Long Terminal Repeats of Human Endogenous Retrovirus H Family Provide Alternative Polyadenylation Signals to NADSYN1 Gene

The NADSYN1 gene containing 21 exons was located in human chromosome 11q13.4. Using the computational screening of expressed sequence tag (EST) database, we found alternative transcript of NADSYN1 gene that was related to the HERV-H LTR element. The HERV-H LTR donated the last 22 nd exon for NADSYN1 gene and also provided an alternative polyadenylation signal. In the comparison of expression pattern between cellular and alternative transcripts, the cellular transcript has been expressed more frequently than alternative transcript in various normal tissues and cancer cells. The HERV-H LTR element seems to be integrated into our common ancestor genome after the divergence of hominoid primate and Old World monkeys, approximately 25 million years ago. By the integration event of HERV-H LTR in hominoid lineage, specific alternative transcript of NADSY1 gene has been created in the human. The data suggests that HERV-H LTR element of the NADSY1 gene has biological role during primate radiation.