COMPARISON OF PLANT‐ADAPTED RHABDOVIRUS PROTEIN LOCALIZATION AND INTERACTIONS

• Main Author: Martin, Kathleen Marie
• Format: Others
• Published: UKnowledge 2011
• Subjects: rhabdovirus; Nicotiana benthamiana; BiFC; interaction; localization; Agriculture; Plant Pathology
• Online Access: http://uknowledge.uky.edu/gradschool_diss/172; http://uknowledge.uky.edu/cgi/viewcontent.cgi?article=1164&context=gradschool_diss

Sonchus yellow net virus (SYNV), Potato yellow dwarf virus (PYDV) and Lettuce Necrotic yellows virus (LNYV) are members of the Rhabdoviridae family that infect plants. SYNV and PYDV are Nucleorhabdoviruses that replicate in the nuclei of infected cells and LNYV is a Cytorhabdovirus that replicates in the cytoplasm. LNYV and SYNV share a similar genome organization with a gene order of Nucleoprotein (N), Phosphoprotein (P), putative movement protein (Mv), Matrix protein (M), Glycoprotein (G) and Polymerase protein (L). PYDV contains an additional predicted gene between N and P, denoted as X, that has an unknown function. In order to gain insight into the associations of viral proteins and the mechanisms by which they may function, we constructed protein localization and interaction maps using novel plant expression vectors. Sub‐cellular localization was determined by expressing the viral proteins fused to green fluorescent protein in leaf epidermal cells of Nicotiana benthamiana. Protein interactions were tested in planta using bimolecular fluorescence complementation (BiFC). All three viruses showed Mv to be localized to the cell periphery and the G protein to be membrane associated. Comparing the interaction maps revealed that only the N‐P and M‐M interactions are common to all three viruses. Associations unique to only one virus include G‐Mv for SYNV, M‐Mv, M‐G, and N‐M for PYDV and P‐M for LNYV. The cognate N‐P proteins of all three viruses exhibit changes in localization when co‐expressed. To complement the mapping data, we also mapped the functional domains in the glycoproteins of SYNV and LNYV. The truncation of the carboxy terminus has no effect on localization compared to the full‐length protein; the nuclear localization signals (NLSs) present in SYNV‐G do not interact with known importins. These data suggest that although the interactions of the three viruses differ, each protein may have similar functional domains.