Molecular cloning of six novel Kruppel-like zinc finger genes from hematopoietic cells and identification of a novel transregulatory domain KRNB

To clone zinc finger genes expressed in hematopoietic system, we designed p rimers based on conserved Cys(2)/ His, zinc finger sequences to amplify cor responding domains from mRNA of normal bone marrow and leukemia cell line N B4, DNA fragments of novel zinc finger genes were chosen and used as probe pool to screen cDNA libraries or subject to rapid amplification of cDNA end s in order to obtain full-length cDNA, Six cDNAs including whole open readi ng frame of zinc finger proteins, named. as ZNF191, ZNF253 (BMZF-1), ZNF255 (BMZF-2), ZNF256 (BMZF-3), ZNF257 (BMZF-4), and ZNF254 (BMZF-5) were obtai ned. All six belong to the Kruppel-like zinc finger gene family, and typica l transcriptional regulatory motifs exist in the N-terminal moiety, such as the SCAN box in ZNF191, and the KRAB domains in ZNF253, ZNP254, ZNF256, an d ZNF257, A previously undefined sequence nominated as Ki kruppel-related n ovel box, which may represent a new transregulatory motif, was revealed at the N terminus of ZNF255. The transregulatory function of non-zinc finger r egions of ZNF191, ZNF253, and ZNF255 were addressed in yeast and mammalian cells. The re suits indicated that ZNF255 might be a conditional transactiv ator, whereas ZNF253 and ZNF191 displayed a suppressive effect on the trans cription in yeast and/or mammalian systems.