Diagram illustrating HIV-CaMV replication element interchangability from John Innes Centre and Sainsbury Laboratory Annual Report 1998/1999 p 62 : R.Noad, R.Viallana, D. Turner, K. Moffat and S.Covey: "Analysis of animal retroviral elements utilising a plant pararetroviral vector".
| Fig. 67 (a) The circular, double-stranded DNA genome of CaMV showing the viral genes, including the reverse transcriptase (RT) with its RNase H domain (pink). CaMV has two polypurine primers (PPT) which interact with the RNase H regulating DNA plus-strand synthesis. A new site of DNA plus-strand synthesis has been engineered in CaMV into which the equivalent primer sequence from HIV-1 has been inserted, (b) RT typically has a 'hand' structure, with the reverse transcriptase domain towards one end of the molecule and the RNase H domain at the other. TheCaMV RNAse H domain recognises the HIV-1 primer for DNA plus-strand synthesis during infection of plants. |
Extract below taken from authors’ reply to critiques on "Cauliflower Mosaic Viral Promoter – A Recipe for Disaster?" by Hoe, M.W., Ryan, A.and Cummins, J. (1999). Microbial Ecology in Health and Disease
"....There is no evidence that CaMV promoter per se is active in animal cells. However, on account of the modularity of its structure, small motifs and elements within the CaMV promoter may be interchangeable with those of the animal viruses. HIV is a retrovirus that depends on integration into the host genome for replication, and its complementary DNA will therefore be present in the genome of humans infected with the virus. Hepatitis B virus, being a pararetrovirus, does not require integration for replication, but its genome has, nevertheless, been found in human chromosomes in liver tissue, and is associated with liver carcinoma (see ref. 19).
The initiation site for the +DNA strand synthesis in CaMV is a polypurine tract (PPT). It has recently been reported that the PPT from HIV-1 gives up to 50% of the efficiency for CAMV +DNA strand synthesis as CaMV’s own element (29). All eukaryotes and prokaryotes share the core TATA box promoter element. It is not inconceivable that the TATA box, as well as other elements and motifs within the CaMV promoter, when recombined with dormant animal viral promoters, may reactivate the virus, generate new viruses or give functional viral promoters that make cellular oncogenes over-express, resulting in cancer...."
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