To enable expression of the VP60 gene in potatoes, a synthetic VP60
gene was introduced into potato plants via Agrobacterium
tumefaciens-mediated gene transfer. This gene contains the sequence
information of the VP60 gene from the RHDV virus isolate R-592, and
codon-optimised using the tobacco genetic code. The synthetic gene
fragment is 75% identical to the nucleotide sequence of VP60-gene
and 100% identical to the amino acid sequence of the VP60 protein.
A DNA fragment that encodes the SEKDEL amino acids was added to the
VP60 C-terminus sequence, thereby effecting the retention of the
protein to the endoplasmic reticulum in the secretory pathway of
protein synthesis. This is aimed at stabilising the protein.
In the plant, the expression is regulated by the 35S promoter from
the cauliflower mosaic virus leading to expression in all plant
parts throughout the entire lifecycle of the potato.
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