Leader Proteinase of Beet Yellows Virus Functions in Long-Distance Transport

AUTOR(ES)

Peng, Chih-Wen

FONTE

American Society for Microbiology

RESUMO

The 66-kDa leader proteinase (L-Pro) of the Beet yellows virus (BYV) possesses a nonconserved N-terminal domain and a conserved, papain-like C-terminal domain. Previous work revealed that the N-terminal domain functions in RNA amplification, whereas the C-terminal domain is required for autoproteolysis. Alanine-scanning mutagenesis was applied to complete the functional analysis of L-Pro throughout the virus life cycle. This analysis indicated that the C-terminal domain of L-Pro, in addition to being required for proteolysis, also functions in RNA amplification and that these two functions are genetically separable. Examination of the role of L-Pro in BYV cell-to-cell movement revealed that none of the 20 examined replication-competent mutants was movement defective. In contrast, six of the L-Pro mutations affected the long-distance transport of BYV to various degrees, whereas three mutations completely abolished the transport. Because these mutations were located throughout the protein molecule, both domains of L-Pro function in virus transport. We conclude that in addition to previously identified functions of L-Pro, it also serves as the BYV long-distance transport factor.

Documentos Relacionados

• Interaction between Long-Distance Transport Factor and Hsp70-Related Movement Protein of Beet Yellows Virus
• Long-Distance Water Transport in Aquatic Plants.
• Long-distance movement factor: a transport function of the potyvirus helper component proteinase.
• Long-distance transport of L-ascorbic acid in potato
• Long-Distance Phloem Transport of Glucosinolates in Arabidopsis1