FIGURE 6.

Lysine residues 160 and 164 of embigin are involved in DIDS-mediated cross-linking to MCT1. COS cells were transfected as detailed under “Experimental Procedures” with the following pCIneo vector constructs. A, first and second lanes, MCT1 + embigin; third lane, MCT1 + K104/105/120/137/141Q embigin; fourth lane, MCT1 + K104/105/120/137/141/222/226Q embigin; fifth lane, MCT1 + K104/105/120/137/141/222/226/252Q embigin. Arrows 1–3 indicate the positions of MCT1-embigin cross-linked product, MCT1 dimer, and MCT1 monomer, respectively. B, MCT1 plus the embigin mutant indicated. COS cells were harvested 48 h after transfection and treated ± 0.2 mm DIDS, washed, and lysed. SDS-PAGE and Western blots were performed on the crude lysates using anti-MCT1 antibody. WT, wild type.