Anti-53BP1/TP53BP1 Antibody Picoband® Fluoro647 Conjugated

TP53BP1 (Tumor Protein p53-Binding Protein 1), also called 53BP1, is a protein that in humans is encoded by the TP53BP1 gene. Iwabuchi et al. (1998) mapped the TP53BP1 gene to 15q15-q21 by FISH. Iwabuchi et al. (1994) showed that TP53BP1 binds to the conformationally sensitive central domain of wildtype p53 but not to mutant p53 in vitro. Immunoblot analysis by Iwabuchi et al. (1998) showed that expression of TP53BP1 or TP53BP2 enhances the transactivation function of p53 and induces the expression of p21 (CDKN1A) . Wang et al. (2002) used small interfering RNA ed against TP53BP1 in mammalian cells to demonstrate that TP53BP1 is a key transducer of the DNA damage checkpoint signal. TP53BP1 was required for p53 accumulation, G2/M checkpoint arrest, and the intra-S-phase checkpoint in response to ionizing radiation.

Widely expressed. High levels are found in spleen, peripheral blood leukocytes, small intestine and thymus, but also in K-562 erythroleukemia cells, MCF-7 breast carcinoma cells and activated T-cells.

Plays a key role in the response to DNA damage. May have a role in checkpoint signaling during mitosis. Enhances TP53- mediated transcriptional activation. .

1. Iwabuchi, K., Bartel, P. L., Li, B., Marraccino, R., Fields, S. Two cellular proteins that bind to wild-type but not mutant p53. Proc. Nat. Acad. Sci. 91: 6098-6102, 1994. 2. Iwabuchi, K., Li, B., Massa, H. F., Trask, B. J., Date, T., Fields, S. Stimulation of p53-mediated transcriptional activation by the p53-binding proteins, 53BP1 and 53BP2. J. Biol. Chem. 273: 26061-26068, 1998 3. Wang, B., Matsuoka, S., Carpenter, P. B., Elledge, S. J. 53BP1, a mediator of the DNA damage checkpoint. Science 298: 1435-1438, 2002.

Nucleus. Chromosome, centromere, kinetochore. Associated with kinetochores. Both nuclear and cytoplasmic in some cells. Recruited to sites of DNA damage, such as double stand breaks. H4K20me2 is required for efficient localization to double strand breaks and removal of proteins that have a high affinity for H4K20me2 such as L3MBTL1 and KDM4A is needed.