EMBO/soda-nel huggingface dataset:
Cytoskeletal tension actively sustains the migratory T cell synaptic contact (2019)
Figure 3

Figure 3. Foci associated mechanical forces are linked to synapse symmetry.

(A-B) Foci -deficient cells display poor traction forces in their synapse. WT or WASP-/- T cells were incubated on polyacrylamide substrates covalently functionalized with anti-CD3 and ICAM1, and traction force measurements were carried out as described in 'Methods'. The images in the right show traction force maps without (left panels) or with (right panels) force vectors. p value, **P<0.005 as determined by using Mann-Whitney two-tailed test between populations of cells within the same experiment, n = 9 and 11.

(C) SIM imaging of WT or WASP-/- T cells activated by APS for 5'. The graphs show quantification of actin foci (derived from phalloidin staining), pCasL and talin levels in the synapse normalized to the 'WT' mean value in each case (Middle graph; in the case of foci, n= 63 for WT and 86 for WASP-/-; in the case of pCasL n= 63 for WT and 78 for WASP-/-; in the case of Talin, n= 59 for WT and 73 for WASP-/-; in the case of AR, n= 46 for WT and 42 for WASP-/-); right graph shows AR measurement. ***P <0.0001; p value for talin *P=0.07, as determined by using Mann-Whitney two-tailed test between populations of cells within the same experiment.

(D) Human WAS patient CD4+T cells- APC conjugates display synapse symmetry defects similar to those observed in mouse WASP-/- CD4+ T cells. CD4+T cells purified from healthy controls or WAS patients were incubated with superantigen loaded HUVEC cells for 5' (APC; see 'Methods') and imaged using confocal microscopy. Each image represents a maximum intensity projection of the synaptic area. Graph in the middle shows values normalized to the mean value of the 'Healthy' case. In the case of 'actin' and 'actin foci', n= 87 for healthy and n= 63 for WAS; in the case of pCasL, n=56 for healthy and n= 21 for WAS; for 'AR' graph, n= 88 for healthy and n= 63 for WAS case. P values; ***P <0.001; n.s. P=0.09, as determined by using Mann-Whitney two-tailed test between populations of cells within the same experiment.

Data information: Central values in the graphs represent Mean and error bars represent ± SEM. These experiments were repeated at least twice with similar results. Scale bar, 5µm.
Cytoskeletal tension actively sustains the migratory T cell synaptic contact (2019)
Figure 5

Figure 5. Pharmacological interrogation of actin foci-myosin crosstalk in sustaining symmetry.

(A) Schematic of the cytoskeletal inhibitors and their targets used in the experiments.

(B-E) SIM imaging of mouse T cells activated for 5' on APS, then treated with the indicated inhibitors or vehicle control. Shown are the representative SIM images (B), and quantification of actin foci (from the phalloidin images), talin, or pCasL in the contact interface (normalized to the mean value in the control case, C), and measured cell morphology aspect ratios (D, E). Since CK666 treatment reduces F-actin intensity Kumari et al., 2015(), the 'actin' image of the CK666 treated cell in (B) was contrasted differently than the 'control' and 'Blebb.' cases for a clearer visualization of F-actin. p values, *P =0.02, **P =0.001, n.s. >0.05. For the rest of the comparisons between the control and treatment cases, p <0.0001. For the bar graph in (B), n for foci groups are 214, 83, 92, 98; for pCasL groups are 100, 68, 91, 92; and for Talin groups are 102, 70, 89, 93 respectively. p value for the n.s. cases is > 0.05, *P =0.02. In the foci, pCasL and talin groups, when not indicated, the p values are <0.0001 using Mann-Whitney two-tailed test. Central values in the graphs represent Mean and error bars represent ± SEM. These experiments were repeated at least thrice with similar results. Scale bar, 5µm.

(F-G) Simulation of synaptic F-actin network following localized myosin inactivation and inactivated myosin-mediated F-actin cross-linking within the area marked with dotted line in the left image. The graph shows the predicted alteration in mechanical stress profile, as myosin is inactivated crosslinked in the defined region (marked by an arrow), (G).

(H-I) Experimental confirmation of localized actomyosin crosslinking and symmetry breaking. LifeAct-GFP expressing T cells were incubated with activating substrates, treated with vehicle control or 1µM Azido-blebb and their contact interface imaged using low excitation laser power (0.5 mW), using a spinning disc confocal microscope (H). The montage shows the shape change and movement that synapse undergoes after it is exposed to a brief flash of blue light crosslinking Azido-Blebb and actomyosin network within the illuminated area (shown with a box in the image). The deflection in center of mass (COM) within a minute was calculated and plotted for at least 10 cells in each case (graphs in I). The left graphs in (I) show individual COM trajectory, and the graph on the right shows average COM movement of cells within a minute post photo-inactivation of myosinII. This experiment was repeated twice with similar results. Scale bar, 5µm.
Cytoskeletal tension actively sustains the migratory T cell synaptic contact (2019)
Figure 6

Figure 6. WASP-/- T cells are predisposed to symmetry breaking regardless of the substrate stiffness.

(A, B) T cells were activated using Alexa568-2C11 and ICAM1 reconstituted lipid bilayers for 5 min, fixed, stained with phalloidin and imaged using SIM. In the graph, n= 50 for WT and 61 for WASP-/-, P value, P***<0.0001, obtained using Mann-Whitney two-tailed test. The graphs in (B) show synaptic levels of indicated proteins, normalized to the mean levels of '+WASP' in each case. For the left graph, n= 48, 46, 52, 46 respectively, and p value, P *= 0.03. For the right graph, n= 50 for WT and n= 61 for WASP-/- in 'Actin', 'Foci', as well as 'pCasL' cases. P values P*** <0.0001, obtained using Mann-Whitney two-tailed test.

(C) Synapse breaking behavior of T cells on hydrogels of indicated stiffness, covalently conjugated with 2C11 and ICAM1. These experiments were repeated at least thrice with similar results. In the left graph, n for WT= 14, for WASP-/-, n= 19; P**= 0.0015; in the graph on the right, n for WT= 40, n for WASP-/-= 36, P***= 0.0006, as assessed using Mann-Whitney two-tailed test.

Data information: Central values in the graphs represent Mean and the error bars represent ± SEM.

Expanded View Figure Legends
Structural basis for receptor recognition and pore formation of a zebrafish aerolysin-like protein (2015)
Figure 1

Figure 1: Overall structure of Dln1 dimer.

A. Cartoon representation of the Dln1 dimer (PDB 4ZNO). Subunit A is colored in gray. The lectin module of subunit B is colored in yellow, whereas the middle and C-terminal moieties of the aerolysin module are colored in hot pink and green, respectively. The pre-stem hairpin is colored in blue. The bound sucrose molecules are shown as light pink sticks.

B. The dimeric interface. Residues involved in dimeric interactions are shown as sticks.

C. Multiple-sequence alignment of the pre-stem hairpin (the putative transmembrane region) from different aerolysin members. The members include Dln1, the earthworm Eisenia foetida lysenin, the mushroom Laetiporus sulphureus lectin (LSL) and Aeromonas hydrophila aerolysin. The alignment is generated according to the alternating pattern of hydrophilic and hydrophobic residues by GeneDoc. The hydrophilic and hydrophobic residues are marked in hot pink and gray, respectively.
Structural basis for receptor recognition and pore formation of a zebrafish aerolysin-like protein (2015)
Figure 2

Figure 2: The sugar-binding specificity of the lectin module.

A. A close-up view of the sucrose-binding pocket. Residues hydrogen-bonding with sucrose are shown as yellow sticks, and the sucrose molecule is shown as light pink stick.

B. The glycan binding profile of Dln1. This profile represents FITC-labeled Dln1 at 200 μg/ml screened against 609 printed glycans on Mammalian Printed Array version 5.2 in replicates of six. A list of top 8 hits reacted with a concentration of 200 μg/ml is shown in Appendix Table S1. The two kinds of Dln1-binding glycan structures (No. 214 and 316) are illustrated in schematic.

C&D. Close-up views of Manα1-2Man and Manα1-3Man binding sites. The mannobiose molecules are shown as cyan and gray sticks, respectively. The Fo-Fc electron density maps of disaccharides and the disaccharide-binding sites are shown as gray mesh and countered at 3.0 . The hydrogen-bonding residues are shown as yellow sticks. Polar interactions with the mannobiose are shown as dashed lines.
Structural basis for receptor recognition and pore formation of a zebrafish aerolysin-like protein (2015)
Figure 3

Figure 3: Binding of Dln1 to high-mannose glycans.

A&B. ELISA of Dln1 towards glycosylated gp120 or yeast mannan. The curve represents the average of triplicate detections, using BSA as the control. Points are averages (±standard error of the mean) of triplicate determinations.

C. Binding of FITC-labeled Dln1 and D135A mutant to saccharomyces cerevisiae cells. The scale bar represents 5 μm.

D. Immunoblot analysis of Dln1 and D135A mutant after incubating with S. cerevisiae cells. The seeing bands represent the cell-bound protein after extensive washing the yeast cells. The monomer and oligomer bands are highlighted by the black arrow.
Structural basis for receptor recognition and pore formation of a zebrafish aerolysin-like protein (2015)
Figure 4

Figure 4: In vitro oligomerization and pore-forming activities of Dln1.

A. Oligomerization of Dln1 in the presence of S. cerevisiae mannan or liposomes at different pH values. Histograms are averages (±standard error of the mean) of triplicate determinations.

B&C. Dye release velocity from the liposomes in the presence of Dln1 at different concentrations, and various pH values. Liposomes were incubated with Dln1 of different concentrations at pH 5.5, and 1 μM Dln1 at various pH values, respectively.

D. Oligomerization of Dln1M5 with or without liposomes at different pH values. All samples for electrophoresis were prepared with boiling at 95°C for 5 min, and the comparative gels were processed in parallel. The oligomer band was quantified by Image J software with the average of triplicate detections, using the marker band as a sample processing control. The SDS-PAGE profiles of Dln1 oligomerization were shown in Appendix Fig S4. Histograms are averages (±standard error of the mean) of triplicate determinations.

E. Liposomes were treated with Dln1M5 or Dln1 of different concentrations at a fixed pH value of 5.5.

F. The inhibition of dye release in presence of 0.5 M Dln1M5 and 25 mM polyethylene glycols (PEG) of different molecular weights at a fixed pH value of 5.5. Dye efflux was monitored in a period of 1400 sec. Triton X-100 at 0.1% was added to completely disrupt liposomes. Dye efflux was measured as a percentage to the maximal release upon addition of Triton X-100. Carboxyfluorescein was loaded in the liposomes for the detection of dye efflux.
Structural basis for receptor recognition and pore formation of a zebrafish aerolysin-like protein (2015)
Figure 5

Figure 5: 3D reconstruction of Dln1 octamer.

A. Negative-stain electron microscopy image of Dln1M5 in presence of liposomes.

B. Side views of Dln1M5 oligomers attached to the membrane of liposomes. The inset represents the respective class averages.

C&D. Transmission electron microscope micrograph of dispersed ring-like structures of Dln1M5 or Dln1D135A oligomers on lipid monolayer. The inset represents a few 2D class averages showing the octamer pattern from some individual rings.

E. EM picture of a negatively stained 2D crystal of Dln1M5 on the lipid monolayer. The inset represents the computed diffraction pattern Fourier transform of the image.

F. Projection map with a P4 symmetry.

G. The top, side and cut-open views of the 3D reconstruction of Dln1M5 octamer at 20 Å resolution are shown as gray surface representation. The surface of membrane is indicated by dashed lines. The scale bar is 10 nm.
Structural basis for receptor recognition and pore formation of a zebrafish aerolysin-like protein (2015)
Figure 6

Figure 6: Molecular docking and simulation.

A. Top and side views of eight lectin modules docked to the 20 Å EM map. Due to the moderate resolution of the EM map, the flexible aerolysin module cannot be fit in the map. It is important to notice that this model is only a hypothetical fit. Each pair of the lectin modules are colored in yellow and orange, respectively. The β-barrel of γ-hemolysin (PDB 3B07) was used to mimic the β-barrel backbone of Dln1. The position of cell membrane is indicated by dashed lines.

B. B-factor of Dln1 subunit B. The mobility is represented by coil thickness from thin (low) to thick (high), and color from blue (low) to red (high). Notably, the pre-stem hairpin and distal moiety of aerolysin module are particularly mobile.

C. Position of Cα atoms along MD simulations of apo-form (red) and the pre-stem hairpin extraction form (blue) are shown with the lectin modules superimposed (200 structures for each).
Uncoupling endosomal CLC chloride/proton exchange causes severe neurodegeneration (2020)
Figure 1

Figure 1. Hippocampal morphology and expression of intracellular CLC proteins of Clcn3 mouse models.

(A) Nissl-stained sagittal brain sections reveal no change in hippocampal morphology between Clcn3unc/unc and Clcn3+/+ mice at P45 or after 20 months. In contrast, the hippocampus was absent (indicated by asterisk) in 3 months-old Clcn3-/- mice (scale bar: 200 µm).

(B) Nissl-stained paraffin sections show intact retinal layers in 20 months old Clcn3unc/un mice. Neurodegeneration in Clcn3-/- mice however, results in a loss of retinal structure already at 11 weeks of age (scale bar: 100 µm). RPE, retinal pigment epithelium; OS, photoreceptor outer segments; IS, photoreceptor inner segments; ONL, outer nuclear layer; OPL, outer plexiform layer; INL, inner nuclear layer; IPL, inner plexiform layer; GCL, ganglion cell layer.

(C) Immunoblots for ClC-3, -4 and -5 of membrane fractions of WT (+/+), Clcn3unc/unc (unc/unc), Clcn3unc/+ (unc/+) and Clcn3-/- (-/-) mice. β-actin, loading control.

(D) Representative Western blot for ClC-4 of membrane fractions from brain and kidney of WT (+/+), Clcn3+/- (+/-) and Clcn3-/- (-/-) mice. β-actin, loading control.

(E) Quantification of ClC-4 immunoblots including those shown in (C and D) (normalized to actin). Mean values ± s.e.m. Average from ≥5 animals per genotype and at ≥2 immunoblots per animal. *** p < 0.0005 , ** p < 0.005, * p < 0.05 (two-tailed unpaired t test).
Uncoupling endosomal CLC chloride/proton exchange causes severe neurodegeneration (2020)
Figure 2

Figure 2. Formation of ClC-3/ClC-4 heteromers.

(A) Co-immunoprecipitation reveals a ClC-3-ClC-4 complex. 10% of solubilized brain membranes of WT and Clcn3unc/unc mice were directly loaded on the gel (input, or first immunoprecipitated (IP) with antibodies against ClC-3 or ClC-4. Western blots were probed for ClC-3 and ClC-4. Equivalent amounts of lysates and precipitates were loaded. * unspecific band / contamination.

(B) FRET experiments show homo- and heteromerization of ClC-3 and ClC-4 constructs (fused to yellow fluorescent protein (YFP) and cyan fluorescent protein (CFP)) overexpressed in COS-7 cells. Co-expressed constructs are indicated. Graph represents energy transfer efficiencies from acceptor photobleaching, depicted as bleach corrected values (subtraction of ClC-4CFP alone). Mean values ± s.e.m. N = 20 (ClC-3YFP / ClC-4CFP); 33 (ClC-3YFP / ClC-3CFP); 26 (ClC-4YFP / ClC-4CFP); 42 (ClC-3YFP / Lamp-1CFP) cells. *** p < 0.0005 (two-tailed unpaired t test)

(C) Immunolabelling shows subcellular localization of hClC-4 (top, green in merge), hClC-3 (middle, green in merge) and hClC-3unc (bottom, green in merge) of transiently transfected COS-7 cells, in comparison to either PDI or Lamp-1 (both red) as marker for the ER and late endosomes/lysosomes, respectively.

(D) Co-localization of hClC-3 and hClC-4 in cytoplasmic vesicles of COS-7 cells transfected with hClC-4 cDNA (hemagglutinin (HA) tagged) together with either hClC-3 or hClC-3unc. Immunostaining used antibodies against ClC-3 and HA tag (green and red in merge, respectively).

Data information: DNA stained with DAPI in (C) and (D), (scale bar in (C) and (D): 20 µm).
Uncoupling endosomal CLC chloride/proton exchange causes severe neurodegeneration (2020)
Figure 3

Figure 3. Life span and neurodegeneration of Clcn3/Clcn4 mouse models.

(A) Clcn3unc/unc/Clcn4-/- and Clcn3-/- mice died within 3-4 weeks after birth. Approximately 20% of the animals survived in either line (Clcn3unc/unc/Clcn4-/-, n = 136 and Clcn3-/-, n = 187). All Clcn3-/-/Clcn4-/- mice (n= 4) died within 1-2 weeks after birth.

(B) Nissl-stained paraffin sections show progressive neuronal cell loss (arrows) that begins in hippocampal CA1 region of P14 Clcn3unc/unc/Clcn4-/- mice and results in a complete loss of the hippocampus at P28. Neurodegeneration progresses slower in Clcn3-/- mice Stobrawa et al, 2001() (scale bar: 200 µm).

(C) Semi-thin sections of P28 retinae revealed degeneration of photoreceptor cells in the outer nuclear layer and outer and inner segment of Clcn3unc/unc/Clcn4-/-, but not of Clcn3unc/unc or Clcn4-/- mice (scale bar: 50 µm). RPE, retinal pigment epithelium; OS, photoreceptor outer segments; IS, photoreceptor inner segments; ONL, outer nuclear layer; OPL, outer plexiform layer; INL, inner nuclear layer; IPL, inner plexiform layer; GCL, ganglion cell layer.
Uncoupling endosomal CLC chloride/proton exchange causes severe neurodegeneration (2020)
Figure 4

Figure 4. Subcellular localization of VenusClC-3 and ClC-4 in neurons.

(A) GFP antibodies immunolabel VenusClC-3 (green) in the somata of CA1 pyramidal neurons of Clcn3ven/ven, but not Clcn3+/+ brain sections. sp, stratum pyramidale (scale bar: 20 µm).

(B) Co-immunolabelling of VenusClC-3 (green) with ClC-4 (red) in the CA3 region of Clcn3ven/ven mice (scale bar: 20 µm). sl, stratum lucidum; sp, stratum pyramidale.

(C) Co-immunostaining of VenusClC-3 (green) with EEA1 (red, left panel), Lamp-1 (red, middle panel) or synaptophysin (red, right panel) in either CA1 or CA3 region of Clcn3ven/ven mice. Arrows indicate structures of overlap (scale bar: 5 µm).

(D) GFP antibody immunolabels VenusClC-3 (green) in neurites of cultured neurons. EEA1 and VGLUT1 are co-stained (both in red; left and right panel, respectively). The dendritic marker MAP2 is stained in blue (right panel) (scale bars: 10 µm). DNA stained with DAPI.

(E) Immuno-blot analysis of fractions collected during preparation of SVs from brain of Clcn3ven/ven mice. VenusClC-3 (detected with GFP antibody) co-purified with SV marker protein synaptophysin.

(F) Fluorescence of immobilized Venus-tagged SVs imaged with TIRF microscopy. Scale bar, 2 µm.

(G, H) Co-localization between the Venus-tagged vesicles with antibodies against VGLUT1 and synaptophysin was analyzed. (G) 11.4 ± 0.6 (SD) of VGLUT1-labeled SVs and 8.2 ± 2 (SD) of synaptophysin-labeled SVs showed Venus fluorescence (n=6). (H) 65 ± 5.4 (SD) and 79.4 ± 3.8 (SD) of Venus-tagged SVs showed co-localization with VGLUT1 and synaptophysin, respectively (n=6).

(I) Co-immunolabelling of VenusClC-3 (green) with synaptophysin (red) of immobilized SVs imaged with TIRF microscopy. Vesicle in quadrant delimited by dashed line is shown in higher magnification in merge. Scale bar, 2 µm.
Uncoupling endosomal CLC chloride/proton exchange causes severe neurodegeneration (2020)
Figure 5

Figure 5. ATP-induced acidification of synaptic vesicle-enriched LP2 fraction derived from different Clcn3 and Clcn4 mouse models.

(A) Immunoblots for ClC-3, ClC-4, VGLUT1, VGLUT2, VGAT, GluR4 and GABAA-R-α1 of whole lysates from brain of Clcn3+/+ and Clcn3-/- mice at 2, 6 and 12 weeks of age.

(B) Acidification of synaptic vesicle LP2 fractions from Clcn3unc/unc and Clcn3+/+ mice at one year of age (upper panel, n= 2 animals each and ≥3 measurements per animal), 10-weeks-old Clcn4-/- and WT mice (middle panel, n= 3 animals each and ≥3 measurements per animal), and 4-6-weeks-old Clcn3unc/unc/Clcn4-/- and control mice (lower panel, 6 animals each with ≥2 measurements per animal). A decrease in fluorescence reflects acidification. The protonophore FCCP dissipated the pH gradient. Mean values ± s.e.m.

(C) Quantification of ATP-induced acidification of LP2 fractions derived from 2, 6, and 10-12 weeks-old Clcn3-/- compared to wild-type mice. Acidification measured by acridine orange fluorescence in the presence of 60 mM KCl. At least 2 animals in at least 2 independent experiments were pooled. Each measurement was performed at least 3 times. Mean ± s.e.m. is shown.* p < 0.05, *** p < 0.0005 (two-tailed unpaired t test).

(D) Immunoblot revealed strong reduction of VGLUT1 levels in the homogenate (H) and LP2 fraction of Clcn3unc/unc/Clcn4-/- mice.

(E) Endosomal pH of Clcn3+/+ and Clcn3-/- primary hippocampal neurons determined with a pH-sensitive transferrin conjugate. N= 5 independent cell lines with at least 2 live cell dishes per cell line with about 10 images each and ≥10 Tfn-positive compartments per image and genotype were analysed. Mean ± s.e.m. is shown.
Uncoupling endosomal CLC chloride/proton exchange causes severe neurodegeneration (2020)
Figure 6

Figure 6. Impact of Clcn3 and Clcn4 genotypes on synaptic vesicle exocytosis.

(A-E) Miniature inhibitory postsynaptic currents (mIPSCs) measured in CA1 pyramidal neurons in different mouse models at P14-P16. (A) example mIPSCs of WT (left) and Clcn3-/- neurons. (B-E) Mean values ± s.e.m. and cumulative histogram of amplitude (top) and frequency/interevent-interval (bottom) of mIPSCs in different mouse-models as indicated . Several cells of 3 mice of each genotype were analyzed. Compared genotypes were siblings. No difference in amplitude or frequency/ interevent-interval distribution of mIPSCs was found in (B) Clcn3-/- and Clcn3+/+ (Clcn3+/+: 16 cells, Clcn3-/-: 15 cells; mean amplitude: p > 0.8, t test; mean frequency: p > 0.4, MW-test), in (C) Clcn3unc/unc and Clcn3+/+ (Clcn3+/+: 21 cells, Clcn3unc/unc: 13 cells; mean amplitude: p > 0.7; mean frequency: p = 0.3, t test), and in (D) Clcn4-/- and Clcn3+/+ (Clcn3+/+: 18 cells, Clcn4-/-: 18 cells; mean amplitude: p > 0.3, t-test; mean frequency: p = 0.6, MW-test). (E) No difference in mean amplitude (p > 0.5, t test), in cumulative amplitude and mean frequency of mIPSCs (p > 0.1, t test) was found in Clcn3unc/unc/Clcn4-/- and Clcn3+/+/Clcn4-/-. The interevent-interval distribution was shifted to the right, indicating a reduced frequency of mIPSCs in Clcn3unc/unc/Clcn4-/- (KS-test, p < 0,05) (Clcn3+/+/Clcn4-/-: 16 cells, Clcn3unc/unc/Clcn4-/-: 12 cells).

(F,G) miniature excitatory postsynaptic currents (mEPSCs). (F) example traces of mEPSCs in WT and Clcn3-/- neurons (G) No significant difference between Clcn3unc/unc/Clcn4-/- and Clcn3+/+/Clcn4-/- mEPSCs in mean amplitudes (p > 0.9, t test) or in the distribution of amplitudes (Clcn4-/-: 12 cells, 2 mice; Clcn3unc/unc/Clcn4-/-: 8 cells, 2 mice).

(H) Primary hippocampal neurons co-transfected with ClC-3 and synaptobrevin (syb2), both luminally tagged with pHluorin or the pH-sensitive mOrange Ramirez et al, 2012(), respectively, were stimulated by 200 action potentials (APs) at 20 Hz (indicated by bar). Vesicle exocytosis was monitored by fluorescence increase upon exposure to extracellular neutral pH. Note that only Syb2 and not ClC-3 shows signs of exocytosis. Traces were corrected for photobleaching. The initial decay of the pHluorin signal is probably due to the high light exposure, which forces the fluorophores into a transient dark-state Dean et al, 2011(). Averaged fluorescence traces (n=10), error bars, s.e.m.

Expanded View figure legends