title: Potato virus Y HC-Pro Reduces the ATPase Activity of NtMinD, Which Results in Enlarged Chloroplasts in HC-Pro Transgenic Tobacco.
abstract: Potato virus Y (PVY) is an important plant virus and causes great losses every year. Viral infection often leads to abnormal chloroplasts. The first step of chloroplast division is the formation of FtsZ ring (Z-ring), and the placement of Z-ring is coordinated by the Min system in both bacteria and plants. In our lab, the helper-component proteinase (HC-Pro) of PVY was previously found to interact with the chloroplast division protein NtMinD through a yeast two-hybrid screening assay and a bimolecular fluorescence complementation (BiFC) assay in vivo. Here, we further investigated the biological significance of the NtMinD/HC-Pro interaction. We purified the NtMinD and HC-Pro proteins using a prokaryotic protein purification system and tested the effect of HC-Pro on the ATPase activity of NtMinD in vitro. We found that the ATPase activity of NtMinD was reduced in the presence of HC-Pro. In addition, another important chloroplast division related protein, NtMinE, was cloned from the cDNA of Nicotiana tabacum. And the NtMinD/NtMinE interaction site was mapped to the C-terminus of NtMinD, which overlaps the NtMinD/HC-Pro interaction site. Yeast three-hybrid assay demonstrated that HC-Pro competes with NtMinE for binding to NtMinD. HC-Pro was previously reported to accumulate in the chloroplasts of PVY-infected tobacco and we confirmed this result in our present work. The NtMinD/NtMinE interaction is very important in the regulation of chloroplast division. To demonstrate the influence of HC-Pro on chloroplast division, we generated HC-Pro transgenic tobacco with a transit peptide to retarget HC-Pro to the chloroplasts. The HC-Pro transgenic plants showed enlarged chloroplasts. Our present study demonstrated that the interaction between HC-Pro and NtMinD interfered with the function of NtMinD in chloroplast division, which results in enlarged chloroplasts in HC-Pro transgenic tobacco. The HC-Pro/NtMinD interaction may cause the formation of abnormal chloroplasts in PVY-infected plants.
authors: State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, P.R. China.
authors: Yayi
authors: Y
authors: Tu
authors: State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, P.R. China.
authors: Zhenqian
authors: Z
authors: Zhang
authors: State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, P.R. China.
authors: Daofeng
authors: D
authors: Li
authors: State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, P.R. China.
authors: Heng
authors: H
authors: Li
authors: State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, P.R. China.
authors: Jiangli
authors: J
authors: Dong
authors: State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, P.R. China.
authors: Tao
authors: T
authors: Wang
mesh_terms: D000251:Adenosine Triphosphatases / Q000378:metabolism*; D002736:Chloroplasts / Q000648:ultrastructure*; D003546:Cysteine Endopeptidases / Q000235:genetics / Q000378:metabolism*; D010935:Plant Diseases / Q000821:virology; D010940:Plant Proteins / Q000378:metabolism; D030821:Plants, Genetically Modified; D017800:Potyvirus / Q000378:metabolism*; D014026:Nicotiana / Q000235:genetics / Q000821:virology*; D014764:Viral Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D010940:Plant Proteins; D014764:Viral Proteins; D003546:Cysteine Endopeptidases; C072775:HC-Pro protein, potyvirus; D000251:Adenosine Triphosphatases