Abstract
Senescence is a program to recover the nutrients from aged tissues. These nutrients are utilized in younger leaves or indispensable organs, such as shoots or flowers. Chloroplast is a major organelle to store the nitrogenous compounds of proteins. Mechanisms of protein degradation in chloroplast are one of the remaining problems to be solved.
FtsH protease is ATP-dependent protease which localized on thylakoid membranes. This protease degrades photo-damaged subunits in photosystem II. Therefore, this is a major candidate to manage the protein breakdown in chloroplasts.
Overexpression systems of FtsH protease from Arabidopsis were previously constructed, however the expressed proteins were deposited as inclusion bodies. This made difficult to promote biochemical investigations of FtsH protease. In this study, the inclusion bodies were solubilized, when the urea denatured proteins were dialyzed against the buffers containing the reduced reagents. We characterized the biochemical properties of FtsH proteases from Arabidopsis.
