EMBO/SourceData huggingface dataset:
Figure 3Growth factor-depleted Huh7.5 cells were prestimulated with 2.8 pM, 28 pM, 1400 pM IFNα or left untreated and were stimulated with 1400 pM IFNα 24 hours later. IFNα-induced signaling was measured by time-resolved quantitative immunoblotting and detected with chemiluminescence using a CCD-based camera. Data was normalized to reference proteins Calnexin or HDAC1, scaled and subjected to model calibration.   Model calibration with time-resolved IFNα-induced phosphorylation of STAT1 and STAT2 and induced feedback proteins upon prestimulation with 0, 2.8 pM, 28 pM or 1400 pM IFNα. Cytoplasmic lysates were subjected to quantitative immunoblotting. Experimental data is represented by filled circles with errors representing 1σ confidence intervals estimated from biological replicates (N=3 to N=23) using a combined scaling and error model. Model trajectories are represented by lines. pSTAT1, pSTAT2 represent phosphorylated STAT1 and STAT2 on residue Tyr701 and Tyr690, respectively. tSTAT1 and tSTAT2 represent total form of STAT1 and STAT2 comprising both phosphorylated and unphosphorylated STAT1, STAT2, respectively.   Model calibration with time-resolved IFNα-induced feedback transcripts upon prestimulation with 0, 2.8 pM, 28 pM or 1400 pM IFNα, assessed by qRT-PCR. mRNA levels were normalized to the geometric mean of reference genes GAPDH, HPRT and TBP. Experimental data is represented by filled circles with errors representing 1σ confidence-interval estimated from biological replicates (N=3 to N=14) using a combined scaling and error model. Model trajectories are represented by lines.Model calibration with the amount of molecules per cell of STAT1, STAT2, IRF9 and USP18 determined 24 hours after prestimulation with 0, 2.8 pM, 28 pM or 1400 pM IFNα. Calibrator proteins were spiked into 10 µg of total protein lysate and subjected to quantitative immunoblotting. Immunoblot detection was performed by chemiluminescence using a CCD-camera-based device. Averaged values (N=4) are displayed with standard deviations. Green squares indicate amounts estimated by the mathematical model.Model calibration of IFNα-induced phosphorylation of STAT1 and STAT2 upon stimulation of Huh7.5 prestimulated with 0, 2.8 pM, 28 pM or 1400 pM IFNα. Nuclear lysates were subjected to quantitative immunoblotting. Experimental data is represented by filled circles with errors representing 1σ confidence-interval estimated from biological replicates (N=4 to N=22) using a combined scaling and error model. Model trajectories are represented by lines.
Figure 5Knockdown of USP18 results in sustained signaling. USP18 knockdown efficiency determined by quantitative immunoblotting of cytoplasmic lysates of Huh7.5 transfected with USP18 siRNA relative to parental Huh7.5 cells and Huh7.5 cells transfected with non-targeting siRNA. Cells were stimulated with 1400 pM IFNα for 24 hours. Error bars represent 1σ confidence intervals estimated from biological replicates (N=6 to N=10) (left). Model fit and experimental data of Huh7.5 cells transfected with control siRNA or USP18 siRNA are shown. Cells were transfected with USP18 siRNA or control siRNA 1 day prior to growth factor-depletion. Next, cells were prestimulated with 1400 pM IFNα (yellow background) and stimulated with 1400 pM IFNα at 24 hours or untreated (white background). IFNα-induced phosphorylation of STAT1 and STAT2 and induction of USP18 and tSTAT1, comprising both phosphorylated and unphosphorylated STAT1 protein, are displayed. Experimental data were obtained by quantitative immunoblotting using chemiluminescence and CCD camera device (ImageQuant). For model purposes data in control siRNA and untransfected Huh7.5 are combined to one condition. Data from multiple time courses scaled together is displayed as filled circles with errors representing 1σ confidence interval estimated from biological replicates (N=2 to N=10) using a combined scaling and error model. Lines represent model trajectories.Overexpression of Huh7.5 is not sufficient to explain negative memory. Induced expression of USP18 after treatment of Huh7.5-TetON-USP18 and Huh7.5-TetON-control cells with doxycycline for 24 hours in comparison with parental Huh7.5 cells treated with 1400 pM IFNα for 24 hours. Analysis was performed by quantitative immunoblotting. Error bars represent 1σ confidence intervals estimated from biological replicates (N=3 to N=5) (left). Model fits and experimental data of Huh7.5-TetON-USP18 treated with doxycycline for 24 hours and stimulated with 1400 pM IFNα or parental Huh7.5 cells prestimulated with 0 or 1400 pM IFNα and stimulated with 1400 pM IFNα after 24 hours are shown. The dynamics of IFNα-induced phosphorylation of STAT1 and STAT2 and induction of USP18 are depicted. Experimental data was obtained by quantitative immunoblotting using chemiluminescence and CCD camera device (ImageQuant). For modeling purposes data from Huh7.5-TetON empty vector control and untransduced Huh7.5 are combined to one condition. Data is displayed as filled circles with errors representing 1σ confidence-interval estimated from biological replicates (N=3 to N=4) using a combined scaling and error model. Line represents model trajectories.
Figure 6The number of molecules per cell for STAT1, STAT2, IRF9 and USP18 were determined experimentally in primary human hepatocytes from six different patients. Cells were harvested without pretreatment and different amounts of protein calibrators were spiked in total cell lysates and lysates were subjected to immunoblotting. Detection was performed with antibodies specific to STAT1, STAT2, IRF9 or USP18 using chemiluminescense on a CCD camera-based device (ImageQuant). Average of at least N=3 are displayed with standard deviations. Data was used for calibration of a primary human hepatocyte-specific mathematical model and estimated values are shown with green squares.Experimental data and model fits of IFNα- and Roferon-induced phosphorylation of cytoplasmic or cellular STAT1 and STAT2 in growth factor-depleted primary human hepatocytes prestimulated with 0, 2.8 or 1400 pM IFNα (patients 1-3) or 0, 1.2 or 608 pM Roferon (patients 4-6). Primary human hepatocytes from the same patients 1-6 as in (B) were used. Experimental data is represented by filled circles (N=1 per patient). Experimental errors were estimated from the signal variance of the hepatocytes prestimulated with 1400 pM IFNα. Lines indicate model fits.
Figure 7Plasma levels of IFNα were measured in a cohort of 36 patients with chronic HBV.
Figure 1(C) Western blot showing that Hel2(1-315) is defective in RQC but not in NGD. The arrest products derived from the R(CGN)12 reporter in ltn1∆ cells expressing truncated Hel2 mutant protein were detected with an anti-GFP antibody.(D) Northern blot showing the 5' NGD-IM derived from the R(CGN)12 reporter in ski2∆ cells expressing the indicated Hel2 mutant proteins. 5' NGD-IMs were detected with a DIG-labelled GFP probe.(E) Primer extension mapping of 5' ends of 3' NGD-intermediates in Hel2-WT or Hel2(1-315) mutant cells at nucleotide resolution. . The primer extension samples were analysed using 5% TBE-Urea-PAGE and detected by fluorescence. Non-specific reverse transcription (ReTr) products are indicated by asterisks.
Figure 2(A) Northern blot analysis demonstrating that K63-linked ubiquitination was required for an endonucleolytic cleavage by R(CGN)12. The ski2∆UB-WT and ski2∆ub-K63R cells were transformed with the R(CGN)12 reporter, and total RNA samples were separated by 2% agarose/MOPS gel. 5'NGD-IMs in the cells were detected as in Fig 1D.(B) Western blot showing that K63-linked ubiquitination was required for RQC. Protein samples from UB-WT, UB-WT ltn1∆, ub-K63R, ub-K63R ltn1∆ cells expressing the GFP-R(CGN)12-HIS3 reporter were subjected to Western blot analysis using an anti-GFP antibody to detect the arrest products. Note the accumulation of RQC-specific CAT-tails in lane 2.(C) Western blot analysis demonstrating polyubiquitination of uS10: Affinity-tagged Hel2-Flag-TEV-ProteinA (FTP) was co-purified with ribosomes harbouring HA-tagged wild type uS10 (uS10-3HA ribosomes) or uS10 mutated in its ubiquitination sites (K6/8R). Western blots of whole protein extracts were performed using an anti-HA antibody to detect polyubiquitinated uS10-3HA.(D) Western blot analysis showing that uS10-polyubiquitination in Hel2-bound ribosomes was mainly K63-linked: Affinity tagged Hel2(Hel2-ProteinA-TEV-His6; PTH-Hel2) was co-purified with ribosomes from a strain expressing wild type ubiquitin (UB-WT) or K63R mutant ubiquitin (ub-K63R) and HA-tagged uS10 (uS10-3HA). Western blot analysis of whole protein extracts was performed using anti-HA antibody.(E) Western blot of in vitro polyubiquitination assays of uS10. Reactions were performed with the indicated components including His-tagged ubiquitin and several ubiquitin mutants. Polyubiquitinated HA-tagged uS10 (uS10-3HA) was detected by Western blot analysis using an anti-HA antibody.(F-H) Northern blot analysis of NGD-cleavage sites in the absence of uS10 ubiquitination or RQT complex components: The full-length GFP-R(CGN)12-FLAG-HIS3 mRNA and 5' NGD-intermediates (5' NGD-IM) or 3' NGD-intermediates (3' NGD-IM) were detected in the indicated mutant cells by Northern blotting with DIG-labelled probes. 5' NGD-intermediates were detected by DIG-labelled GFP probe and 3' NGD-intermediates were detected by the DIG-labelled HIS3 probe. SCR1 was used as loading control. FL = full-length. Note the upstream shift of NGD cleavage sites in lanes F4, G4, H6, and H8.(I) Mapping of 5' ends of 3' NGD-intermediates as demonstrated in Fig 1E. Non-specific reverse transcription (ReTr) products are indicated by asterisks. Note that both uS10 ubiquitination and Slh1/Rqt2 were required for an endonucleolytic cleavage within the road-blocked ribosome (X1-X4).
Figure 3Both RQC and NGDRQC+ are triggered by a (CGA-CCG) dicodon containing arrest sequence in vivo. (B) Western blot showing the arrest products derived from the GFP-X-FLAG-HIS3 reporter. Translation products were detected by western blot using an anti-GFP antibody.Both RQC and NGDRQC+ are triggered by a (CGA-CCG) dicodon containing arrest sequence in vivo. (C) Northern blot for the 5' NGD-IM derived from the (CGA-CCG) reporter in ski2∆ cells. 5'-NGD-IMs were detected with a DIG-labelled GFP probe. SCR1 was used as a load control.(D) Western blot of test translations using the (CGA-CCG) dicodon stalling mRNA reporter shown in (A). The mRNA reporter was added to a yeast in vitro translation extract obtained from a ski2∆uS10-3HA strain. Expression of the translation products (free His- and V5 tagged truncated uL4 protein and the same protein attached to tRNA) was visualized with an anti-V5 antibody.(E) Sucrose gradient fractions (top) and western blot analysis (bottom) of the (CGA-CCG) dicodon-stalled RNC samples. After the translation reaction, the RNCs were affinity-purified as indicated in (C). The eluate was loaded on a 10-50 % sucrose gradient and fractionated. Each collected fraction was analysed using anti-HA antibody to detect uS10-HA. Note that disomes are preferentially polyubiquitinated over monosomes.
Figure 6(A) Western blot analysis after overexpression of Hel2 in strains expressing HA-tagged ribosomal proteins using an anti-HA antibody. Note the increase of the polyubiquitinated eS7 as well as uS10 and uS3.(C) Western blot analysis showing the role of Hel2 and Not4 in eS7A ubiquitination: Both copies of eS7 (eS7A and eS7B) were deleted and transformed with a plasmid containing HA-tagged eS7A (eS7-WT) or eS7A mutated in the four potential ubiquitination sites (4KR). Whole protein extracts we obtained from eS7AΔeS7BΔ cells or cells with an additional deletion in E3 ligases Hel2 and Not4 (hel2Δ and not4Δ). Note that the four mutated lysine residues were responsible for Not4-dependent monoubiquitination.(D) Western blot showing that Not4 was required for Hel2-mediated polyubiquitination of eS7 in Hel2-bound ribosomal complexes: Cells expressing HA-tagged eS7A or the eS7-4KR mutant, as well as PTH-tagged Hel2 in eS7AΔeS7BΔ and eS7AΔeS7BΔnot4Δ background were probed for eS7-ubiquitination. Either cell lysates or affinity-purified Hel2-ribosome complexes were used. The levels of the ubiquitinated eS7A in the lysates and in the affinity-purified samples with PTH-Hel2 were determined by Western blot analysis using an anti-HA antibody to detect eS7.(E) Western blotting of in vitro ubiquitination assays of eS7A. The reactions were performed with the indicated components including His-tagged ubiquitin. Ribosomes were purified from Hel2Δ cells expressing HA-tagged eS7A. Polyubiquitinated HA-tagged eS7A (eS7A-3HA) was detected by Western blot analysis using an anti-HA antibody. We observed Hel2-mediated polyubiquitination of the monoubiquitinated eS7A.(F) Western blot analysis of eS7A in vitro ubiquitination assays showing that Hel2-mediated polyubiquitination of eS7 was mainly K63-linked and required Not4-dependent monoubiquitination: These assays were performed similarly as described in (E) except yeast strains were lacking Not4 (not4Δ). Reactions were performed with the indicated components including His-tagged ubiquitin and several ubiquitin mutants and eS7A-ubiquitination was monitored using an anti-HA antibody.
Figure 7(A-C) Northern blots probing for the 5' NGD-IM in mutant cells expressing the R(CGN)12 reporter. (A) 5' NGD-IM detection in not4∆ski2∆, hel2∆ski2∆, slh1∆ski2∆, not4∆ slh1∆ski2∆. Quantification of full length and the 5'NGD-IM relative to the loading control (SCR1) is given below. Note the size difference of 5'-NGD IMs resulting from NGDRQC+ and NGDRQC- and that the shorter 5'-NGD intermediate (representing intermediates of the NGDRQC- pathway) was reduced in not4∆slh1∆ski2∆ mutant cells.Northern blots probing for the 5' NGD-IM in mutant cells expressing the R(CGN)12 reporter. (B) Northern blot as in (A) except uS10-WTski2∆ or uS10-K6/8Rski2∆ mutant cells with or without a deletion of Not4 (not4∆) were used. Note that the shorter 5'-NGD intermediates are also reduced in ski2∆not4∆uS10-K6/8R cells.Northern blots probing for the 5' NGD-IM in mutant cells expressing the R(CGN)12 reporter. (C) Cells expressing HA-tagged eS7A or the eS7A-4KR mutant in a ski2ΔeS7AΔeS7BΔ or ski2ΔeS7AΔeS7BΔslh1Δ backgrounds were probed for 5'-NGD intermediates by Northern blotting. Note that the four mutated lysine residues in eS7 were responsible for NGDRQC- in the R(CGN)12 reporter.(D) Western blot analysis showing that K83 and K84 of eS7A are main target sites for Hel2 and Not4-mediated ubiquitination: Similarly, as in Fig 6C, eS7AΔeS7BΔ mutant cells were used and wild type and single mutants of HA-tagged eS7A were expressed. Ubiquitinated eS7-HA was monitored using an anti-HA antibody.(E) Northern Blot analysis probing for the levels of 5' NGD-IM derived from the R(CGN)12 reporter expressed in eS7AΔeS7BΔski2Δ cells and HA-tagged eS7 or eS7 mutants. We observed, that ubiquitination at K83 or K84 of eS7A is mainly responsible for NGDRQC-.(F) The levels of polyubiquitinated eS7A were increased by the overproduction of wild-type Hel2 (FL) but neither Hel2ΔRING nor Hel2(1-315) mutants. eS7A-3HAhel2Δ mutant cells harbouring the indicated plasmids expressing wild-type Hel2 (FL), Hel2ΔRING or Hel2(1-315) mutant proteins were harvested. Protein samples were analysed by Western blotting with an anti-HA (Top panel) or anti-FLAG antibody (Bottom panel).(G) Hel2(1-315) polyubiquitinates eS7A but not uS10. Western blotting after an in vitro ubiquitination assay using the Hel2-(1-315) mutant and purified ribosomes containing HA-tagged uS10.
Figure 4M-O: Schematic describing the measurement of a cell's approach angle to the nearest point on the AER (M). Merged, immunofluorescent images of WT (top), slit3sq49 (centre) and s1pr2te273 (below) mesenchymal cells in sqet37Et background stained for EGFP (green), Gamma tubulin (red) and DAPI (blue). White lines run from the centre of nucleus to the nearest point on the AER, through the MTOC (N). Graph depicting the approach angles to AER of leading (Tier 1), following (Tier 2) and trailing (Tier 3) cells of WT, slit3sq49 and s1pr2te273 embryos (O). A minimum of 30 cells were measured for each tier of each genotype. *p<0.05; **p<0.005; ***p<0.001; ANOVA with Fisher's post-test.
Figure 5C-E: Lateral Nomarski images of 48hpf larval fins which are WT (C) or slit3+/sq49 heterozygotes (D) and are injected with 300µM fn1a morpholino. Blisters are observed only when there is reduced Fn1a in slit3 heterozygotes (quantified in E).F-G: Lateral Nomarski images of 48hpf WT larval fins injected with 200µM gna13b alone (F) or with 300µM fn1a morpholino (G). H: Quantification of the proportion of larvae with fin blisters when low amounts of gna13 morpholinos (125µM each gna13a and gna13b MO combined or 200µm gna13b MO alone) are injected into WT, fn1a morphants (300µM MO), fn1a+/- heterozygotes and fn1a-/- mutants. Loss of a single or both copies of fn1a exacerbates reduced gna13 levels, as does knockdown of fn1a.
Figure 1Immunoblot analyses of TDG and TDG-SUMO in whole cell extracts of mESCs and MEFs. TDG and TDG-SUMO conjugates before (2i, 0 h) and during differentiation of TDG wildtype (TDGwt) and TDG deficient (TDGnull) mESC and MEFs (5 µM all-trans retinoic acid (RA, 24 h, 48 h). Percentages of TDG-SUMO relative to total TDG signal are indicated.Immunoblot analyses of TDG, TDG-SUMO in whole cell extracts of mESCs TDG and TDG-SUMO before and after H2O2 treatment (10 mM, 15 min).Immunoblot analyses of TDG and TDG-SUMO in whole cell extracts of mESCs Chromatin fractionation from mESCs expressing wildtype (ESC-TDGwt) or SUMOylation-deficient TDG (ESC-TDGsnm). Sol, chromatin unbound proteins; Chr1, chromatin associated proteins; Chr2, chromatin bound fraction; Histone H2B, stably chromatin bound marker.Immunoblot analyses of XRCC1 and , XRCC1-SUMO, in whole cell extracts of mESCs and MEFs. XRCC1 and XRCC1-SUMO conjugates before (2i, 0 h) and during RA-induced differentiation (24 h, 48 h) in mESCs and MEFs. Percentages of XRCC1-SUMO relative to total XRCC1 signal are indicated.Immunoblot analyses of XRCC1 and XRCC1-SUMO, in whole cell extracts of mESCs XRCC1 SUMOylation in native whole cells extracts before and after incubation with purified SUMO protease (SENP2364-489).Immunoblot analyses of , XRCC1 and XRCC1-SUMO in whole cell extracts of mESCs XRCC1 SUMOylation before and after exposure to H2O2 (5 mM, 15 min).Immunoblot analyses of TET1 isoforms in whole cell extracts of mESCs and MEFs. TET1 and TET1s isoform protein levels in mESCs during RA induced differentiation and in MEFs.Fluorescence microscopy of GFP-TDGwt GFP-TDGpip in mESCs. Scale bar: 100µM. Quantitation of fluorescence signals of GFP-TDGwt and GFP-TDGpip in mESCs. median with interquartile range. >470 cells were analysed of each GFPTDGwt and GFPTDGpip ESCs.Immunoblot analysis of XRCC1 and XRCC1-SUMO in GFP-TDGwt and GFP-TDGpip mESCs.
Figure 2"Far Western" blot analyses of BER protein interactions. Recombinant purified human TDG (10 µg), POLß (1 µg), APE1 (1 µg), and LIGIII (1 µg) probed with XRCC1 and XRCC1-SUMO (20 µg) and immune-stained for XRCC1.Immunoblot analysis of interactions of XRCC1 and XRCC1-SUMO with endogenous TDG. Purified 6hisXRCC1 or in vitro modified and purified 6hisXRCC1-SUMO was coupled to Ni-NTA agarose and incubated with mESC extracts. Input (I), last wash (LW) and elution (E) fractions.0.5 µM TDGwt, were incubated with biotinylated 5caC substrate (G•5caC DNA, 1 µM) and homoduplex competitor DNA (G•C DNA, 10 µM) and equimolar amounts of XRCC1, POLβ and LIGIII proteins.Schematic of biotin-5caC DNA substrate pulldown experiment. 0.5 µM TDGwt or TDGcat (TDG(N140A)) incubated with biotinylated 5caC substrate (G•5caC DNA, 1 µM) and homoduplex competitor DNA (G•C DNA, 10 µM) as indicated and equimolar amounts of XRCC1-SUMO (>50% SUMOylated), POLβ and LIGIII.1 µM biotinylated 5caC substrate (G•5caC DNA) and 10 µM homoduplex competitor DNA (G•C DNA) were incubated with XRCC1-SUMO (50% SUMOylated) and BER proteins as indicated.0.5 µM human TDGwt protein were incubated with 1 µM biotinylated 5caC substrate (G•5caC DNA), 0.5 µM SUMO and 10 µM homoduplex competitor DNA (G•C DNA) as indicated. Shown is an immunoblot analysis of TDG and free SUMO."Far Western" blot analyses of TDGwt and TDGE310Q with 6hisXRCC1 and 6hisXRCC1-SUMO. TDGwt or TDGE310Q was dot blotted on nitrocellulose membranes and probed with XRCC1 or XRCC1-SUMO (probe:XRCC1 or XRCC1SUMO) where indicated. TDG and XRCC1 probes were detected by immunoblotting with anti TDG and anti XRCC1 antibodies as indicated.Schematic of biotin-5caC DNA substrate pulldown experiment. Immunoblot analysis of purified TDGwt or TDG SUMO-binding mutant (TDGE310Q), 6hisXRCC1/XRCC1-SUMO and 6his BER proteins bound to Streptavidin (St) Biotin-5caC DNA substrate. 0.5 µM TDGwt or TDG SUMO-binding mutant (TDGE310Q) were incubated with biotinylated 5caC substrate (G•5caC DNA, 1 µM) and homoduplex competitor DNA (G•C DNA, 10 µM) as indicated and equimolar amounts of XRCC1, POLβ, APE1 and LIGIII proteins. Grey ovals, BERosome.
Figure 3Reconstitution SUMO conjugation/de-conjugation reaction with purified SAE1/2, UBC9, SUMO protease SENP2364-489), free SUMO in equimolar amounts and 20-fold molar excess over TDG. TDG SUMOylation was performed in the presence or absence of AP-site containing synthetic DNA double-strands as (as indicated (G•AP). TDG and TDG-SUMO were detected by immunoblotting. SUMOylation of DNA (G•AP) bound TDG is strongly reduced but a 20-fold molar excess of free SUMO compensates the inhibitory effect of DNA.Reconstitution SUMO conjugation/de-conjugation reaction with purified SAE1/2, UBC9, SUMO protease SENP2364-489), free SUMO in equimolar amounts and 20-fold molar excess over TDG. TDG SUMOylation was performed in the presence or absence of AP-site containing synthetic DNA double-strands as (as indicated (G•AP). TDG and TDG-SUMO were detected by immunoblotting. SUMOylation of DNA (G•AP) bound TDG is strongly reduced but a 20-fold molar excess of free SUMO compensates the inhibitory effect of DNA. SUMOylation assay as in (A) with SUMO provided as XRCC1-SUMO instead of free SUMO.Reconstitution SUMO conjugation/de-conjugation reaction with purified SAE1/2, UBC9, SUMO protease SENP2364-489), free SUMO in equimolar amounts and 20-fold molar excess over TDG. TDG SUMOylation was performed in the presence or absence of AP-site containing synthetic DNA double-strands as (as indicated (G•AP). TDG and TDG-SUMO were detected by immunoblotting. SUMOylation of DNA (G•AP) bound TDG is strongly reduced but a 20-fold molar excess of free SUMO compensates the inhibitory effect of DNA. SUMO transfer as depicted in (B) with additional APE1, POLß, LIGIII, and TDG.Immunoblot analysis of XRCC1, TDG, TDG-SUMO in TDGwt (wt), TDGsnm (snm) and XRCC1null mESCs (null).Immunoblot analysis of TDG and TDG-SUMO in TDGwt (wt) and XRCC1null mESCs (null) exposed to H2O2 as indicated.Top: Schematic of the SUMO-mediated TDG-BERosome (grey oval) formation and DNA processing. Bottom: Reconstitution of active DNA demethylation on a 5caC containing synthetic DNA double-strands in presence of dynamic SUMO-conjugation/de-conjugation. Left panels lanes 3-14: BER reconstitution with XRCC1 or XRCC1-SUMO as indicated. Right panels lanes 15-21: BER reconstitution with free SUMO or XRCC1-SUMO as SUMO donor as indicated. ds59merDNA substrates: lane 1-2 CG/CG HpaII methylation sensitive restriction site, cleavable by HpaII; lane 3-6, 8-14, 15-17, 21 HpaII methylation sensitive restriction site restriction site with a caC (5caCG/CG), not cleavable by HpaII; lane 7 and 20 repaired Product (CC/CG) that is cleavable by HpaII after excision/repair of caC/CG to CG/CG by BER. Percentage of total signal of fully repaired product is indicated. ss59merDNA, single stranded DNA.