53BP1 Antibody [E7B6] Datasheet

Biological Description

Specificity	53BP1 Antibody [E7B6] detects endogenous levels of total 53BP1 protein.
Background	53BP1, or tumor protein p53-binding protein 1, functions as a central mediator in the DNA damage response, originally identified as a p53 transcriptional coactivator and now recognized for orchestrating double-strand break (DSB) repair pathway choice. It features an N-terminal region with multiple ATM/ATR-phosphorylated S/TQ sites, a central oligomerization domain flanked by a GAR motif and LC8-binding site, tandem Tudor domains binding dimethylated histone H4K20, a ubiquitin-dependent recruitment (UDR) motif engaging H2AK15ub, and C-terminal BRCT repeats. Recruitment to DSBs occurs via H4K20me2 and H2AK15ub recognition following RNF8/RNF168 ubiquitination downstream of γH2AX-MDC1, with oligomerization amplifying chromatin binding and ST/Q phosphorylation recruiting effectors Rif1 and PTIP. 53BP1 promotes classical non-homologous end-joining (c-NHEJ) by recruiting Rif1 to block CtIP-dependent 5′ resection, favoring ligation over homology-directed repair (HDR), while PTIP aids NHEJ in BRCA1-deficient contexts; it enhances heterochromatic repair via BRCT-KAP1/EXPAND1 interactions and stimulates DSB mobility/synapsis for efficient joining in CSR and telomere fusion. ATM phosphorylates multiple sites including Ser25/29/166/Ser25, but these prove dispensable for focus formation yet essential for effector binding. 53BP1 ensures G2/M and intra-S checkpoints via p53/Chk2/Brca1 phosphorylation, supports immunoglobulin class switch recombination and V(D)J joining, and maintains telomere stability. Loss impairs G2/M arrest post-IR, reduces Brca1 foci, and shifts repair toward HDR, sensitizing to PARP inhibitors in BRCA1-null settings while promoting synthetic lethality reversal.

Specificity

53BP1 Antibody [E7B6] detects endogenous levels of total 53BP1 protein.

Background

53BP1, or tumor protein p53-binding protein 1, functions as a central mediator in the DNA damage response, originally identified as a p53 transcriptional coactivator and now recognized for orchestrating double-strand break (DSB) repair pathway choice. It features an N-terminal region with multiple ATM/ATR-phosphorylated S/TQ sites, a central oligomerization domain flanked by a GAR motif and LC8-binding site, tandem Tudor domains binding dimethylated histone H4K20, a ubiquitin-dependent recruitment (UDR) motif engaging H2AK15ub, and C-terminal BRCT repeats. Recruitment to DSBs occurs via H4K20me2 and H2AK15ub recognition following RNF8/RNF168 ubiquitination downstream of γH2AX-MDC1, with oligomerization amplifying chromatin binding and ST/Q phosphorylation recruiting effectors Rif1 and PTIP. 53BP1 promotes classical non-homologous end-joining (c-NHEJ) by recruiting Rif1 to block CtIP-dependent 5′ resection, favoring ligation over homology-directed repair (HDR), while PTIP aids NHEJ in BRCA1-deficient contexts; it enhances heterochromatic repair via BRCT-KAP1/EXPAND1 interactions and stimulates DSB mobility/synapsis for efficient joining in CSR and telomere fusion. ATM phosphorylates multiple sites including Ser25/29/166/Ser25, but these prove dispensable for focus formation yet essential for effector binding. 53BP1 ensures G2/M and intra-S checkpoints via p53/Chk2/Brca1 phosphorylation, supports immunoglobulin class switch recombination and V(D)J joining, and maintains telomere stability. Loss impairs G2/M arrest post-IR, reduces Brca1 foci, and shifts repair toward HDR, sensitizing to PARP inhibitors in BRCA1-null settings while promoting synthetic lethality reversal.

Usage Information

Application

WB, IHC, IF

Dilution

WB	IHC	IF
1:1000	1:200 - 1:800	1:1600 - 1:6400

Reactivity

Human

Source

Rabbit Monoclonal Antibody

MW

450 kDa

Storage Buffer

PBS, pH 7.2+50% Glycerol+0.05% BSA+0.01% NaN3

Storage
(from the date of receipt)

-20°C (avoid freeze-thaw cycles), 2 years

References

https://pubmed.ncbi.nlm.nih.gov/24094932/
https://pubmed.ncbi.nlm.nih.gov/12364621/

53BP1 Antibody [E7B6]

Biological Description

Usage Information

References

Application Data