J. Virol., 10 1996, 6803-6809, Vol 70, No. 10
Copyright © 1996, American Society for Microbiology

A host factor that binds near the termini of hepatitis B virus pregenomic RNA

S Perri and D Ganem
Department of Microbiology, University of California, San Francisco 94143-0414, USA.

The terminal regions of hepatitis B virus (HBV) pregenomic RNA (pgRNA) harbors sites governing many essential functions in the viral life cycle, including polyadenylation, translation, RNA encapsidation, and DNA synthesis. We have examined the binding of host proteins to a 170- nucleotide region from the 5' end of HBV pgRNA; a large portion of this region is duplicated at the 3' end of this terminally redundant RNA. By UV cross-linking labeled RNA to HepG2 cell extracts, we have identified a 65-kDa factor (p65) of nuclear origin which can specifically bind to this region. Two discrete binding sites were identified within this region; in vitro cross-competition experiments suggest that the same factor binds to both elements. One binding site (termed UBS) overlaps a portion of the highly conserved stem-loop structure (epsilon), while the other site (termed DBS) maps 35 nucleotides downstream of the hexanucleotide polyadenylation sequence. Both binding sites are highly pyrimidine rich and map to regions previously found to be important in the regulation of viral polyadenylation. However, functional analysis of mutant binding sites in vivo indicates that p65 is not involved in the polyadenylation of HBV pgRNA. Potential roles for the factor in viral replication in vivo are discussed.

This article has been cited by other articles:

• Liu, N., Ji, L., Maguire, M. L., Loeb, D. D. (2004). cis-Acting Sequences That Contribute to the Synthesis of Relaxed-Circular DNA of Human Hepatitis B Virus. J. Virol. 78: 642-649 [Abstract] [Full Text]  
• Kreft, S. G., Nassal, M. (2003). hRUL138, a novel human RNA-binding RING-H2 ubiquitin-protein ligase. J. Cell Sci. 116: 605-616 [Abstract] [Full Text]  
• Yuan, T. T.-T., Lin, M.-H., Qiu, S. M., Shih, C. (1998). Functional Characterization of Naturally Occurring Variants of Human Hepatitis B Virus Containing the Core Internal Deletion Mutation. J. Virol. 72: 2168-2176 [Abstract] [Full Text]  
• Qing, K., Wang, X.-S., Kube, D. M., Ponnazhagan, S., Bajpai, A., Srivastava, A. (1997). Role of tyrosine phosphorylation of a cellular protein in adeno-associated virus 2-mediated transgene expression. Proc. Natl. Acad. Sci. USA 94: 10879-10884 [Abstract] [Full Text]  
• Dietrich-Goetz, W., Kennedy, I. M., Levins, B., Stanley, M. A., Clements, J. B. (1997). A cellular 65-kDa protein recognizes the negative regulatory element of human papillomavirus late mRNA. Proc. Natl. Acad. Sci. USA 94: 163-168 [Abstract] [Full Text]