Review



ramos b cells  (Thermo Fisher)


Bioz Verified Symbol Thermo Fisher is a verified supplier
Bioz Manufacturer Symbol Thermo Fisher manufactures this product  
  • Logo
  • About
  • News
  • Press Release
  • Team
  • Advisors
  • Partners
  • Contact
  • Bioz Stars
  • Bioz vStars
    • 99
      Buy from Supplier

    Structured Review

    Thermo Fisher ramos b cells
    Ramos B Cells, supplied by Thermo Fisher, used in various techniques. Bioz Stars score: 99/100, based on 1 PubMed citations. ZERO BIAS - scores, article reviews, protocol conditions and more
    https://www.bioz.com/product/buffer+b/RIPA+buffer/pm41998187-308-6-56
    Average 99 stars, based on 1 article reviews
    ramos b cells - by Bioz Stars, 2026-09
    99/100 stars

    Images

    Related Articles

    Incubation:

    Article Title: New dengue virus inhibitors targeting NS3-NS5 interaction identified by in silico screening
    Article Snippet: .. After overnight incubation, cells were pelleted and resuspended with buffer B (20 mM Tris-HCl, pH 7.4, 150 mM NaCl, 2 mM DTT, 10% glycerol) supplemented with 1 mg/mL lysozyme, 25 U/mL Pierce Universal Nuclease (Thermo Fisher Scientific) and protease inhibitor Cocktail (Thermo Fisher Scientific). ..

    Protease Inhibitor:

    Article Title: New dengue virus inhibitors targeting NS3-NS5 interaction identified by in silico screening
    Article Snippet: .. After overnight incubation, cells were pelleted and resuspended with buffer B (20 mM Tris-HCl, pH 7.4, 150 mM NaCl, 2 mM DTT, 10% glycerol) supplemented with 1 mg/mL lysozyme, 25 U/mL Pierce Universal Nuclease (Thermo Fisher Scientific) and protease inhibitor Cocktail (Thermo Fisher Scientific). ..

    Article Title: Structure-Activity and Structure-Degradation Relationship Studies of 2-Amino-6-(benzimidazol-2-ylmethyl)-N9-heteroarylpurines as Potent and Selective CDK12/13 Inhibitors and Cyclin K Degraders.
    Article Snippet: Targeted modulation of the CDK12/CycK complex offers a compelling avenue for exploiting transcriptional addiction in cancer.. Among emerging strategies, small molecule CDK12/13 inhibitors that induce selective CycK degradation via proximitybased mechanisms are demonstrating encouraging preclinical results.. However, the rational design of molecular glue degraders remains challenging as the structural principles governing efficient target degradation are not always well understood.

    Amplification:

    Article Title: A denaturation-free protocol for in situ visualization of short nuclear DNA sequences using padlock probes with rolling-circle amplification
    Article Snippet: Holes of the SecureSeal were covered by sealing tape (95.1994, Sarstedt) to avoid evaporation of the ligation solution. .. After washing once with buffer B (2 × SSC buffer with 0.05% Tween20) at 37°C, circularized probes were amplified in an RCA mixture (200 μg/ml bovine serum albumin, 1 mM DTT (A39255, Thermo Fisher), 250 μM dNTP (R0181, Thermo Fisher), 1 μM RCA primer 1, 25 nM fluorophore-conjugated detection oligonucleotide (Texas-red or Alexa Fluor-594-conjugated detection 1 and/or Alexa Fluor-488-conjugated detection 2), 25 nM Hoechst 33342 (62249, Thermo Fisher) and 0.5 U/μl phi29 DNA polymerase (4002, Monserate) in 1 × phi29 buffer) for 2 h at 37°C. .. The cells were washed twice with buffer B and mounted with SlowFade Gold Antifade (S36936, Thermo Fisher).

    Concentration Assay:

    Article Title: Localization and functional exploration of leiomodin-2's C-terminal binding sites.
    Article Snippet: Molecular masses of bands corresponding to individual proteins and protein complexes were estimated using Bio-Rad Unstained Precision Plus Protein Standards and ImageLab software (Hercules, California, USA). .. Lmod2[454–521] was reconstituted in Buffer B (20 mM Tris-HCl (pH 7.5), 100 mM KCl, 2 mM MgCl2, 1 mM DTT) and concentration was determined using Pierce BCA Protein Assay Kit (Thermo Scientific, Waltham, MA). ..

    Bicinchoninic Acid Protein Assay:

    Article Title: Localization and functional exploration of leiomodin-2's C-terminal binding sites.
    Article Snippet: Molecular masses of bands corresponding to individual proteins and protein complexes were estimated using Bio-Rad Unstained Precision Plus Protein Standards and ImageLab software (Hercules, California, USA). .. Lmod2[454–521] was reconstituted in Buffer B (20 mM Tris-HCl (pH 7.5), 100 mM KCl, 2 mM MgCl2, 1 mM DTT) and concentration was determined using Pierce BCA Protein Assay Kit (Thermo Scientific, Waltham, MA). ..

    Staining:

    Article Title: SUPPORTING INFORMATION MbtH-like proteins are integral components of bacterial non-ribosomal peptide synthetases
    Article Snippet: .. Fractions containing H6-CmnO, based on SDSPAGE/Coomassie blue staining, were pooled and dialyzed at 4°C overnight against buffer B (Tris HCl, pH 8.0 [50 mM], NaCl [100 mM], glycerol [10% v/v]) using 3500 MWCO SnakeSkin® Pleated Dialysis Tubing (Thermo Scientific). ..

    Generated:

    Article Title: Structure-Activity and Structure-Degradation Relationship Studies of 2-Amino-6-(benzimidazol-2-ylmethyl)-N9-heteroarylpurines as Potent and Selective CDK12/13 Inhibitors and Cyclin K Degraders.
    Article Snippet: Targeted modulation of the CDK12/CycK complex offers a compelling avenue for exploiting transcriptional addiction in cancer.. Among emerging strategies, small molecule CDK12/13 inhibitors that induce selective CycK degradation via proximitybased mechanisms are demonstrating encouraging preclinical results.. However, the rational design of molecular glue degraders remains challenging as the structural principles governing efficient target degradation are not always well understood.

    Infection:

    Article Title: Structure-Activity and Structure-Degradation Relationship Studies of 2-Amino-6-(benzimidazol-2-ylmethyl)-N9-heteroarylpurines as Potent and Selective CDK12/13 Inhibitors and Cyclin K Degraders.
    Article Snippet: Targeted modulation of the CDK12/CycK complex offers a compelling avenue for exploiting transcriptional addiction in cancer.. Among emerging strategies, small molecule CDK12/13 inhibitors that induce selective CycK degradation via proximitybased mechanisms are demonstrating encouraging preclinical results.. However, the rational design of molecular glue degraders remains challenging as the structural principles governing efficient target degradation are not always well understood.

    Centrifugation:

    Article Title: Structure-Activity and Structure-Degradation Relationship Studies of 2-Amino-6-(benzimidazol-2-ylmethyl)-N9-heteroarylpurines as Potent and Selective CDK12/13 Inhibitors and Cyclin K Degraders.
    Article Snippet: Targeted modulation of the CDK12/CycK complex offers a compelling avenue for exploiting transcriptional addiction in cancer.. Among emerging strategies, small molecule CDK12/13 inhibitors that induce selective CycK degradation via proximitybased mechanisms are demonstrating encouraging preclinical results.. However, the rational design of molecular glue degraders remains challenging as the structural principles governing efficient target degradation are not always well understood.



    Similar Products

    rt buffer b  (10X Genomics)
    86
    10X Genomics rt buffer b
    Rt Buffer B, supplied by 10X Genomics, used in various techniques. Bioz Stars score: 86/100, based on 1 PubMed citations. ZERO BIAS - scores, article reviews, protocol conditions and more
    https://www.bioz.com/product/buffer+b/pm42260119-394-14-17
    Average 86 stars, based on 1 article reviews
    rt buffer b - by Bioz Stars, 2026-09
    86/100 stars
    		  Buy from Supplier
    buffer b  (Fisher Scientific)
    86
    Fisher Scientific buffer b
    Buffer B, supplied by Fisher Scientific, used in various techniques. Bioz Stars score: 86/100, based on 1 PubMed citations. ZERO BIAS - scores, article reviews, protocol conditions and more
    https://www.bioz.com/product/buffer+b/buffer+lysis/bio_rxiv__64898__2026__05__13__724352-122-9-16
    Average 86 stars, based on 1 article reviews
    buffer b - by Bioz Stars, 2026-09
    86/100 stars
    		  Buy from Supplier
    tris wash buffer b  (Zytomed Inc)
    86
    Zytomed Inc tris wash buffer b
    Tris Wash Buffer B, supplied by Zytomed Inc, used in various techniques. Bioz Stars score: 86/100, based on 1 PubMed citations. ZERO BIAS - scores, article reviews, protocol conditions and more
    https://www.bioz.com/product/buffer+b/buffer+tris+wash/pm42122993-104-10-15
    Average 86 stars, based on 1 article reviews
    tris wash buffer b - by Bioz Stars, 2026-09
    86/100 stars
    		  Buy from Supplier
    ramos b cells  (Thermo Fisher)
    99
    Thermo Fisher ramos b cells
    Ramos B Cells, supplied by Thermo Fisher, used in various techniques. Bioz Stars score: 99/100, based on 1 PubMed citations. ZERO BIAS - scores, article reviews, protocol conditions and more
    https://www.bioz.com/product/buffer+b/RIPA+buffer/pm41998187-308-6-56
    Average 99 stars, based on 1 article reviews
    ramos b cells - by Bioz Stars, 2026-09
    99/100 stars
    		  Buy from Supplier
    buffer b trf2 rap1  (Bio-Rad)
    96
    Bio-Rad buffer b trf2 rap1
    <t>TRF2–RAP1</t> <t>interaction</t> enhances TRF2’s binding to telomere R-loops. ( A, B ) TRF2 binds 32 P-TERRA and telomere R-loops. His-tagged TRF2 protein (0–80 nM) was incubated with 5 nM radiolabeled TERRA (A) or telomere R-loops (B). The mobility shifts of the TRF2–RNA complex were analyzed by 10% native polyacrylamide gel electrophoresis. ( C ) Quantification of the binding data in panels (A, B). The error bars represent mean values ± SD of data from three independent experiments. ( D ) TRF2–RAP1 interaction enhances TRF2’s binding to telomere R-loops. Purified WT TRF2, mutants TRF2 ΔB , TRF2 L288R , TRF2 ΔB,L288R , and WT RAP1 alone or in the indicated combinations were tested for telomere R-loop binding. The mobility shift of the TRF2–RNA complexes was analyzed by 10% polyacrylamide gels. ( E, F ) Quantification of the R-loop binding data in panel (D). Error bars represent mean values ± SD of data from three independent experiments. ( G ) TRF2 (50, 100, 150, 200, and 250 nM) without or with RAP1 (100 nM) was incubated with telomere dsDNA and R-loops (10 nM each) to determine relative binding affinities. The ability of TRF2 or TRF2–RAP1 to bind to these nucleic acid substrates was analyzed by 10% polyacrylamide gels. ( H, I ) The R-loop and dsDNA binding data in panel (G) were quantified and plotted. Error bars represent mean values ± SD of data from three independent experiments.
    Buffer B Trf2 Rap1, supplied by Bio-Rad, used in various techniques. Bioz Stars score: 96/100, based on 1 PubMed citations. ZERO BIAS - scores, article reviews, protocol conditions and more
    https://www.bioz.com/product/buffer+b/Micro+Bio-Spin+6/pmc13036488-88-19-16
    Average 96 stars, based on 1 article reviews
    buffer b trf2 rap1 - by Bioz Stars, 2026-09
    96/100 stars
    		  Buy from Supplier
    wash buffer b  (Biosearch Technologies Inc)
    86
    Biosearch Technologies Inc wash buffer b
    <t>TRF2–RAP1</t> <t>interaction</t> enhances TRF2’s binding to telomere R-loops. ( A, B ) TRF2 binds 32 P-TERRA and telomere R-loops. His-tagged TRF2 protein (0–80 nM) was incubated with 5 nM radiolabeled TERRA (A) or telomere R-loops (B). The mobility shifts of the TRF2–RNA complex were analyzed by 10% native polyacrylamide gel electrophoresis. ( C ) Quantification of the binding data in panels (A, B). The error bars represent mean values ± SD of data from three independent experiments. ( D ) TRF2–RAP1 interaction enhances TRF2’s binding to telomere R-loops. Purified WT TRF2, mutants TRF2 ΔB , TRF2 L288R , TRF2 ΔB,L288R , and WT RAP1 alone or in the indicated combinations were tested for telomere R-loop binding. The mobility shift of the TRF2–RNA complexes was analyzed by 10% polyacrylamide gels. ( E, F ) Quantification of the R-loop binding data in panel (D). Error bars represent mean values ± SD of data from three independent experiments. ( G ) TRF2 (50, 100, 150, 200, and 250 nM) without or with RAP1 (100 nM) was incubated with telomere dsDNA and R-loops (10 nM each) to determine relative binding affinities. The ability of TRF2 or TRF2–RAP1 to bind to these nucleic acid substrates was analyzed by 10% polyacrylamide gels. ( H, I ) The R-loop and dsDNA binding data in panel (G) were quantified and plotted. Error bars represent mean values ± SD of data from three independent experiments.
    Wash Buffer B, supplied by Biosearch Technologies Inc, used in various techniques. Bioz Stars score: 86/100, based on 1 PubMed citations. ZERO BIAS - scores, article reviews, protocol conditions and more
    https://www.bioz.com/product/buffer+b/a+buffer+wash/pmc12968391-111-9-12
    Average 86 stars, based on 1 article reviews
    wash buffer b - by Bioz Stars, 2026-09
    86/100 stars
    		  Buy from Supplier
    ice cold lysis buffer b  (Nacalai)
    86
    Nacalai ice cold lysis buffer b
    <t>TRF2–RAP1</t> <t>interaction</t> enhances TRF2’s binding to telomere R-loops. ( A, B ) TRF2 binds 32 P-TERRA and telomere R-loops. His-tagged TRF2 protein (0–80 nM) was incubated with 5 nM radiolabeled TERRA (A) or telomere R-loops (B). The mobility shifts of the TRF2–RNA complex were analyzed by 10% native polyacrylamide gel electrophoresis. ( C ) Quantification of the binding data in panels (A, B). The error bars represent mean values ± SD of data from three independent experiments. ( D ) TRF2–RAP1 interaction enhances TRF2’s binding to telomere R-loops. Purified WT TRF2, mutants TRF2 ΔB , TRF2 L288R , TRF2 ΔB,L288R , and WT RAP1 alone or in the indicated combinations were tested for telomere R-loop binding. The mobility shift of the TRF2–RNA complexes was analyzed by 10% polyacrylamide gels. ( E, F ) Quantification of the R-loop binding data in panel (D). Error bars represent mean values ± SD of data from three independent experiments. ( G ) TRF2 (50, 100, 150, 200, and 250 nM) without or with RAP1 (100 nM) was incubated with telomere dsDNA and R-loops (10 nM each) to determine relative binding affinities. The ability of TRF2 or TRF2–RAP1 to bind to these nucleic acid substrates was analyzed by 10% polyacrylamide gels. ( H, I ) The R-loop and dsDNA binding data in panel (G) were quantified and plotted. Error bars represent mean values ± SD of data from three independent experiments.
    Ice Cold Lysis Buffer B, supplied by Nacalai, used in various techniques. Bioz Stars score: 86/100, based on 1 PubMed citations. ZERO BIAS - scores, article reviews, protocol conditions and more
    https://www.bioz.com/product/buffer+b/buffer+ripa/pm41905287-73-8-31
    Average 86 stars, based on 1 article reviews
    ice cold lysis buffer b - by Bioz Stars, 2026-09
    86/100 stars
    		  Buy from Supplier
    b v co  (Miltenyi Biotec)
    95
    Miltenyi Biotec b v co
    <t>TRF2–RAP1</t> <t>interaction</t> enhances TRF2’s binding to telomere R-loops. ( A, B ) TRF2 binds 32 P-TERRA and telomere R-loops. His-tagged TRF2 protein (0–80 nM) was incubated with 5 nM radiolabeled TERRA (A) or telomere R-loops (B). The mobility shifts of the TRF2–RNA complex were analyzed by 10% native polyacrylamide gel electrophoresis. ( C ) Quantification of the binding data in panels (A, B). The error bars represent mean values ± SD of data from three independent experiments. ( D ) TRF2–RAP1 interaction enhances TRF2’s binding to telomere R-loops. Purified WT TRF2, mutants TRF2 ΔB , TRF2 L288R , TRF2 ΔB,L288R , and WT RAP1 alone or in the indicated combinations were tested for telomere R-loop binding. The mobility shift of the TRF2–RNA complexes was analyzed by 10% polyacrylamide gels. ( E, F ) Quantification of the R-loop binding data in panel (D). Error bars represent mean values ± SD of data from three independent experiments. ( G ) TRF2 (50, 100, 150, 200, and 250 nM) without or with RAP1 (100 nM) was incubated with telomere dsDNA and R-loops (10 nM each) to determine relative binding affinities. The ability of TRF2 or TRF2–RAP1 to bind to these nucleic acid substrates was analyzed by 10% polyacrylamide gels. ( H, I ) The R-loop and dsDNA binding data in panel (G) were quantified and plotted. Error bars represent mean values ± SD of data from three independent experiments.
    B V Co, supplied by Miltenyi Biotec, used in various techniques. Bioz Stars score: 95/100, based on 1 PubMed citations. ZERO BIAS - scores, article reviews, protocol conditions and more
    https://www.bioz.com/product/buffer+b/MACSima+Running+Buffer/pmc12796729-42-6-4
    Average 95 stars, based on 1 article reviews
    b v co - by Bioz Stars, 2026-09
    95/100 stars
    		  Buy from Supplier

    Image Search Results


    TRF2–RAP1 interaction enhances TRF2’s binding to telomere R-loops. ( A, B ) TRF2 binds 32 P-TERRA and telomere R-loops. His-tagged TRF2 protein (0–80 nM) was incubated with 5 nM radiolabeled TERRA (A) or telomere R-loops (B). The mobility shifts of the TRF2–RNA complex were analyzed by 10% native polyacrylamide gel electrophoresis. ( C ) Quantification of the binding data in panels (A, B). The error bars represent mean values ± SD of data from three independent experiments. ( D ) TRF2–RAP1 interaction enhances TRF2’s binding to telomere R-loops. Purified WT TRF2, mutants TRF2 ΔB , TRF2 L288R , TRF2 ΔB,L288R , and WT RAP1 alone or in the indicated combinations were tested for telomere R-loop binding. The mobility shift of the TRF2–RNA complexes was analyzed by 10% polyacrylamide gels. ( E, F ) Quantification of the R-loop binding data in panel (D). Error bars represent mean values ± SD of data from three independent experiments. ( G ) TRF2 (50, 100, 150, 200, and 250 nM) without or with RAP1 (100 nM) was incubated with telomere dsDNA and R-loops (10 nM each) to determine relative binding affinities. The ability of TRF2 or TRF2–RAP1 to bind to these nucleic acid substrates was analyzed by 10% polyacrylamide gels. ( H, I ) The R-loop and dsDNA binding data in panel (G) were quantified and plotted. Error bars represent mean values ± SD of data from three independent experiments.

    Journal: Nucleic Acids Research

    Article Title: TRF2–RAP1 inhibits homology-directed repair of telomeres by promoting BLM-mediated removal of telomere R-loops

    doi: 10.1093/nar/gkag272

    Figure Lengend Snippet: TRF2–RAP1 interaction enhances TRF2’s binding to telomere R-loops. ( A, B ) TRF2 binds 32 P-TERRA and telomere R-loops. His-tagged TRF2 protein (0–80 nM) was incubated with 5 nM radiolabeled TERRA (A) or telomere R-loops (B). The mobility shifts of the TRF2–RNA complex were analyzed by 10% native polyacrylamide gel electrophoresis. ( C ) Quantification of the binding data in panels (A, B). The error bars represent mean values ± SD of data from three independent experiments. ( D ) TRF2–RAP1 interaction enhances TRF2’s binding to telomere R-loops. Purified WT TRF2, mutants TRF2 ΔB , TRF2 L288R , TRF2 ΔB,L288R , and WT RAP1 alone or in the indicated combinations were tested for telomere R-loop binding. The mobility shift of the TRF2–RNA complexes was analyzed by 10% polyacrylamide gels. ( E, F ) Quantification of the R-loop binding data in panel (D). Error bars represent mean values ± SD of data from three independent experiments. ( G ) TRF2 (50, 100, 150, 200, and 250 nM) without or with RAP1 (100 nM) was incubated with telomere dsDNA and R-loops (10 nM each) to determine relative binding affinities. The ability of TRF2 or TRF2–RAP1 to bind to these nucleic acid substrates was analyzed by 10% polyacrylamide gels. ( H, I ) The R-loop and dsDNA binding data in panel (G) were quantified and plotted. Error bars represent mean values ± SD of data from three independent experiments.

    Article Snippet: The deproteinized reaction mixtures by SDS and proteinase K were passed through Micro Bio-Spin 6 Column (Bio-Rad), equilibrated with buffer B. TRF2–RAP1 (50 nM) was pre-incubated with the D/R-loop substrate (2.5 nM) on ice for 10 min. Then BLM (20–80 nM) was added and incubated at 37°C for 20 min.

    Techniques: Binding Assay, Incubation, Polyacrylamide Gel Electrophoresis, Purification, Mobility Shift

    TRF2–RAP1 promotes BLM-mediated unwinding of telomere R-loops. ( A ) (Top) Schematic of the oligo-based telomere R-loop unwinding assay. Telomere R-loop substrates were generated by hybridizing 32 P-labeled TERRA and two telomere DNA fragments (TDR2 and TDR3). TRF2 and/or RAP1 were pre-incubated with the R-loops and then BLM was added to the reaction, and the complex was resolved by 10% native polyacrylamide gel electrophoresis to monitor for R-loop unwinding. Displacement of the invading radiolabeled TERRA from R-loops indicates that R-loop unwinding. (Bottom) The TRF2–RAP1 complex promotes BLM-mediated unwinding of telomere R-loops. The effects of TRF2 alone (40, 80 nM) or in combination with RAP1 (20, 40, 80 nM) on the ability of BLM (20 nM) to unwind telomere R-loops were examined. 32 P-labeled TERRA and R-loops were resolved by native-PAGE and shown in lanes 1 and 2. ( B ) Quantification of BLM-mediated R-loop unwinding reactions in panel (A). The percentages of unwound R-loops are shown as mean values ± SD from three independent experiments. Statistical evaluation was performed by ANOVA test. ns: non-significant ( P = .9485); **** P < .0001. ( C ) The TRF2 basic domain is required for efficient unwinding of telomere R-loops. The effect of WT TRF2, TRF2 ΔB , TRF2 ΔB,L288R , and RAP1 to enhance BLM-mediated telomere R-loop unwinding was examined. The sizes of 32 P-labeled TERRA and R-loops were resolved by native-PAGE, as shown in lanes 1 and 2. ( D ) Quantification of BLM-mediated R-loop unwinding reactions in panel (C). The percentages of unwound R-loops are shown as mean values ± SD from three independent experiments. Statistical evaluation was performed by ANOVA test. **** P < .0001. ( E ) The TRF2–BLM interaction enhances telomere R-loop unwinding. The effect of TRF2–RAP1 on the ability of WT and mutant BLM (3A or P690L) to unwind telomere R-loops was tested as in Fig. . 32 P-labeled TERRA and R-loops were loaded as size markers (lanes 1 and 2) and resolved by native-PAGE. ( F ) Quantification of the percentages of unwound R-loops in panel (E) as mean ± SD from three independent experiments. Statistical evaluation was performed by ANOVA test. ns: non-significant ( P = .98); **** P < .0001.

    Journal: Nucleic Acids Research

    Article Title: TRF2–RAP1 inhibits homology-directed repair of telomeres by promoting BLM-mediated removal of telomere R-loops

    doi: 10.1093/nar/gkag272

    Figure Lengend Snippet: TRF2–RAP1 promotes BLM-mediated unwinding of telomere R-loops. ( A ) (Top) Schematic of the oligo-based telomere R-loop unwinding assay. Telomere R-loop substrates were generated by hybridizing 32 P-labeled TERRA and two telomere DNA fragments (TDR2 and TDR3). TRF2 and/or RAP1 were pre-incubated with the R-loops and then BLM was added to the reaction, and the complex was resolved by 10% native polyacrylamide gel electrophoresis to monitor for R-loop unwinding. Displacement of the invading radiolabeled TERRA from R-loops indicates that R-loop unwinding. (Bottom) The TRF2–RAP1 complex promotes BLM-mediated unwinding of telomere R-loops. The effects of TRF2 alone (40, 80 nM) or in combination with RAP1 (20, 40, 80 nM) on the ability of BLM (20 nM) to unwind telomere R-loops were examined. 32 P-labeled TERRA and R-loops were resolved by native-PAGE and shown in lanes 1 and 2. ( B ) Quantification of BLM-mediated R-loop unwinding reactions in panel (A). The percentages of unwound R-loops are shown as mean values ± SD from three independent experiments. Statistical evaluation was performed by ANOVA test. ns: non-significant ( P = .9485); **** P < .0001. ( C ) The TRF2 basic domain is required for efficient unwinding of telomere R-loops. The effect of WT TRF2, TRF2 ΔB , TRF2 ΔB,L288R , and RAP1 to enhance BLM-mediated telomere R-loop unwinding was examined. The sizes of 32 P-labeled TERRA and R-loops were resolved by native-PAGE, as shown in lanes 1 and 2. ( D ) Quantification of BLM-mediated R-loop unwinding reactions in panel (C). The percentages of unwound R-loops are shown as mean values ± SD from three independent experiments. Statistical evaluation was performed by ANOVA test. **** P < .0001. ( E ) The TRF2–BLM interaction enhances telomere R-loop unwinding. The effect of TRF2–RAP1 on the ability of WT and mutant BLM (3A or P690L) to unwind telomere R-loops was tested as in Fig. . 32 P-labeled TERRA and R-loops were loaded as size markers (lanes 1 and 2) and resolved by native-PAGE. ( F ) Quantification of the percentages of unwound R-loops in panel (E) as mean ± SD from three independent experiments. Statistical evaluation was performed by ANOVA test. ns: non-significant ( P = .98); **** P < .0001.

    Article Snippet: The deproteinized reaction mixtures by SDS and proteinase K were passed through Micro Bio-Spin 6 Column (Bio-Rad), equilibrated with buffer B. TRF2–RAP1 (50 nM) was pre-incubated with the D/R-loop substrate (2.5 nM) on ice for 10 min. Then BLM (20–80 nM) was added and incubated at 37°C for 20 min.

    Techniques: Generated, Labeling, Incubation, Polyacrylamide Gel Electrophoresis, Clear Native PAGE, Mutagenesis

    BLM preferentially releases TERRA over ssDNA from telomere D/R-loops. ( A ) Schematic of the assay used to measure how TRF2–RAP1 promotes BLM-mediated unwinding of RAD51/ssDNA and RAD51AP1/TERRA-generated telomeric D/R-loops. Telomere D/R-loops were generated by incubating RAD51 with IRDye-700-labeled telomere ssDNA (red), RAD51AP1 with IRDye-800-labeled TERRA (green), and telomere plasmids together as described in Fig. . Native plasmid-sized telomere D/R-loops were obtained after deproteinization and column purification. BLM with or without TRF2–RAP1 was then incubated with these D/R-loops, and ssDNA, TERRA release, or D/R-loop unwinding was analyzed by 1% agarose gels. ( B ) BLM preferentially releases TERRA over ssDNA from telomere D/R-loop. BLM (20, 40, 80 nM) was tested for its ability to unwind telomere D/R-loops or TRF2–RAP1-bound D/R-loops. ssDNA, TERRA release, or D/R-loop unwinding was analyzed by 1% agarose gels. The unwinding of telomere D/R-loops by BLM was enhanced by TRF2–RAP1. ( C ) Quantification of the amount of D- and R-loops relative to the negative control (no proteins, lane 1). Data were plotted as mean ± SD from three independent experiments. Statistical evaluation was performed by ANOVA test. * P = .02282; ** P = .001278; *** P = .0007284; **** P < .0001. ( D ) The effects of TRF2–RAP1 on WT BLM, the helicase-dead BLM K695R or BLM mutants on D/R-loop unwinding were tested as in panel (B). In contrast to WT BLM, TRF2–RAP1 cannot enhance BLM ’s ability to unwind telomere D/R-loops. D/R-loop unwinding was analyzed by 1% agarose gels. ( E ) Quantification of the relative amounts of D-loops or R-loops to the control without proteins (lane 1) is shown as mean ± SD from three independent experiments. ANOVA test was used to evaluate statistical differences. ns: non-significant ( P = .15; .4147; .8026); ** P = .001193; *** P = .000158.

    Journal: Nucleic Acids Research

    Article Title: TRF2–RAP1 inhibits homology-directed repair of telomeres by promoting BLM-mediated removal of telomere R-loops

    doi: 10.1093/nar/gkag272

    Figure Lengend Snippet: BLM preferentially releases TERRA over ssDNA from telomere D/R-loops. ( A ) Schematic of the assay used to measure how TRF2–RAP1 promotes BLM-mediated unwinding of RAD51/ssDNA and RAD51AP1/TERRA-generated telomeric D/R-loops. Telomere D/R-loops were generated by incubating RAD51 with IRDye-700-labeled telomere ssDNA (red), RAD51AP1 with IRDye-800-labeled TERRA (green), and telomere plasmids together as described in Fig. . Native plasmid-sized telomere D/R-loops were obtained after deproteinization and column purification. BLM with or without TRF2–RAP1 was then incubated with these D/R-loops, and ssDNA, TERRA release, or D/R-loop unwinding was analyzed by 1% agarose gels. ( B ) BLM preferentially releases TERRA over ssDNA from telomere D/R-loop. BLM (20, 40, 80 nM) was tested for its ability to unwind telomere D/R-loops or TRF2–RAP1-bound D/R-loops. ssDNA, TERRA release, or D/R-loop unwinding was analyzed by 1% agarose gels. The unwinding of telomere D/R-loops by BLM was enhanced by TRF2–RAP1. ( C ) Quantification of the amount of D- and R-loops relative to the negative control (no proteins, lane 1). Data were plotted as mean ± SD from three independent experiments. Statistical evaluation was performed by ANOVA test. * P = .02282; ** P = .001278; *** P = .0007284; **** P < .0001. ( D ) The effects of TRF2–RAP1 on WT BLM, the helicase-dead BLM K695R or BLM mutants on D/R-loop unwinding were tested as in panel (B). In contrast to WT BLM, TRF2–RAP1 cannot enhance BLM ’s ability to unwind telomere D/R-loops. D/R-loop unwinding was analyzed by 1% agarose gels. ( E ) Quantification of the relative amounts of D-loops or R-loops to the control without proteins (lane 1) is shown as mean ± SD from three independent experiments. ANOVA test was used to evaluate statistical differences. ns: non-significant ( P = .15; .4147; .8026); ** P = .001193; *** P = .000158.

    Article Snippet: The deproteinized reaction mixtures by SDS and proteinase K were passed through Micro Bio-Spin 6 Column (Bio-Rad), equilibrated with buffer B. TRF2–RAP1 (50 nM) was pre-incubated with the D/R-loop substrate (2.5 nM) on ice for 10 min. Then BLM (20–80 nM) was added and incubated at 37°C for 20 min.

    Techniques: Generated, Labeling, Plasmid Preparation, Purification, Incubation, Negative Control, Control

    TRF2–RAP1–BLM is required to resolve telomere R-loops in U2OS cells. ( A ) U2OS cells expressing TRF2 ΔB, L288R were treated with shControl, shBLM, or shTRF2. Immunofluorescence-FISH analysis of cells containing UTs (PNA telomere probe, red) co-localized with R-loops (S9.6 antibody, green) and DAPI-stained nuclei (blue). White arrow: co-localization of R-loops on UTs. U2OS cells expressing shBLM-resistant WT BLM cDNA and indicated BLM mutants were treated with shBLM, shTRF2, and TRF2 ΔB, L288R . IF-FISH analysis was performed to detect UT/R-loop co-localization. White arrow: co-localization of R-loops on UTs. ( C ) Quantification of data from Fig. and , showing the number of UT/R-loop colocalizations per U2OS cell. Data from three independent experiments is shown as mean ± SEM from minimum 200 nuclei per experiment. Statistical evaluation was performed by one-way ANOVA test. ns: non-significant ( P > .9999); ** P = .0032; .0035; .0062; .0092; .0052; **** P < .0001. ( D ) Model showing that TRF2–RAP1 inhibits telomere HDR by promoting BLM-mediated telomere R-loop removal. RAD51AP1 and TERRA-dependent R-loops promote RAD51-mediated telomere D-loop formation. The TRF2–RAP1 complex and TRF2–BLM interaction are required to promote BLM helicase-mediated unwinding of telomere R-loops and then D-loops. The RAP1–TRF2–BLM complex represses HDR on telomeres by removing R-loops to inhibit telomere D-loop formation.

    Journal: Nucleic Acids Research

    Article Title: TRF2–RAP1 inhibits homology-directed repair of telomeres by promoting BLM-mediated removal of telomere R-loops

    doi: 10.1093/nar/gkag272

    Figure Lengend Snippet: TRF2–RAP1–BLM is required to resolve telomere R-loops in U2OS cells. ( A ) U2OS cells expressing TRF2 ΔB, L288R were treated with shControl, shBLM, or shTRF2. Immunofluorescence-FISH analysis of cells containing UTs (PNA telomere probe, red) co-localized with R-loops (S9.6 antibody, green) and DAPI-stained nuclei (blue). White arrow: co-localization of R-loops on UTs. U2OS cells expressing shBLM-resistant WT BLM cDNA and indicated BLM mutants were treated with shBLM, shTRF2, and TRF2 ΔB, L288R . IF-FISH analysis was performed to detect UT/R-loop co-localization. White arrow: co-localization of R-loops on UTs. ( C ) Quantification of data from Fig. and , showing the number of UT/R-loop colocalizations per U2OS cell. Data from three independent experiments is shown as mean ± SEM from minimum 200 nuclei per experiment. Statistical evaluation was performed by one-way ANOVA test. ns: non-significant ( P > .9999); ** P = .0032; .0035; .0062; .0092; .0052; **** P < .0001. ( D ) Model showing that TRF2–RAP1 inhibits telomere HDR by promoting BLM-mediated telomere R-loop removal. RAD51AP1 and TERRA-dependent R-loops promote RAD51-mediated telomere D-loop formation. The TRF2–RAP1 complex and TRF2–BLM interaction are required to promote BLM helicase-mediated unwinding of telomere R-loops and then D-loops. The RAP1–TRF2–BLM complex represses HDR on telomeres by removing R-loops to inhibit telomere D-loop formation.

    Article Snippet: The deproteinized reaction mixtures by SDS and proteinase K were passed through Micro Bio-Spin 6 Column (Bio-Rad), equilibrated with buffer B. TRF2–RAP1 (50 nM) was pre-incubated with the D/R-loop substrate (2.5 nM) on ice for 10 min. Then BLM (20–80 nM) was added and incubated at 37°C for 20 min.

    Techniques: Expressing, Immunofluorescence, Staining