Figure 1. p115 knockdown displaces Rab1b from the Golgi. HeLa cells expressing GalNAcT2-GFP were either mock transfected or transfected with siRNA against p115. GalNacT2-GFP and either p115 (A-D) or Rab1b (E-J) were visualized 72 h later. Bar = 10µm. (K) Quantified average signal intensity of Golgi membrane associated Rab1b is shown for mock and p115 knockdown cells (mean ± SD; n = 2; > 15 cells each). To allow direct comparison of distinct experiments, values were normalized by dividing by the mean values of the entire data set for a given experiment. (L) HeLa cells expressing GalNAcT2-GFP, plated on 35-mm dishes, were either mock transfected or transfected with siRNA against p115. After 72 h, the cells were digitonin permeabilized and the amount of released Rab1b and tubulin was determined by immunoblotting with anti-Rab1b and anti-tubulin antibodies (mean ± SD; n = 2).