IKAROS Family Zinc Finger Protein 1 (IKZF1)

The deduced human and mouse Ikaros proteins are 95% identical. Ikaros proteins are conserved in sequence composition and relative expression between human T cells and mouse thymocytes. The deduced 519-amino acid protein is 93% identical to the mouse Ikaros isoform 1/LyF1 isoform VI and contains 4 N-terminal and 2 C-terminal zinc finger domains. Ikaros is expressed in the hormone-producing pituitary corticomelanotroph cells of mice, where it binds the proopiomelanocortin promoter and regulates endogenous gene expression. Ikaros-null mice had contraction of the pituitary corticomelanotroph population, reduced circulating adrenocorticotrophic hormone levels, and adrenal glucocorticoid insufficiency.