Proteins expressing PSD-95/Dlg/ZO-1 (PDZ) domains are commonly involved in moderating receptor, channel and transporter activities at the plasma membrane in a variety of cell types. At the apical membrane of renal proximal tubules (PT), the type IIa Na/Pi co-transporter (NaPiIIa) binds specific PDZ domain proteins. Shank2E is a spliceoform of a family of PDZ proteins that is concentrated at the apical domain of liver and pancreatic epithelial cell types and is expressed in kidney. In the present study, immunoblotting of enriched plasma membrane fractions and immunohistology found Shank2E concentrated at the brush border membrane of rat PT cells. Confocal localization of Flag-Shank2E and EGFP-NaPiIIa in co-transfected OK cells showed these proteins co-localized in the apical microvilli of this PT cell model. Shank2E co-immunoprecipitated with NaPiIIa from rat renal cortex tissue and HA-NaPiIIa co-precipitated with Flag-Shank2E in co-transfected HEK cells. Domain analysis showed the PDZ domain of Shank2E specifically bound NaPiIIa, truncation of the C-terminal TRL motif from NaPiIIa abolished this binding and FarWestern blotting showed the Shank2E-NaPiIIa interaction occurred directly between the two proteins. NaPiIIa activity is regulated by moderating its abundance in the apical membrane. High phosphate conditions induce NaPiIIa internalization and degradation. In both rat kidney PT cells and OK cells, shifting to high phosphate conditions induced an acute internal redistribution of Shank2E and, in OK cells, a significant degree of degradation. In sum, Shank2E is concentrated in the apical domain of renal PT cells, specifically binds NaPiIIa via PDZ interactions and undergoes phosphate-induced internalization.