Abstract
Vacuole plays an important role in maintaining the homeostasis of plant cells through the regulation of development of turgor pressure, the accumulation of various inorganic ions and metabolites, and the degradation of discarded proteins. However, the molecular mechanisms underlying the diverse vacuolar functions are not fully understood. To get insight into the molecular basis of the vacuolar functions, we conducted the post-genome analyses of the vacuole. We have directly and comprehensively analyzed proteins and metabolites of the intact vacuoles using LC-MS, CE-MS and FT-ICR-MS. The target analyses of metabolites have revealed the existence of organic phosphate compounds in the vacuole. The list of the vacuolar metabolites identified by non-target analyses is also constructed. Proteomic analyses have suggested that the unexpected enzyme reactions exist in the vacuole besides degradative activity. We are also analyzing functions of unknown vacuolar membrane proteins using the transgenic Arabidopsis suspension-cultured cells. In the present report, we would like to discuss the effect of autophagy inhibitor on dynamics of vacuolar metabolites, too.
