Regulation of Autophagy for the Increased Production of Acid α-glucosidase in Rice Cell Suspension Cultures

초록

Pompe disease caused by the deficiency of lysosomal acid α-glucosidase (GAA) is one of the lysosomal storage diseases. In this study, GAA was produced in rice cells using RAmy3D promoter that expresses the target protein by sugar starvation. However, when the rice cells are transferred to sugar-free medium for GAA production, rapid autophagy formation is observed due to nutrient depletion. This cell death affects both the viability of cells and protein quality. Four different autophagy regulators (enhancers: rapamycin, CCI-779/ inhibitors: concanamycin A, bafilomycin A1) were supplemented in order to examine their regulatory effects on autophagy in rice cell suspension cultures to increase GAA production. Among them, autophagy inhibition by concanamycin A and bafilomycin A1 showed higher GAA production (39.5 mg/L and 41.3 mg/L, respectively) than that of control (34.5 mg/L). Also, viability of rice cells at day 3 was significantly improved when autophagy was inhibited. But autophagy enhancers did not show any effect. In conclusion, autophagy inhibition by using inhibitors enhanced the production of the target protein with increased viability in rice cell suspension cultures.