The human CBFA1 gene

The CBFA1 gene, at chromosome location 6p21,
encodes a transcription factor of the core-binding
factor (CBF) family. The human CBFA1 gene
has two alternative transcription initiation sites
with two promoters (P1 and P2) and seven
exons. Part of exon 1 and exons 2 and 3 encode
the DNA-binding runt domain; exons 4, 5, 6, and
7 code for transcriptional activation and repression
domains. The nuclear localization signal
(NLS) is located at the 5" end of exon 3. Exon 6 is
alternatively spliced and unique to CBFA1. The
role of the CBFA1 gene also includes amajor regulatory
function in chondrocyte differentiation
during endochrondral bone formation (Mundlos,
1999). As such, it functions as a “master
gene” in bone development.