NPM3 - A NOVEL, WIDELY EXPRESSED GENE ENCODING A PROTEIN RELATED TO THE MOLECULAR CHAPERONES NUCLEOPLASMIN AND NUCLEOPHOSMIN

We report the cloning and initial characterization of the cDNAs, gene, and pseudogene of Npm3, a novel murine gene that encodes a protein re lated to the nuclear chaperone phosphoproteins, nucleoplasmin and nucl eophosmin. Npm3 is located approximately 5 kb upstream of Fgf8 on mous e Chromosome 19 and consists of six exons spanning 2 kb, The first fiv e exons code for an acidic protein of 19.0 kDa that contains a potenti al nuclear localization signal and potential phosphorylation sites for several kinases. Npm3 was expressed in all mouse tissues examined. On the basis of the similarity of Npm3 to nucleoplasmin and nucleophosmi n in amino acid sequence, protein features, and exon structure, we pro pose that Npm3 is a new member of, and may share basic functions with, the nucleo plasmin/nucleophosmin family of molecular chaperone protei ns. (C) 1997 Academic Press.