Identifying HRNT-1 (Human ZA73)

The recent focus of the Human Genome Project has undoubtedly shifted towards characterization of the coding DNA component and the development of a human gene map (placing of all 65000-80000 human genes on the hysical map). This has happened because of the sheer speed with which large-scale automated sequencing approaches can generate thousands of ESTs( Expresed Sequence Tag), and the ability to map the ESTs quickly. A considerabe variety of EST projects have been spawned. In many cases, identifying disease-gene has been facilitated.A lot of basic and clinic studies were made to investigate the function and mechanism of relative genes involved in lung cancer in our laboratory . Rat ZA73 ( GenBank Accession Number: AF011363 ) , an EST was cloned from rat tracheal epithelial ( RTE ) neoplastic transformed cell model induced by a-particles radiation using mRNA differential display. Northern blottingting showed that rat ZA73 expressed higher in RTE transformed cells than in normal cells. Homology search in GenBank showed rat ZA73 was a novel EST. On the basis of those findings, the full-length sequence and function of HRNT-1 (Human ZA73 ) were set to identify.According to the sequence of rat ZA73, HRNT-1 (Human ZA73 ) was cloned by Gene trapper and Marathon RACE( rapid amplification of cDNA ends ) . Theresults were as follows: (1) The length of HRNT-1 (Human ZA73) is 4.256 kb, with an ORF located in the region between 28 to 3104 bp. There are 9 TPR (tetratricopeptide repeat) in the sequences of ORF. 5' UTS (untranslated sequences ) is 253 bp, 3' UTS is 1240 bp, no promoter and poly A sequences were found. (2) HRNT-1 (Human ZA73) was submitted to GenBank and the datas were released on the web (http//www.ncbi.nlm.nih.gov) . The accession number is AF223393. BLAST search showed HRNT-1 (Human ZA73) was fairly homologic with the genes which were submitted to GenBank in 1999. These genes accession numbers in GenBank are AL050366.1(GI: 4914599) , AL049950 (GI: 4884197), OGT NM₀03605.1(GI: 4505498), and OGT NM₀03605.2 (GI: 6006036) . HRNT-1(Human ZA73 ) possesses the same ORF as AL049950, OGT NM₀03605.1 and NM₀03605.2, except for 3' untranslated region. (3) RT-PCR showed that HRNT-1(Human ZA73) expressed higher in BEP2D neoplastic transformed cells than in normal cells. (4) Northern blottingting revealed that HRNT-1 (Human ZA73 ) presented a higher expression in pancreatic tissue , lung carcinoma cell and Burkitt's lymphoma Raji cell, and a lower expression in lung, liver, and melanoma cell. It suggested that HRNT-1 ( Human ZA73 ) may involved in neoplastic transformation of bronchial epithelial cells.