Isolation and characterization of the human forkhead gene FOXQ1.

We have isolated a human genomic and cDNA clone that encodes a protein of 403 amino acids and belongs to the family of the FOX transcription factors (previously called HNF-3/forkhead transcription factors). The 2.7-kb transcript of the human FOXQ1 gene is expressed predominantly in the stomach, trachea, bladder and salivary gland. Additionally, overexpression of human FOXQ1 was shown in colorectal adenocarcinoma and lung carcinoma cell lines. The FOXQ1 gene is located on chromosome 6p23-25. Databank analysis shows 82% homology with the mouse Foxq1 gene (formerly Hfh-1L) and with a revised sequence of the rat FoxQ1 gene (formerly HFH-1). The DNA-binding motif, named HNF-3/forkhead domain, is well conserved, showing 100% identity in human, mouse, and rat. The human protein sequence contains two putative transcriptional activation domains, which share a high amino acid identity with the corresponding mouse and rat domains.