Molecular cloning and expression analysis of a putative nuclear protein, SR-25

We cloned a full-length mouse cDNA and its human homologue encoding a novel protein designated as "SR-25." In Northern blot analysis, SR-25 mRNA was e xpressed in all organs tested, and relatively abundant in testis and thymus . Deduced amino acid sequences of mouse SR-25 and human SR-25 showed 77.7% identity. SR-25 has a serine-arginine repeat (SR repeat) and two types of a mino acid clusters: a serine cluster and a highly basic cluster. Based on t he presence of many nuclear localizing signals and a similarity to RNA spli cing proteins, SR-25 is strongly suggested to be a nuclear protein and may contribute to RNA splicing. (C) 2000 Academic Press.