Identification of domains of the Tomato spotted wilt virus NSm protein involved in tubule formation, movement and symptomatology

Authors: LI, WEIMIN - UNIV. OF FLORIDA; LEWANDOWSKI, DENNIS - OHIO STATE UNIVERSITY; Hilf, Mark; Adkins, Scott

Submitted to: Virology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/28/2009
Publication Date: 6/1/2009
Citation: Li, W., Lewandowski, D.J., Hilf, M.E., Adkins, S.T. 2009. Identification of domains of the Tomato spotted wilt virus NSm protein involved in tubule formation, movement and symptomatology. Virology. 390:110-121.

Interpretive Summary: Functional characterization of viral proteins is complicated in the absence of a reverse genetics system. We have successfully identified domains of the Tomato spotted wilt virus NSm protein building on our previous results using a Tobacco mosaic virus expression system. These findings are likely to be more broadly applicable to other tospovirus NSm proteins as the sequences are highly conserved.

Technical Abstract: Deletion and alanine-substitution mutants of the Tomato spotted wilt virus NSm protein were generated to identify domains involved in tubule formation, movement and symptomatology, using a heterologous expression system derived from Tobacco mosaic virus. Two regions of NSm were required for both tubule formation in protoplasts and cell-to-cell movement in plants, indicating a clear correlation between these biological activities. Three amino acids/groups of amino acids within NSm were linked with systemic movement in Nicotiana benthamiana. Another region was identified as the major determinant for development of foliar necrosis in N. benthamiana. These findings are likely to be more broadly applicable to other tospovirus NSm proteins as the sequences are highly conserved.