ISOLATION OF A CDNA-ENCODING A NOVEL ZINC-FINGER PROTEIN FROM NEUROBLASTOMA X GLIOMA NG108-15 CELLS

A subtraction cDNA library was constructed from control hybrid NG108-1 5 (mouse neuroblastoma x rat glioma) cells and NG108-15 cells which ha d been treated for 48 h with the sigma opioid agonist D-Ala(2)-D-Leu(5 ) enkephalin (DADLE) to down-regulate the sigma-opioid receptor on the se cells. Among the clones isolated from this library was NGD16-4, a 2 768-bp clone encoding a putative 64-kDa protein containing 14 tandemly repeated zinc fingers (Zf) with high homology to the Kruppel family o f Zf proteins, NGD16-4 also contains a region homologous to the A elem ent of the Kriippel Associated Box (KRAB) domain, a domain recently li nked to transcriptional repression. Southern and Northern analyses ind icate that NGD16-4 is derived from the mouse genome. Northern analysis also demonstrates that expression of NGD16-4 mRNA is much higher in s everal mouse neuroblastoma cell lines than in mouse brain or other tis sues, Although the function of NGD16-4 is unclear, the expression patt ern of NGD16-4 indicates a possible association with the processes of differentiation or transformation in the mouse.