Characterization of KIF12 gene in silico.

Kinesin family (KIF) proteins with Kinesin motor catalytic (KISc) domain and Coiled-coil domain are micro-tubule-dependent molecular motors. KIF proteins produce forces by using the energy from ATP hydrolysis within the KISc domain. We have recently identified that KIF27 is one of mammalian orthologs for Drosophila Costal-2 (Cos2), functioning as regulator of Hedgehog signaling pathway. Mouse Kif12 RefSeq (NM_010616.1) contains the complete coding sequence (CDS); however, human KIF12 Refseq (NM_138424.1) encodes an N-terminally truncated KIF12 protein corresponding to codon 134-642 of mouse Kif12. Here, we characterized the human KIF12 gene by using bioinformatics. Complete CDS of human KIF12 was determined by assembling nucleotide sequences of BQ129377.1 EST, CD358781.1 EST and NM_138424.1 RefSeq. KIF12 gene at human chromosome 9q32 consists of 19 exons. NM_138424.1 RefSeq was a variant KIF12 cDNA with alternative transcription start site (TSS) and skipping of exon 4. NM_138424.1 RefSeq encoded a 513-amino-acid aberrant KIF7 protein with N-terminal-truncation, while KIF12 complete CDS encoded a 651-amino-acid full-length KIF12 protein. Representative human KIF12 and mouse Kif12 proteins with 80.8% total-amino-acid identity shared the common domain architecture, consisting of KISc domain, Coiled-coil domain with internal hinge region, and C-terminal tail domain. KIF12 mRNA was expressed in fetal liver, adult brain and pancreatic islet as well as in kidney tumors, uterus cancer and pancreatic cancer. This is the first report on comprehensive characterization of the human KIF12 gene.