Related Experiment Videos
Phosphorylation of tobacco mosaic virus movement protein abolishes its translation repressing ability
O V Karpova1, N P Rodionova, K I Ivanov
1Department of Virology, Moscow State University, Moscow, 119899, Russia.
Abstract:
Previously we showed that the ribonucleoprotein complexes (RNPs) of the TMV 30-kDa movement protein (MP) with TMV RNA are nontranslatable in vitro and noninfectious to protoplasts, but are infectious to intact plants. It has been suggested that MP-TMV RNA complexes could be converted into the translatable and replicatable form in planta in the course of passage through plasmodesmata (Karpova et al., 1997, Virology 230, 11-21). The role of TMV MP phosphorylation was investigated in terms of its capacity to modulate the translation-repressing ability of the MP. Phosphorylation of the TMV MP, either before or after RNP complex formation, caused a conversion of nontranslatable MP-RNA complexes into a form that was translatable in vitro and infectious to protoplasts and plants.
Insights
Phosphorylation of the Tobacco Mosaic Virus (TMV) movement protein (MP) converts nontranslatable MP-RNA complexes into a translatable and infectious form. This finding is crucial for understanding TMV infection and spread in plants.
Area of Science:
- Plant virology
- Molecular biology
- Biochemistry
Background:
- Ribonucleoprotein complexes (RNPs) of Tobacco Mosaic Virus (TMV) movement protein (MP) with TMV RNA are nontranslatable in vitro but infectious to intact plants.
- It is hypothesized that MP-TMV RNA complexes convert to a translatable form during passage through plasmodesmata in planta.
- The role of MP phosphorylation in modulating its translation-repressing ability requires investigation.
Purpose of the Study:
- To investigate the role of TMV MP phosphorylation in modulating its translation-repressing ability.
- To determine if phosphorylation converts nontranslatable MP-RNA complexes into a translatable and infectious form.
Main Methods:
- Investigated the effect of TMV MP phosphorylation on RNP complex translatability and infectivity.
- Examined phosphorylation before and after RNP complex formation.
Main Results:
- Phosphorylation of TMV MP, irrespective of timing (before or after RNP complex formation), converted nontranslatable MP-RNA complexes.
- The converted complexes became translatable in vitro and infectious to protoplasts and plants.
Conclusions:
- TMV MP phosphorylation is a key mechanism for converting nontranslatable MP-RNA complexes into a translatable and infectious state.
- This phosphorylation event is critical for TMV infection and spread within plant tissues.