Identification of a novel gene encoding a p53-associated protein

p53 exerts important physiological functions in cell-cycle control, gene re gulation, cell differentiation, apoptosis and tumor suppression by interact ing with many cellular proteins. Using the yeast two-hybrid system, we scre ened a HeLa cDNA library and identified a novel gene encoding a p53-binding protein (p53BP3). The full-length cDNA of p53BP3 was isolated from a HeLa lambda gt10 cDNA library. This predicted protein was composed of 815 amino acids. Sequence analysis indicated that p53BP3 contained two bipartite nucl ear localization signals and was confirmed to be a nuclear protein. FISH ma pping results showed that this novel gene was located at human chromosome 1 2, region p11.2-p12.1. Northern blot analysis suggested that p53BP3 was bro adly expressed in human tissues. A further study showed that p53BP3 had a h omologue in mouse. (C) 1999 Elsevier Science B.V. All rights reserved.