All normal retroviral particles contain a dimer of genomic RNA. The physical structure of the dimer, and of the linkage between the two monomers, is not understood. We reported some years ago that the viral nucleocapsid protein alters the linkage between the monomers when it is released from Gag during viral maturation. This stabilization of the dimeric linkage results from the nucleic acid chaperone activity of nucleocapsid. We have continued to probe the structure of viral RNA within authentic virus particles. We have recently analyzed the RNA by cleaving it at specific sites using RNase H and short oligodeoxynucleotides complementary to specific sequences in the RNA. The results of these experiments, for the first time, localized the most stable linkage between the monomers to the region near their 5' ends, in both immature and mature murine leukemia virus particles. The experiments also revealed the existence of additional, less stable linkages between the monomers. Retroviral nucleocapsid proteins are highly active nucleic acid chaperones. The mechanism of this crucial activity is not well understood. We have analyzed the binding of HIV-1 nucleocapsid to a very short (8-base) oligodeoxynucleotide in great detail, using several biophysical techniques. We found that a single nucleocapsid molecule can bind simultaneously to two nucleic acid molecules; conversely, a single nucleic acid molecule can bind two nucleocapsid molecules. It seems likely that the ability of the protein to interact with more than one nucleic acid molecule is a critical element in its nucleic acid chaperone activity.

Agency
National Institute of Health (NIH)
Institute
Division of Basic Sciences - NCI (NCI)
Type
Intramural Research (Z01)
Project #
1Z01BC010512-04
Application #
7338625
Study Section
(RRL)
Project Start
Project End
Budget Start
Budget End
Support Year
4
Fiscal Year
2006
Total Cost
Indirect Cost
Name
Basic Sciences
Department
Type
DUNS #
City
State
Country
United States
Zip Code
Wilkinson, Kevin A; Gorelick, Robert J; Vasa, Suzy M et al. (2008) High-throughput SHAPE analysis reveals structures in HIV-1 genomic RNA strongly conserved across distinct biological states. PLoS Biol 6:e96
Rulli Jr, Samuel J; Mirro, Jane; Hill, Shawn A et al. (2008) Interactions of murine APOBEC3 and human APOBEC3G with murine leukemia viruses. J Virol 82:6566-75
Rulli Jr, Samuel J; Hibbert, Catherine S; Mirro, Jane et al. (2007) Selective and nonselective packaging of cellular RNAs in retrovirus particles. J Virol 81:6623-31
Fisher, Robert J; Fivash, Matthew J; Stephen, Andrew G et al. (2006) Complex interactions of HIV-1 nucleocapsid protein with oligonucleotides. Nucleic Acids Res 34:472-84
Kol, Nitzan; Gladnikoff, Micha; Barlam, David et al. (2006) Mechanical properties of murine leukemia virus particles: effect of maturation. Biophys J 91:767-74
Kovaleski, Brandie J; Kennedy, Robert; Hong, Minh K et al. (2006) In vitro characterization of the interaction between HIV-1 Gag and human lysyl-tRNA synthetase. J Biol Chem 281:19449-56
Cruceanu, Margareta; Urbaneja, Maria A; Hixson, Catherine V et al. (2006) Nucleic acid binding and chaperone properties of HIV-1 Gag and nucleocapsid proteins. Nucleic Acids Res 34:593-605
Hibbert, Catherine S; Rein, Alan (2005) Preliminary physical mapping of RNA-RNA linkages in the genomic RNA of Moloney murine leukemia virus. J Virol 79:8142-8
Muriaux, Delphine; Costes, Sylvain; Nagashima, Kunio et al. (2004) Role of murine leukemia virus nucleocapsid protein in virus assembly. J Virol 78:12378-85
Oshima, Masamichi; Muriaux, Delphine; Mirro, Jane et al. (2004) Effects of blocking individual maturation cleavages in murine leukemia virus gag. J Virol 78:1411-20

Showing the most recent 10 out of 12 publications