Tomato leaf curl Yunnan virus-encoded C4 induces cell division through enhancing stability of Cyclin D 1.1 via impairing NbSKη -mediated phosphorylation in Nicotiana benthamiana

• Published in: PLoS pathogens Vol. 14; no. 1; p. e1006789
• Main Authors: Mei, Yuzhen, Yang, Xiuling, Huang, Changjun, Zhang, Xiuren, Zhou, Xueping
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 01.01.2018; Public Library of Science (PLoS)
• Subjects: Agrobacterium tumefaciens - physiology; Begomovirus - metabolism; Begomovirus - pathogenicity; Biology and Life Sciences; Cell Division; Cyclin D1 - chemistry; Cyclin D1 - metabolism; Gene Deletion; Glycogen Synthase Kinase 3 - metabolism; Luminescent Proteins - chemistry; Luminescent Proteins - genetics; Luminescent Proteins - metabolism; Nicotiana - genetics; Nicotiana - metabolism; Nicotiana - microbiology; Nicotiana - ultrastructure; Phosphorylation; Phylogeny; Plant Leaves - genetics; Plant Leaves - metabolism; Plant Leaves - microbiology; Plant Leaves - ultrastructure; Plant Proteins - antagonists & inhibitors; Plant Proteins - chemistry; Plant Proteins - genetics; Plant Proteins - metabolism; Plants, Genetically Modified - genetics; Plants, Genetically Modified - metabolism; Plants, Genetically Modified - microbiology; Plants, Genetically Modified - ultrastructure; Point Mutation; Proteasome Endopeptidase Complex - metabolism; Proteasome Endopeptidase Complex - ultrastructure; Protein Interaction Domains and Motifs; Protein Processing, Post-Translational; Protein Serine-Threonine Kinases - antagonists & inhibitors; Protein Serine-Threonine Kinases - chemistry; Protein Serine-Threonine Kinases - genetics; Protein Serine-Threonine Kinases - metabolism; Protein Stability; Protein Transport; Proteolysis; Recombinant Fusion Proteins - chemistry; Recombinant Fusion Proteins - metabolism; Research and Analysis Methods; RNA Interference; Viral Proteins - chemistry; Viral Proteins - metabolism
• ISSN: 1553-7374; 1553-7366; 1553-7374
• DOI: 10.1371/journal.ppat.1006789

The whitefly-transmitted geminiviruses induce severe developmental abnormalities in plants. Geminivirus-encoded C4 protein functions as one of viral symptom determinants that could induce abnormal cell division. However, the molecular mechanism by which C4 contributes to cell division induction remains unclear. Here we report that tomato leaf curl Yunnan virus (TLCYnV) C4 interacts with a glycogen synthase kinase 3 (GSK3)/SHAGGY-like kinase, designed NbSKη, in Nicotiana benthamiana. Pro32, Asn34 and Thr35 of TLCYnV C4 are critical for its interaction with NbSKη and required for C4-induced typical symptoms. Interestingly, TLCYnV C4 directs NbSKη to the membrane and reduces the nuclear-accumulation of NbSKη. The relocalization of NbSKη impairs phosphorylation dependent degradation on its substrate-Cyclin D1.1 (NbCycD1;1), thereby increasing the accumulation level of NbCycD1;1 and inducing the cell division. Moreover, NbSKη-RNAi, 35S::NbCycD1;1 transgenic N. benthamiana plants have the similar phenotype as 35S::C4 transgenic N. benthamiana plants on callus-like tissue formation resulted from abnormal cell division induction. Thus, this study provides new insights into mechanism of how a viral protein hijacks NbSKη to induce abnormal cell division in plants.