tumor suppressor p53-binding protein 1; p53-binding protein 1; p53BP1; 53BP1 (TP53BP1)

Function

• may have a role in checkpoint signaling during mitosis
• enhances TP53-mediated transcriptional activation.
• plays a role in the response to DNA damage
• phosphorylated at basal level in the absence of DNA damage
• hyper-phosphorylated (ATM-dependent) in response to DNA damage induced by ionizing radiation
• hyper-phosphorylated in (ATR-dependent) in response to DNA damage induced by UV irradiation
• interacts with IFI202A (putative)
• binds to the central domain of TP53/p53.
• interacts with DCLRE1C
• interacts with histone H2AFX; this requires phosphorylation of H2AFX on Ser-139
• interacts with histone H4 dimethylated at Lys-20
• low affinity for histone H4 containing monomethylated Lys-20
• does not bind histone H4 containing unmethylated or trimethylated Lys-20
• low affinity for histone H3 that has been dimethylated on Lys-79
• very low affinity for histone H3 monomethylated on Lys-79 (in vitro)
• does not bind unmethylated histone H3.
• interacts with MUM1/EXPAND1

Structure

• may form homo-oligomers
• asymmetrically dimethylated on Arg residues by PRMT1
  • methylation is required for DNA binding
• contains 2 BRCT domains

Compartment

• nucleus
• kinetochore
• associated with kinetochores
• both nuclear & cytoplasmic in some cells
• recruited to sites of DNA damage, such as double stand breaks
• methylation of histone H4 at Lys-20 is required for efficient localization to double strand breaks

Alternative splicing

named isoforms=2

More general terms

• apoptosis stimulating protein of p53; p53-binding protein (ASPP)

Database

• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=7158
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:7158
• OMIM: https://mirror.omim.org/entry/605230
• UniProt: http://www.uniprot.org/uniprot/Q12888.html