Figure 2. Interaction between GST-filensin-tail or GST-filensin-rod and AQP0 in rat lens extract. The interaction between purified recombinant GST-filensin-tail or GST-filensin-rod with lens AQP0 was detected by western blotting with an anti-AQP0 COOH-terminal antibody. Lane 2 shows a 23 kDa AQP0 protein band present in the Triton-X100 extract fraction from rat lens. Incubation of GST-filensin-tail with the Triton-X100 extract fraction from rat lens revealed an AQP0 protein band at 23 kDa, illustrating the interaction between the filensin tail region and AQP0 (lane 3). In the absence of lens extract, the purified GST-filensin-tail construct did not react with the anti-AQP0 antibody (lane 4). There was no interaction between the purified filensin rod domain and AQP0 in the lens extract fraction (lane 5). In the absence of lens extract, GST-filensin-rod conjugated to glutathione beads did not contain a peptide that reacted with the anti-AQP0 antibody (lane 6). No AQP0 band was detected when GST alone was incubated with lens extract (lane 7). Anti-AQP0 antibody did not react with GST (lane8). Lane 1 shows molecular weight markers.