| First Author | Watanabe N | Year | 2003 |
| Journal | J Biol Chem | Volume | 278 |
| Issue | 28 | Pages | 26102-10 |
| PubMed ID | 12730195 | Mgi Jnum | J:121604 |
| Mgi Id | MGI:3710720 | Doi | 10.1074/jbc.M303518200 |
| Citation | Watanabe N, et al. (2003) Identification and characterization of BCL-3-binding protein: implications for transcription and DNA repair or recombination. J Biol Chem 278(28):26102-10 |
| abstractText | A putative oncogene bcl-3 was originally identified and cloned at the breakpoint in the recurring chromosome translocation t(14;19) found in some cases of B cell chronic lymphocytic leukemia. Studies of bcl-3-deficient mice demonstrated a critical role for bcl-3 in the development of a normal immune response and the formation of germinal centers in secondary lymphoid organs. However, the molecular mechanism that underlies B cell leukemogenesis and the knockout mouse phenotype remains unclear. Here we have identified and characterized BCL-3-binding protein (B3BP) as a protein interacting specifically with the bcl-3 gene product (BCL-3) by a yeast two-hybrid screen. We found that B3BP associates with not only BCL-3 but also p300/CBP histone acetyltransferases. The N-terminal region of B3BP that contains the ATP-binding site is important for the interaction with BCL-3 and p300/CBP. Homology searches indicate that the ATP-binding region of B3BP, which contains a typical Walker-type ATP-binding P-loop, most resembles that of 2',3'-cyclic nucleotide 3'-phosphodiesterase of mammals and polynucleotide kinase of T4 bacteriophage. In fact B3BP shows intrinsic ATP binding and hydrolyzing activity. Furthermore, we demonstrated that B3BP is a 5'-polynucleotide kinase. We also found a small MutS-related domain, which is thought to be involved in the DNA repair or recombination reaction, in the C-terminal region of B3BP, and it shows nicking endonuclease activity. These observations might help to gain new insights into the function of BCL-3 and p300/CBP, especially the coupling of transcription with repair or recombination. |
