Subcellular localization of grapevine red blotch-associated virus ORFs V2 and V3.

Grapevine red blotch-associated virus is a recently discovered plant monopartite gemini-like virus found in North American grapevines. Leaf discoloration and a decrease in fruit quality are associated with its infection. Two of its six open reading frames (ORFs), V2 and V3, are of unknown function and share no obvious homology with plant or viral genes. Transient expression of these ORFs in fusion with the green fluorescent protein demonstrated that the V2 protein localizes in the nucleoplasm, Cajal bodies, and cytoplasm; and the V3 protein localizes in various unidentified subnuclear bodies. Additionally, the V2 protein is redirected to the nucleolus upon co-expression with the nucleolus and Cajal body-associated protein Fib2.