This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Ling, J. Articles by Tuan, D. Search for Related Content PubMed PubMed Citation Articles by Ling, J. Articles by Tuan, D.

 Previous Article  |  Next Article 

Journal of Virology, March 2002, p. 2410-2423, Vol. 76, No. 5
0022-538X/02/$04.00+0     DOI: 10.1128/jvi.76.5.2410-2423.2002
Copyright © 2002, American Society for Microbiology. All Rights Reserved.

The Solitary Long Terminal Repeats of ERV-9 Endogenous Retrovirus Are Conserved during Primate Evolution and Possess Enhancer Activities in Embryonic and Hematopoietic Cells

Department of Biochemistry and Molecular Biology,¹ Institute of Molecular Medicine and Genetics, School of Medicine, Medical College of Georgia, Augusta, Georgia,² Hematology Division, Department of Medicine, Vanderbilt University and VA Medical Center, Nashville, Tennessee³

Received 11 September 2001/ Accepted 26 November 2001

The solitary long terminal repeats (LTRs) of ERV-9 endogenous retrovirus contain the U3, R, and U5 regions but no internal viral genes. They are middle repetitive DNAs present at 2,000 to 4,000 copies in primate genomes. Sequence analyses of the 5" boundary area of the erythroid ß-globin locus control region (ß-LCR) and the intron of the embryonic axin gene show that a solitary ERV-9 LTR has been stably integrated in the respective loci for at least 15 million years in the higher primates from orangutan to human. Functional studies utilizing the green fluorescent protein (GFP) gene as the reporter in transfection experiments show that the U3 region of the LTRs possesses strong enhancer activity in embryonic cells of widely different tissue origins and in adult cells of blood lineages. In both the genomic LTRs of embryonic placental cells and erythroid K562 cells and transfected LTRs of recombinant GFP plasmids in K562 cells, the U3 enhancer activates synthesis of RNAs that are initiated from a specific site 25 bases downstream of the AATAAA (TATA) motif in the U3 promoter. A second AATAAA motif in the R region does not serve as the TATA box or as the polyadenylation signal. The LTR-initiated RNAs extend through the R and U5 regions into the downstream genomic DNA. The results suggest that the ERV-9 LTR-initiated transcription process may modulate transcription of the associated gene loci in embryonic and hematopoietic cells.

This article has been cited by other articles:

• Yu, X., Zhu, X., Pi, W., Ling, J., Ko, L., Takeda, Y., Tuan, D. (2005). The Long Terminal Repeat (LTR) of ERV-9 Human Endogenous Retrovirus Binds to NF-Y in the Assembly of an Active LTR Enhancer Complex NF-Y/MZF1/GATA-2. J. Biol. Chem. 280: 35184-35194 [Abstract] [Full Text]  
• Ling, J., Ainol, L., Zhang, L., Yu, X., Pi, W., Tuan, D. (2004). HS2 Enhancer Function Is Blocked by a Transcriptional Terminator Inserted between the Enhancer and the Promoter. J. Biol. Chem. 279: 51704-51713 [Abstract] [Full Text]  
• Potgens, A.J.G., Drewlo, S., Kokozidou, M., Kaufmann, P. (2004). Syncytin: the major regulator of trophoblast fusion? Recent developments and hypotheses on its action. Hum Reprod Update 10: 487-496 [Abstract] [Full Text]  
• Pi, W., Yang, Z., Wang, J., Ruan, L., Yu, X., Ling, J., Krantz, S., Isales, C., Conway, S. J., Lin, S., Tuan, D. (2004). The LTR enhancer of ERV-9 human endogenous retrovirus is active in oocytes and progenitor cells in transgenic zebrafish and humans. Proc. Natl. Acad. Sci. USA 101: 805-810 [Abstract] [Full Text]  
• Ling, J., Pi, W., Yu, X., Bengra, C., Long, Q., Jin, H., Seyfang, A., Tuan, D. (2003). The ERV-9 LTR enhancer is not blocked by the HS5 insulator and synthesizes through the HS5 site non-coding, long RNAs that regulate LTR enhancer function. Nucleic Acids Res 31: 4582-4596 [Abstract] [Full Text]