Homeobox Protein A13 (HOXA13)

HOXA13 is part of the A cluster on chromosome 7 and encodes a DNA-binding transcription factor which may regulate gene expression, morphogenesis, and differentiation. HOXA13 expression was associated with distal sites and was required for activation of distal-specific gene expression, including expression of WNT5A. Depletion of HOXA13 in human plantar fibroblasts reduced expression of distal-specific keratin-9 (KRT9), and KRT9 expression was rescued by addition of recombinant purified WNT5A. In situ hybridization showed that Hoxa13 and Wnt5a were spatially and temporally coexpressed in distal limb bud during mouse development.HOXA13 control of WNT5A expression in distal fibroblasts can regulate site-specific epidermal differentiation.