S4250 MPEP Tocris Cat# 1212 {"type":"entrez-nucleotide","attrs":{"text":"LY367385","term_id":"1257996803","term_text":"LY367385"}} LY367385 Tocris Cat# 1237 Biocytin Sigma-Aldrich Cat# B4261 TFLLR Sigma-Aldrich Cat# T7830 DHPG Sigma-Aldrich Cat# D3689 L-glutamic acid Sigma-Aldrich Cat# G1251 ATP Sigma-Aldrich Cat# A2383 2,3,5-Triphenyltetrazolium chloride Sigma-Aldrich Cat# T8877 QX-314 Tocris Cat# 2313 Experimental Models: Cell Lines Human: Human Embryonic Kidney (HEK) 293T cells ATCC Cat# CRL-3216 Human: HeLa cells ATCC Cat# CCL-2 Experimental Models: Organisms/Strains Mouse: mGFAP-cre; (B6.

Techniques: RNAscope, Multiplex Assay, Recombinant, Software