A palindrome regulatory site within vertebrate GATA-1 promoters requires both zinc fingers of the GATA-1 DNAbinding domain for high-affinity interaction

GATA-1, a transcription factor essential for the development of the erythroid lineage, contains two adjacent highly conserved zinc finger motifs. The carboxy-terminal finger is necessary and sufficient for specific binding to the consensus GATA recognition sequence: mutant proteins containing only the amino-terminal finger do not bind. Here we identify a DNA sequence (GATApal) for which the GATA-1 amino-terminal finger makes a critical contribution to the strength of binding. The site occurs in the GATA-1 gene promoters of chickens, mice, and humans but occurs very infrequently in other vertebrate genes known to be regulated by GATA proteins. GATApal is a palindromic site composed of one complete [(A/T)GATA(A/G)] and one partial (GAT) canonical motif. Deletion of the partial motif changes the site to a normal GATA site and also reduces by as much as eightfold the activity of the GATA-1 promoter in an erythroid precursor cell. We propose that GATApal is important for positive regulation of GATA-1 expression in erythroid cells. The erythroid transcription factor GATA-1 is the prototype of a family of DNA-binding proteins, the GATA factors. The protein was identified as a positive regulator of globin gene transcription. Later it was shown that GATA-1 is involved in the regulation of all erythroid cell-specific genes which hav