FIGURE 2.
Effects of α-arrestins on lactate output and glucose uptake. α-Arrestin-mCherry fusions were transfected into 293T cells. Confocal image sections show localization of A, mCherry alone, B, Txnip-mCherry, C, Arrdc4-mCherry, and D, Arrdc3-mCherry (blue, nuclear staining with Hoechst dye 33342; scale bar, 5 μm). E, lactate release to the medium was measured after transfection of 293T cells with α-arrestin-mCherry fusions. Lactate was significantly lower for both Txnip and Arrdc4 (n = 6; ***, p < 0.001 versus mCherry alone). F, 2-[3H]deoxyglucose uptake was measured in primary human skin fibroblasts after lentiviral overexpression of α-arrestin-mCherry fusions. Uptake was normalized to total protein content and expressed relative to the mean value of uptake for mCherry alone. 2-Deoxyglucose uptake was significantly inhibited by both Txnip and Arrdc4 but not Arrdc3 compared with mCherry alone (n = 5; **, p < 0.01; ***, p < 0.001).