Abstract
Proteasome is a large multisubunit complex that degrades damaged or ubiquitinated proteins. Although it is one of the most important features of plant proteasome that the most subunits are coded by duplicated genes, specific functions of each paralogous subunit are still unclear.
We have demonstrated that loss-of-function mutant of the specific paralogous protein shows aberrant response to nutritional stress. Furthermore, it has been reported that peptidase activities of proteasome were changed in response to nutritional and oxidative stress, suggesting that plant proteasome enables to transform structure and function to response to environmental stress conditions. To evaluate this hypothesis, we tried to identify the subunit composition of proteasome under various stress conditions.
We have succeeded in established high-throughput method to identify and quantify composition of paralogous proteins with affinity purification and combination of 2D-PAGE and MS analysis. Proteasome transformation in response to environmental stress will be discussed.
