EMBO/SourceData huggingface dataset:
Figure 1A Representative images of eyes and lenses from 6-7 week old wildtype (WT) and nervous system-specific YME1L knockout (NYKO) mice. Orange dashed lines mark eye morphology. Scale bars 5 mm.Retinal sagittal cross-sections from 6-7 week old mice stained with hematoxylin and eosin. NFL = Nerve fiber layer, IPL = inner plexiform layer, INL = inner nuclear layer, OPL = outer plexiform layer, ONL = outer nuclear layer, R&C = Rods and cones. Scale bars 30 µQuantification of nuclei in OPL (area = 1000 µm2) from retina cross-sections of 6-7 week old WT (n = 4) and NYKO (n = 4) mice. Data were analyzed using unpaired t-test, *P ≤ 0.05, **P ≤ 0.01, ***P ≤ 0.001, ****P ≤ 0.0001, ns = not significant. Data are means ± SEM.D Immunoblot analysis of retinal lysates from 6-7 week old WT and NYKO mice. GFAP was used as a marker for reactive astrogliosis and SDHA as a loading control. Data were analyzed using unpaired t-test, *P ≤ 0.05, **P ≤ 0.01, ***P ≤ 0.001, ****P ≤ 0.0001, ns = not significant. Data are means ± SEM.E mRNA levels of proinflammatory cytokines and NF-κB target genes from 6-7 week old retinas (WT, n = 5; NYKO, n = 5). Transcript levels were normalized to Hprt mRNA levels. Data were analyzed using unpaired t-test, *P ≤ 0.05, **P ≤ 0.01, ***P ≤ 0.001, ****P ≤ 0.0001, ns = not significant. Data are means ± SEM.mRNA levels of Fgf21 from 6-7 week old retinas (WT, n = 5; NYKO, n = 5). Transcript levels were normalized to Hprt mRNA levels. Data were analyzed using unpaired t-test, *P ≤ 0.05, **P ≤ 0.01, ***P ≤ 0.001, ****P ≤ 0.0001, ns = not significant. Data are means ± SEM.G Transmission electron micrographs of optic nerves from 6-7 week old WT and NYKO mice. Scale bars 2 µm.
Figure 2Mean body weight of male wild type (WT, n = 15), NYKO (n = 12) and heterozygous NYKO (het NYKO, n = 7) mice from 4-32 weeks. Unpaired t-test was used for the comparison of two groups, ordinary one-way ANOVA for the comparison of three groups. *B Body composition analysis by nuclear magnetic resonance (NMR) of 31-32 week old male WT (n = 12) and NYKO (n = 7) mice. Unpaired t-test was used for the comparison of two groups, ordinary one-way ANOVA for the comparison of three groups. *P ≤ 0.05, *** P ≤ 0.001, ****P ≤ 0.0001. Data are means ± SEM.C Whole-body energy expenditure per kg lean mass of 26 week old male WT (n = 5) and NYKO (n = 5) mice after disease onset. Unpaired t-test was used for the comparison of two groups, ordinary one-way ANOVA for the comparison of three groups.Walking beam test of 6-7 week old (WT, n = 10; NYKO, n = 10), 17-18 week old (WT, n = 8; NYKO, n = 9) and 31-32 week old mice (WT, n = 12; NYKO, n = 19; het NYKO, n = 9). Unpaired t-test was used for the comparison of two groups, ordinary one-way ANOVA for the comparison of three groups. *P ≤ 0.05, *** P ≤ 0.001, ****P ≤ 0.0001. Data are means ± SEM.Walking beam test of 6-7 week old (WT, n = 10; NYKO, n = 10), 17-18 week old (WT, n = 8; NYKO, n = 9) and 31-32 week old mice (WT, n = 12; NYKO, n = 19; het NYKO, n = 9). Hind limb slips per run are shown in E. Unpaired t-test was used for the comparison of two groups, ordinary one-way ANOVA for the comparison of three groups. *P ≤ 0.05, *** P ≤ 0.001, ****P ≤ 0.0001. Data are means ± SEM.F Representative images of 31-32 week old WT and NYKO mice showing aberrant positioning of hind limbs.
Figure 3Brain weights were monitored at 31-32 weeks of age (WT, n = 15; NYKO, n = 14). Unpaired t-test, ns = not significant. Data are means ± SEM.B Nissl stainings of sagittal sections across brain regions from 31-32 week old WT and NYKO mice. 4x and 40x enlargements are shown in the left and right panels, respectively. Scale bars 4x = 500 µm, 40x = 50 µm.C Morphometric analysis of different brain regions from 31-32 week old WT (n = 6) and NYKO (n = 6) mice. GCL = Granule cell layer, ML = Molecular layer. Unpaired t-test, ns = not significant. Data are means ± SEM.Immunoblot analysis of tissue lysates (FB = forebrain; CB = cerebellum) from 31-32 week old WT and NYKO mice, using GFAP-specific and, as a loading control, GAPDH-specific antibodies. Unpaired t-test, ns = not significant. Data are means ± SEM.
Figure 4B Transverse semithin sections of spinal cords of WT and NYKO mice of the indicated age. Sections were stained with toluidine blue. Orange arrows indicate degenerating neurons (Myelin dense bodies, MDBs). Scale bars 25 µm.C Myelin dense bodies (MDBs) in dorso-lateral tracts of 6-7 week old WT (n = 4) and NYKO (n = 4), 17-18 week old WT (n = 4) and NYKO (n = 4) and 31-32 week old WT (n = 6-7) and NYKO (n = 5-6) mice spinal cords. Unpaired t-test, *P ≤ 0.05, ***P ≤ 0.001, ****P ≤ 0.0001, ns = not significant. Data are means ± SEM.D Immunoblots of 31-32 week old spinal cord lysates. GAPDH was used to control for gel loading.E mRNA levels of proinflammatory cytokines from spinal cords of 31-32 week old mice (WT, n = 5; NYKO, n = 5). Transcript levels were normalized to Hprt mRNA levels. Unpaired t-test, *P ≤ 0.05, ***P ≤ 0.001, ****P ≤ 0.0001, ns = not significant. Data are means ± SEM.
Figure 5Fluorescence images of isolated cortical neurons from Yme1lfl/fl animals expressing CAG-GFP (WT) or CAG-Cre-IRES-GFP (Yme1l-/-) at DIV12 and stained with TOMM20 to visualize mitochondria. Scale bars 30 µm.B - E Quantification of total axon length (WT, n = 13 neurons; Yme1l-/-, n = 13 neurons), total dendritic length (WT, n = 12 neurons; Yme1l-/-, n = 13 neurons), axonal branch points (WT, n = 12 neurons; Yme1l-/-, n = 13 neurons) and number of dendrites (WT, n = 12 neurons; Yme1l-/-, n = 13 neurons). Individual neurons originate from two independent preparations. Unpaired t-test, ns = not significant, *P ≤ 0.05.F, G Kymographs showing mitochondrial movements in representative axons. Vertical lines correspond to stationary mitochondria and diagonal lines to moving mitochondria. Mitochondria were stained using Mitotracker. In total 39 axonal segments were analyzed for WT control neurons and 37 axonal segments for Yme1l-/- neurons at DIV7. Data are means of three independent experiments ± SEM. Unpaired t-test, ns = not significant, *P ≤ 0.05.H, I Kymographs showing mitochondrial movements in representative axons. Vertical lines correspond to stationary mitochondria and diagonal lines to moving mitochondria. Mitochondria were stained using Mitotracker. In total 120 axonal segments were analyzed for WT control neurons and 107 axonal segments for Yme1l-/- neurons at DIV10-14. Data are means of three independent experiments ± SEM. Unpaired t-test, ns = not significant, *P ≤ 0.05.J Axonal area occupied by mitochondria in Yme1l-/- neurons relative to WT controls. In total 120 axonal segments were analyzed for WT control neurons and 107 axonal segments for Yme1l-/- neurons at DIV10-14. Data are means of three independent experiments ± SEM. Unpaired t-test, ns = not significant, *P ≤ 0.05.
Figure 6A, B Oxygen consumption rates of spinal cord mitochondria isolated from WT (n = 4) and NYKO (n = 4) mice in the presence of pyruvate-glutamate-malate (C I) and pyruvate-glutamate-malate + succinate (C I + C II) as substrates. State 3 (substrates + ADP), state 4 (+ oligomycin), uncoupled (+ FCCP). Unpaired t-test, *P ≤ 0.05, **P ≤ 0.01, ***P ≤ 0.001, ns=not significant. Data are means ± SEM.C, D TEM of dorso-lateral tracts of spinal cords of 6-7 week old WT (n = 4, 1209 mitochondria) and NYKO (n = 4, 1792 mitochondria) mice, 17-18 week old WT (n = 4, 442 mitochondria) and NYKO (n = 4, 724 mitochondria) mice and 31-32 week old WT (n = 3, 764 mitochondria) and NYKO (n = 3, 817 mitochondria) mice. Scale bars, 200 nm. Unpaired t-test, *P ≤ 0.05, **P ≤ 0.01, ***P ≤ 0.001, ns=not significant. Data are means ± SEM.
Figure 7A TEM analysis of sagittal spinal cord sections of 6-7 week old WT and NYKO mice. Scale bars 500 nm.B Frequency distribution of mitochondrial lengths in spinal cords of 6-7 week old WT (182 mitochondria) and NYKO mice (192 mitochondria). Kruskal-Wallis test, *P < 0.05C TEM analysis of cerebellar sections of 28-32 week old WT and NYKO mice. Scale bars 1 µm. D Frequency distribution of mitochondrial aspect ratios were calculated from WT (n = 210) and NYKO (n = 230) mitochondria. Mann-Whitney test, ****P < 0.0001. Data are presented as median values. Immunoblot analysis of forebrain, cerebellar and spinal cord lysates from 31-32 week old WT and NYKO mice (n = 3) using the indicated antibodies. SDHA and LONP1 were used to control for gel loading. * indicates unspecific antibody binding.
Figure 8Immunoblot analysis of retinal and spinal cord lysates from 6-7 week old WT, NYKO, NOKO and NYOKO mice (n = 3) using the indicated antibodies. SDHA was used as a loading control. * was not reproducibly detectable in all experiments.B Frequency distribution of mitochondrial lengths in spinal cords of 6-7 week old NYOKO mice (176 mitochondria) compared to WT Kruskal-Wallis test, ns = not significant. Data were analyzed using one-way ANOVA.Representative images of eyes and lenses from 6-7 week old WT and mice lacking OMA1 (NOKO) or both YME1L and OMA1 (NYOKO) in the nervous system. Orange dashed lines mark eye morphology. Scale bars 2.5 mm.D Immunoblot analysis of retina lysates of 6-7 week old WT, NYKO, NOKO and NYOKO mice (n = 3). SDHA was used to control for gel loading.E Transverse semithin sections of spinal cords of 6-7 week old WT, NOKO and NYOKO mice. Sections were stained with toluidine blue. Orange arrows point to MDBs indicating degenerating neurons. Scale bars 25 µm.F MDBs in dorso-lateral tracts of 6-7 week old WT (n = 3), NOKO (n = 3), and NYOKO (n = 3) mice. Data were analyzed using one-way ANOVA. ***P ≤ 0.001, ****P ≤ 0.0001, ns = not significant. Data are means ± SEM.G Walking beam test of 6-7 week old WT (n = 6), NOKO (n = 5) and NYOKO (n = 7) mice. Data were analyzed using one-way ANOVA. ***P ≤ 0.001, ****P ≤ 0.0001, ns = not significant. Data are means ± SEM.
Figure 2 B In vitro substrate ubiquitylation assay for Hrd1 with Ubc7 (left) and Ubc6 (right). Ubc7 reactions contained equimolar amounts of Cue1 and were performed with Ub(K48R). Top: representative immunoblot using a poly-clonal α-RNase A antibody; "no E3" reactions do not contain S-Hrd1, "no ATP" reactions do not contain ATP, but S-Hrd1. The RNase-Ub2 band co-migrates with a nonspecific band (#) common to all samples. Bottom: Quantification of RNase-Ub signals is shown. Values are reported as means ± standard deviation (n = 3). Significances for pairwise comparisons were determined by One-way ANOVA Test; * p < 0.05. For clarity, only significances related to the "no E3" control of a given E2 are shown.  C In vitro Ub nucleophile discharge assays for Hrd1 with U7BR/Ubc7 (top - yellow) and Ubc6 (bottom - green) with ethanolamine as nucleophile. Representative Coomassie gels are shown.  D Quantification of Ub nucleophile discharge assays for Hrd1 with U7BR/Ubc7 (left) and Ubc6 (right). Plots of E2~Ub discharge (dots) as a function of time with first-order reaction models fitted to the discharge data (lines) are shown. Values for each time point are reported as means ± standard deviation (n = 3). Insets show reaction rates derived from these fits. Significances were determined by student T-test; * p < 0.05. (E) Stimulation of U7BR/Ubc7 and Ubc6 discharge activities by Hrd1. E2 stimulation is reported as the ratio of rates derived from RING-catalyzed reactions and "no E3" controls in D. Values are reported as means ± standard deviation (n = 3). Significance was determined by student T-test; * p < 0.05.
Figure 3 A In vitro Ub nucleophile discharge assays for U7BR/Ubc7 with indicated Hrd1 (left) and Doa10 (right) variants. E2 stimulation is shown as the ratio of rates derived from RING-catalyzed reactions and the "no E3" control (see Fig. EV2C-D). Values are reported as means ± standard deviation (n = 3). Significances for pairwise comparisons were determined by One-way ANOVA Test; * p < 0.05. For clarity only significances related to the "no E3" control are shown. In addition, reactions for Hrd1(400R) and Doa10(94R) are significantly faster than all other reactions and the reaction for Doa10(94H) is significantly faster than that for Doa10(94E). The wild-type E3s are identified by black frames for each set.  B In vitro Ub chain formation assay by Ubc7 with indicated Hrd1 (left) and Doa10 (right) variants in the presence of indicated Cue1 variants. Rates for reactions of mono-Ub to di-Ub and di-Ub to tri-Ub with fluorescently-labeled Ub are shown on a logarithmic scale. Values are reported as means ± standard deviation (n = 3). Significances for pairwise comparisons were determined by One-way ANOVA Test; * p < 0.05. For clarity only significances related to the "no E3" control of given reaction set are shown.  D Protein degradation in indicated yeast strains monitored by pulse-chase experiments for the Hrd1 model substrate PrA*-3xHA (left) and by CHX decay assays for the Doa10 model substrate Deg1-eGFP2 (right). Values for each time point are reported as means ± standard deviation (n = 4 for PrA*-3xHA and n = 3 for Deg1-eGFP2).
Figure 4 A Protein degradation in indicated yeast strains monitored by pulse-chase experiments for the Hrd1 model substrate PrA*-3xHA (left) and by CHX decay assays for the Doa10 model substrate Deg1-eGFP2 (right). Values for each time point are reported as means ± standard deviation (n = 4 for PrA*-3xHA and n = 3 for Deg1-eGFP2). Data for control strains (Hrd1(400R) wt, Δhrd1, Doa10(94H) wt and Δdoa10) is the same as in Fig. 3D.  B In vitro substrate ubiquitylation assay for Hrd1 variants with Ubc7. Ubc7 reactions contained equimolar amounts of Cue1 and were performed with Ub(K48R). Top: representative immunoblot using a poly-clonal α-RNase A antibody; "no E3" reaction does not contain any S-Hrd1, "no ATP" reaction does not contain ATP, but wild-type S-Hrd1(400R). The RNase-Ub2 band co-migrates with a nonspecific band (#) common to all samples. Bottom: Quantification of RNase-Ub signals is shown. Values are reported as means ± standard deviation (n = 3). Significances for pairwise comparisons were determined by One-way ANOVA Test; * p < 0.05. For clarity, only significances related to the "no E3" control are shown. In addition, the reaction containing S-Hrd1(400R) shows significantly more ubiquitylation than those with other E3 variants.  C In vitro Ub nucleophile discharge assays for Ubc6 with indicated Doa10 variants. E2 stimulation is shown as the ratio of rates derived from RING-catalyzed reactions and the "no E3" control (see Fig. EV2E). Values are reported as means ± standard deviation (n = 3). Significances for pairwise comparisons were determined by One-way ANOVA Test; * p < 0.05. For clarity only significances related to the "no E3" control are shown. In addition, the reaction for Doa10(94R) is significantly faster than that for Doa10(94H) and (94E). The wild-type E3 is identified by a black frame. The scale of the y-axis was set identical to that of plots from other discharge assays  D In vitro substrate ubiquitylation assay for Doa10 variants with Ubc7 (left) and Ubc6 (right). Ubc7 reactions contained equimolar amounts of Cue1 and were performed with Ub(K48R). Top: representative immunoblot using a poly-clonal α-RNase A antibody; "no E3" reaction does not contain any S-Doa10, "no ATP" reaction does no contain ATP, but wild-type S-Doa10(94H). The RNase-Ub2 band co-migrates with a nonspecific band (#) common to all samples. Bottom: Quantification of RNase-Ub signals is shown. Values are reported as means ± standard deviation (n = 3). Significances for pairwise comparisons were determined by One-way ANOVA Test; * p < 0.05. For clarity, only significances related to the "no E3" control of a given E2 are shown. In addition, the reaction containing Ubc7 and S-Hrd1(400R) shows significantly more ubiquitylation than those with Ubc7 and other E3 variants.
Figure 5 A E2~Ub hydrolysis assays for U7BR/Ubc7 and Ubc6. E3-independent Ub discharge assays for both E2s in PBS (absence of nucleophile = hydrolysis) were performed at 32°C. Left: representative Coomassie gels. Right: Plots of E2~Ub hydrolysis (dots) as a function of time with first-order reaction models fitted to the discharge data (lines) are shown. Values for each time point are reported as mean ± standard deviation (n = 3).  B HSQC-TROSY experiments comparing free and E2-conjugated (15N)Ub. Top: CSPs of (15N)Ub(G76C) conjugated to indicated E2s via disulfide bond (775 µM each) compared to free (15N)Ub(G76C) are shown; Ub resides known to be involved in the closed conformation interface are underlined in grey; * = number of resonances with perturbations too large to be assigned confidently (shown as off-scale in diagram). Bottom: Spectra of resonances for selected residues in Ub's hydrophobic patch for free Ub(G76C) (gray) and Ub conjugated to Ubc6 (green) and U7BR/Ubc7 (yellow).
Figure 6 Protein degradation in indicated yeast strains monitored by pulse-chase experiments for the Hrd1 model substrates PrA*-3xHA Values for each time point are reported as means ± standard deviation (n = 4 for PrA*-3xHA For A, data for control strains (Hrd1(400R) wt, Hrd1(400H) and Δhrd1) are the same as in Fig. 3D and 4A.  Protein degradation in indicated yeast strains monitored by CHX decay assays for the Doa10 model substrates Deg1-eGFP2 Values for each time point are reported as means ± standard deviation n = 3 for Deg1-eGFP2  Protein degradation in indicated yeast strains monitored by CHX decay assays for the Doa10 model substrates FLAG-Sbh2 Values for each time point are reported as means ± standard deviation n = 3 for FLAG-Sbh2  Protein degradation in indicated yeast strains monitored by pulse-chase experiments for the Hrd1 model substrates PrA*-3xHA Values for each time point are reported as means ± standard deviation (n = 4 for PrA*-3xHA For D, data for control strains (Doa10(94H) wt and Δdoa10) are the same as in Fig 3D and 4A.  Protein degradation in indicated yeast strains monitored by pulse-chase experiments for the lysine-less CPY*-K0-HA Values for each time point are reported as means ± standard deviation  Protein degradation in indicated yeast strains monitored by pulse-chase experiments for FLAG-Sbh2 Values for each time point are reported as means ± standard deviation n = 3 for FLAG-Sbh2
Figure 2C. Confocal images of U2OS cells transiently expressing lifeAct-GFP wild type and mutants of lifeAct residues interacting with F-actin, cells were additionally stained with SiR-actin to confirm the actin filaments. The line scan as indicated with yellow line on the cells shows the extent of lifeAct (green) and SiR-actin (magenta) co-staining of actin structures. Scale bar = 5µm.D. Binding affinities calculated from titration data of co-sedimentation assays of lifeAct-14 (1.2µM) and lifeAct-17 (2.2µM) as indicated. Data points for each concentration were averaged from 3 independent experiments, error bars represent S.D between independent experiments.
Figure 3C. Representative TIRF images of lifeAct binding experiments as indicated. The remaining lifeAct concentration images are shown in Supplement Figure 4. Scale bar = 5µm.D. Mean ratio of lifeAct fluorescent intensity bound to phalloidin and jasplakinolide F-actin (mean and s.e.m; n = 2 or 3 independent experiments with >50 actin filament for each set).
Figure 5A. Representative Coomassie stained SDS-PAGE gels of UTRN-ABD and UTRN-V87D co-sedimentation with F-actin. Pellet (top) and supernatant (bottom) fractions of individual co-sedimentation reactions of increasing utrophin concentrations, uncropped gel images of all the co-sedimentation reactions are presented in Supplement Figure 6.B. Apparent Kd indicated was calculated from the titration data of co-sedimentation assays of utrophin wildtype (1.8µM) and mutants; H29A (2.8µM), I22D (38µM), V87D (>100µM) and N109A (55µM) as indicated. Data points for each concentration were averaged from 3 independent experiments, error bars represent S.D between independent experiments.C. Confocal images of U20S cells transfected with GFP tagged UTRN-mini and mCherry UTRN-ABD, stained with SIR-Actin shows F-actin structures, mainly stress fibers. Scale bar = 5µm.
Figure 1Electron microscopy revealed a number of demyelinated or degenerated axons in PLP-150Q mice at the age of 5 months. LAQ (5 mg/kg) treatment at 3 months of age for 2 months improved myelination in PLP-150Q mice. Scale bars: 2μm (Low magnification) and 0.5 μm (High magnification).G-ratios, which were calculated and plotted against axon diameter with linear regression, were shown beneath the micrographs and were significantly decreased in PLP-150Q mice after LAQ treatment (G=0.6418±0.0191), compared with age-matched vehicle group (G=0.7727±0.0203). One-way ANOVA with Tukey's test. *P=0.0166. At least 182 axons per genotype were examined from 3 mice in each group.Western blotting showing that LAQ (5 or 25 mg/kg) treatment for 2 months up-regulates multiple myelin proteins (MBP, MOBP and MOG) in the corpus callosum in PLP-150Q mice, which were treated from 3 months of age. Ratios of MBP, MOBP or MOG to vinculin obtained from 3 independent experiments were presented on the right. One-way ANNOVA followed with Tukey's test. MBP: ***P=0.0009; MOG: ***P=0.0003; MOBP: **P=0.0067. Data are mean ±SEMQuantitative PCR of the transcript expression of myelin associated genes (MBP and MOG) in PLP-150Q mouse corpus callosum at 5 months of age after LAQ (5 or 25 mg/kg) treatment for 2 months. Student's t-test. MBP: ***P=0.0007; MOG: ***P=0.0009. Data are mean ±SEM (n=3).The MBP DNA promoter was inserted into the pGL4.1 luciferase report vector and was co-expressed with N-terminal MYRF (nMYRF) and mHTT to assess its transcription activity via the luciferase assay. MYRF markedly enhanced the MBP promoter activity. N-terminal mutant HTT significantly inhibited the reporter activity, ***P< 0.001; which was reversed by LAQ (5 μM) treatment, **P< 0.01. The ratios were obtained from 3 independent experiments. One-way ANNOVA followed with Tukey's test. Data are mean ±SEM.Immunoprecipitation of transgenic mHTT from 3-month-old PLP-150Q mouse brains revealed that 5 or 25 mg/kg LAQ treatments for 2 months reduced the interaction between transgenic mutant HTT and MYRF. fMYRF: full-length MYRF; nMYRF: N-terminal MYRF. The ratio of immunoprecipitated MYRF to input obtained from 3 independent experiments was shown on the right. One-way ANNOVA followed with Tukey's test. **P=0.009. Data are mean ±SEM.