May confer resistance to the antitumor agent cisplatin. Binds to DNA and RNA. Homodimer. Isoform 3 and isoform 10 are predominantly nuclear and nucleolar. After treatment with proteasomal inhibitors and mild heat-shock stress, isoform 1, isoform 3, isoform 5, isoform 7, isoform 8 and isoform 10 are relocalized to the nucleolus as dot-like or irregular subnuclear structures. Isoform 1 colocalized with nuclear promyelocytic leukemia (PML) and Cajal bodies (CB); this association with nuclear bodies is enhanced in response to proteotoxic stress. Isoform 3, but not isoform 1 and isoform 5, is relocalized in nucleolar caps during transcriptional arrest. Isoform 1 is predominantly cytoplasmic. Isoform 1 colocalized with nuclear promyelocytic leukemia (PML) and Cajal bodies (CB); this association with nuclear bodies is enhanced in response to proteotoxic stress. Expressed in testis. Heat-shock stress up-regulated mRNA expression of isoform 10 and isoform 11. Heat-shock stress down-regulated short N-terminal mRNA expression of isoform 2, isoform 4, isoform 6 and isoform 9. C-terminal half (amino acids 134-284) contains cytoplasmic retention domains as well as determinants involved in its stress-induced nucleolar accumulation. Produced by alternative promoter usage. Produced by alternative promoter usage. Produced by alternative splicing of isoform 1. Produced by alternative splicing of isoform 2. Produced by alternative splicing of isoform 1. Produced by alternative splicing of isoform 2. Produced by alternative splicing of isoform 1. Produced by alternative splicing of isoform 1. Produced by alternative splicing of isoform 2. Produced by alternative splicing of isoform 1. In cells exposed to a mild heat schock. Produced by alternative splicing of isoform 2. In cells exposed to a mild heat schock.