Transcriptional factor involved in bone development. Acts as an immediate early BMP-responsive transcriptional activator essential for osteoblast differentiation. Stimulates ALPL promoter activity in a RUNX2-independent manner during osteoblast differentiation. Stimulates SP7 promoter activity during osteoblast differentiation. Promotes cell proliferation by up-regulating MYC promoter activity. Involved as a positive regulator of both chondrogenesis and chondrocyte hypertrophy in the endochondral skeleton. Binds to the homeodomain-response element of the ALPL and SP7 promoter. Binds to the MYC promoter. Requires the 5'-TAATTA-3' consensus sequence for DNA-binding. Interacts with XRCC6 (Ku70). Expressed in osteoblasts and chondrocytes. Expressed in the otic vesicle, mandibular arch, branchial arches 2 and 3, in proximal anterior mesodermal domain in the limb, immature and proliferating chondroblasts at 14.5 dpc. Up-regulated by BMP2. Phosphorylated. Phosphorylation of Ser-34 and Ser-217 by MAPK14 enhances its transcriptional activity. Phosphorylation by CaMK2 increases its protein stability. Belongs to the distal-less homeobox family.