Fig. 6.

Knockdown of endogenous DYNLRB1 with gene-specific siRNA decreases carrier-mediated folic acid uptake. A: Caco-2 cells were grown in DMEM medium and treated with DYNLRB1 specific small interfering RNA (siRNA). Initial rate (5 min) of [³H]folic acid (2 μM; pH 7.4) uptake was measured after 48 h of siRNA transfection. Values are means ± SE of 3–4 separate uptake determinations. *P < 0.01. B: semiquantitative RT-PCR analysis was performed with mRNA from Caco-2 cells and the specific primers for DYNLRB1, hRFC, and 18S rRNA as described in materials and methods. Results of a representative experiment are shown.