The goal of this project is to define the molecular mechanisms involved in the replication of enveloped RNA viruses and in particular, to understand the factors which influence the regulation and expression of viral genetic information. Studies are being carried out with the murine leukemia virus system. Current interest is focused on the organization of the MuLV pol gene and on correlation of genetic structure with pol-associated enzymatic functions. Molecular clones containing MuLV reverse transcriptase and/or endonuclease gene segments have been expressed in E. coli and specific antisera hav been generated against the expressed bacterial proteins. These antisera are useful reagents for characterizing viral pol proteins, and serve as probes for the protein structure of the virus. Recently, studies with an antiserum directed against endonuclease alone have led to the observation that the viral reverse transcriptase and endonuclease can be associated as a complete involving both non-covalent and disulfide bonds. The exact nature of this association within the virion is under investigation. The sera are also being used to define the defect in a viral mutant with an in-frame deletion in the endonuclease coding region. in addition, a clone expressing only reverse transcriptase sequences has been used to make a monospecific anti-polymerase serum and to provide a source of highly active enzyme. Large scale preparations of bacterial extracts of this clone have now been extensively purified by standard biochemical procedures and characterization of the purified bacterially expressed reverse transcriptase is in progress.

Project Start
Project End
Budget Start
Budget End
Support Year
14
Fiscal Year
1986
Total Cost
Indirect Cost
Name
U.S. National Inst/Child Hlth/Human Dev
Department
Type
DUNS #
City
State
Country
United States
Zip Code
Iwatani, Yasumasa; Chan, Denise S B; Wang, F et al. (2007) Deaminase-independent inhibition of HIV-1 reverse transcription by APOBEC3G. Nucleic Acids Res 35:7096-108
Tang, Shixing; Ablan, Sherimay; Dueck, Megan et al. (2007) A second-site suppressor significantly improves the defective phenotype imposed by mutation of an aromatic residue in the N-terminal domain of the HIV-1 capsid protein. Virology 359:105-15
Wu, Tiyun; Heilman-Miller, Susan L; Levin, Judith G (2007) Effects of nucleic acid local structure and magnesium ions on minus-strand transfer mediated by the nucleic acid chaperone activity of HIV-1 nucleocapsid protein. Nucleic Acids Res 35:3974-87
Iwatani, Yasumasa; Takeuchi, Hiroaki; Strebel, Klaus et al. (2006) Biochemical activities of highly purified, catalytically active human APOBEC3G: correlation with antiviral effect. J Virol 80:5992-6002
Opi, Sandrine; Takeuchi, Hiroaki; Kao, Sandra et al. (2006) Monomeric APOBEC3G is catalytically active and has antiviral activity. J Virol 80:4673-82
Miles, Lesa R; Agresta, Beth E; Khan, Mahfuz B et al. (2005) Effect of polypurine tract (PPT) mutations on human immunodeficiency virus type 1 replication: a virus with a completely randomized PPT retains low infectivity. J Virol 79:6859-67
Levin, Judith G; Guo, Jianhui; Rouzina, Ioulia et al. (2005) Nucleic acid chaperone activity of HIV-1 nucleocapsid protein: critical role in reverse transcription and molecular mechanism. Prog Nucleic Acid Res Mol Biol 80:217-86
Heilman-Miller, Susan L; Wu, Tiyun; Levin, Judith G (2004) Alteration of nucleic acid structure and stability modulates the efficiency of minus-strand transfer mediated by the HIV-1 nucleocapsid protein. J Biol Chem 279:44154-65
Imamichi, Tomozumi; Murphy, Michael A; Adelsberger, Joseph W et al. (2003) Actinomycin D induces high-level resistance to thymidine analogs in replication of human immunodeficiency virus type 1 by interfering with host cell thymidine kinase expression. J Virol 77:1011-20
Iwatani, Yasumasa; Rosen, Abbey E; Guo, Jianhui et al. (2003) Efficient initiation of HIV-1 reverse transcription in vitro. Requirement for RNA sequences downstream of the primer binding site abrogated by nucleocapsid protein-dependent primer-template interactions. J Biol Chem 278:14185-95

Showing the most recent 10 out of 18 publications