Developmentally Regulated Mouse Gene NK10 Encodes a Zinc Finger Repressor Protein with Differential DNA-Binding Domains

Using oligonucleotides complementary to the conserved inter-finger region of a variety of previously described zinc finger-encoding genes, a novel mouse gene was cloned and characterized. The gene is localized on chromosome 8 and comprises five exons. Its corresponding mRNA is developmentally regulated in various tissues and includes an open reading frame encoding a protein of 72,422 daltons. It shares amino-terminal homologies with human KRAB (or FPB) boxes, and contains 13 zinc fingers of the C2-H2 type. The NK10 KRAB domains exhibit repressing activity when tested in GAL4 fusion protein assays. Cloning of putative target sequences revealed that the individual domains differentially contribute to zinc-dependent target DNA binding.