Cloning and characterization of a novel zinc-finger protein-encoding cDNA from the mouse eye lens.

Zinc fingers (Zf) are a common structural motif found in many nucleic acid-binding proteins. In an effort to identify potential transcription factors in the mouse eye lens, we have isolated a Zf-containing clone from a newborn mouse lens cDNA library. The clone, named pMLZ-4, is 4.5 kb in length and contains an open reading frame of 1073 bp. The putative pMLZ-4 protein consists of a short, N-terminal acidic domain followed by twelve tandemly arrayed Zf of the C2H2 variety. The remaining 3.2 kb of the cDNA comprises the 3'-untranslated region. PCR analysis detected the presence of pMLZ-4 RNA in liver, heart, kidney, spleen and brain of newborn mice. Hybridization of pMLZ-4 to genomic DNA from a number of species of vertebrates revealed the presence of homologous sequences only in mouse and rat. Unexpectedly, the probe also hybridized to a single band in yeast DNA digested with EcoRI. NIH3T3 cells were stably transformed with a construct that over-expresses the pMLZ-4 mRNA. The stably transformed cells did not differ in appearance from untransformed cells, and an analysis of proteins from transformed and untransformed cells failed to detect any differences resulting from over-expression of the pMLZ-4 mRNA.