| First Author | Shirakawa H | Year | 2000 |
| Journal | J Biol Chem | Volume | 275 |
| Issue | 9 | Pages | 6368-74 |
| PubMed ID | 10692437 | Mgi Jnum | J:60860 |
| Mgi Id | MGI:1354028 | Doi | 10.1074/jbc.275.9.6368 |
| Citation | Shirakawa H, et al. (2000) NBP-45, a novel nucleosomal binding protein with a tissue-specific and developmentally regulated expression. J Biol Chem 275(9):6368-74 |
| abstractText | Here we characterize a novel murine nuclear protein, which we named NBP-45, that is related to the ubiquitous nuclear proteins HMG-14/-17, binds specifically to nucleosome core particles, and can function as a transcriptional activator. NBP-45 mRNA is expressed at low levels and in variable amounts in all mouse tissues tested but is especially abundant in RNA extracted from 7-day-old mouse embryos, suggesting that it functions in early embryonic development. NBP-45 is composed of 406 amino acids and is encoded by a single size transcript. The region spanning the N-terminal 85 amino acids contains three segments that are highly homologous to functionally important domains in the HMG-14/-17 protein family: the nuclear localization signal, the nucleosome binding domain, and the chromatin unfolding domain. The protein region spanning the C-terminal 321 amino acids has a 42% content of negatively charged residues. The first 23 amino acids contain a region necessary for nuclear entry of the protein, the region spanning residues 12-40 is the main nucleosomal binding domain of the protein, and the negatively charged, C-terminal domain is necessary for transcription activation. The functional domains of NBP-45 are indicative of a nuclear protein that binds to nucleosomes, thereby creating a chromatin region of high local negative charge. Our studies establish the nucleosomal binding domain as a protein motif that is present in other than just the ubiquitous HMG-14/-17 proteins. We suggest that the nucleosomal binding domain motif is a protein module that facilitates binding to nucleosomes in chromatin. |
