TXNIP interaction mediates the lysosomal degradation of GLUT1.

(A) HeLa cells stably expressing HA-GLUT1 were infected with lentiviruses carrying vector control, TXNIP gene, or TXNIP-ARR gene, and surface HA-GLUT1 was examined by FACS analysis. (B) HeLa cells were transduced with lentiviruses carrying vector control, TXNIP gene, or TXNIP-ARR gene, and relative glucose uptake was examined by 3H-2DG tracing. Data are represented as mean ± SEM. (C) HeLa cells expressing vector control or TXNIP were treated with MG-132 or bafilomycin A1 for 12 hrs, and the cell lysates were subjected to GLUT1, HA, and EGFR blots. (D) Confocal image of HeLa cells expressing TXNIP-VN together with TXNIP-VC, GLUT1-VC, or N31-HA-VC. Green fluorescent signal represents VN&VC complexes. (E) Confocal image of HeLa cells expressing TXNIP-VN & GLUT1-VC with endosomal markers Rab5a, Rab5a-QL, Rab7a, or lysosomal Lamp1 as well as Golgi marker Rab1a. (F) Confocal image of HeLa cells expressing GLUT1-VC together with TXNIP-VN, TXNIP-ARR-VC, TXNIP-LL2A-VC, or TXNIP-2PYAA-VC. (G) HeLa cells expressing vector control, TXNIP, TXNIP-LL2A mutant, or TXNIP-2PYAA mutant were examined by Western blot for the expression of endogenous GLUT1, HA and ACTIN. (H) HeLa cells stably expressing HA-GLUT1 were transduced with lentiviruses carrying vector control, TXNIP gene, TXNIP-LL2A gene, or TXNIP-2PYAA gene, and surface HA-GLUT1 was examined by FACS analysis.