Transforming Growth Factor β Signaling Upregulates the Expression of Human GDP-Fucose Transporter by Activating Transcription Factor Sp1
Figure 1
TGF-β1 stimulates the GDP-fucose transporter expression.
HeLa cells were serum-starved, then cultured in presence of human recombinant TGF-β1 and harvested over the time course during TGF-β1 induction. A. RT-PCR analyses of NST expression. Total RNA was isolated from the cells treated with TGF-β1 at the indicated times (top) and reverse transcribed. RT-PCR was carried with the primers specific to the GDP-fucose (GDP-Fuc), CMP-sialic acid (CMP-SA) and UDP-GlcA/GalNAc transporters as well as β-actin (panels 1–4, respectively). PCR products were analyzed on a 1% agarose gel. B. qRT-PCR analyses of NST expression. Experiment with the similar time course upon TGF-β1 induction was performed but with three replicates (see Materials and Methods for details). Total RNA and cDNA were obtained as in A. qRT-PCR was carried out with the primers for GDP-Fuc and β-actin. Error bars represent standard deviation from three replicates. P values were obtained with t-test as compared with time 0. **, P<0.01. C. Western analysis of GDP-fucose transporter expression. Total cell lysates were prepared from the cells treated without (lane 1) or with (lane 2) TGF-β1 for 10 h. Blot was probed with antibodies against GDP-fucose transporter (top) and β-actin (bottom) (left panel). Quantification of GDP-fucose transporter expression (right panel) was obtained from densitometric analyses of three Western blots as in left panel. **, p<0.01 (t-test).