Hepatocyte Nuclear Factor 6 Alpha (HNF6a)

HNF6a encodes a member of the onecut family of transcription factors, which are characterized by a cut domain and an atypical homeodomain. The protein binds to specific DNA sequences and stimulates expression of target genes, including genes involved in melanocyte and hepatocyte differentiation. This CCDS representation uses the 5'-most in-frame start codon, which is conserved in other vertebrates, including mouse, opossum, pig and zebrafish. An alternative downstream start codon, which has a stronger Kozak signal, also exists. It is possible that leaky scanning by ribosomes would allow the downstream start codon to be used, at least some of the time. The use of the downstream start codon would result in a protein that is 20 aa shorter at the N-terminus. There is no experimental evidence showing which start codon is preferentially used in vivo.