Identification and characterization of human FOXK1 gene in silico.

Forkhead-box (FOX) family transcription factors are implicated in carcinogenesis and embryogenesis. Here, we identified and characterized the human FOXK1 gene by using bioinformatics. Complete coding sequence of human FOXK1 cDNA was determined by assembling CB959941 EST, AW206906 EST, and 5'-truncated FLJ16099 (AK122663.1) cDNA. FOXK1 gene, consisting of nine exons, was mapped to human chromosome 7p22.1. Mouse Foxk1 (NM_199068.1) was an aberrant cDNA with frame shifts due to multiple insertions and deletions, while mouse IMAGE6853263 (BC060238.1) was a Foxk1 cDNA with a frame shift due to two base deletions. Complete coding sequence of mouse Foxk1 cDNA was determined by inserting CA nucleotides between nucleotide position 1628 and 1629 of BC060238.1. Foxk1 gene, consisting of nine exons, was mapped to mouse chromosome 5G2. Because interleukin enhancer-binding factor 1 (ILF1) gene at human chromosome 17q25.3 was the paralog of FOXK1 gene, ILF1 gene was designated the FOXK2 gene. Xenopus BC046369.1 cDNA was Foxk2 ortholog rather than Foxk1 ortholog. Human FOXK1 (733 aa) showed 88.7% total amino-acid identity with mouse Foxk1 (719 aa), 48.7% total amino-acid identity with human FOXK2, and 47.5% total amino-acid identity with Xenopus Foxk2. Forkhead associated (FHA) domain and FOX domain were conserved among human FOXK1, FOXK2, mouse FoxK1, and Xenopus Foxk2. At least 42 FOX family genes, including FOXK1, FOXN5 (FOXR1) and FOXN6 (FOXR2), have been identified within the human genome.