Activation of the programmed cell death pathway by inhibition of proteasome function in plants

Cited 177 time in scopus
Metadata Downloads
Activation of the programmed cell death pathway by inhibition of proteasome function in plants
Moonil Kim; Joon Woo Ahn; Un Ho Jin; Do Il Choi; K H Paek; Hyun Sook Pai
Bibliographic Citation
Journal of Biological Chemistry, vol. 278, no. 21, pp. 19406-19415
Publication Year
Proteasomes constitute the major machinery to degrade or process proteins by ATP/ubiquitin-mediated proteolysis. Recent findings suggest a pivotal role of the ubiquitin/proteasome pathway in the regulation of apoptosis in animal cells. Here we show that virus-induced gene silencing of two different subunits of the 26 S proteasome, the α6 subunit of the 20 S proteasome and RPN9 subunit of 19 S regulatory complex, both activated the programmed cell death (PCD) program, accompanied by reduced proteasome activity and accumulation of polyubiquitinated proteins. These results demonstrate that disruption of proteasome function leads to PCD in plant cells. The affected cells showed morphological markers of PCD, including nuclear condensation and DNA fragmentation, accompanied by the 10-fold higher production of reactive oxygen species and increased ion leakage for 3-fold. Similar to apoptosis in animal system, mitochondrial membrane potential was decreased, cytochrome c released from mitochondria to cytosol, and caspase 9- and caspase 3-like proteolytic activities detected in the cells. Interestingly, this proteasome-mediated PCD stimulated the expression of only a subset of transcripts that are highly induced during pathogen-mediated hypersensitive response cell death, indicating that the two PCD pathways are differentially regulated. Taken together, these results provide the first direct evidence that proteasomes play a role in the regulatory program of PCD in plants. Controlled inhibition of proteasome activities may be involved in developmentally or environmentally activated plant cell death programs.
Amer Soc Biochemistry Molecular Biology Inc
Appears in Collections:
Critical Diseases Diagnostics Convergence Research Center > 1. Journal Articles
Files in This Item:
  • There are no files associated with this item.

Items in OpenAccess@KRIBB are protected by copyright, with all rights reserved, unless otherwise indicated.