Identification and characterization of human KIAA1391 and mouse Kiaa1391 genes encoding novel RhoGAP family proteins with RA domain and ANXL repeats.

The commonly deleted region of breast cancer at human chromosome 11q23.1 is located between microsatellite markers D11S927 and D11S1347. We have previously identified and characterized the KIAA1735 gene, encoding MTH and DIX domain protein, within the 11q23.1 commonly deleted region. The BTG4 gene, encoding BTG/TOB family protein, as well as the SIK2 gene, encoding salt-inducible serine/threonine kinase 2, were also located within the 11q23.1 region. We identified and characterized the KIAA1391 gene within the 11q23.1 commonly deleted region by using bioinformatics. The nucleotide position 11-3586 of human KIAA1391 cDNA was predicted as the coding region of human KIAA1391 gene. Mouse Kiaa1391 gene was located within mouse genome sequences RP23-95E13 (AC102770.4), RP23-212M11 (AC140363.1), and mouse chromosome 9 genomic contig NT_039473.1. Exon-intron structure was well conserved between human KIAA1391 gene and mouse Kiaa1391 gene. Nucleotide sequence of mouse Kiaa1391 cDNA was determined in silico by assembling nucleotide sequences of exon 1-15 of mouse Kiaa1391 gene. Human KIAA1391 protein (1191 aa) and mouse Kiaa1391 protein (1182 aa) showed 79.1% total-amino-acid identity. RA domain (codon 198-274), RhoGAP domain (codon 363-546), and two Annexin-like (ANXL) repeats (codon 657-767 and 796-909) of human KIAA1391 protein were conserved in mouse Kiaa1391 protein. This is the first report on the comprehensive characterization of human KIAA1391 gene and mouse Kiaa1391 gene, encoding RhoGAP proteins with RA domain and two ANXL repeats.