Fig. 4.

Identification of the PDZ in synapse-associated protein-97 (SAP97) that is involved in the aquaporin-2 (AQP2) shuttle. A: glutathione-S-transferase (GST) pulldowns between AQP2 and the individual PDZ domains of SAP97 were conducted as described in methods and probed for AQP2 pulldown by Western blot [immunoblot (IB)]. B: LLC-PK₁ cells stably expressing c-Myc-AQP2 (pseudo red) were transfected with the indicated PDZ of SAP97 in pIRES-EGFP (pseudo green) before the distribution of AQP2 in response to buffer (a, c, e, and g) or arginine-vasopressin (AVP; b, d, f, and h) was determined by dual fluorescence microscopy. Scale bars = 5 μm. C: average ± SD values of AQP2 pixels outside a 300-nm partition derived from 30 control (open bars) or AVP-exposed (closed bars) images from n = 3 experiments. Statistical comparisons were carried out by one-way ANOVA followed by a Bonferroni’s test. WT, wild-type.