EXPO Sequesters Cytosolic SAMS2-GFP in Arabidopsis Protoplasts.
(A) When transiently expressed in Arabidopsis protoplasts, SAMS2-GFP showed cytosol and nucleus patterns at early stages (24 h) but became punctate at later stages (a; 48 h). By contrast, YFP remained cytosolic in both stages (b).
(B) When coexpressed with Exo70E2-mRFP in Arabidopsis protoplasts, SAMS2-GFP showed cytosol and nucleus patterns at early stages (c), but at later stages, SAMS2-GFP became colocalized with Exo70E2-mRFP in EXPO (d). Bar = 50 μm.
(C) Immunoblot detection of Exo70E2-GFP proteins in the culture medium of transgenic Arabidopsis cells expressing Exo70E2-GFP. S, secretion medium proteins; I, intracellular proteins; day, days after subculture.