Anti-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.

Heterogeneous nuclear ribonucleoprotein (hnRNP) that associates with nascent pre-mRNAs, packaging them into hnRNP particles. The hnRNP particle arrangement on nascent hnRNA is non- random and sequence-dependent and serves to condense and stabilize the transcripts and minimize tangling and knotting. Packaging plays a role in various processes such as transcription, pre-mRNA processing, RNA nuclear export, subcellular location, mRNA translation and stability of mature mRNAs (PubMed:19099192) . Forms hnRNP particles with at least 20 other different hnRNP and heterogeneous nuclear RNA in the nucleus. Involved in transport of specific mRNAs to the cytoplasm in oligodendrocytes and neurons: acts by specifically recognizing and binding the A2RE (21 nucleotide hnRNP A2 response element) or the A2RE11 (derivative 11 nucleotide oligonucleotide) sequence motifs present on some mRNAs, and promotes their transport to the cytoplasm (PubMed:10567417) . Specifically binds single-stranded telomeric DNA sequences, protecting telomeric DNA repeat against endonuclease digestion (By similarity) . Also binds other RNA molecules, such as primary miRNA (pri-miRNAs) : acts as a nuclear 'reader' of the N6-methyladenosine (m6A) mark by specifically recognizing and binding a subset of nuclear m6A-containing pri-miRNAs. Binding to m6A-containing pri- miRNAs promotes pri-miRNA processing by enhancing binding of DGCR8 to pri-miRNA transcripts (PubMed:26321680) . Involved in miRNA sorting into exosomes following sumoylation, possibly by binding (m6A) -containing pre-miRNAs (PubMed:24356509) . Acts as a regulator of efficiency of mRNA splicing, possibly by binding to m6A- containing pre-mRNAs (PubMed:26321680) .

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.