Fig. 4

MCT12 contribution to creatine transport in TR-CSFB3 cells. A Time-course of [¹⁴C]creatine uptake by TR-CSFB3 cells. The uptake was measured for the indicated time periods at 37 °C. B Time-course of [¹⁴C]creatine efflux from TR-CSFB3 cells. After pre-incubation of [¹⁴C]creatine for 20 min at 37 °C, the efflux transport was measured for the indicated time periods at 37 °C (open circles) or 4 °C (closed circles). C Immunoblotting of the crude membrane fractions of TR-CSFB3 cells after the transfection of negative control (N.C.) or MCT12-specific small interfering RNA (siRNA). D Protein expression levels of MCT12 in TR-CSFB3 cells after MCT12 specific-siRNA transfection. Intensity of the signal was evaluated using the ImageJ software and the signal levels of MCT12 were normalized to that of Na⁺, K⁺-ATPase α1. E [¹⁴C]Creatine uptake by TR-CSFB3 cells after MCT12 specific-siRNA transfection. The uptake was measured for 20 min at 37 °C. F and G Efflux transport of [¹⁴C]creatine from TR-CSFB3 cells after the knockdown of MCT12. After pre-incubation of [¹⁴C]creatine for 20 min at 37 °C, efflux was measured for 20 min at 37 °C (F) or 4 °C (G). H Subtraction of the efflux at 4 °C (G) from that at 37 °C (F). Each column represents the mean ± standard deviation (S.D.) (n = 3). Each open and closed circle represents an individual data point. *p < 0.05, **p < 0.01, significantly different from the conditions of N.C. siRNA transfection