Fig. 2.

Effect of knocking down the sodium-dependent multivitamin transporter (SMVT) system of pancreatic beta-TC-6 cells on carrier-mediated biotin and pantothenic acid uptake. Following induction of the knockdown with doxycycline (DOX) (see materials and methods), the following were examined: level of expression of the SMVT mRNA (quantitative real-time PCR; expression was relative to beta-actin) (A), level of expression of the SMVT protein (Western blotting; expression was relative to respective beta-actin) (B), initial rate of carrier-mediated biotin uptake (C), and the effect of knocking down the SMVT system on carrier-mediated pantothenic acid uptake (another substrate of the SMVT system) (D). Inset in B shows a representative gel image. All values are means ± SE of at least 3 independent experiments. *P < 0.01.