Coat proteins of Rice tungro bacilliform virus and Mungbean yellow mosaic virus contain multiple nuclear-localization signals and interact with importin alpha.
Fiche publication
Date publication
juin 2005
Auteurs
Membres identifiés du Cancéropôle Est :
Pr SCHMIT Anne-Catherine
Tous les auteurs :
Guerra-Peraza O, Kirk D, Seltzer V, Veluthambi K, Schmit AC, Hohn T, Herzog E
Lien Pubmed
Résumé
Transport of the viral genome into the nucleus is an obligatory step in the replication cycle of plant pararetro- and geminiviruses. In both these virus types, the multifunctional coat protein (CP) is thought to be involved in this process. Here, a green fluorescent protein tagging approach was used to demonstrate nuclear import of the CPs of Rice tungro bacilliform virus (RTBV) and Mungbean yellow mosaic virus--Vigna (MYMV) in Nicotiana plumbaginifolia protoplasts. In both cases, at least two nuclear localization signals (NLSs) were identified and characterized. The NLSs of RTBV CP are located within both N- and C-terminal regions (residues 479KRPK/497KRK and 744KRK/758RRK), and those of MYMV CP within the N-terminal part (residues 3KR and 41KRRR). The MYMV and RTBV CP NLSs resemble classic mono- and bipartite NLSs, respectively. However, the N-terminal MYMV CP NLS and both RTBV CP NLSs show peculiarities in the number and position of basic residues. In vitro pull-down assays revealed interaction of RTBV and MYMV CPs with the nuclear import factor importin alpha, suggesting that both CPs are imported into the nucleus via an importin alpha-dependent pathway. The possibility that this pathway could serve for docking of virions to the nucleus is discussed.
Référence
J Gen Virol. 2005 Jun;86(Pt 6):1815-26.