sentence: For example , overexpression of GFP-SYP31 , which was reported to perturb the endomembrane system ( Bubeck et al ., 2008 ) , did not affect the normal localizations of ST-mRFP and mRFP-VAM3 ( Supplemental Figure S1 ) in our experimental system.We first observed dynamics of the Golgi stacks upon BFA treatment ( 50 μ M BFA for 2 h ) .