Phosphorylation of TGB1 by protein kinase CK2 promotes XXXX movement in monocots and dicots.

@entity2247 @entity71866 @entity71867 @entity71870 @entity281 @entity18084 @entity71869 @entity71868 @entity71871
UNASSIGNED: The @entity18084 ) triple gene block 1 (TGB1) protein is required for virus cell-to-cell movement. However, little information is available about how these activities are regulated by post-translational modifications. In this study, we showed that the @entity18084 Xinjiang strain TGB1 (XJTGB1) is phosphorylated in vivo and in vitro by protein kinase CK2 from @entity2247 and Nicotiana benthamiana. Liquid chromatography tandem mass spectrometry analysis and in vitro phosphorylation assays demonstrated that Thr-401 is the major phosphorylation site of the XJTGB1 protein, and suggested that a Thr-395 kinase docking site supports Thr-401 phosphorylation. Substitution of @entity71866 ( @entity71867 ) only moderately impaired virus cell-to-cell movement and @entity281 . In contrast, the @entity71868 ( @entity71869 ) virus mutant was unable to systemically infect N. benthamiana but had only minor effects in monocot hosts. Substitution of @entity71870 interfered with monocot and dicot cell-to-cell movement and the plants failed to develop @entity281 . However, virus derivatives with single @entity71871 developed nearly normal @entity281 in the monocot hosts but were unable to infect N. benthamiana systemically, and none of the double mutants was able to infect dicot and monocot hosts. The mutant XJTGB1 @entity71867 / @entity71869 weakened in vitro interactions between XJTGB1 and XJTGB3 proteins but had little effect on XJTGB1 RNA-binding ability. Taken together, our results support a critical role of CK2 phosphorylation in the movement of @entity18084 in monocots and dicots, and provide new insights into the roles of phosphorylation in TGB protein functions.
