HOXA1: Proteins and Enzymes

HOXA1 (Homeobox A1; also Hox-1F) is a 35 kDa member of the Antp homeobox family of transcription factors. It is expressed in epithelium and is upregulated by E-cadherin signaling, whereupon it suppresses apoptosis and promotes anchorage-dependent growth. Human HOXA1 is 335 amino acids (aa) in length. It contains two poly-His sequences (aa 65 - 74 and 142 - 146), a PBX binding segment (aa 204 - 209) and a DNA-binding homeobox domain (aa 229 - 288). There are multiple HOXA1 splice variants. There is a potential alternate start site at Met6 that may be paired with a nine aa substitution for the C-terminal 117 aa, or a 19 aa substitution for the C-terminal 217 amino acids. Over aa 1 - 118, human HOXA1 shares 92% and 90% aa identity with mouse and canine HOXA1, respectively.