Identification and characterization of human TIPARP gene within the CCNL amplicon at human chromosome 3q25.31

Array CGH combined with mRNA microarray analyses was successfully applied for genome-wide screening of proto-oncogenes as well as tumor suppressor genes in 2002. It has been reported that an uncharacterized gene, corresponding to a 5'-truncated partial cDNA DKFZp434J214, is amplified and up-regulated together with CCNL in head-and-neck squamous cell carcinoma (HNSCC). Here, we identified that the novel gene, corresponding to the 5'-truncated DKFZp434J214 cDNA, is the human ortholog of mouse Tiparp gene, by using bioinformatics. Complete coding sequence of human TIPARP mRNA was determined in silico by assembling nucleotide sequences of BC034397 and DKFZp434J214 cDNAs. Human TIPARP gene, consisting of six exons, was located between SSR3 and CCNL genes at human chromosome 3q25.31. Fugu tiparp gene was located around nucleotide position 14280-23355 of fugu genome draft sequence CAAB01003597.1. Human TIPARP showed 91.8% and 52.7% total amino-acid identity with mouse Tiparp and fugu tiparp, respectively. TPH domain (codon 242-296 of human TIPARP), WWE domain (codon 329-378) and PARP-like domain (codon 465-648) were evolutionarily conserved among TIPARP proteins. CCCH-type zinc finger was located within the N-terminal part of the TPH domain. Human TIPARP showed 27.5% and 26.0% total-amino-acid identity with human FLJ22693 and ZAP, respectively. TIPARP, FLJ22693 and ZAP, sharing the common structure with the TPH, WWE and PARP-like domains, were found to constitute the TIPARP family. This is the first report on human TIPARP and fugu tiparp genes as well as on the TIPARP family.