Interaction between PVY HC-Pro and the NtCF1β-subunit reduces the amount of chloroplast ATP synthase in virus-infected tobacco.
The photosynthetic rate of virus-infected plants is always reduced. However, the molecular mechanism underlying this phenomenon remains unclear. The helper component-proteinase (HC-Pro) of Potato virus Y (PVY) was found in the chloroplasts of PVY-infected tobacco, indicating some new function of HC-Pro in the chloroplasts. We generated HC-Pro transgenic plants with a transit peptide to target the protein to chloroplast. The HC-Pro transgenic tobacco showed a decreased photosynthetic rate by 25% at the light intensity of 600 μmol m(-2) s(-1). Using a yeast two-hybrid screening assay to search for chloroplast proteins interacting with HC-Pro, we identified that PVY HC-Pro can interact with the chloroplast ATP synthase NtCF1β-subunit. This interaction was confirmed by GST pull-down and co-immunoprecipitation assays. HC-Pro didn't interfere with the activity of assembled ATP synthase in vitro. The HC-Pro/NtCF1β-subunit interaction might affect the assembly of ATP synthase complex. Quantitative western blot and immunogold labeling of the ATP synthase indicated that the amount of ATP synthase complex was decreased in both the HC-Pro transgenic and the PVY-infected tobacco. These results demonstrate that HC-Pro plays an important role in reducing the photosynthetic rate of PVY-infected plants, which is a completely new role of HC-Pro besides its multiple known functions.
State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing 100193, China.
Yayi
Y
Tu
State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing 100193, China.
Yongsheng
Y
Jin
State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing 100193, China.
Dongyuan
D
Ma
State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing 100193, China.
Heng
H
Li
State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing 100193, China.
Zhenqian
Z
Zhang
State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing 100193, China.
Jiangli
J
Dong
State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing 100193, China.
Tao
T
Wang
D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism / Q000821:virology*; D015153:Blotting, Western; D025222:Chloroplast Proton-Translocating ATPases / Q000235:genetics* / Q000378:metabolism; D002736:Chloroplasts / Q000821:virology*; D003546:Cysteine Endopeptidases / Q000235:genetics* / Q000378:metabolism; D007150:Immunohistochemistry; D010788:Photosynthesis / Q000502:physiology*; D010935:Plant Diseases / Q000821:virology; D030821:Plants, Genetically Modified / Q000821:virology; D017800:Potyvirus / Q000472:pathogenicity; D012441:Saccharomyces cerevisiae / Q000235:genetics; D014026:Nicotiana / Q000235:genetics / Q000378:metabolism / Q000821:virology*; D020798:Two-Hybrid System Techniques; D014764:Viral Proteins / Q000235:genetics* / Q000378:metabolism
D014764:Viral Proteins; D003546:Cysteine Endopeptidases; C072775:HC-Pro protein, potyvirus; D025222:Chloroplast Proton-Translocating ATPases