Isolation, expression, and characterization of the human ZCRB1 gene mapped to 12q12.

While isolating morphine-dependence-related genes with differential display, we cloned a novel human gene, zinc finger CCHC-type and RNA-binding motif 1 (ZCRB1, alias MADP-1) encoding a nuclear protein (217 residues). The ZCRB1 gene consists of eight exons and seven introns. It is mapped to 12q12, which is within a locus reported for Parkinson disease (M. Funayama et al., Ann. Neurol. 51 (2002) 296-301). The 5'-flanking region contains an enhancer core motif and binding sites for AP-1, AP-2, and LF-A1. ZCRB1 is characterized by an RNA-binding motif and a CCHC zinc finger motif. The latter overlaps the C..C...GH....C core nucleocapsid motif. ZCRB1 is conserved from zebrafish to human and shares homology with cold-inducible RNA-binding protein. Transfection assay showed that ZCRB1 is located in the nucleoplasm, but outside the nucleolus. ZCRB1 gene expression was stimulated by morphine, inhibited by 30-36 degrees C, and up-regulated by 39 degrees C incubation in SH-SY5Y neural cells. Zcrb1 gene expression is highest in the heart and testes, lower in the cerebellum, and lowest in the liver in mice. ZCRB1 mRNA expression is specifically elevated in hepatocarcinoma HepG2 cells. These data provide new clues for further understanding of morphine dependence, heat shock, and hepatocarcinoma.