IBBEA   24401
INSTITUTO DE BIODIVERSIDAD Y BIOLOGIA EXPERIMENTAL Y APLICADA
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Plant-virus interactions: role of NABP virulence factors of Alpha- and Betaflexiviruses on the suppression of post-transcriptional gene silencing.
Autor/es:
1. PUCCIO F, BEY P., GONZALEZ P., BINAGHI M., MECCHIA M., MENTABERRY A. AND ZELADA A.
Lugar:
Foz de Iguazu
Reunión:
Congreso; 11th International Congress on Plant Molecular Biology; 2015
Resumen:
One of the main ways plants restrain viral infection is by post-transcriptional gene silencing (PTGS), an adaptive defence mechanism that leads to the degradation of viral RNA. In response, plant viruses produce a variety of PTGS suppressor proteins exhibiting great sequence and mechanistic diversity. Alphaflexiviruses Allexi- and Mandarivirus as well as Betaflexiviruses Viti-, Carla- and Trichovirus encode a related protein named NABP (Nucleic Acid Binding Protein). In our lab, we have shown that the 15K NABP of the Alphaflexiviruses Garlic virus A (GarV-A) act as both local and systemic PTGS suppressors. Here, we identify three highly conserved motifs present in the NABPs of 34 viruses of 5 different genera of Alpha- and Betaflexiviruses. By introducing mutations in the 15K protein of GarV-A, we determined that the motifs are necessary for the PTGS suppressor activity of the protein. In addition, we found that 15K can complement the cell-to-cell movement of a defective Potato Virus X (PVX), indicating for the first time a role for this protein in viral mobilization. By fluorescent microscopy, we found that 15K localizes to the nucleus and cytoplasm, and we found that the motifs influence the subcellular localization of the protein. Thus, our work points to an essential role for the 15K NABP of GarV-A in PTGS suppression and viral movement and subcelular localization and, since the functional motifs are phylogenetically conserved, the importance of 15K is likely to be a feature shared by plant viruses of several families and genera.