Sequence Analysis of the 5′-Flanking Region of the Gene Encoding Human HOXA-7

Abstract

We have isolated and characterized the immediate 5′-flanking region (886 bp) of the gene encoding human HOXA-7. When the total sequence was compared with those of mice, 93% of the 3′ 518 bp (nt 370–886) sequences were identical, in which the 245 bases just preceding theAUG initiator codon (nt 614) was as highly conserved as in the coding region (nt 614–886). Sequences further upstream (nt 1–370) by comparison were highly diverged. In the 245 bp region, 8 stop and 3 initiation (including the initiator) codons were located, and a 50-aa long presumptive polypeptide was encoded. Nucleotide sequence analysis revealed three Spl and oneAP2 binding sites, as well as one CAATbox. However, there was no consensus sequence for a TATA box in the 5′ flanking region. One RARE repeat, one krox20 and three Hox-PBC binding sites were detected. Since many of the factor recognition sites were located in the immediate 5′ flanking sequences of a highly-conserved region, it might be speculated that a regulatory mechanism for Hox gene expression is conserved throughout the evolution and one possible mechanism could be at the post-translational level.