ISOLATION OF CDNA CLONES FOR 42 DIFFERENT KRUPPEL-RELATED ZINC-FINGERPROTEINS EXPRESSED IN THE HUMAN MONOBLAST CELL-LINE U-937

To study the complexity and structural characteristics of zinc finger proteins expressed during human hematopoiesis and to isolate novel reg ulators of blood cell development, a degenerate oligonucleotide probe specific for a consensus zinc finger peptide domain was used to isolat e 63 cDNA clones for Kruppel-related zinc finger genes from the human monoblast cell line U-937. By extensive nucleotide sequence and Northe rn blot analysis, these cDNA clones were found to originate from appro ximately 42 different genes (HZF 1-42) of which only 8 have previously been described. Northern blot analysis showed that a majority of thes e genes were expressed at comparable levels in U-937 and HeLa cells. T he large number of individual genes represented among the 63 clones an d their apparent non-cell-type-specific expression suggest that the ma jority of the Kruppel-related zinc finger genes are likely to be expre ssed in most human tissues. In contrast, some of the genes displayed a restricted expression pattern, indicating that the represent potentia l regulators of monocyte differentiation or proliferation. Detailed st ructural analysis of the first 12 cDNAs (HZF 1-10) and a partial chara cterization of HZF 11-42 revealed that a common feature of human Krupp el-related zinc finger proteins is the presence of tandem arrays of zi nc fingers ranging in number from 3 to over 20 that are preferentially located in the carboxy-terminal regions of the proteins. In addition, several novel KRAB-containing zinc finger genes and a novel conserved sequence element were identified.