Viral protein R

Okui N, Kobayashi N, Kitamura Y (1998) Production of uninfectious human immunodeficiency virus type 1 containing viral protein R fused to a single-chain antibody against viral integrase. J Virol 72 6960-6964... 

Other HIV proteins include regulator of viral expression (Rev), negative effectors (Nef), viral protein R (Vpr), viral protein U (Vpu), viral infectivity factor (Vif) and transactivator protein (Tat). These proteins are instrumental in viral mRNA expression, viral replication and transactivation, viral release and maturation, viral infection, and maintenance of viral transcript activation and expression, respectively (Tripathi and Agrawal 2007). 

Initiation of reverse transcription in HIV-infected cells relies on a critical RNA-RNA interaction between tRNA y s, which is preferentially packaged into the viral particle, and a specific viral RNA seqnence. The 3 -terminaI 18 nucleotides of tRNA y are complementary to the primer binding site (PBS) sequence located in the 5 -Iong terminal repeat (LTR) of the viral RNA genome (Figure 10.3). The UUU anticodon of the tRNA is complementary to and binds to an adenosine rich loop located 8 nucleotides upstream (5 ) of the PBS. This RNA-RNA duplex which is formed when tRNA y s binds to the PBS fits within the active site of HIV-1 reverse transcriptase, bnt mnitiple interactions between the viral RNA and tRNA y are necessary for efficient initiation of reverse transcription. This interaction nucleates the reverse transcription complex which contains viral RNA, reverse transcriptase, tRNA y pl , nncleocapsid p7, and Vpr (Viral protein R), as well as multiple host factors." ... 

Popov, S., Rexach, M., Ratner, L., Blobel, G. and Bukrinsky, M. (1998a) Viral protein R regulates docking of the HIV-1 preintegration complex to the nuclear pore complex. J. Biol. Chem., 273, 13347-13352. 

The viral protein R (Vpr) of HIV-1 plays a significant role early in the viral life cycle by facilitating the nuclear import of the preintegration complex in non-dividing cells. The C-terminal domain of Vpr (Vpr52-96), which condenses plasmid DNA, mediates DNA transfection in a variety of human and non-human cell lines (Table 16.7). The Vpr52-96 sequence... 

Kichler, A., Pages, J.C., Leborgne, C., Druillennec, S., Lenoir, C., Coulaud, D. et al. (2000) Efficient DNA transfection mediated by the C-terminal domain of human immunodeficiency virus type 1 viral protein R. J. Virol., 74, 5424-5431. 

Dedera, D., Hu, W., Vander Heyden, N., et al. (1989). Viral protein R of human immunodeficiency virus types 1 and 2 is dispensable for replication and cytopathogenicity in lymphoid cells. J. Virol, 63, 3205-3208. 

HIV is a retrovirus in which the virus uses the body s cellular machinery to transform RNA to DNA. The number of helper T cells is dramatically reduced thereby lowering the body s immune response. GP-120 is essential to the virus binding to the cell surface receptor for entry into the cell. 14-3-3-0 is specifically implicated in the G2 checkpoint for cell cycle arrest for the HIV-1 VPR (viral protein R) accessory protein, which is associated with cell death since VPR is necessary for viral infection of helper T cells (Bolton et al. 2008). 14-3-3-0 can bind to several cyclin-dependent kinases that regulate the cell cycle leading to overall neurodegeneration in this immune disorder. Lipid peroxidation of the 14-3-3 family of proteins may cause reduced interaction with protein kinases, which can result in reduced signal transduction by which protein synthesis, cell cycle regulation, and DNA repair may be affected. 

Underwood M, Harvey R, Stanat S, Hemphill M, Miller T, Drach J, Townsend L, Biron K (1998) Inhibition of human cytomegalovirus DNA maturation by a benzimidazole ribonucleoside is mediated through the UL89 gene product. J Virol 72 717-725 Van Maele B, Debyser Z (2005) HlV-1 integration an interplay between HIV-1 integrase, cellular, and viral proteins. AIDS Rev 7 26 3... 

Figure 2.3 Tetracycline regulated gene expression (Adapted from Applied Molecular Genetics, R.Miesfeld, Wiley publishing, New York, 1999, p. 190). Terminology CMV (cytomegalovirus) VP (activating domain of viral protein VP 16) fefR (Tet represser) tTA (tetracycline-regulated trans-activator protein) rtTA (reverse let transactivator protein) (tel())- (repeat of 7 tet operator sequences) TATA (transcription initiation consensus sequence).

Smith, C. A., Farrah, T., and Goodwin, R. G. (1994). The TNF receptor superfamily of cellular and viral proteins Activation, costimulation and death. Cell ll, 959-962. 

Shaw, S. Y., Lawson, R. A., and Lees, M. B., Analagous amino acid sequence in myelin proteolipid and viral proteins, FEBS Lett., 207, 266, 1986. 

DIO. Drzeniek, R., Reichel, C., Wiegers, K. J., Hamann, A., and Hilbrig, M., Isoelectric focusing and two-dimensional electrophoresis of viral proteins and virus infected cells. In Electrophoresis 79 (B. J. Radola, ed.), pp. 475-489. Walter de Gruyter, Berlin, 1980. 

B., Sadoul, R. and Martinou, J.C. (1995) Viral proteins E1B19K and p35 protect sympathetic neurons from cell death induced by NGF deprivation. J. Cell Biol. 128 201-208. 

R. G. (1990) A receptor for tumor necrosis factor defines an unusual family of cellular and viral proteins. Science 248 1019-1023. 

Fig. 43.2. Replicative cycle of HIV. (1) The virus gp120 protein binds to CD4 resulting in fusion of the viral envelope and the cellular membrane and the release of viral nucleocapsid into the cytoplasm. (2) The nucleocapsid is uncoated, and viral RNA is reverse transcribed by reverse transcriptase (RT). (3) The resulting double-stranded proviral DMA migrates into the cell nucleus and is integrated into the cellular DMA by integrase (IN). (4) Proviral DNA is transcribed by the cellular RNA polymerase II. (5) The mRNAs are translated by the cellular polysomes. (6) Viral proteins and genomic RNA are transported to the cellular membrane and assemble. Immature virions are released, and polypeptide precursors are processed by the viral protease (PR) to produce mature vital particles. (Adapted from Sierra S, Kupfer B, Kaiser R. Basics of the virology of HIV-1 and its replication. J Clin Virol 2005 34 233 with permission from Elsevier.)...

Bernard, A., Fevre-Montange, M., Giraudon, P., Hardin, H., Wild, T.F., and Belin, M.F. 1991. Demonstration of viral proteins and RNA in hypothalamus of mice infected by canine distemper vims. C. R Acad. Sci. Ill 313, 545-551. 

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