Nucleocytoplasmic Shuttling of Geminivirus C4 Protein Mediated by Phosphorylation and Myristoylation Is Critical for Viral Pathogenicity.
Mol Plant
; 11(12): 1466-1481, 2018 12 03.
Article
en En
| MEDLINE
| ID: mdl-30523782
ABSTRACT
Many geminivirus C4 proteins induce severe developmental abnormalities in plants. We previously demonstrated that Tomato leaf curl Yunnan virus (TLCYnV) C4 induces plant developmental abnormalities at least partically by decreasing the accumulation of NbSKη, an ortholog of Arabidopsis BIN2 kinase involved in the brassinosteroid signaling pathway, in the nucleus through directing it to the plasma membrane. However, the molecular mechanism by which the membrane-associated C4 modifies the localization of NbSKη in the host cell remains unclear. Here, we show that TLCYnV C4 is a nucleocytoplasmic shuttle protein, and that C4 shuttling is accompanied by nuclear export of NbSKη. TLCYnV C4 is phosphorylated by NbSKη in the nucleus, which promotes myristoylation of the viral protein. Myristoylation of phosphorylated C4 favors its interaction with exportin-α (XPO I), which in turn facilitates nuclear export of the C4/NbSKη complex. Supporting this model, chemical inhibition of N-myristoyltransferases or exportin-α enhanced nuclear retention of C4, and mutations of the putative phosphorylation or myristoylation sites in C4 resulted in increased nuclear retention of C4 and thus decreased severity of C4-induced developmental abnormalities. The impact of C4 on development is also lessened when a nuclear localization signal or a nuclear export signal is added to its C-terminus, restricting it to a specific cellular niche and therefore impairing nucleocytoplasmic shuttling. Taken together, our results suggest that nucleocytoplasmic shuttling of TLCYnV C4, enabled by phosphorylation by NbSKη, myristoylation, and interaction with exportin-α, is critical for its function as a pathogenicity factor.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Proteínas Virales
/
Núcleo Celular
/
Procesamiento Proteico-Postraduccional
/
Geminiviridae
/
Ácido Mirístico
/
Citoplasma
Tipo de estudio:
Prognostic_studies
Idioma:
En
Revista:
Mol Plant
Asunto de la revista:
BIOLOGIA MOLECULAR
/
BOTANICA
Año:
2018
Tipo del documento:
Article
País de afiliación:
China