TP53BP1
TP53BP1 (tumour protein p53 binding protein 1, also known as 53BP1, p202 and TDRD30) is a double-strand break repair protein that shapes the cell's response to DNA damage. It promotes non-homologous end joining and limits homologous recombination. Browse Assay Genie's current range of TP53BP1 research reagents below, or read on for the biology behind the target.
TP53BP1 functions in the choice between DNA double-strand break (DSB) repair pathways. It promotes repair by non-homologous end joining (NHEJ) and specifically counteracts the homologous recombination repair protein BRCA1. It also limits end resection after a break, promotes checkpoint signalling following DNA damage, and acts as a scaffold that recruits other DNA damage response proteins to damaged chromatin.
Recruitment to DSB sites depends on chromatin recognition. TP53BP1 binds histone H2A monoubiquitinated at Lys-15 (H2AK15Ub) and histone H4 dimethylated at Lys-20 (H4K20me2), two histone marks present at DSB sites. Phosphorylation by ATM promotes interaction with RIF1 and dissociation from NUDT16L1/TIRR, which leads to its recruitment to the break. Through its interaction with PAXIP1, it also promotes NHEJ of dysfunctional telomeres.
The protein is also required for immunoglobulin class-switch recombination during antibody genesis, a process that generates DNA DSBs. There it participates in the repair and orientation of the broken DNA ends. In contrast, it is not required for classic NHEJ or V(D)J recombination, although the NCBI summary notes that its roles are also relevant to V(D)J recombination and unprotected telomeres. UniProt places the protein in the nucleus, on chromosomes and at the kinetochore. The HGNC classes the TP53BP1 gene in the Tudor domain containing group, and alternative splicing yields multiple transcript variants encoding different isoforms. The mouse ortholog is Tp53bp1.
TP53BP1 scaffolds the recruitment of repair proteins to damaged chromatin and promotes checkpoint signalling after DNA damage.
By promoting NHEJ, limiting end resection and counteracting BRCA1, TP53BP1 helps determine whether a double-strand break is repaired by NHEJ or homologous recombination.
TP53BP1 is required for class-switch recombination, where it participates in repair and orientation of broken DNA ends.
TP53BP1 promotes NHEJ of dysfunctional telomeres through its interaction with PAXIP1, linking it to telomere dynamics.
TP53BP1 is a double-strand break repair protein. It promotes non-homologous end joining, limits end resection and counteracts BRCA1-driven homologous recombination. It also scaffolds recruitment of DNA damage response proteins, supports checkpoint signalling, and is required for class-switch recombination during antibody genesis.
The HGNC-approved name is tumour protein p53 binding protein 1. Aliases and previous symbols include 53BP1, p202 and TDRD30, and UniProt calls it TP53-binding protein 1. An earlier name was tumour protein p53-binding protein, 1. Alternative splicing produces multiple isoforms.
A mouse ortholog, Tp53bp1, is recorded for the human gene, so the protein can be studied in mouse models. No rat ortholog is listed in the data here. Check the datasheet of any product for its validated reactivity.
Other p53-related proteins and nuclear factors with products at Assay Genie.
Gene and protein annotations from HGNC, NCBI Gene and UniProt Q12888; product specifications from Assay Genie datasheets.