Cloning of a housekeeping-type gene (MER5) preferentially expressed in murine erythroleukemia cells.

DNA complementary to mRNA preferentially produced in murine erythroleukemia (MEL) cells was cloned from a cDNA library of anemic mouse spleen mRNAs. An open reading frame was noted in the cloned DNA, and was tentatively designated MER5. The MER5 mRNA is abundant in three MEL cell lines, but less in other tissues or cell lines. The levels of the MER5 mRNA changed periodically during MEL cell differentiation and decreased as globin mRNA accumulated. The MER5 promoter region contained no typical TATA-like sequence, but possible target sequences for AP1, AP2, SP1 and octamer-binding protein. More interestingly, this promoter contained the duplicated CACCC boxes, which are common in the adult beta-globin promoter from many species, but uncommon for promoters of other eukaryotic genes.