"In our previous study we suggested, C. elegans DIC-1 was localized in the inner membrane of mitochondria at cristae and its knockdown resulted in the formation of mitochondria containing numerous internal vesicles. When DIC-1 was overexpressed under a heat shock promoter in a transgenic C. elegans line, the number of cristae per cross-sectional area of mitochondria was greatly increased, supporting the role of DIC-1 in cristae formation. The oxygen consumption rate of the
dic-1 knockdown strain was similar to that of control worms, but interestingly, the
dic-1 overexpression line showed an increased oxygen consumption rate. The ATP content of the
dic-1 knockdown strain was decreased compare to that of control worms, but
dic-1 overexpressed line showed an increased ATP content. One peculiar characteristic of the worms after the knockdown was a greatly increased resistance of the worms to paraquat, which is usually observed in worms with a decreased mitochondrial activity. Nevertheless, the intracellular level of H2O2-related reactive oxygen species was slightly increased after the
dic-1 knockdown, opposing the possibility that the increased resistance to paraquat was due to a low ROS level. By contrast, the
dic-1 overexpression line showed hypersensitivity to paraquat. In summary, C. elegans DIC-1 plays a critical role in the formation of normal morphology of mitochondrial cristae/inner membrane and affects physiological properties of the worms, such as respiration rate, ATP contents, intracellular ROS level, and sensitivity to exogenous oxidative stress. This work was supported by Seoul Development Institute."