Figure 1
From: Pdx-1 or Pdx-1-VP16 protein transduction induces β-cell gene expression in liver-stem WB cells
PTD Pdx-1 and TAT fusion protein synthesis and their ability to transduce HepG2 and WB cells. (a) Schematic structure (top panel) and purity (bottom panel) of fusion proteins. PTDPdx-1 and TAT represent protein transduction domains of the Pdx-1 protein and the HIV TAT protein, respectively. His represents hexahistidine tag used to purify proteins by His-tag affinity chromatography. Purified proteins were run on a SDS-PAGE gel (8%) stained with Coomassie blue. Molecular weights are 28 kDa for eGFP, 31 kDa for PTDPdx-1-eGFP and TAT-eGFP. (b) Observation by confocal microscopy of eGFP fluorescence in HepG2 and WB cells treated for 24 hours with 15 μM PTDPdx-1-eGFP, TAT-eGFP, or eGFP protein lacking PTD. Treated cells were observed by confocal microscopy without being fixed in order to exclude artifactual protein uptake [24]. CM-Dil was used to visualize cytoplasmic membrane (red staining). Scale bars = 50 μm.