Abstract
Proteomic analysis with isolated vacuoles from Arabidopsis leaves detected a major protein that belongs to GDSL-lipase family. We designated it as VML (Vacuolar Major Lipase). Arabidopsis has more than 100 GDSL-lipase family proteins. However, the physiological roles are not fully understood. To analyze the nature of the protein, subcellular fractionation was carried out. The result revealed that VML was concentrated in the 100,000-g-pellet fraction. Further fractionation by linear sucrose-density-gradient centrifugation concentrated VML in the fraction that did not overlap marker proteins for vacuolar membranes, ER, or Golgi complex. VML was detected as large oligomers by treatment with various concentrations of cross-linker. These findings suggest that VML forms a large complex within the vacuoles. We obtained VML-deficient mutant and analyzed it to elucidate the physiological function.
